I have three questions about using/installing trucks and couplers.
1. I have trucks some of which flex and others are rigid. When is each used?
2. What are self-centering trucks and are the worth the trouble to install?
3. In trying upgrade some cars I've run into couplers that were screwed in and others that were attached with glue. Is there any preference?
Thanks in advance.
I'm certainly no expert, but here's my experience, for what it's worth.
1) When you say the trucks "flex", do you mean they have actual springs in them, or rocking back and forth on the kingpost? I have never tried the spring-mounted trucks, but the kingposts should have a little flex in the mounting, to allow the car to move on inclined curves, handle inclines in the track, and react to the motions of the cars in front and behind. Too much play will make the car unstable.
2) They are exactly what they sound like: trucks which are sprung in an attempt to return them to the centerline of the car. I've only ever had one. It sucked -- derailed all the time. Never again.
3) I'm assuming that these are used cars. The coupler mount may be glued on, or even physically part of the car body (or truck, for the cheap ones). That doesn't matter, although it's easier to replace ones that are held on with the coupler screw. As far as the coupler itself, only a screw works... Period. Don't ever glue a coupler (as opposed to the box it's mounted in) in place.
Connecticut Valley Railroad A Branch of the New York, New Haven, and Hartford
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tedski I have three questions about using/installing trucks and couplers. 1. I have trucks some of which flex and others are rigid. When is each used?
Back in the day most HO trucks had side frames with real coil springs that actually moved up and down. They looked cool and a lotta people still like them. Later, trucks molded from solid nylon plastic became popular with manufacturers 'cause of lower costs and simplier assembly. They roll just fine. Take your pick.
tedski 2. What are self-centering trucks and are the worth the trouble to install?
"self-centering" is a new word to me. Dunno what to say about it.
tedski 3. In trying upgrade some cars I've run into couplers that were screwed in and others that were attached with glue. Is there any preference? Thanks in advance.
I like to assemble my couplers with screws, so that should they need to be replaced I can do it with ease and grace (and a screwdriver). Murphy's law states that glued in place couplers are always the ones that break.
David Starr www.newsnorthwoods.blogspot.com
tedskiI have trucks some of which flex and others are rigid. When is each used?
Are the ones that "flex" plastic trucks without springs? ExactRail and older Intermountain trucks for example have sideframes that can rotate, allowing for some equalization. They don't seem to track much differently than rigid trucks. They, along with fully sprung trucks, can be used more or less interchangeably with one-piece rigid types.
What are self-centering trucks and are the worth the trouble to install?
Kadee uses the term "self centering" to refer to its bolster design. These trucks have bolsters that are split down the middle like so:
Image from http://www.kadee.com/htmbord/page570.htm .
An insert into the enlarged mounting hole retains the two halves of the bolster, and the screw holds the whole assembly onto the car. Unlike other trucks, essentially all of the motion is dependent on the truck assembly itself instead of the interface between the truck and body bolsters. All they require is a flat mounting surface. They aren't any real trouble to install. If you have a car with a typical body bolster, all you need to do is file or cut any projecting material away so it's flat (normally this means you just remove the cast-on bushing around the mounting hole).
The intent of the design was partly to hold the truck parallel to the floor of the car, making it easy to get the car on the track - that's the "self centering" feature. In practice, if you have a car that is difficult to tune up due to a poor body bolster design (e.g. Accurail 89' piggyback flats), Kadee trucks can often make the car derailment-free.
Rob Spangler