Making “2.2mm” rod

AndyS · **on:** February 01, 2021, 01:36:04 AM

Hi all!

I’ve had a crack at making my own “2.2mm” H62 brass rod by drawing down 2.5mm rod. The “quotations” is where I need help...

The rivet washer that holds the backside tools ID is 2.19mm, so right from the get go, 2.2mm rod would not fit. The spring pivot rivet measures right at 2.2mm.

I can successfully draw my wire down to ~2.08-2.10mm, effectively giving ~0.05mm on either side of the rivet/washer for clearance (and expansion during peening) What do you guys think, am I splitting hairs or will this work!? I need the help of the SAKnights!!

kamakiri · **Reply #1 on:** February 01, 2021, 02:40:58 AM

I think there’s something wrong as you should be able to use wire up to 2.25mm without issue.

Sometimes making things perfectly round and smooth are the fix.

Coarseness of the surface is likely skewing your measurements.

I’d open up the bushing to 2.25mm before going thinner on the wire.

Don Pablo · **Reply #2 on:** February 01, 2021, 10:04:37 AM

Yup,

That bushing fits the 2.25mm rod I bought.

hiraethus · **Reply #3 on:** February 01, 2021, 10:24:41 AM

The holes in the tools should be guiding your pin sizes, as the brass parts are easy to modify. I’d be aiming for a close but free moving fit to the tools, then size the pins and bushes accordingly. You’re not making a precision bearing, so don’t over think it.

(Note that calipers can under read on small internal diameters)