Bushing an LBSC unbushed backhead

Hi Folks,

I have asked this question elsewhere but am now able to also post images here to go with the query.

I would like to add bushes to an LBSC 'unbushed' backhead but on the regulator I am a little tight for space. I propose to replace the original 9/16" dia clearance hole with a 3/4" dia hole for a 7/8" dia bush. Whilst this is an improvement on screwing straight into the 13g backhead, it does means that the fixing screws threads are partly in the bush and partly in the backhead.

Thoughts please...

Edited By David Haynes on 26/03/2015 20:19:20

Can you not take the hole upto 13/16" so more of the fixings are in teh bush? you will still have a 1/32" lip all round to locate the bush, may have to nick the inside of the flange for it to fit in.

Does your drawing have the bush higher up eg ctr 1/2" diwn from the wrapper top rather than 1/2" down from the flanged backhead?

Edited By JasonB on 26/03/2015 20:27:05

With 13g copper as per your post you won't need to notch for a 13/16" hole but if 12g like on the LBSC drawing then a slight notch which won't hurt will be needed

then keeping teh bush at 7/8" OD it will stop the holes going through the side

Edited By JasonB on 26/03/2015 21:00:18

Thanks Jason,

I has wondered about reducing the step on the bush to only 1/32". However, as this step is only to act as a register for concentricity and give a greater solder contact area, and not resist pressure, that should not be a problem.

Dave

Edited By David Haynes on 26/03/2015 22:37:02

hi david,

what you propose above is what alec farmer of Reeves fame always advocated and in his book, and what don young did in his later designs, and what i have always done.

cheers,

julian

Thanks Julian,

Jason, I have corrected the small error - it looks better now.

Dave