Spark Eroding – Will The Caliper Be Okay Now?

[Atari Boy 11]

Familiar story, snapped bleed nipple in a caliper. I failed to find a decent replacement and mentioned this to a chap at work who works on old (1930’s) MG’s and knows what I would call old school engineering. He suggested I let a mate of his look at the clipper has he could ‘spark erode’ the snapped bleed nipple (and half a broken stud extractor).

A week later and I collected the caliper and he has got it out, the caliper looks okay. I understand, now the principal of what he has done, but will the caliper be okay?

 

Thanks

 

Jonny

[brianthemagical 1]

Are you meaning as a result of the EDM? If the thread is still intact then it will be fine. They are usually submerged in parrafin or the like so give it a clean and it should be fine.

[Atari Boy 11]

I don't know what EDM is but yes the thread is okay from the looks of things.

[Veero 1]

EDM (electrostatic discharge machining) is when the component being machined is earthed on a machine bed, usually submerged in electrolyte solution and a high voltage head is brought very near the work piece in a controlled manner, the subsequent discharge of electricity across the spark gap erodes a small piece of the workpiece at a time. So long as the machining head has all been set up properly and the operater is good then there's no reason to suggest it won't be fine.

 

I only know about this as I worked in a engineering firm specialising in EDM. Personally I would have thought it was a labour intesive way to get it out but if they have the right programs set up for sparking threads then it could have been a very quick and precise way for him to get the broken part out. I guess the only way to tell is to fit it back on the car, fill the system with brake fluid, close the new nipple and see if it leaks, if not then it's fine I suppose.

[brianthemagical 1]

EDM is spark errosion. I think the way it's done is just machining the minor diameter then finishing it by other means.

[Atari Boy 11]

Great, thanks. I didn't know half of that.