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Low Profile Wheel Sets on N-Scale Locomotives

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  • Member since
    October 2019
  • 28 posts
Low Profile Wheel Sets on N-Scale Locomotives
Posted by jpdriver on Sunday, December 22, 2019 6:45 AM

I have recently gotten back into the hobby. My new layout is using Atlas code 55 rail. I had previously used code 80 rail. Completed the first turn of a helix yesterday and tested a few cars. I was dismayed at the wheels riding on the ties. Did some research and found this to be a problem with older wheels and the new NMRA standards for code 55 rail. Seems to be an easy (yet not economically friendly) fix to my fleet. 

I then turned to the locomotives. I pulled out an older Kato SD-45 and sure enough it has the same problem. I also tried a new Intermountain SD-40T-2 and it also rides the ties. Found that Kato low profile geared wheel sets for around $7.00 a set of 6. These are an offset gear and seem to be the only ones out there available. There is no information on specific models the wheel sets fit. Just a statement of "fits multiple models". I know Kato/Atlas produced some locos with center axle gears. Does anyone have knowledge of locos the offset geared wheels will/will not fit through their own trial and error?

Have over 50 locos dating back to the mid 1980s. Almost all Kato/Atlas/Intermountain. Thinking I have a major project in front of me and I am not keen on the idea of trial and error turning of individual wheels on a grinding wheel. Crossing fingers that I have a few in the fleet that do not need modified. Will find out this week as I test them all...

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Posted by Overmod on Sunday, December 22, 2019 3:06 PM

Modern replacement wheels from a number of manufacturers (e.g. Intermountain 'high detail' in 33" and 36") are made to suit code 40 rail presumably with American-style fixation to ties.  I believe these are now made and sold with appropriate types of axle to suit most manufactured cars.

The Europeans developing good finescale standards for 9mm gauge a couple of decades ago had an almost cavalier vision for flange reshaping, saying something like 'a microdrill, a good digital caliper, and some shaped files' are all that is necessary for locomotive flanges.  You take the wheel set out of the locomotive, chuck or collet the axle or tread, and work the adjacent flange so there is very little wobble and controlled force and heat.  They do not say anything about grinding with something like a stone in a Dremel but with great care and slowness and perhaps cooling with pressurized inert gas or air you could work metal rims on plastic wheels without slipping or distortion from metal heating or melting plastic centers.  I looked into multi piece chucks that could be applied to the axle between a wheel and center drive gear but still leave access for filing or grinding a flange; that's a one-time solution but it involves considerable working precision in what may be hard or temperamental material to make correctly.

I took a leaf from the watch industry, which used high-magnification optical comparometers (300x for Hamilton) to visualize things like precise escape-wheel tooth profile.  You could easily set up to compare a flange profile seen as silhouette side-by-side with a tread and flange gauge for comparison and eliminate much of the guesswork; again you'd only need one optical setup and it could then be shared with other modelers as a resource.

There are people on here who know far more than I do about machining molded-on plastic wheels for better concentricity and scale flange and tread profile dressing -- I hope they will reply in detail here.

Look up references for FS160 or FiNe scale to see what's current.  I believe NMRA has a current AAR-referenced flange profile comparable to the one for HO, and that would be the thing I'd use for locomotives and look for in replacement wheelsets.  

There was at one point some discussion about producing 'corrective lenses' for the awful generation of pizza-cutter wheels (with reference to the fixing of the Hubble space telescope, which probably dates it); these were thin metal rings that would fit the pizza wheels on their tread and gauge faces and present an appropriate (if a bit wider) tread, fillet and flange at nominally larger wheel OD.  You'd chill down the pizza wheels and heat the rings in hot water or the oven, then use a jig and press to align them for assembly and retention in alignment until the 'interference fit' was established at correct standards gauge.  That is still at least in theory an option for locomotives that can't be converted any other way.

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Posted by jpdriver on Sunday, December 22, 2019 5:08 PM

Somewhat good news on the loco front. Almost half of the fleet are either ok or need a good test run before there is any certain problem with contact. The other half are all for certain going to need replacement wheels and all appear to be offset gears meaning I can go Kato for all. No rhymn nor reason as to which locos will need modified. Newer Intermountains are rubbing the ties. Some older Kato and Atlas are not. Era of manufacture does not seem to be a determining factor. 

Noted on a Micro Trains car I just acquired that was recently manufactured that it was shipped with scale 36" wheels and had scale 33" wheels included in the box. Swapping to the 33" wheels quickly fixed this car. At $22 per hundred wheels from MT, looks like it is going to cost several hundred to convert all the old pizza cutters in my collection!

 

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Posted by Overmod on Sunday, December 22, 2019 8:20 PM

There may be one other possibility.  At one time, Peco made track that had rail clamps on the outsides of the rails, but deeper clearance inside the gauge so that pizza-cutting flanges would clear in operation.

You might be able to relieve the 'detail' on the inside edges of the ties via some relatively easy bulk method to secure the necessary clearance.  Somone here could advise what, if any, special care or gluing would be necessary to hold gauge effectively during and after that process..

  • Member since
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  • From: Pacific Northwest
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Posted by SPSOT fan on Monday, December 23, 2019 2:26 AM

I had to replace my entire fleet of Micro-Trains cars (and a few Atlas cars with Mirco-Trains trucks). It was quite expensive but I saved my using plastic Mirco-Trains wheels over metal ones. The Micro-Trains “medium” flange wheels are what you need (I guess ”small” would work, but I’ve never seen those. IDK if they exist).

Some newer Micro-Trains cars come with replacement wheels if you need them. That is nice, especially on the pocket.

I have heard other brands (i.e. Peco) track doesn’t have the same issue, but as I also only use Atlas code 55 I can’t say for sure!

Regards, Isaac

I model my railroad and you model yours! I model my way and you model yours!

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Posted by jpdriver on Monday, December 23, 2019 6:13 PM

Thanks for the thoughts on the Peco track. I just personally like the looks of the Atlas better and it is less expensive. Trade-offs I guess. Ordered a set of low profile Kato wheels for one of the SD-45s as a test. If it works, this is about a $7.00 mod per loco. I can do 25 cars for about $22.00, so over time I can get my 500 or so swapped over.

  • Member since
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  • From: Pacific Northwest
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Posted by SPSOT fan on Tuesday, December 24, 2019 4:15 AM

jpdriver

Thanks for the thoughts on the Peco track. I just personally like the looks of the Atlas better and it is less expensive. Trade-offs I guess. 

Agreed! Those reasons and my past experience are exactly why I went with Atlas! Definitely where trade offs! Still I likely would have wanted to get rid of those pizza cutters anyway!

Regards, Isaac

I model my railroad and you model yours! I model my way and you model yours!

  • Member since
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  • From: Blair, Nebraska
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Posted by Boiler-man on Tuesday, December 24, 2019 7:29 AM

I started my N-Scale railroad using Atlas code 55 track back in 2004 and also found that some of my cars and locos which were purchased in the mid 70's would not run on the code 55 track. I jumped on the internet to find out what the fix was, some of my locos required the disassembly of the trucks and taking the wheels and chucking them in a drill then using a file to reduce the flange, each took about 20 to 30 minutes once I got the system coing. If you use the drill to spin the wheel all that is required is a light touch of the file and I found that an automotive point file worked better than the course bulky file you would buy at the home improvement or hardware store. The point file is smaller, lighter, and takes a finer cut making it easer to control and less chance of over reducing the flange.

You may want to post the question on one of the N-Scale forums for more input on this subject.

Boilerman

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