A Model Railroader’s Toolroom in 24" by 24"

“Have Mini Toolroom, will Engineer!” is the real motto of this thread.  If you can’t buy it, make it!  If you can buy it, make it better/cheaper. 

Canada’s “Grizzly Light”, Busy BeeTools, has had a very good sale running over the fall.  Most of their machine tools are built by  Sieg and white-labelled under the Craftex brand, similar to at least two dozen other sources (listed in various subsequent posts).

I miss having access to my larger shop and machine tools at the farm when I am at my away work place.  So, I’ve set up a tiny mobile “toolroom” on a mobile DeWalt Planer stand that has a built in lift and three point wheels.

While it won’t rotate on the spot, it does rotate 180 degrees in short order with a minor amount of back and forth and pivot movement, or a I can place it so I can access both sides with my rolling chair.  It has a 20” x 24” surface which fit both machines, but I’ve added two 24” x 24” 3/4 inch plywood project panels on top to provide additional support, as well as an overhang to get at the lathe bed bolts and to provide a surface for a gorgeous little clamp on swivel vice (shown) that I found on a deep sale at KMS Tools.

Below, mounted on the mobile stand, both sides of the "toolroom": Dr Spin and Mr. Vice as it were I suppose.

The blue vice on the mill is temporary.  They were out of proper milling vices so until that arrives, I’ve mooched the one off my drill press.  Sacrilege!

My next enhancement will be machine specific rolling drawers on the shelf underneath, and a bottom shelf for heavier accessories and metal stock.  The stand is specified for up to 300 pounds so knowing DeWalt, it is over-engineered for a fair bit more.  The two mini-machines shown with all their normal bits are just over 200 pounds combined so a good margin of safety.

I suppose I could have bought a combo lathe/mill, but IMHO, this setup is: cheaper, smaller, and far more versatile in the size of work that can be accommodated.  Combo machines are normally a bit limited for milling and one is forever removing the top slide.  But then Kozo Hiraoko has turned out some of the most magnificent live steam projects ever imagined on a combo machine. 

It's already been mentioned in one post that this is just another hobby within a hobby, and that is true, but like others, it can be a big enabler of one's primary hobby. 

• How many of us have had a model with something broken, rendered unfixable because parts are no longer available? 
• I read almost weekly about split gears.  Well, maybe the gear you need is available in brass from NWSL or plastic from Athearn but the bore is too small for your axles, and changing axels won't fit your wheels ... fear not, you can just drill the gear out to a one thou press fit with your lathe! 
  • You can't find a bit the right size you say?  Read on - at some point, we will cover number, Letter and metric bits, and if there isn't one in there, then we can use our lathe to turn and grind a D-Bit out of drill rod to whatever dimension we need, and harden it and the drilling will be easy.   
• I read today on here that a certain cast bell is too big scale wise.  Bells are not hard to turn to the exact size needed out of real brass.
• Need something "just so" for a turntable pit ...
• Someone mentioned flimsy plastic parts - make metal ones.
• Someone may want to print a tool up in 3D, but isn't sure if the design will work.  Perhaps make it first out of metal or wood and prove out the design, and then 3D print the finalized design.

Reading or participating in this thread is completely voluntary.  Chances are if you have a question there are many learned folks on this overall forum who have used machines like these and will have answers or suggestions.

Enjoy the journey!

Sieg Type Mini-Lathes & General Terminology

Hopefully this thread won't bore people or prove too redundant.  All this and more is in basic lathe books, but to save people the time and cost of finding one of those, I've tried to provide the basics here.

One of the first things that confuses people in their journey into machine tools are basic definitions, names of parts, and how they apply to the problems they are trying to solve.  Generally most things here will apply to every lathe from the tiniest Minimat, Sherline, Taig etc. up to very large industrial machines.  They all do the same thing - shave metal off spinning metal.

First things first, the major parts of a lathe, using the CX704 as an example.  

The first bit of jargon that may creep into these discussions is the difference between the sizes of lathes.  Here's my stab at a category listing - I'll add more pictures as time permits.  I'll explain critical terms like swing a bit later on in the post.  Features are generally additive as you work your way down the list.

While there is no absolute definition, for the purpose of establishing something in the way of a baseline, if we look to Sieg of Shanghai as a major manufacturer of machine tools of many sizes, and who operate around much of the world, we can can safely adopt their definitions for the micro and mini-categories.  

It would seem that many of the companies who white-label their machines retain their conventions, albeit often with different model numbers. Here are examples from their catalog of a micro and a mini lathe.  The beautiful thing about lathes, in addition to perhaps being Homo sapiens' greatest invention after the wheel, is that the names of common parts across all sizes of lathe are identical, or nearly so.

• Micro (including "baby) - key thing typically missing on these little guys is a powered feed screw to move the apron along the bed to enable thread cutting or automated feed. Short work is limited by the holding capacity of the chuck.  Work is Limited by the hole behind the chuck through the spindle (if one even exists!). All said though, unless one needs to cut screw threads, for making small parts in metal, plastic or wood, one of these would be a great addition to a workshop.  Unless precision is a huge issue, they need not be fastened and are light enough to be slid to an out of the way spot on the workbench and moved front and center when needed.  Many of the original Unimat 3 type lathes would fit in this category.  When I first got into these things almost 40 years ago, they were about the only micros I recall being available.  Today, there are many more options, Proxxon and Sherline (both shown below) are two that come to mind.  Hopefully people using these will post about their experiences.

  
For those shopping for their very first NEW lathe, my advice is go up to at least the mini size, and larger if you can.  Absolutely no offence to anyone who already owns one, but will all the great Asian machines available today, at today's prices, the Micros are very expensive for what you get.  It’s easy to get into one of them for $2,500 by the time you have everything required, and still only have a machine that is only really ideal for very light work on plastic, aluminum or brass.  
Years ago, they were all that was available, and I remember a friend who had more $$$$ into his little Unimat 3 than I did in my first 12/18 x 40 Engine Lathe. Today, for far less money, you can acquire a mini-level or bench-level machine that will handle much larger, harder work. 
Again, no offence meant and the advice only meant for people shopping for a new first lathe.  These can be great lathes if they can be acquired at a reasonable cost. 

• Mini - Tend to have powered longitudinal feeds and can undertake a wide range of thread cutting, typically 12 TPI to 52 TPI.  Generally no power cross feed, which is more of an issue in making larger parts.  Facing something large, or doing larger milling operations in the lathe without a power cross feed can be tedious. The real major weakness at this size is the lack of a quick change gear box for selecting threads.  If you want to change either the feed speed ("fine-ness" of cut), or the threads per inch for cutting a screw, you get to learn all about gear ratios and change gears at the end of the headstock! It's not a big deal and machinists did this regularly for 200 years following the invention of the lathe, but if you're planning on turning a ton of threads, and for convenience in general, you are better to go up to the next scale of machine (bench lathe).

Just to provide a complete reference, here are the larger sizes:

• Benchtop - generally small enough to fit on a sturdy wooden or light metal bench or stand.  When I bought my first lathe it was a 12/18 x 40 on a steel stand designed for that lathe, with storage cabinets, and that was a common size in those days.  They seem to have shrunk a bit lengthwise now.  These typically have a bigger hole through the headstock, perhaps up to 1.25" and also have a powered cross-feed enabling very even work across the face of the chuck as well as along the bed.  Perhaps the biggest major advantage at this size is the addition of a quick change gearbox enabling different feed speeds and threads without changing any gearing manually in the headstock.  That's what the three levers on the bottom of the headstock do.  Myford is perhaps the most esteemed and coveted "classic" brand globally.  Here is a 12 x 36:

Grizzly sell beautiful little 8, 9, 10 and 11" bench lathes with quick change gear boxes.  If you have the room (I don't where the mini-lathe is) and the money, start here. Sadly Busy Bee seems to have discontinued their great little 8 x 18 that was south of $2,000 Cdn.  I'd have likely sprung for that if they still sold them, although I suppose I can change a lot of gears for the extra $900! 

• Floor/Engine/Gunsmith - Generally comes with a fully integrated and heavy base which may include integrated controls like an emergency stop pedal.  These typically have a much larger hole through the headstock (1.5" and larger")  to accommodate large gun barrels and are much more sturdy and therefore precise. 
  • Note the integrated emergency stop pedal on the base of this one.  They often come with coolant systems pre-installed in the base. 
  • Shown is the Grizzly version of the Craftex 14 x 40 I have at the farm which, sadly, Busy Bee no longer sells. This is a serious machine, with a fully geared head, but I wish it had a slower lowest speed.  20-30 rpm is great for slow work on cast iron.  In the old days the lathes had belt drives and you could even slip the belt to go slower and the back gear was often really slow.  Super slow speed was really nice for turning big locomotive wheels.

• Industrial - These are at least 16" swing and very heavy - typically 72" or more  between centers
• Heavy Industrial - These models are huge and vary in size - Perhaps start at 24" swing and they can easily get to 20' long and weigh many tons.  I'd include wheel lathes used in locomotive driver maintenance in this grouping. 
• CNC - These come in all shapes and sizes, and the large, industrial integrated turning centers feature automated tool changes and both turning and milling operations.  Typically $50,000 to $100,000 or much more, this is the land of cutting plastic injection molds and machining things like jet engine parts and engine blocks. An individual tool can easily cost as much as the first four lathes in the list above.

While we are focused here on smaller lathes of general use to model railroaders, specifically micro and mini-machines, it is a fact that you can make really small things with big lathes, but you cannot make really big things on small lathes, so you should always try and find a lathe that will accommodate the largest thing you need to swing in a circle to machine.  

Little Machine Shop carries a wide variety of small machine tools and supporting accessories.  Some of their offerings are various upgrade products for the machines that they and others sell, and it is from them that I borrow this list of compatible models to the Sieg C2/C3 (“mini”) shown above.

• Enco 110-0803 Enco 7x10 Mini Lathe
• Harbor Freight 33684 Central Machinery 7x10 Mini Lathe
• Harbor Freight 93212 Central Machinery 7x10 Mini Lathe
• MSC 0192857 Enco 7x10 Mini Lathe
• Bolton CQ9318 7x12 Mini Lathe

• Busy Bee Tools CX704 Craftex 7x12 Mini Lathe (my little guy featured here)

• Cummins (Tools Now) 5278 7x12 Mini Lathe
• Eastwood 32497 7x12 Mini Lathe
• Grizzly G8688 7x12 Mini Metal Lathe
• Harbor Freight 93799 Central Machinery 7x12 Mini Lathe
• Homier 03911 Speedway 7x12 Mini Bench Metal Lathe
• Northern Tool 49656 KLUTCH 7x12 Mini Lathe
• Princess Auto 8507659 Powerfist 7x12 Mini Lathe
• SIEG C2 7x12 Mini Lathe
• Tormach 30689 7x12 Duality Lathe
• Travers Tools OT222300 OTMT 7x12 Mini Lathe
• Warco 3004 7x12 Mini Lathe (Metric)
• Warco 3005 7x12 Mini Lathe (Imperial)
• WEN 3455 WEN 7x12 Mini Lathe
• Micro-Mark 82500 MicroLux 7x12 Mini Lathe
• LittleMachineShop.com 4200 HiTorque 7x12 Deluxe Mini Lathe
• LittleMachineShop.com 4100 HiTorque 7x12 Mini Lathe
• SIEG SC2 7x12 Mini Lathe
• Micro-Mark 82710 MicroLux 7x14 Mini Lathe
• LittleMachineShop.com 4959 SIEG 7x14 Mini Lathe
• SIEG C3 7x14 Mini Lathe
• Big Dog BD-0618Ax300 7x14 Mini Lathe
• Big Dog BD-0618x300 7x14 Mini Lathe
• Warco 4820-350 7x14 Mini Lathe (Metric)
• Warco 4800-350 7x14 Mini Lathe (Imperial)
• Grizzly G0765 7x14 Mini Lathe
• Micro-Mark 84631 MicroLux 7x16 Mini Lathe

Some Important Definitions to begin, with measurements provided for the little Craftex 704 which is a white-labelled Sieg C2:

• Swing / Maximum Swing / Swing Over Bed: This is the maximum diameter of the work that can be rotated by the spindle and cut by the tool post.  My lathe says it has a 7" swing, so the largest locomotive driver I could ever machine would be one that started life as a rough casting not more than 7" wide. Generally this dimension is most relevant to work being done in a chuck that does not need to clear the apron.  More on this below.  Divide this number in half to get the maximum radius of the job you can turn.
  Some lathe manufacturers seem a bit "optimistic" in their assessment of swing, and there may not be enough room for a cutter to actually engage with the work.  It is best to ask confirming questions in advance and make sure there is a money back guarantee if any lies have been told.  My own best practice is to go to the shop with a measuring tape and borrow a cutter to be sure.  Places like Grizzly and Busy Bee are always happy to help out.
  Occasionally you will see the swing listed as something like 12/18.  This means that the lathe has a small removable section ("Gap Bed" typically 6" or so in length) of it's bed right by the headstock permitting swinging larger work in that area for machining over size items in a chuck or on a faceplate.  My first lathe was a 12/18 and I took the gap out once just to see what it looked like, but never needed to use it.  They seem to have fallen out of favour in recent years and you seldom see new ones advertized.

There are some other critical dimensions to be aware of, especially for work that needs to be done between centers and which will by definition need to clear the lathe apron:

• Swing over Saddle: The maximum size of work that can be turned above the saddle of the lathe.  This is always smaller than the maximum swing of the lathe.  in the case of my lathe, it is 5".
• Swing over cross slide: The maximum size of work that can be accommodated in front of the cross slide.  This is always less than the swing over the saddle and is really the most critical dimension for smaller lathes as it is the limiting factor.  In my lathe's case, only 2 1/8".  See why the 7" is misleading?  All in all, if you're in O Scale and wanting to scratch build, a 72" driver is going to come out at 1.5", so AOK.  Anything larger than O and you are likely pressing your luck.
   
• Distance between Centers: Just like it sounds, the length of work that can be accommodated for machining.  12" in my case.  Work requiring extreme accuracy or complicated structures such as crankshafts (engines, drive lines on shays, etc.) are typically turned between centers.  The chuck is removed and centers inserted in both the headstock and tail stock.  Here an image from Practical Machinist.com showing a crankshaft being turned between centers.  The circled gadget is called a lathe dog and allows the job to be spun around without slipping on the center.  In this example, the cutter is likely being used to either turn the shaft to finished outside diameter, and/or to face the cams.  Better to buy longer than you think you need as things like tailstock drill chucks tend to hang out a long ways and your 12" lathe may quickly end up with 8" or less usable length.  If you’ve got room and funds, I’d recommend the 16” version. As mine is really only 8” to the chuck once I install the tailstock drill chuck.

Spindle bore:  The diameter of the hole in the headstock through which the work may be passed.  20mm or a bit over 3/4" in my lathe's case.  You are not putting an O scale, or even an HO scale boiler tube through the headstock.  Ok for N scale though.   This is especially relevant to people turning very long boilers, rods (pipe, gun barrels, etc.) that are longer than the distance between centers.  In this case, the work is held in a chuck and may or may not also be held by a center in the tailstock, but in any case, it extends to the left through the headstock.  I once turned a thread onto a piece of pipe 16' long.  I rigged up a steady rest on a sawhorse to steady the far end as it was handing 15' out of the chuck, and you do not want a 15' piece of pipe flailing around.  Pipe bends and harmonic oscillations can quickly set up causing a deflection of a foot or more at the outer end which is hell on a machine or any bystanders!    My current big lathe has a steady built into the left end of the spindle which  I would imagine is really cool for turning gun barrels (not that I have ever tried to turn one!)  BTW, if you are setting up a heavy lathe in your shop, make sure you leave room to the nearest wall for the biggest length of pipe you are ever going to have hanging out of the headstock.  I saw one guy with a hole in the garage wall with a pivoting cover that he could move to handle long pipe.

Lead Screw Threads Per Inch: I mention this because the threads the lathe will turn are typically a multiple of this number and unless there is very complicated gearing it is unlikely the lathe will cut a thread less than this value.  Lathes 12" swing and up typically feature an 8 TPI (or 8 pitch) lead screw.and offer threads from 8 TPI and up. Some claim that they will cut a 4TPI thread, but I’ve never been inside one to figure out how.   If you think about a 1/4 by 24 bolt, this has a 24 TPI thread and could easily be cut on most lathes.  I am no expert on metric anything and will only say that every lathe I have ever owned has come with a complete set of metric change gears, and I have NEVER once installed any of them!  I have cut a lot of American Standard and British BA and Whitworth threads over the years though!  Need a plastic 72 TPI machine screw on a weekend when nothing is open or you live a hundred miles from nowhere?  Your lathe is your friend!  You can also cheat and use a tap or a die in your lathe with some hexagonal bar stock and turn out a huge number of bolts or nuts in an afternoon!  (Thats how they’re made folks, in machining centers that can pop them out at about 1/second).  The lead screw on my lathe is 12 TPI, and nicely shielded from swarf  by the black metal cover. 

Thread Cutting Range - the range of threads, typically some kind of multiple of the lead screw.  The star of this thread, my Craftex CX704 has a 12 pitch lead screw and cuts threads from 12 - 52 TPI.  Plus all the metric stuff.  If I'd had time, I might have tried to cut some M6-1 x 75 mm bolts to fit the lathe bed to bolt it to my table, but it was cheaper and easier to order them off Amazon at midnight and have them arrive the next day.

Headstock and Tailstock Taper - Machine tools use something called a  Taper to hold round tooling. The mini-lathe here has Morse Taper #3 in the headstock and MT#2 in the Tailstock, which is pretty normal for smaller machines up to Myfords. 
Now with all that in place, here in one place are specifications for the CX704 and Sieg C2:

• Motor: 1/2 HP 110 V, 60 Hz, Single Phase, 3 Amps
• Number Of Speeds: Variable (Low 0 - 1100, High 0 - 2500 RPM)
• Swing Over Bed: 7"
• Distance Between Centres: 12"
• Swing Over Cross Slide (RD): 2-1/8"
• Swing Over Saddle: 5"
• Compound Slide Travel: 2-3/4"
• Carriage Travel: 10-1/2"
• Cross Slide Travel: 2-3/4"
• Maximum Tool Bit Size :5/16"
• Headstock Construction: Cast Iron
• Spindle Bore: 20mm
• Spindle Size: 3"
• Spindle Taper: MT#3
• Range of Spindle Speeds: Low 0 - 1100, High 0 - 2500 RPM
• Tailstock Travel: 2-1/2"
• Tailstock Taper: MT#2
• No. of Inch Threads: 18
• Range of Inch Threads: 12 - 52 TPI
• No. of Metric Threads: 10
• Range of Metric Threads: 0.4 - 2.0mm
• Bed Construction: Cast Iron
• Overall Dimension of the lathe: 28" x 12" x 12"
• Weight: 75 lbs
• Warranty: 3-Years (Busy Bee)

If you can only afford or fit one machine tool, get a lathe.  You can mill on a lathe, either in a chuck, with an endmill in a chuck, or with a vertical milling attachment.  But it is very hard to turn things in a mill.  Mills are generally for square stuff, although some folks do some amazing round work on them!

This is a vertical milling attachment.  Pricey at almost $400 which is almost half of the cost of a mill that will do jobs at least 3 times as big.

 
That’s it for now on the lathe, on to the mill, the first of which was no doubt built with a lathe!  

Sieg Type Mini-Mills and General Terminology

Moving on to the Mini-Mill the photos indicate major parts.  Busy Bee didn't have a right side photo so I mooched one for the equivalent machine at Grizzly.  The differences seem to come down to paint colour and labelling.  When I was younger, Busy Bee used the same green as Grizzly, and I have heard rumours over the years that the founders of both organizations are related.  No idea if it's true, but if they are, I wish Busy Bee would carry Grizzly's superior selection, starting with the small surface grinder!

Milling Machine Terminology and Considerations

The graduated dials on the X-Y and Z feeds are all in thousandths (or parts of a mm if the machine is metric) and checking them all over 1, 10 and 100 thou, mine are dead on.  If you're buying at a store, take a dial indicator and make sure the indicated measurements hold true.

Tilting/Rotating Columns

I'm not a big fan of tilting or rotating columns, but some folks swear by them - I find they are difficult to get square again and it's easier to use an angled vise on the table.  I note on Sieg's website that they have a version of this mill without the tilting column.  Had I the choice, I would have opted for that.  My knee mill at home has a head that will swivel 360 degrees to get at a huge job in back, and it will roll over 90 degrees in both directions.  I have never used either feature as I've never had the need.

Critical Dimensions - on a Milling machine

When looking for a Mill one needs to determine first what kind and size of work they are doing which impacts the required values for the following critical capacities.

• Quill to table - How tall a job can the machine handle.  Remember that the tooling required goes above the job so the effective distance available is lower by that amount.  A Drill Chuck and a large bit can make for very little capacity remaining.
• Quill to Column - How wide a job can it accommodate and still allow Y direction table travel for milling and drilling operations?
• Quill Travel - How deep can it drill/bore?
• Table Size - how big a job overall will it hold?  Important, but less so I think than the table travel measurement.
• Table Travel - How much of the job can we get at to work on without having to reposition the job on the table.  Remember that it's not just the job that matters, but also the size of cutters that need to clear the job on each end so you have room to maneuver.

All in all, I can't see this machine having any troubles with anything up to G Scale (~1/2"), and one might even pull off a 3/4" scale live steamer, although the locomotive frame (especially a long steamer) would need to be moved a lot for drilling and milling.  Since precise layout is more easily accomplished with a long frame clamped once and staying put until every hole is drilled, these kinds of considerations should help you decide on table size and travel.

Both of these machines are white-labelled Sieg X2's.

Specifications as Follows:

Motor: 1/2 HP, 110-V, 4.5 Amp 
Drilling Capacity: 1/2" (13mm) 
End Mill Capacity: 5/8” (16mm) 
Face Mill Capacity: 1-1/8” (30mm) 
Spindle Taper: R8 
Head Tilt: + - 45 Degree 
Number of Spindle Speeds: Variable 
Range of Spindle Speeds: Low: 0 – 1100 RPM, High:0 - 2500 RPM 
Max. Table Longitudinal Travel: 8-1/2” (220mm) 
Max. Table Cross Travel: 4” (100mm) 
Maximum Spindle Travel: 7" (180mm) 
Table Size: 4” x 16”
Number of T-Slots: 3 
Net Weight (approx): 50 Kg 
Warranty: 3-Years

This same machine is available under multiple brands and models, the bolded entries are the reference model plus the ones used in the photos above:

• Bolton XJ-9510 Mill/Drill
• Clarke CMD300 Milling Drilling Machine
• Grizzly G8689 Mini Milling Machine
• Hare & Forbes HM-10 Mill/Drill
• Princess Auto 8507667 Powerfist Mini Mill
• SIEG X2-MT3 Mini Mill
• Micro-Mark 82573 MicroLux Milling Machine
• BusyBee CX605 Craftex Mini Mill (featured in this post)
• Cummins (Tools Now) 7877 Mini Mill
• Eastwood 32498 Mini Mill
• Harbor Freight 44991 Central Machinery Mill/Drill
• Homier 03947 Speedway Mini Mill
• Northern Tool 49657 KLUTCH Mini Mill
• Penn Tool Co XJ-9510-1 Precise Mini Mill
• SIEG X2-R8 Mini Mill
• Travers Tools OT2213 OTMT Mini Mill
• SIEG X2P Mini Mill
• LittleMachineShop.com 4962 SIEG Mini Mill
• SIEG X2D Mini Mill
• SIEG X2L Mini Mill
• WEN 33013 WEN Mini Mill

You Have My Interest

I'm sure you know from some of my past posts that I use machine tools for model railroading. I do have three large machines, a Logan 10" lathe, a Bridgeport mill  and a small manual surface grinder. On the smaller tool side I have a CNC Sherline which can be set up to be either a vertical or horizontal mill and a Sherline manual lathe that also has a mill set up option. On the list to buy is a Sherline CNC lathe. Also have a manual Grizzly mini-mill.

I also have an interest in live steam. I gave that hobby up. I discovered if you have to many interests that you don't get anything done. At least that is my problem. I still have a set of castings for a 3 truck Shay in 1.5" scale. Have also scratch built several table top stationary steam engines. Never got around to building a boiler though.

So I'll follow along to see how this thread develops. 

Bernd

Great topic

This would be a good topic to make a sticky out of.  I have used my full sized milling and Lathe machines for small things including HO locomotives.  I made clearance in a cast metal  frame to house a speaker that was to large. It would be nice to have a few Mini machines in the basement just for model railroad however having the full size unit's in the shop  will have to do.

More "micro" sized equipment

Hi,

this is a great thread!

First addition: get a base for your Dremel/Proxxon type tool. Proxxon offers something that clamps to the table and has a swivel accepting the mini-grinder. With that, the tool can be held securely while working with small or fragile parts that may not be easy to clamp. I was even able to do some milling with the tool clamped and the workpiece sliding on a block of wood. Very useful.

Second addition: There is a "kit" for various sub-mini machine tools: https://thecooltool.com/en/products/unimat-metalline - it can be configured into a variety of different machines. Yes, it may lack some features (no powered feeds), but I can use it for some model-size work. There are even additions for going CNC with that tool. With a bit of patience and some ingenuity one can do much machine-tool work for models with this. It is actually a lot of fun.

Have fun!

@Darkstar

Believe it or not, I think I have an old Unimat 1 Classic at home in a box that has barely seen the light of day.  I bought it likely 35 years ago.  It’s red and black.  Long before I got into live steam.  I probably thought I could use it for something in N Scale 

The pictures in your link resurfaced it in my memory. I recall the tiny three jaw chuck being plastic which is likely what caused me to shelve it, and not too long after I borrowed a bunch of money and got my first big lathe and mill and promptly forgot about it.  I must open it up next time I’m home and take some pictures to post.

A needed topic

There are various model railroad forums where this topic (machining) comes up sporadically, as you noted, Mike. There are also machining-specific forums that are helpful, but sometimes it's good to have a place where those two parts of the Venn Diagram actually are overlapping. 

The topic that interested me the last time I had questions in this area was machining plastic . Specifically, I was looking for recommendations on end mill types (flute count / diameter) and cutting speeds to remove details from the side of a hopper for a back-dating project. 

A sub-category of that discussion veered down the work mounting question - specifically, ways to mount the car body that is stable (to prevent vibration), yet relatively easy to mount/dismount.

I am in the position that I have the machinery, but not practical experience in some areas (though thanks to that sporadic discussion, I have an approach). Hopefully, this thread will be a good place to kick that particular can. 

Mounting Body Shells

Following up on my last post:

Here's some advice I received on holding the body shell. This comes from Dennis Storzek from Accurail.

Another approach that I learned here on MRH from @Pierre52 ( here) is super-gluing painters tape to a mandrel (like described above) with the low-tack sticky side up to hold the car body. 

On the cutter front, I received advice to use both four-flute and two-flute cutters for plastic. I'm leaning toward two-flute based on the following comment. I ended up buying both types - and a bur (like a rotating rasp) to experiment with .  

Milling Plastic Bodies

Matt,

Here's how I shortened the "B" unit on a set of Stewart FTB's.

http://kingstonemodelworks.com/StewartFT-3.html

Bernd

Holding and cutting plastic

Matt Goodman’s post has a ton of solid info, and the link @Bernd provided on his work shortening carbodies is full of great techniques.

I like the inside block idea with a rag or something to protect the outside from clamping. hmmm, why clamp it at all? What if a person used their mill To make the block a perfect size to fit, right?  Hmmmm, what about a universal (per scale) inside clamping block?  Be interesting to measure the inside width of a bunch of locos and cars in a given scale to see how much they vary and determine the range of adjustment necessary, and see if a person might machine up a fairly precise “adjustable inside holding vise”.  Hardwood maybe, or aluminum, with a spigot in the base so it could be clamped in a small milling vice (many of which are width challenged).  I’m staring at the dovetail on my boring head thinking about how best to make such a thing that is expandable in one thou increments.  Debating a sliding slope longitudinally, or a cross dovetail.  Have Mini Toolroom, will Engineer!” is the real motto of this thread.

Per @Bernd’s  photos, hold down “step clamps” (very gently) might help with some jobs depending on the shape.  I’ll include pictures and a discussion about these in a subsequent milling machine post.

For milling plastic, as others have said, four flutes for shaving, two for drilling and/or slotting, and only enough speed so the plastic is coming off like fine dust. 

For background, here is a photo of a set of 3 four-flute endmills ($30 for the set), and one 1/4" two-flute ($7.49).  All have 3/8” shanks, and I have put the two that are 1/4” at the bitey end to the right to show the differences. The two-flute variety are also called “slot drills” because they can be drilled down the depth of a slot (a keyway for example) and then moved laterally to cut a slot. Trying this with a four-flute endmill in anything but soft plastic is going to have you on your way to the endmill store for a replacement.
Slot Drills are fine endmills as well, but at equal RPM, you should feed them laterally at about half the speed of a four-flute because they only have two cutting surfaces, either that or increase the RPM. In my own experience, a four-flute leaves a finer grain in the finish.

Just like with cutting metal, Speed = Heat, and it is easy to get the plastic melting and welded to a cutter.  If this happens, stop, and wait until everything cools off completely.  Then you can probably peel the plastic loose, but be careful, endmills are ground as sharp as razor blades.  If you have sprue material from the same model, best to practice there first. 

Take very light cuts as well, no more than three to five thousandths of an inch to start.  That's 0.003" to 0.005" or as I would normally say 3 to 5 thou. A cigarette paper is typically 1 to 2 thou, a human hair, 1 to 10 thou.

You really need to think through what you're trying to accomplish, though.  In many cases, I'd be inclined to saw and strip sand, or file first, and use the mill for final clean up if it's needed.  This is what Bernd shows in the link in his post - definitely worth a look.

Tooling?

A lathe is just the start. What tooling is necessary for model making or modifications?  I bought a mini lathe years ago to turn O scale flanges down to P48 size but since then haven't found much use for the lathe, mostly from lack of tooling and lack of desire to spend more time learning how to find uses for it :> ) ....DaveB

Essential Tooling for a Mini Lathe

To Dave’s question about tooling … not that much really, and as you progress, you can make a lot of it.  

Sadly, the small lathes don't come with much these days.  In my youth, they came with a 3 and 4 jaw chuck, both centers, a faceplate, a steady and follow rest, and a tailstock drill chuck, and the machine tool place usually gave you a few things to get going. Not any more.  Now you get one chuck (if you're lucky), very basic tools, and change gears.  Everything else is extra. My big 14x40 came with all that, and more.  Inflation I guess.

For my big lathe, I generally use HSS cutter blanks, carefully ground to the shape I need and generally reserve carbide for getting under the hard skin of cast iron castings.  [Recently I have been using a lot more carbide for everything].

For the time being, here is the stuff acquired so far for the mini-lathe.  Re Dave's post, I would consider most of these to be essential from the outset.  All told, perhaps a bit over $100 for all of it as you don't need the full set of cutters - just buy a couple individually to get going.

• Cutters, Carbide tipped or HSS:

While there are plenty of affordable High Speed Steel ("HSS") cutter blanks and carbide tipped bits available, I began with a set of these with indexed carbide tipped cutters.  I found a cute little 3" bench grinder with an outboard shaft that I will mount on the bench at some point for grinding HSS bits, always being careful that grinder dust does not get onto the ways or into the workings of the mill or lathe where it will wear things away.

• The set shown has angles for left and right steps, facing and threading.  
• $45 Cdn for the set at Busy Bee Tools.  The blue fixed carbide bits are less than $3 each!  And HSS blanks that can be ground to any shape you want are 3 for $10.
• 1/4” square shanks for the mini-lathe sized turret toolpost shown here.  3/8 shanks are just a hair tall but could be used over center, or the toolpost lowered a few though by facing the bottom.

• Since many will be in the U.S., here's a direct link to Grizzly's 1/4" Tool-Bits 

• Parting Off Tool and Holder - Sized just right for the Mini-Lathe.  $17 complete.  Blades are $9.50.  These are also called Cutoff Tools.  You can by specialized versions of these with carbide tips, etc. but they get costly in a hurry.  Expect to break blades as you learn.  Parting off is likely the hardest operation on a lathe.  It's all touch and feel and speed (and oil!). 

I once watched Geoffrey part off wheel blanks for me out of a 5" diameter piece of nickle-chrome shafting and it was something to see. I was so proud of this painted chunk of shafting that I'd bought at an auction for $5.  He looked at it and told me to mount it as it was too heavy for him.  It already had a center hole in it so I used his live center.  As soon as he started cutting it he said, "I was afraid of that.  It was too heavy to check on the grinder."
I asked him what was wrong, and he looked at up at me his little gleam and said, "That's Nickle Chrome, that, very hard to cut.  Run in and ask Marie for some bacon grease."  Toolmaker's wives, trained as machinists by toolmakers, know what to keep around in the kitchen!

And cut it he did, Changed the spindle speed three times as he parted off each wheel blank with bacon grease as cutting oil.  He never even step cut it.  Pure technique and feel.  I still have that piece of shaft and the wheel blanks turned into very fine wheels - once cut into disks he suggested I anneal them before I wear out cutters trying to machine them!  I've moved that shaft several times a d keep it for sentimental value - it's a reminder of one of my fondest memories of watching him work his craft.

• Tailstock Drill Chuck: making round holes in other things is one of a lathe’s most useful features. Most often the work is spun, and a drill bit fed into it. That handle on the end of the tailstock is there to do just that. Holding the bit is the job of a drill chuck, mounted on an arbor which is part of a tapered shaft that fits the tailstock perfectly.  My last two lathes came with this, and so did the mini-mill.  For the lathe, I had to part with about $45.  
   
• Center and Center Drills: Starting a hole in a spinning shaft is best done with a center drill, which also leaves a conical hole that perfectly fits a lathe center.  Once the hole is started, you switch to regular drill bits and orient them so the flutes are horizontal.  My toolmaker friend showed my why, and the physics are very complex, so just do it - its the best way to get a round hole with a bit.  Perfect holes still require reamers or boring bars.

Pictured here, a Morse #2 Dead Center and 4 Center drills, #1, #2, #3 #4.  I think the Center came with the lathe.  If not, they are $10.  The Center Drills range from about $2 to $4 each and seem to last a lifetime based on the ones I have at home.  If you look close, the angle on the tapered shoulder after the pilot drill is identical to that on the Center.  Note they are laid down in the orientation in which they should be installed with the cutting flutes horizontal.

In case you are wondering about the sizes of Center Drills, they are highly standardized.  Here is a handy reference chart (scalable) of the diameters of the various surfaces.

• Boring Tool: Perhaps not essential right away, but will be just as soon as you need to create a perfect size and perfectly round inside hole.  Reamers work great to if you can find and afford them, but are only available in "typical dimensions", whereas the boring tool can make whatever size hole you need.
  • The first style shown came with the holder for about $12.  HSS blanks were about $5 each I think. It's used for bigger holes with HSS bits ground from cutter blanks to the shape required.  The holder shown is oriented 90 degrees from correct to see the slit that is squeezed in the toolpost to lock the bar in place at whatever angle you choose.

• You can buy the holder for $8, or make one just like it from 50 cents worth of 1/2” square bar.  Cut the bar to length and put in a four jaw chuck and get it dialed in concentric.  Run a couple of drills thorugh it working your way up to 3/8".  If you have a mill and a slitting saw, then mill the slit.  If not, cut the straightest line you can muster with a hacksaw.  You may need to put it back on the lathe after and run the drill through it again to clean up after the saw. 
• The second style is a set of small boring tools made for a boring tool in a milling machine.  These were $22 Cdn.  Over the years I have found these to be excellent for use in a lathe as well.  They have 3/8" shanks so fit the boring tool holder shown above, and are shown here using it.  I'll describe the boring tool that these are intended for later under the Mini-Milling Machine post.  Nothing cooler than boring a piston cylinder in a model V8 block with a boring tool.  My toolmaker friend was working on a gasoline engine for a Holt tractor model ( like a cat dozer) he was building when he took ill.

First Test!
Below, the first test of the wee lathe and cutters on a chunk of bronze shafting using default fine power feed.  I forgot how much of a mess bronze makes.  Lol.  Hmmm … I think I need a gold mine on my layout so as to not waste this shiny swarf.

I think it gives a pretty decent finish.  If I wanted it dead smooth, I'd make sure the top slide is dialed in at a perfect 90 degrees, set the cutter at a rubbing angle to take off about 1/10 of a thou, and hand feed it.  I bought a few pieces of brass and bronze square and round stock out of the cutoff bin at Metal Supermarkets for $20.  Small scrap they will often sell at weight alone.  This chunk had been clamped so tight that it was about 10 thou out of round and the cut was interrupted until I got in about that far and the cutter started to engage continuously.  You can see it in the picture if you look carefully.

I’ll do a post some day on using taps & dies in the lathe, and perhaps making a die holder for the little lathe.  You’ll never get better results than with a lathe because everything is perfectly aligned.

I'm awaiting Busy Bee to get backordered stock in for a face plate ($20) and maybe a steady rest ($65) and a 4-Jaw ($145) and then the mini-lathe is as complete as I need it.

One other essential thing is a precision measurement device. Micrometers are very accurate, but you tend to need one for every incremental inch.  For what I’m doing, this 6” digital caliper is more than adequate.  It works in inches or metric, has an auto zero button, and cost all of $30 at Princess Auto.  I think my dial style Mitutoyu Caliper at home was well over $100, 35 years ago, and it is no more accurate.

Some folks buy fancy add on tool posts to hold their cutters.  I've never found a need for one.  [Update: Inhave since succumbed and bought a good two position, wedge type one.  Now I see what allthe fuss is about - no more shims for me!]
   

Their main advantage is unlimited swapability of pre-mounted cutters/tools and built in precision height adjustment.  But they are pricey - typically a couple of hundred bucks. I was trained on a 4 -way turret-type like the one shown below, so happy with that, and it comes with the lathe!  Shims are cheap!  In my case, I will just mill extra turrets out of the cheapest CRS scrap I can find with a base at a perfect height for my carious cutters.

Hope this helps.  We’ll discuss more exotic tooling, like clamp knurlers, later on.  (Please don’t use a push type knurler on these little lathes - you're just going to wear things out.)

A closing thought on this post, from the Wisdom of Geoffrey Tuck:

A “D-Bit” made from a few inches of drill rod (tool steel) in the needed diameter, ground flat to half its diameter and hardened will give you a workable equivalent of a $20 - $60 (depending on size) reamer for a couple of bucks.  I will make feeble attempts on an ongoing basis to impart bits of wisdom like this, passed along to me by Geoffrey Tuck, Master Toolmaker, that I had the luxury of receiving so many years ago.

Essential Tooling for a Mini-Mill

Photos and discussion soon. 

I'm swamped with the real work required to pay for my flying and MR habits for a few days, so will get back to this once I'm above water again,

Stay tuned for content on:

• Drills
  • Decimal
  • Metric
  • Letter
  • Number
• Endmills and Holders
  • Dedicated holders
  • Individual R-8 Collets
  • E32 Collet Holder and Collet Sets
• FlyCutters
• Boring Head and Boring Bars
• Step Clamps
• Vices
• Dividing Heads and Gear Cutting
• V-Blocks

Stand and Installation of Machine Tools

At this point I’m not going to go into too much detail about the DeWalt Planer Stand I'm using.  It's designed for the DeWalt Dw735 Planer and Busy Bee had them on sale for $249.  I did some measuring in the show room and was convinced both machines would fit nicely.  They do, and it is very sturdy. 

The turning wheel/lift foot can be mounted inside or outside the stand.  I tried it underneath as shown here, initially thinking about saving space and removing a tripping hazard, but it turned out to be impossible to get a foot in there and lift the pedal to lower the base.  It looks easy here, but they don't have the supplied shelf installed!  I moved it outside the frame where it works perfectly, and steers better.  Inside mounting also kills a lower shelf position, and I managed to have the whole thing drop on my forearm reaching in to lift the pedal in trying to lower it.  Nice scratch and a bruise.  It only moves a half an inch, but with a couple of hundred pounds on it, it comes down hard. OUCH!

There is a metal shelf on it as well, not shown here, just the rails it sits on, but likely evident in some of my other pictures, and I am going to add a lower plywood shelf on the frame for metal and heavier accessory storage.

The Mill, having a fairly small footprint, puts a lot of weight in a small area, and I noticed it's weight was deflecting the supplied surface a bit.  I also I wanted a studier and slightly larger base to facilitate access to the lathe from underneath, clear of the stand’s metal parts, so grabbed two 3/4” GIS 24” x 24” panels. This provided a bit of extra space and a nice overhang for getting at the lathe bed for bolt up as well as a spot for a wee vice.

Mounting and Dialing in the Mill

3/8" bolts, washers both sides and lock washers in all four positions.  I got the machine exactly where I wanted it, drilled right through all four spots with a 3/8" bit, and bolted it up.  

Test Dial Indicator

This may be a bit of a luxury but I wouldn't be without one with machine tools.  While I have a much better one at home, Princess Auto had these for $30 plus the 175 pound magnetic base which was on sale for about the same.  The plunger is super sensitive and has 0.001" graduations.  You definitely cannot pull this vice off when the magnet is on.

Dialing in the Mill

First thing to do with any machine tool is confirm that it is square and not deformed or bent in any direction. 

I did the ground surface of the backside of the table first and it was within one thou end to end.  Check!  

 
Then I did the T-Slots. All were within a thou.  Check! 

I didn't take pictures in the Y direction, but it was all square that way to. Check!

Then I did the table surface to check the column for plumb as it can be tilted 45 degrees. 

Again within a thou. Check!

 
I checked all the graduated dials as well and everything is spot on. If I move it so many thousandths on any of the feed wheels, it shows the same deflection on the dial indicator.  Check!

Very well made little machine tool.

Mounting the Vice

Next up, my temporary vice, mooched off my drill press until the real machine vice arrives. 

This thing is not remotely square and the fixed jaw edge has all sorts of undulations and imperfections.  I gave up trying to dial it in, and just centered it, squared it up to the table with a metal square and bolted it up to the T-Nuts provided with the Mill with two 10-1.5 x 30mm bolts and some washers.  Normally, I machine one piece T-Nuts with a thread to grab the vice, but that will be a job for when the vice arrives. This will do to hold this thing down until then.

All in a night's work:

Mounting the Lathe

Much harder job than the mill owing to having to get at it from underneath and thread into the M6 holes that need to be found to bolt up from underneath.  I put it on it's back and pulled the chip tray off and used it to mark the holes.  I had quite a time finding M6-1 x 75 mm bolts and ended up ordering a 140 piece set with free overnight prime delivery for $26.  It paid for itself already as 4 of these bolts (1) cannot be found in Vancouver without wasting $50 worth of gas, and (2) 2 60mm versions were $9 at the big box store.

Needless to say, some drilling and a lot of finessing things and finally I got all the bolts into the holes.  The lathe has cross braces with rubber feet and those, plus the chip tray, plus the lathe bed all have to get aligned while trying to work underneath the stand which has rather deep side braces.  All in all, a solid hour and a few choice words, but it got done. For now, I have not tightened it down - just snugged up the bolts as one needs to be careful bolting down a lathe so as not to introduce any twist into the bed which will cause it to turn taper.

A job for a calm day and lots of patience with the dial indicator being watched by a helper as the bolts are gradually snugged up, the base shimmed where necessary.  I may yet modify the mounting to include more nuts to support the cross rails and reduce chance of warping the bed.  Too hard to explain though, easier to rig it and take pictures.

Sadly, I was preoccupied with getting the bolts to find the holes and did not take any pictures during the operation.  Here's one after all was said and done showing the foundation at the tailstock end with one of the bolts peeking through after passing through three layers of wood, the foot, the chip tray and the lathe pedestal.

A first project on the mini-mill

Soon. tools: endmill holder, end mill, drill chuck and drill.

Tools

Hi Mike, For narrowing and cutting smaller flanges on wheels I found arbors of the correct size were handy..... DaveB

Arbors and Mandrels

Indeed, Arbors (and Mandrels - between centers) are very useful for repetitive work that needs to end up identical. This post to illustrate what Dave mentioned. Dave, it would be wonderful if you could do a post about your O scale arbors with photos and video - it would be cool to see wheels made this way in model railroad Scales.  It would also give you cause to turn your lathe on!  My smallest wheels to date are about 3 1/2 inches in diameter!

Arbors are fixtures, rather than tools per se.  They are machined with a chuck and then left in it while all pieces are machined so as to maintain centricity with the spindle.  (I have a few at home from various live steam adventures and will post some pictires next time I am there).  Best to mark a register with the number one jaw of the chuck in case they need to be taken out, and then they need to be dialed in to ensure centricity if re-installed.

I generally rough drilled (undersize) and then, bored or reamed my castings (or round stock) in the chuck to the exact size of the axles, and then made an arbor with a spindle (threaded at the end so the wheel could be squeezed on solid with a nut) that exact size.  Then each wheel is in turn mounted to the arbor and all operations completed either one at a time or in batch mode.  Removing a wheel from an arbor foes not lose centricity so long as the arbor is left in place  

Hard to find photos of some things these days, and there are many techniques used to machine wheels.  I was taught to do it using an arbor, so here are a few photos to give the general idea. The first photo is misleading as it's actually an already turned wheel being reamed to a precise bore.  Note the use of a 4 jaw chuck to get perfect centricity.  This kind of job is extremely finicky to get dialed in, which is why I use the technique described above, because I am a lazy sod.
The middle photo has the arbor, held in a chuck, with the wheel a precise fit on the arbor and a thread on the end of the arbor to take a nut which clamps the wheel firmly.

The last shot is a profile gauge that the model engineer has made to check wheel treads and flanges to be certain they are identical.   Some folks are able to make profile cutters on larger machines that do the whole operation in one shot.  

Per Dave's post, It would be very cool to make a set of N, HO, O wheel arbors to fit each size axle one has (or make your own axles) and machine absolutely to scale wheelsets!  One could then re-machine existing wheelsets to Proto:87 or Proto:48 standards this way.  The trick is figuring out if you can do it without buggering the axle holes.  If you have a variety of axles in use, you'll need to measure carefully to be sure that your arbor doesn't render them oversize for reinstallation on the axles.    

While i find this topic

While i find this topic interesting…. this is really another example if having a completely separate hobby  that just happens to be useful in some) model railroading situation,

Electronics, Wood Working, Computers and such are a few more examples if this.

-Doug M

my BP20 project

This was started quite a number of years ago, and never completed YET due to a number of factors. My tools were basically hand held ones, but I'm sure I could make use of a mill of some sort for some of the work.

https://forum.mrhmag.com/post/brass-vs-plastic-12199233

Cutting Body Shells

At the same time I was cutting body shells to make a B-unit for my DL109. I recall that I had a hard time finding a way to get a perfectly perpendicular  cut on those shells. Most of the miter boxes for modelers were too shallow.

https://forum.mrhmag.com/post/brass-vs-plastic-12199233

Very nice work on those models Brian

And yes, a small mill would be a lot of help, if for no other reason than saving you all the exercise you're getting with the files!  Still, you can be really proud of a great cutting and filing job like you have done here.  You do very nice work!

For the extension of the frames, a small slitting saw in a mill or drill press with X-Y capabilities would enable a perfect cut, and I would imagine a small channel milled into both adjoining pieces and the extension piece (brass or mild steel) would enable a brass rectangle to be inset and fitted up, and everything bolted back together with flush fitting screws drilled into very precise holes made with the mill or  drill press.

Check out my post below about affordable milling.

Incidentally, I’ve had this little arbor and slitting saws around for decades in my woodworking box (sacrilege!).  I bought it to cut a super small channel for an inlay in a table, and it will cut a super straight line mounted in a drill press.  I think it was about $20 with three blades. I have slightly bigger ones and an R-8 Arbor for use in the big mill at home, but I brought these to my away place and they will most certainly get a workout shortly cutting my toolbit shims to length.  I absolutely suck at cutting straight lines with a hacksaw!

 
 

Shop Safety

For anyone reading this, please do not attempt to use one of these in a portable drill.  The slitting saw arbor needs to be very tightly mounted in a mill or drill press and the job you're slitting needs to be equally firmly mounted in a vice that is also firmly bolted down.  Therefore an X-Y table is also critical to their use.  Eye protection is also a must.  These blades can break and go flying, and if everything isn’t fastened very firmly, your fingers are not nearly as hard as the steel these are designed to cut. They could be severed before you realize a job has jammed or come loose.

I would

love a small mill, but for the few projects I would have liked it for, it doesn't seem worth the cost for me.  I need a buddy with one that we can barter on reciprocal services.

@Skilof ...

A mini-mill (or a larger knee mill) would be a GREAT investment for a club, and a friend with one is even better. 

If you're in my neck of the woods where freight doesn't become a big cost for either of us, I'm happy to take on small jobs, probably more so if I ever manage to retire.  The issue with me at present is just availability as I am away a lot for work.