Speaking generally, what size screws shall I seek to attach trucks to HO rolling stock?
Heh Heh Heh…
LION uses such screws as king pins on occasion.
What size to use. Well I hate to be the bearer of bad news, but the correct answer is “Whatever Works”,
What is the diameter of the hole in the bolster. LIONS do not like to enlarge these holes for you may eliminate a boss at the top. Him uses a sheet metal screw, and makes a hole in the car floor that will accommodate it.
The thing you want to set up is 1) the trucks must rotate freely, 2) the couplers must end up at the correct height, 3) one truck must not wobble from side to side to keep the car running without wobbling, 4) the other truck must be able to wobble from side to side to allow the car to negotiate any uneven track without derailing.
ROAR
Entertaining and, yes, helpful in a general way. So the answer is to take a few screws to a really good old-fashioned hardware store and let the old guy in the blue shirt tell me what size they are?
I generally stick with 2-56 screws. Some trucks are actually designed to use 2-56 screws as the kingpin, and for others (such as Athearns), a 2-56 with the center of a Kadee #5 coupler box is a perfect fit. So yes, whatever works for you is what’s best![:D]
Lion has it right. It’s going to vary widely. In HO, the most common size I have seen is #2 wood screws or 2-56 machine screws. Wood screws are the cheap, easy way to mount to a wood or plastic underframe. The machine screws often screw into a threaded plastic or metal post, which serves as a kingpin for the truck bolster. But I have seen #4 screws for trucks as well. Trucks with shouldered screws are common, as are #2 screws with fender washers to help stabilize the truck similar to the shouldered screws.
Back in the old days, Central Valley made a snap setup replacement for truck screws that allowed one to snap trucks on an off. Train set cars have often used some form of plastic push pins for truck mounting.
my thoughts, your choices
Fred W
The common 2-56 screw is a good all around answer for plastic, and for a lot of metal and wood applications, too.
For some wood apps, the #2 that Fred mentioned is handy, although sometimes too large. I do narrowgauge, too, so find that the #1 and #0 wood screws, about 3/8" long, are good for HO and HOn3.
I used to work part time at the local “old fashioned” hardware store where we had an entire aisle devoted to nuts, bolts, washers, etc. Through extensive experimentation I have determined the best method of attaching HO scale trucks was a 2-56 x 3/8 machine screw.
Thankew sewmudge.
While at your Local Hardware Store, pick up a couple of those clear plastic boxes with dividers in them. I’ve got one just for assorted small screws and nuts. As your years in the hobby grow, so too will your collection of small screws, and you’d might as well start off right and keep them organized. I’ve got another box for LEDs and resistors, and one for Kadee couplers, draft gear boxes, springs and such.
LION is organized too!
Wow, you must have a pretty strong magnet to keep all those items in place with the bin propped up against the wall like that.