The story so far

Reviewing my Wordpress blog, it seems I've been working on this engine for more than two years already!  Most of that has been design work and skills growth, however.  So, MRH readers have not missed much.

The Canada Atlantic had six locomotives nearly identical to 622.  I intend to build two or three, and so, this is kind of like building a kit for myself.  As such, I am hoping to reduce the number of parts I have to fabricate.  I will have most of the metal parts etched, and other parts will be 3D-printed.  With luck, the number of parts will be in the low hundreds, which compares favourably to my other engine, containing well over 1100 pieces.

At this point, I've completed the design.  You can explore it in OnShape yourself if you like.  I've uploaded the parts that will be 3D-printed to Shapeways, and mostly finished the patterns for etching.  However, I'm going to hold off on ordering these pieces until after I've made the wheels.  If I can't make wheels, there's no point in getting the other parts made.

And now you're mostly up-to-date.

Cheers,
Rene

Following

Do I see another book on the horizon? 

Your blogs on Wordpress have really whet my appetite to build an engine! I look forward to your posts - successes and the inevitable not so successful attempts that you seem to take in stride.

Book?

Thanks Neil,

We'll see about the book idea.  The first one wasn't exactly a New York Times bestseller.  However, if we can get the work down to a manageable amount, perhaps I'll assemble it into a book again.  Mostly, I put the first one together so I could have it on my shelf!

Cheers,
Rene

looking foward to the saga

Admiration runs both ways

Cheers Scott.

Rene

Have you looked at???

Hi Rene,

have you looked at some of the commercial wheel suppliers? Like Romford/Markits from the UK. This gives you the driving wheel/axle/crankpin as an assembly. There are others out there as well that might be quicker than doing the wheels yourself,

Following

Also following.

UK wheels

Hi John,

I have, and indeed #10 is shod with Sharman wheels.  Sadly the old mm range is gone, and with it the 30” wheels required for the engine truck.  So, I started down the scratchbuilt wheel path.  In for a penny, in for a pound: if you’re doing four, you may as well do 16 wheels!

thanks, 

Rene

Closing in on cast wheels

Thanks to Brian Pate, and to Don Mitchell who suggested I call him, I’ve started vacuuming my castings when I pour them. Brian indicated that he liked to vacuum before and after pouring, but I’ve found the pre-pour treatment makes little difference. The post-pour treatment, on the other hand, dislodges all sorts of bubbles from the deep recesses of my molds.

The resin is Smooth-Cast 310, which has a long pot life of 20 minutes. It also has a commensurately long cure time, which, it turns out, bothers me more than I want to admit. However, the process takes about five minutes so this wouldn’t work with a faster resin like Smooth-Cast 300.

My vacuum isn’t strong enough to collapse every bubble. So the best approach seems to be to pull the vacuum, watch the bubbles foam to the surface, and then release the vacuum and push any remaining bubbles away from the backs of the castings. You can see that there are still a couple of bubbles in the collection pictured here, but the later attempts have had zero.

Until that bad pour.

For some reason, the previously trustworthy jars of resin started dribbling down their sides and into the mixing cup. This lead to a profoundly unbalanced mix of A and B, which didn’t set right, and ultimately damaged the surface of the molds. So, lesson learned: it is better to abandon a potentially bad batch of resin, than pour it into the molds anyway.

At any rate, there is continued forward progress, and I’m sure I will get there. Eventually.

First insertion-cast wheel

On January 1st of this new year, I pulled the first insertion-cast pilot wheel from its mould. This part marks the development of two major new skills - turning and casting.

More importantly, the wheel represents the freedom to build any railway model I want.  The combination of a metal tyre and centre with cosmetic spokes cast in will enable me to make pretty much any wheel I can draw. Not that I need them, but Boxpok and other exotic wheels are completely within my ability now. Okay, some cross-shaped spokes will require me to learn how to do two-sided moulds, but really that is a small increment from where I've come.

Just 15 more wheels to go for #622 to be shod!

Amazing

The part is amazing and your ability certainly without question! This should be a boost of confidence after a, um, wet (?) year. Well done. When is the next book due?

Thanks Neil

Thanks for the vote of confidence, Neil. Yes, the first wheel was hard, but I think it’s pretty much all downhill from here. 

The next book is a long way off for certain!

Rene

Spoke filing fixture

I didn’t write about it before, but filing that first wheel centre was like trying to wash a cat – slippery and occasionally painful. There seemed to be no good way to grasp it. Worse, as I was filing bits away, the challenge levelled up! By the time I was at panther level, I was using a combination of needle nose pliers, fingernails and will to keep the centre from flinging itself into a corner beneath my desk. It took a whole evening.

I don’t have the will or the fingernails to do many more in the same way. So, I had to find an alternate approach. I expected I would have to solder the wheel centres to handles for filing.  But then, I came up with the trivial aid shown. A steel bar with a hole to accept the hub means I am holding the part by the spokes, rather than by the hub. A second hole along with lines helps to hold the little blighter while I scribe guide lines for the spokes.

Using the fixture, spoke filing went almost two quickly. Each centre took only fifteen or twenty minutes; that was good because my weekend turned into a taxi shift. Even working in stolen minutes between bouts of tween transportation, I had time to do a couple extra so I can discard the ones I don’t like.

Soldering wheel centres

I dragged out the resistance soldering unit on Saturday morning to solder those centres into their tyres. On the first wheel, I experimented with solder paste and a torch, but ultimately settled on the RSU. So, with only twelve joins to make, I started work with the RSU again. This time, I found that after the first spoke, the current was passing through that path and refusing to warm up the next joint.

Finally, I gave up and went to dig the trusty Weller out of Mt Deluge. This worked perfectly. A little drop of Carr’s green label and the tiniest smidge of solder offered up to the joint on the tip of the hot iron resulted in a quick poof of noxious vapour known to cause cancer in California and a nice solid joint.

At the end of play: Weller 9 – RSU 3

Missing flange!

I think one of those wheels is missing part of its flange!  That's unlikely to stick to the rail!

First parts on order!

I'm all a-tingle! Today is the day when the designs for 622 start to get realized.

I just uploaded the first files for 3D printing at Shapeways. I've broken the printing in orders parts - the first for the engineering parts required to make a working model, and the second will be for the details. This not only deferred $130 of spending, but may also enable me to take advantage of new technologies when I finally get around to printing! After all, the last engine took four years to complete, and that's a lifetime in the technology business.

PPD is a more hands-on arrangement, and I emailed the artwork. I won't find out until at least Monday if my artwork is even acceptable. For the next time I'm producing artwork for etching, I must remember a couple of things.

• InkScape has a command on the edit menu to enable you to select all items with the same fill colour; I laboriously selected each individual tab and fold line on three of four sides before finding it.
• I should have designed the parts to allow for etching in OnShape, rather than leaving such considerations as minimum widths to the layout stage.
• InkScape introduces some artifacts in the final pdf render. I spent a couple of hours today reviewing each pdf for faint lines where one shape meets another shape.  

Progress update

It's been a month since I last posted here.  Since then, I turned blanks for the drivers:

Then I experimented to find a good solution for creating split axles:

I also confirmed I could cut out the required spokes, and mounted all the drivers on their half-axles:

Meanwhile a package arrived from Shapeways, and I went back and forth with PPD before finally completing the order:

I also thought for a couple of days that I had broken my lathe, but I managed to get it back together again.

Finally, the Railway Modellers' Meet is coming up quickly, and while it doesn't look like much now, I'm hopeful I will have something to show of this project on May 4th.

Progress for March

Cutting even three spokes in each of the stainless steel wheel blanks turned out to be more work than I expected.  However, I persevered, and eventually the job was done.  I can't imagine doing 15 spokes in each wheel!  The plan to cast the rest of the spokes turned out well, although a couple of the wheels needed multiple attempts.

Meanwhile my etchings arrived from PPD Ltd.  

The connecting and main rods were the first etched parts to get pulled off the fret.  I am pleased to say they went together just as planned, and turned out stiffer than the rods on #10.  I needed the rods to start on the crank pins, but decided that 00-90 screws were too big.  I've sent away for some M0.6 screws, in the hopes that those will work better for me.

Meanwhile I got started on the bearings.  Twice, of course.

Finally, it was time to start on the frame.  The firebox went together first, and I just folded up the frame and soldered the firebox into it this evening.

My goal is to have something that looks like a locomotive to show at the Railway Modellers' Meet at the beginning of May.

More in a month!

Rene

Unbelievable!

I can't imagine ever imagining such an effort, much less attempting it. My hat's off to you.

Easier the second time

Thanks Bud.  

It’s actually my second time so I should know better!  My book about the first one is currently on sale on the MRH store, by the way:  https://store.mrhmag.com/store/p124/PAPERBACK_-_Building_an_HO_steam_locomotive_in_brass_and_styrene.html

Cheers,

Rene

WOW!

Following!

What a treat!

I've been following René's work for a few years now and always find it to be absolutely delicious both for its inspiring content and thoughtful and skillful presentation.

I didn't realize the earlier locomotive project was documented in book form and have just eagerly downloaded it. Thanks René and MRH for making this so convenient!

Jeff Allen

Thanks

Thanks for the kind words, Warflight and Jeff.

Progress for April

Back in February, I set myself the goal of having something resembling an engine to show at the Railway Modellers' Meet.  I didn't quite complete everything on my list, largely owing to a long shipping time for crank pin screws.  Perhaps that was a blessing in disguise, as perhaps I would have only wheels to show if they had arrived quickly.

While I was waiting, I made up the driver bearings and their guides.

Then the screws still hadn't come, so I completed the engine truck. 

Still waiting for screws, I folded up the cab.

By the end of April, I was giving up on the screws in terms of displaying the engine, and had resigned to a model without drive rods.  I put the boiler weight together.

Putting all the bits together, it does indeed look kind of like a 4-4-0.  Not bad considering six weeks ago, I was still making wheels.