HO Truck Bolster Clearance Hole


Denny Anspach <danspach@...>
 

I am responding to an older post (16 June) that addresses a common problem: the commonly-wide truck bolster holes that are designed to fit over the shouldered body bolsters common to to almost all production styrene models, but are far larger than the diameter of the common 2-56 screws that most use for truck mounting on those cars without the 'shoulders'.

Tahoe truck bolsters are drilled out to 0.120", while Accurail's are drilled out to 0.125" (1/8").

Even with the pan-head 2-56 screws, these trucks too often still have markedly excessive side play, which can and do play havoc with good reliable centered coupling, particularly with the "scale" couplers with their smaller gathering faces. This is despite taking every other known precaution with accurate wheel sets, careful coupler installs, etc. Very frustrating at times-

One solution is to drill out the body bolsters to first inset and then cement in place a small piece of 1/8" styrene tubing to form a new 'shoulder', which then can be tapped for 2-56.

Denny








Denny S. Anspach MD
Sacramento


John F. Cizmar
 

Denny,
Consider making some "bushings" with the proper o.d. rather than drilling out the bolsters.  This is a quick and dirty method to resolve the disparity between the screw o.d. and the truck i.d.
John F. Cizmar

--- On Wed, 7/23/08, Denny Anspach <danspach@...> wrote:

From: Denny Anspach <danspach@...>
Subject: [STMFC] Re:HO Truck Bolster Clearance Hole
To: STMFC@...
Date: Wednesday, July 23, 2008, 1:50 PM






I am responding to an older post (16 June) that addresses a common
problem: the commonly-wide truck bolster holes that are designed to
fit over the shouldered body bolsters common to to almost all
production styrene models, but are far larger than the diameter of the
common 2-56 screws that most use for truck mounting on those cars
without the 'shoulders'.

Tahoe truck bolsters are drilled out to 0.120", while Accurail's are
drilled out to 0.125" (1/8").

Even with the pan-head 2-56 screws, these trucks too often still have
markedly excessive side play, which can and do play havoc with good
reliable centered coupling, particularly with the "scale" couplers
with their smaller gathering faces. This is despite taking every
other known precaution with accurate wheel sets, careful coupler
installs, etc. Very frustrating at times-

One solution is to drill out the body bolsters to first inset and then
cement in place a small piece of 1/8" styrene tubing to form a new
'shoulder', which then can be tapped for 2-56.

Denny

Denny S. Anspach MD
Sacramento


















[Non-text portions of this message have been removed]


Denny Anspach <danspach@...>
 

Denny,
Consider making some "bushings" with the proper o.d. rather than
drilling out the bolsters. This is a quick and dirty method to
resolve the disparity between the screw o.d. and the truck i.d.
John F. Cizmar
Well, I would certainly agree, but in my experience fabricating
bushings of the proper depth and diameter is commonly much easier said
than done, and it is just one more one-off part to lose. Slicing off
rings from reamed-out styrene tubing might work, if it can be done
without crushing the tubing in the process.

H-mmm.

Denny

Denny S. Anspach MD
Okoboji, IA


Paul Lyons
 

Denny,



The 'bushing", or whatever you want to call it, in a Kadee coupler box works perfectly for most trucks.

Paul Lyons
Laguna Niguel, CA

-----Original Message-----
From: Denny Anspach <danspach@...>
To: STMFC@...
Sent: Wed, 23 Jul 2008 6:32 pm
Subject: [STMFC] Re:HO Truck Bolster Clearance Hole







Denny,
Consider making some "bushings" with the proper o.d. rather than
drilling out the bolsters. This is a quick and dirty method to
resolve the disparity between the screw o.d. and the truck i.d.
John F. Cizmar
Well, I would certainly agree, but in my experience fabricating
bushings of the proper depth and diameter is commonly much easier said
than done, and it is just one more one-off part to lose. Slicing off
rings from reamed-out styrene tubing might work, if it can be done
without crushing the tubing in the process.

H-mmm.

Denny

Denny S. Anspach MD
Okoboji, IA


Frank Greene
 

Denny Anspach wrote:
Well, I would certainly agree, but in my experience fabricating bushings of the proper depth and diameter is commonly much easier said than done, and it is just one more one-off part to lose. Slicing off rings from reamed-out styrene tubing might work, if it can be done without crushing the tubing in the process.

H-mmm.

Denny

Denny S. Anspach MD
Okoboji, IA


Insert a styrene rod that matches the inside diameter of the tubing and make your cut. Sacrifices a small piece of rod, but saves the tube.

--

Frank Greene
Memphis, TN


David North <davenorth@...>
 

I like the way you do it, Danny. I also drill the bolster with a 1/8 drill
and insert and glue with MEK, a short length of #224 Evergreen styrene tube.

I then tap the tube 2-56 as the ID is the correct size.

I'd then file the tubes to length to make one truck rotate freely without
wobble and the other looser for a three point suspension.

Cheers

Dave


richchrysler <richchrysler@...>
 

A bushing of suitable size would certainly be a welcome product. I
need to fabricate these for almost every car I build. Up until now
I've been carefully cutting off the center bushing from Kadee coupler
boxes, filing the height as required and installing. Fiddly business
to say the least.
Rich Chrysler

--- In STMFC@..., Frank Greene <frgreene290@...> wrote:

Denny Anspach wrote:
Well, I would certainly agree, but in my experience fabricating
bushings of the proper depth and diameter is commonly much easier
said
than done, and it is just one more one-off part to lose. Slicing
off
rings from reamed-out styrene tubing might work, if it can be
done
without crushing the tubing in the process.

H-mmm.

Denny

Denny S. Anspach MD
Okoboji, IA


Insert a styrene rod that matches the inside diameter of the tubing
and
make your cut. Sacrifices a small piece of rod, but saves the tube.

--

Frank Greene
Memphis, TN