Colchester Chipmaster Part

[Paul ValenteParticipant @paulvalente12713]

Good afternoon all,

Does anyone have a drawing of or could someone do me a dimensioned sketch of Stud 1228 on the Chipmaster. It’s the one that holds the splash guard to the headstock.

Long shot, but does someone have one for sale??

Even longer shot, is there a Colchester/Chipmaster expert in the Herts/Beds area who likes beer and giving advice?

Thanks

Paul

[Paul ValenteParticipant @paulvalente12713]

Sizes

[DC31kParticipant @dc31k]

Two thirds of it is the same as one of the adjacent 1/4"-20 UNC x 7/8" long socket countersink screws that hold the cover on (including the countersink angle).

So remove one of those to have 67% of your drawing.

The rest of it is a 9/16" A/F hexagon, 7/16" long with a 3/8" diameter groove in it, 0.150" wide.

The remaining 33% of your drawing can therefore be determined by measuring the width and thickness of the semi-circular cut out in the splashback.

[thaiguzziParticipant @thaiguzzi]

Damn!

Answers like the above is what makes forums a great place.

Can't ask for better. Kudos.

[Paul ValenteParticipant @paulvalente12713]

Agreed, that is an absolutely fantastic reply.

I’ve actually got the piece down to the base of the taper. All I really need is an exact length for the threaded portion. So it’s 7/8 minus the countersunk angle?

Thanks

P

[DC31kParticipant @dc31k]

Posted by Paul Valente on 11/10/2019 16:35:46:

I’ve actually got the piece down to the base of the taper.

All I really need is an exact length for the threaded portion.

Which piece do you have? The hexagon part that lives in fresh air or the 1/4" UNC part threaded into the headstock? If the part threaded into the headstock through the aluminium cover is not there (i.e. the female threads in the headstock are clear), it might be a good idea to look inside the headstock to make sure it has not worked its way in there.

This is a situation where you will be really happy to see the broken off end of the fastener in the casting.

A countersunk fastener's length is always given from top of head to end of screw so the length of the threaded part itself is not usually given. Your assumption is correct, so what you have to do is determine the countersink angle. I did not tell you this as I cannot remember if UNC is 90 degrees or 82 degrees. Simply remove one of the other screws nearby and copy it.

[Paul ValenteParticipant @paulvalente12713]

Good Morning,

I have the entire component apart from the threaded portion, so I have the hex head, the slotted section that the splash guard slides into and the “male” part of the countersink. The thread snapped off quite cleanly at the base of the taper. The thread was indeed stuck in the headstock. I promptly extracted it and was feeling very pleased with myself for getting it out so cleanly. Of course this is where it all went wrong as I promptly lost the threaded portion whilst cleaning up. So now I’ve got the other piece and can easily take measurements, but need to know an exact length for the threaded portion of the component.

Thanks

Paul

 

 

 

Edited By Paul Valente on 12/10/2019 10:09:13

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