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Diamond Scale Turnable trucks

Sandy Bridges
 

Thanks, Kenneth. The kit I am building is a different design. I am building the 75 foot small girder turntable. The bridge pivots on a small pin, about 1/4 inch, and the ends of the bridge are supported by dolly trucks on each end. The trucks hold two brass wheels each, which have the very small steel pin through the center. These brass wheels ride along the top of a circular rail which goes around the outer edge of the floor of the pit. The brass wheels do not have any flange or other guide to keep them in place, but rather fit into horizontal journals build into the truck frame. Nothing seems to hold the small pins in the brass wheels. They are not a tight fit at all, and so easily slide out if the truck is tilted (which obviously should not happen once the bridge is in place in the pit.)

Anyone out there who has built and operated this kit?

Sandy Bridges
Florence, SC

--- In HOsteam@..., Kenneth Clark <kenrclark@...> wrote:

Sandy,
Diamond Scale makes several turntables; I won't guess which one is your concern.
Instead I remember building an A Frame strong-arm turntable many years ago, center support
only for the bridge. The center base had several wheels riding on a circular track for support.
Each wheel was on a half axle that fit into a hole in the base. The wheels were held in place
by the circular rail and the weight of the turntable bridge. The half axles were permanently attached
to the wheels.
Your concern is valid, I would probably solder the pin in place (or Lok-Tite) before assembly. Now if the
pins press fit into the base, then the pins must not be bonded to the wheel.






Kenneth R. Clark
P.O. Box 212454
Chula Vista, CA 91921






-----Original Message-----
From: Sandy <smb@...>
To: HOsteam <HOsteam@...>
Sent: Sun, Jun 23, 2013 7:45 am
Subject: [HOsteam] Diamond Scale Turnable trucks






I am building the Diamond Scale turntable and I have a concern about the dolly
truck. The kit has small steel rods to be inserted through holes in the center
of brass wheels. This assembly is the placed into a journal, closed with a
journal lid. The brass wheels ride along the top of the circular rail in the
bottom of the pit.

The steel pin is a loose fit into the brass wheel. If tilted, the pin slips out
easily. My question is whether there is a need to somehow fix the pin in place,
maybe a drop of CA, or if that would interfere with the functioning of the
wheels. I concern is that once the TT bridge is installed and the TT put into
operation, they pin may work out of place.

Am I imagining problem that does not exist, or am i missing something that
should be done to secure the pin in place?

(Please forgive the cross-posting if you see this question on other group
sites.)








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