09-29-2006, 11:32 PM
Join Date: Dec 2002
Location: San Francisco
Originally Posted by Scottrik
OK--who knows what the screw size/pitch of the Lunsford/CRC Ti axles is? I'm talking about the left hand threads that screw into the steering block. The axle nuts are 4-40.
For that matter, what is the thread pitch of the Lunsford Punisher tie rods? I know they are 3mm, but "by what"?
Along those lines, what ARE all the common screw size/pitches in our 1/12 beasties? The ones I know (or THINK I know) for the CK are:
2-26 secure/tighten the pivot assembly
4-40 are VERY common. Most of the screws and ball-studs are 4-40
6-32 right and left hand thread for the camber adjusting turnbuckles
8-32 for the diff adjusting nut and the screws that attach the lower arms
3mm X ?? left and right hand for the Lunsford Punisher tie rods
The reason for my curiosity is I'm starting to build up my two 3.2R's for the upcoming race season and THIS time I'd like to pre-tap all the holes. I'm guessing things might sit flatter if the material from cutting the threads is removed with a tap rather than displaced by running the screws into blank holes. I also think I've got a better shot of getting them screwed in straight. I imagine it should give a better "feel" for torque and allow more fine adjustment if you're not having to reef on things to get them turned in. Easier on the screws too.
Any opinons? OD?
I've done some checking...I can find ALL the taps listed above with the exception of a left hand 3mm (but I CAN find a left hand 3mm die, so go figure...). In fact I already have all the right hand taps.
Sorry I can't tell you the pitch on the steering turnbuckles. I think you typo'd but the pivot socket screws are 2/56.
One thing to consider, most of the holes are made a bit large so the screws will go in without threading them. If you thread the holes on the steering ball cups they may not be tight enough to hold adjustment or might strip more easily (don't know for sure because I've never tried it). Same goes for the camber turnbuckles. If you do choose to tap these items out I would consider only partially threading them, that will help start them straight and still keep them tight.
On the 8/32s that hold the front suspension on you can tighten down the screws so threading the arms works well, I always do this. It makes it easier to screw and unscrew them for ride height changes, and I've never had one come loose.
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