Derby Talk

Does anyone have a sample letter regarding cub and parent commitments in regards to the building of legal PW cars? Does anyone know where I can lay my hands on detail production drawings for standards BSA tires? Guys, looking for drawings showing standard dimensions and tolerance for tire Id, width,...

It’s a tool that forms threads by moving the material not cutting.

Ran a 4-40 cut tap in my adult wheels and wasn’t very impressed. The minor dia ended up around .097” and it was way sloppy on my polished axles. I started thinking of ways to legally shrink the wheel hub and then it came to me, what about a form tap. I tried the form tap and the minor shrank to .088...

We have a lot of fun drawing the cars in ACAD and we print out templates for hole locations and body shaping. No structural analysis software with finite element modeling features...Maybe 20 years from now with the grand kids…

3 Cub Dad, Let us know how your test comes out because the most aggressive CG we have ever used was only 1”. Weight distribution might be close to what you guys published. We will have to record more weight measurements this year on the RR tire which is not something we normally spend a lot of time ...

Mass production = close race, I didn't create this monster but I will say, this will probably be the only time(3 more years) these boys (cubs) will ever operate a lathe or drill press. I hope this is a good experience and at least they understand the process. I’ve never seen the sales types offering...

Tn ,3 cub Dad how much weight are you running on the front and where?

That's what we have done in the past but we are up to 10-12 kids now and most of them have never seen a file.

Has anyone tried a tool post lathe grinder for roughing axles? It’s taking way to long for us to get all the kids axles roughed down to the pre polish size. Turning does not work because the smaller kids aren’t as quick in shutting down the auto feed . I was thinking grinding might be easier and qui...

As I told our district pinewood leader when asked me to suggest some rule changes to reduce the amount of illegal parts and ebay cars. "I didn't create this monster but like NASCAR I like a close race“. We run 10 -12 kids through our garage, building cars while trying to stay inside the rules. ...

We have never tried tapping the wheel hub bore, what are the disadvantages?

We have always used a radius, does anybody have any test data?

Thanks

That’s could question Stan, we could calibrate a simple spring and pointer set-up on each tire for some rough measurements. We only have the one scale and we don’t have any individual load cells to put under each tire. Finding out about the rules to late in the game probably won’t leave much time fo...

Joe, how do shape your RR wheel edge?Angle, Radius?