Simple Trucks

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Bill Shield's version of simple trucks, based on Charles S. Purinton's design:

These do not look like much, but run well, even on the roughest of tracks. You don't really want or need springs on a riding car since (at least I) don't like to feel like I am 'floating'.
This design idea came from Charlie Purinton who used to make them with WOOD side frames for his 3/4" scale tenders and riding cars. Bill Van Brocklin did a few similar.
The ball bearings in the aluminum frame are about 0.020" loose on the diameter and just sit there, allowing for all the needed flex. The bearings are held to the axles with Loctite (what else). Bore has a step on it to allow axles to float about 1/16" side to side. Use very cheap ball bearings (low grade) with rubber flex seals)
The cross bolsters (sorry no pictures) are a piece of 1 x 1.5" hot rolled bar stock.
I made them in a weekend using old scrap wheel / axle sets that failed after 2 years of running from a commercial supplier.
If you want to spruce them up and knock the corners off the side bar, it will take only a few minutes on your handy-dandy belt sander.
As Charlie Purinton once told me "I am building locomotives, not tenders (made his from wood), or fancy riding cars (made the trucks from pieces of oak)". He even had locos that 'shared' tenders. The fun is -> get out there and enjoy yourself. Once you are running you can take 2-3 years building a fancy riding car..or whatever..otherwise, too many people either die of old age or lose interest before the wheels turn on a club track.

Greg Lewis posted the following on Chaski.org:

Here's a design I got from Cal Tinkham. As you can see, a piece of flat bar is the bolster and the sides are cut from plate. I had the side frames laser cut but you can hog them out with a mill or torch-cut them with a template as no dimension is critical. Cal used aluminum plate, I used steel. The axles ride in R8 bearings in bored holes which in the photo are covered with round plates. Click on the photo for a larger view. In that view you can see holes in the side plates adjacent to the bolster which are for brake hangers. The brakes are yet to be made. These trucks are easy to make, ride well. and look plausible.


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