Kevin

Don't think that'll work. The slip ring needs to be mounted in the center of the rotating cab were the motor is mounted. I've been thinking of mounting a motor under the frame and using a gearing system on the next crane.

As far as cutting out a portion of the roof for just a muffler you could just mount the muffler on the roof.

Bernd

Yes, I've thought it out that far.  I have this picture in my head of a brass ring around the well with teeth on the inside and a motor gear that meshes with that...that's all it is so far, just a picture in my head.  Now if I wanted to make such a ringed gear...I'll bet I'd need some special equipment to do that.

Yes the muffler can just go on the roof or out the back for that matter, and I may do that.  I also like the look of the cutout you made for yours.

I was talking about an interference problem earlier. Well, I discovered I had one. Not only that I damaged the 4 mounting posts that hold the shell on the swing base. Here are the pictures.

Oh man!  Sorry about your troubles.  I'll take a lesson from your misfortune and be careful not to do the same thing with my crane.  I recall when I was younger, that an accident like this would have left me thinking I had ruined the project.  Now, older and wiser I know it's not the end of the world but a just frustration and delay.  Ken's got the right ideas.  I like the sound of the brass posts but the styrene rods should work in a pinch too.  This crane may end up being more brass than styrene before you are done.  Don't get too frustrated.  We're all rooting for you!

I was thinking about the problem of how to transfer power to the rotating assembly, and I have an idea.  I realize this is extreme, but so are a couple of the other modifications you've made, and having the tools makes it less so.

Rebuild the turret on which the cab and boom rotate.  Turn down the inside, and replace the removed material with brass or copper.  Do the same on the outside, leaving a thin section of plastic in between to insulate them.  Ideally, you would also make a mating metal ring for the cab floor, which would serve as both bearing and current collector.  A wiper contact could easily be made to travel against the inner ring.

The plastic on plastic bearing just does not seem like a good idea to me, especially since styrene is so soft.  I would think that metal would be much more durable, and might rotate more easily as well.  One of the issues I have with motorized cranes, especially in the smaller scales, is that the parts are so light that the motion is unrealistic.  Making things as massive as possible, and making the bearings as friction-free as possible, should help with that and give the illusion of a much larger and more massive machine.

Ken, I like your second suggestion. If that don't work I can still glue some styrene blocks in.

Those spools, ah yes. I need to drill a hole in them. Just forgot. Glad I didn't ACC them in.

Thanks for posting that link. Now folks can see what I want to do.

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Now you've got me thinking ... What your talking about is on the verge of what's known as a planetary gear. I know were you can get those. Electric portable drills, sound familiar? They have a planetary gear set in them. I know I've got a small one around that I was going to use to drive an O scale diesel.

I'll have those pillars fixed soon. I just need a rest away from the project to recharge so to speak.

I think Ken is on to something with that ring idea.

Bernd

You know Ken that might just work. I'll have to take a look at that on the second crane that I'll build. Going to have to get out the manual rotary table to do that on the mill.

Great idea, many thanks.

Bernd

You know Ken that might just work.. on the second crane that I'll build.

Not that I have a right to dictate what you build, but I don't see any reason why you cannot do it on this one.  I personally do not like the idea of wires between the two pieces, since sooner or later it's likely you'll turn it too far.  The only good way of preventing that would be to put a mechanical limit in place, so that the boom cannot rotate 360 degrees.  Of course, then the question becomes, where does the stop go?

Going to have to get out the manual rotary table to do that on the mill.

Lathe swing not large enough to hold the base?  I was afraid that would be a problem, as would securing it without damage.

Just a thought, for the folks like me who do not have the benefit of machine tools:

It looks like the turret (is there a better name?) has a lip on the outside.  That lip could be removed with a file, and replaced with a similar sized ring made of brass or copper strip bent into a circle.  Some epoxy and a little work with a file would be all that's needed to make it secure and nicely circular.  I like the copper tape inner ring in the article (though of course a solid piece is better if you can make it).  That gives concentric metal rings inside and outside, without the need for a lathe.

Hi,

I have been enjoying and learning from your approach to building your crane!

Electrical connectivity to the cab was probably one of the problems I spent the most time thinking about, and the reason why I started my article with it. You'll note that ANY elctromechanical connection in my crane actually has redundant contacts-- from the individual wheels, to the trucks, to the feeds to the cabs. I was close to paranoid about making these work ALL the time. And I never have had a problem with electical continuity to the decoders inside-- no sound decoder resets, nothing.

You can vastly simplify life by not accepting 360 degree cab rotation and simply feeding two wires up into the cab-- cheap, simple, easy solution. Naturally, I couldn't take that! But I may build another exactly like that! When I scripted operations for the crane video and other animations I came to realize that almost never would you want the crane to traverse competely around-- although I have to say that when you watch it do it-- it is very cool!

Surprisingly, to me, the copper tape ring and wiper worked remarkably well for me, even though I thought the pogo pin was a more elegant and reliable solution. I considered machining a bearing for the cab too, but I wanted to see if I could simplify the project by doing without. I think your cab rotation should work out very nicely.

Someone mentioned plastic on plastic bearings... I have been exploring using teflon film (.003) for such a bearing surface but haven't started down that path yet.

Best Regards,

Geoff Bunza

We moved the bulk of this thread's lead post to the first comment post - to save us all a ton of scrolling on the subsequent pages of the thread.

REMINDER: Post the bare minimum in your lead post of a thread. Then reply to your initial post and put all the long gory details in the FIRST COMMENT. That way you don't get this long first post that repeats from page-to-page.

It's a Drupalism that takes a little learning to get, but once you get it, it's easy enough to do.

Thanks for fixing that for me. Next project I'll know better.

More yet to come on this build. I hope the members are enjoying what I'm doing although it leans heavely toward machining. That was my forte in life. A machinist.

Regards,

Bernd

 have been enjoying and learning from your approach to building your crane!

Thank you for the comment Geoff. My reward is that members are hopefully learning something from this. I'm taking it from a machinist point of view since that was I did for over 30 years.

It's always difficult to come up with ideas to make a circuit on something that rotates. My next installment will be the power ring to the motors. I haven't quiet finish it yet. Hopefully next week.

I'm just going to put a DCC decoder in it for now. I'm close to were they manufacture NCE so I'll be trying one of those.

You can vastly simplify life by not accepting 360 degree cab rotation and simply feeding two wires up into the cab

I was actually thinking about that, but I've already have a ring made and my own wipers. I'll show that in detail next time around.

Your set up is great for the person that only has hand tools. I'm taking it a step further and using machine tools. I think there are a couple of members that want to try their hand at machining.

The brass rings I made are for the next crane project. I have four cranes all together. This one here will be like yours, all plastic, except for the walls inside that held the winches. My opinion on the teflon is that it might work. At this point the whole turret ring seems to function ok with the plastic grease. I had some left over from a Taymia gear box. It works just fine.

Hopefully I'll be posting more come next week. Life got in the way this week.

Bernd

Geoff presented one way of getting power to the DCC decoder. I'm going to show another way of doing this. Same principle but different methods.

My first attempt, yes I can screw up too, didn't work to well. I made a ring using a chemical enchant. The second is using a mechanical method. I will explain both with words and pictures.

Here's the first attempt. First I'd like to point out that I removed what looked like internal gear molded into the plastic on the bottom of the turret ring on the crane. It looks to me like they had at one time thought of powering the crane. I'm using a piece of single sided copper clad circuit board to make the power ring with two separate tracks. I used a Sharpie marker and covered a portion of the board so I could mark the rings with a compass.

The internal dimension of the turret is approximately 1". I set the compass to 1/2" and scribed a circle.

Cut out the circle with my fret saw and a metal cutting blade.

Made sure it fit. Trimmed it with a file for a nice snug fit.

Drew some more circles. Outside circle is for power, next in is for insulation gap, third in is another power ring, inside circle to be cut out.

First I had to drill a hole to put the saw blade through. A bit blurry, sorry about that. BTW, I use a pin vise. Reason is I've done this with a drill press and when the drill broke though it grabbed the work and spun it.

The inside cut out for the motor to fit into.

Unfortunately not big enough.

Ok, bigger is better. Also note that I had to grind down the screws sticking thorough the bottom that holds the D-shaft plate to the bottom.

This is the chemical part of trying to make the power ring. The stuff in the plastic box is ferric chloride etchant. It's very corrosive and will cause burns on your skin. Wear rubber gloves, old clothes and face protection when working with an acid. I believe it's still available from Radio Shack. If not it can also be bought from Jemaco. Here's a link to there page. http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDrillDownView?langId=-1&storeId=10001&catalogId=10001&freeText=copper%20clad%20board&search_type=jamecoall  Use a pair of plastic tweezers or make some from pieces of wood. Using any type of metal tongs or tweezers with destroy them. I put the ring in and kept checking every few minuets. It takes a while to dissolve the copper. I used a Sharpie as a etchant resist. The results were not pretty.

 And here are the not to pretty results. The ink in the Sharpie didn't quite keep the etchant for eating away on the part I didn't want etched.

For some of the readers that have never seen or read about etching copper boards I will do a little demo on alternatives to use on a copper board. First a bit of history. Many years ago a friend of mine and I were going to go into the printed circuit making business. That never panned out. But I learned almost all there was to know about making printed circuit boards. I still have materials left over from those years. I learned how to make silk screen masters of the boards and then print them on copper clad board. That's the Readers Digest version of my knowledge on circuit board making. Anyway, if you'd like to try it here's another way of doing it. On the right is finger nail polish, middle is Floquil Engine Black and on the right is what is used when silk screening. It's a etchant resist paint. I've had a quart of for quite sometime and of course the copper clad board.

I painted on the nail polish, Floquil paint & the resist paint as the control standard that will determine how the etch should look.

Here are the results. The nail polish worked great. It's the first time I ever used that. The Floquil paint didn't fair so well. It got under etched. When I wiped the board off the paint came right off. The control resist paint naturally came out good since that's what it was designed for.

Next up, the mechanical way to make two power tracks.

Clock makers use a method that incorporates what is known as a pot chuck, or one version of it. Take a piece of ferrous material, brass, aluminum, steel and face it flat in the lathe. Then add concentric circles a couple thousands deep. These grooves will hold the excess ACC glue that will be used to glue the copper disk to the chuck. I've blued it up for a better visual appearance.

To center it I used a home made center with a very sharp point to hold the board in the center of the chuck. I already turned a few circles to cut through the copper cladding. This electrically separates the two rings.

Once the ACC glue had dried I cut out the center for the motor to fit into. Unfortunately there is an angle on the inner most ring do to the way the tool is set up which needed to be filed out.

Not to good a job of filing, but the motor fits.

Now that I had the power ring made it was time to figure out a mounting procedure to bring the power from the ring into the shell. I like Geoff's idea of the pogo sticks. Being that dyed in the wool DYI'er I had to make my own. I started by taking the contact point from a relay and soldered it to the end of a piece of 1/16" square tubing.

Next I soldered a piece of 3/32" square tubing to the winch plate. The 1/16" square tubing rides inside the 3/32" tubing. Next is to make a spring that will hold the power pickup pin down firmly.

That's a .017" diameter drill. Remember the thread about drill chucks? Here' the reason to have an expansive chuck. It will hold the smallest drill made. For those that can't visualize .017". Your hair is approximately .003" in diameter. So this drill is 5 times bigger. BTW, I did break it when I wanted to re-drill the hole. I missed the hold coming down and it broke. Oh well.

Here's the complete setup. I made the spring part from a piece of brass angle, a 1/16" od brass tube and a piece of .015" spring wire.

Here's how I mounted the spring wire. I stuck the wire in the end of the tube. Set a 3/16" square lathe tool on top of the pipe. The whole works is sitting on top of a piece of tool steel and gave it a whack with the hammer.

Here's the end result of that whack. A pinched tube holding the spring wire. Now some are going to ask, "why not solder it in". Reason, the heat would take the temper out of the spring wire. Then it wouldn't have any spring to it anymore.

Here's the one for the inside power track of the ring. I had to cut a piece out of the floor to accommodate the 3/32" square tubing, plus add a solid piece bolted to the outside to position it. I also bent the wire 90 degrees to reach the sliding bar and inside power ring. I cut a "V" notch in the tubing to center the spring wire.

Next I looked for a way to bring the power down through the crane frame to the wheels. I figured that the copper scourer wire would work great for this since it's nice and flat. I cut a small portion of the copper out and figured I could solder the copper strand into the ring. Trouble was the solder just won't bridge to both sides of the copper ring. So now I have to make a new ring.

This is were the project stands at now. I was originally going to start on the boom but worked on this end. I think I'm going to take a rest from this project for the time being. I'm getting a little burned out on it.

I would like to start on the layout project mentioned earlier in this thread. It consisted of building a version of the Gump Stump and Snowshoe layout by Chuck Ynugkurth. It'll be in HOn30 of a stone quarry using N scale equipment converted to HO to move the product from storage bins to a small rotary dumper that will load standard gauge HO hopper cars. I plan on animating the loading and unloading of the stone. I'll be posting pictures in a new thread as I go.

Bernd