Drilling 2mm ss track pins

[Peter Silcock]

Converting my US halftracks to alloy tracks and I am making the track pins from 2mm ss bike spokes. Can anyone suggest a means of drilling say .5mm in the pins so that I can use a split pin to retain the track pin. Bear in mind my lack of engineering facilities(and skills) and that I will have 350ish to do!

[leesellars]

Hello Peter

The best bet is by using a drill press.

lee

[Peter Silcock]

Thanks Lee -yes I've got a drill press. Really my concern is trying to drill clean through the centre of the pin. Perhaps some form of jig?

[John Hill]

Hi PETER, the best way is to make a drill guide. If you have a lathe, drill a 2mm hole up the centre of say a bit of 12 mm dia bar. The length of the bar can be the same as the track pin less the head. Carefully cross drill the 0.5mm at the required distance from one end. There are various ways to do this, clamp the bar in a VEE block and drill in your drill press. If you have a lathe, cross drill using a VEE pad in the tail stock or, clamp the bar in the tool post , centre and drill by traversing the saddle. Once you have made the drill guide you can set it up in the drill vice, or VEE block, insert pin and drill the 0.5 mm hole. Care is needed when starting to drill ( use a high speed ) as it will try to rotate the pin.
As bike spokes are tensile you will have to use a cobalt stub drill, preferably a 3 flute type

Hope this helps John

[Peter Curran]

might be worth using a centre drill - as used on lathes , as there is no side deflection as there is on normal hss twist drills - especially small ones.
pete

[Graham Ord]

Hi all
With reference to "as it will try to rotate the pin."
Drill and tap a small threaded hole into the jig a bit further down from the .5mm hole so a screw can be tightened against the track pin to hold it into the jig and stop it rotating/moving.
Graham

[Peter Silcock]

Many thanks Peter John and Graham - I'll have a go as per your suggestions. Maybe resort to threading end of pin and using m2 locknut instead though which might be easier for me!