Screw head size in chassis
 

What size allen key do I need for the screws in the chassis (the 4-40 x 3/8" ones). I've tried the imperial ones, is it 1.5mm?

1/16 or i think its 5/64 = same as 2mm

If you are talking about the countersunk screws (conical head) then you need a 1/16" Allen key.
The hex is slightly bigger than the 1.5mm one.
Don't use the 1.5 metric allen key, you will either round the hex in the screw, round the key or both.

Avner

Hmmm, tried the 1/16 one and it was too big, how odd.

Unless it's a used car and someone replaced the stock screws it should be 1/16". Make sure that the screw head and hex key are clean and not deformed and use a little force to push the key in.

Are you using a L shaped key or a quality screwdriver shaped wrench?

Avner.

Its a screwdriver wrench, I got bought some fasttraxs ones from JE Spares (imperial ones) but its not fitting. Maybe I need to force the end in a bit more.

Sometimes brand new wrenches a a little tight, try more force and make sure the wrench is all the way in the hole before you start twisting.

Also try with several different screws, maybe one or some of them a not shaped correctly.

Avner.

Just tried the 1/16th again, its fine on me screws from atomic carbon, but its a fraction too big for the losi ones. How odd.

Edit: Has to be the 1/16th one, must be knackered screw heads.