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Rich, thanks for the tip. I initially could not find them, but did a search for "bushings" on Doug's site and found them. They are $1.50 for a package of 8 brass bushings for KC trucks. For info, SHS made replacement  metal wheelsets for AF cars that will work great with these bushings, especially on SHS or FasTrack. I have a couple of sets, they improve things even w/o the bushings. They made two styles of the flat end axles, one for power pickup and one standard insulated. Hopefully MTH will re-release these wheelsets.

Marty,

Do you notice much improvement in roll-ability? Probably 15-20 years ago, I bought some brass bushings – eyelets really – and didn’t see much improvement with either Flyer plastic wheelsets or SHS metal replacement wheelsets. Both are blunt axle. I decided it wasn’t worth the effort.

I am curious about the pointy axles. I’m not sure what an eyelet would do for them. Don’t the sideframes made for pointy axels have conical holes to match?

Tom Stoltz

in Maine

Francine, I am afraid the silence is an answer. As I said before, my experiments with the bushings proved that is really wasn’t forth the effort for blunt axles. My guess would be if pointing the axles made any difference, then the SHS replacement wheels would have had pointy axles – they didn’t. I would really like to be wrong about this, but no one is stepping forward.

Tom Stoltz

in Maine

A needle point axle in a properly made bushing will have much lower rotational resistance than a blunt end axle. The question is will that make a difference when running the trains? I have never tried retrofitting the bushings with needle point axles for two simple reasons. I have always operated link coupler equipment with the sheet metal sideframes and the layouts I had were small enough that the layout size limited how many cars I could use. When I get my new permanent layout later this year I will be able to operate much longer trains. After setup I intend to try some "pointy axle" retrofits to determine for myself if it makes a difference. What I suspect will be the case is that I will be able to pull 30 freight cars around the layout with the Flyonel Challengers, BigBoy, YS 3 and Mikado regardless of the wheelsets used.

Hi Tom,

Do you mean bushings that have a conical shape when you say ‘properly made’?  I do not know what the bushing for a needle point axle should be.  Maybe they should be Delran plastic or some form on the ‘slippery’ plastics?  And if that is the case, why aren’t they on the market?

The ones I am familiar with that are on the market now are just brass eyelets and not shaped for pointy axles.  I conducted my tests using link coupler trucks on a 640 hopper.  I had to drill out the hole in the trucks to accept the brass bushing.  The SHS steel wheels made more of a difference than the bushings, but not much.

When you think of friction on the axle, it would seem that the link coupler truck would be far superior because there is only the thin edge of the sheet metal in contact with the axle.  But as we all know, they have very poor roll-ability.  There is obviously more going on here than I know, however this isn’t rocket science and someone should be able to figure it out.  The knowhow exists because the newer SHS & AM trucks roll so easily. Now all we have to do is figure a way to retrofit the technology into older trucks.

Tom Stoltz

in Maine

Tom, I did mean the bushings would need a conical seat. Apparently that is not how the current brass replacements are made and that is why I suspect the result would not be worth the effort.

The link coupler trucks are metal on metal and that has a relatively high coefficient of friction when dry. I can get mine to roll freely by cleaning them with electrical contact cleaner and lightly oiling them. Unfortunately that lasts less than a week. Metal axles on Delrin plasic would be much lower friction in the dry state. I think that is how the new trucks are made.

Just did an impromptu, unscientific test on 3 cars, a Gilbert 937, a 937 equipped with the brass axle bushings and an SHS SF reefer. On parallel tracks with the 937's side by side, I propelled the cars with a piece of plastic spanning the ends of both cars. I applied a light shove for several inches and let the cars roll to a stop. I performed the test about 10-15 times to get an average roll out. Both cars were freshly oiled. The bushing equipped 937 consistently rolled 1/2 to 1 full car length further before stopping. The more force applied, the further the gap widened. The SHS reefer was then compared to the Bushing equipped 937 and at minimum force exceeded the 937 by 3-4 car lengths. I then compared a string of 10 various Gilbert cars to 10 bushing equipped Gilbert cars by trying (unscientifically) to pull on the lead cars knuckle to gauge the force needed to move the cars. The bushing equipped string moved with far less force. I would translate that to an ability of an engine to pull more cars with less exertion. The SHS rolling advantage is probably due to the smaller (conical) axle contact point and the narrower metal wheel contact surface on the rail. A lot of Gilbert axle holes are larger or irregular due to wear and machining and the bushing appears to restrict the axle from excess movement within the journal hole. I feel the bushing equipped cars operate better than the Gilbert trucks and are worth the $2. Are they as good as SHS/AM axles, no.

 

Rich

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