WEAVER TRUCK SCREWS

add a drop of ca glue

Thanks Dave.  Will do....

Then you wil never be able to easily remove the truck. Also, note that I never had that problem when swapping Weaver trucks.

I have never had a problem with the 2-56 machine screws, but if it wont grab, I'd probably switch to a #2-28 plastite screw, which are specifically for grabbing plastic.

Tip #1...  When returning a screw to a previously threaded hole in plastic, insert the screw into the bore and slowly/gently/lightly rotate it in  counter-clockwise direction.  When it has found the proper alignment of the screw and bore threads, you will feel it 'drop' into position.  Then continue to drive the screw in the clockwise direction.  DO NOT overtighten...avoiding easy stripping of the threads!!

Tip #2...   If the 2-56 screw has lost its 'bite' in the original plastic bore, I do the following:

• Get some 1/8" (O.D.) styrene tubing (Evergreen #224)
• Carefully re-bore the stripped hole to 1/8" dia.
• Cut a piece of 1/8" tubing to a minimum length of the bore depth.
• Apply an appropriate liquid cement to the tube and bore (welding type best, CA or epoxy if dissimilar materials) and insert the tube to be flush with the original bore.
• LET IT THOROUGHLY DRY!  (e.g., over night!)
• Re-fasten with the original screw.  If it is self-tapping, run it in a bit, back it off, in a bit further, etc., until fully seated.  If it is a machine thread screw, I prefer to re-tap the hole in the new tube bore.  (2-56 tap drill is 0.070", essentially the same as the bore in the Evergreen 1/8" tubing!)

Tip #3...  Tip #2 variant...if you don't have the tubing, but do have some 0.010" thin and VERY narrow styrene flat strip stock...

• Cut a length of the thin flat strip stock to attach to one side(or 2..maybe two sides if badly stripped!)  of the stripped hole using the above adhesives.
• Again, LET IT THOROUGHLY DRY!
• Re-fasten as above.
• Not as good a solution (IMHO and experience) as when using tubing, but...  (Analogous to inserting a piece of toothpick into a stripped kitchen cabinet hinge bore...as taught by Dad.  )

FWIW...

KD

Thanks for your replies....

I’ve had the same issue a few times and used a size larger screw 2-48

Thanks MR-150....

Not very familiar with Weaver screws sizes, but if it is a standard size machine thread, won’t there be a same size nut or a lock washer and loctite? Then it won’t matter if it threads the plastic as it will secured by the nut.

All the Weaver cars I have ever had that were the made in the USA types, not imports, used 2-56 screws. 

As noted above, I use the technique to rotate the screw counter clockwise until it "finds" the thread start, you can hear and feel a click.  

One thing I totally avoid is using any kind of power device when inserting screws into plastic.   I also generally use on my fingers to tighten the screws - never put my wrist and arm into tightening it.

MR-150

I only find 3-48 size machine screws no 2-48 screws did you mean 3-48?  If not do you have a link to a supplier for 2-48 screws?

thanks!

Mike

I meant 3-48 sorry about the mixup

No worries at all! Thanks for the tip!

So I was reasonably confident that I had stripped the threads in the bores in the plastic bodies of the cars that I was swapping the trucks out on.   It didn't make sense however to at least not try dkdrd's tip #1 which if it worked would save me having to use, glue, styrene or a different screw.  So I tried it, and sure enough felt the screw seat when I turned it counter clockwise in the first bore.  The second truck and bore were a little bit more challenging for some reason, but on the 3rd try, that screw seated as well.  So thanks to dkdrd for "tip #1" and also to members who offered other fixes.....  I always come here first when there is a problem, and, always get good information and support.....

Mike

# 2 Screws are2-56,my Weaver Cars have been #2 self Tap screws.

Part of the discussion, Weaver Truck screws was the length.   When changing from plastic side frame trucks to metal the length of the 2-56 screw became a problem. 3/4" a bit short, needed to be a bit longer, but 7/8"or 1" screw would penetrate the  bottom of a coal hopper.

Make sure the plastic is removed from the screw threads before reinstalling the screw. I usually place my thumb mail into the threads and spin the screw CCW to clean off the plastic embedded into the threads.

As a side note I always put any screws I take off into a plastic container and close the lid. That way I don’t lose anything thus avoiding finding any replacements.