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Source of big potentiometer knob for Myford grinder ?

Milacron

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Dec 15, 2000
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What diameter do you reckon it is?

Looks to be more the size of one of the smaller Variac knobs than an ordinary potentiometer knob. Have one of apparently similar size, albeit rather plainer in style, on a baby Variac in a combined variable AC - DC psu.

Clive
 
It reminds me of the dial on a 1930's radio channel dial...

Yes, but not US, and not consumer. British lab/test gear or transmitter shack goods, aboard ship as well as ashore, and well beyond the 1930's. US had similar sizes, different styles.

That said, you need but the one, so should not be 'unobtanium', so long as we look harder at the likes of Marconi [1] rather than just Myford.

:)

NB: Only one found so far that seems a close match had a chunk busted out of the skirt.

Bill

[1] Knobs were bought-in, but "part of " Marconi was merged with Imperial Cables & Communications, 1931 to form "Cable & Wireless", so you don't HAVE to "ask me how I know"
 
Cincinnati internal grinder (might be with or without Heald) I have seen similar
knob (probably to do the same function).
 
Looks like a collet style knob where a concentric nut tightens a brass collet arrangement to grip the pot shaft, that's why there's metal visible in the middle of the knob: the cover cap to hide the collet is missing.
 
You really need to pull that knob off, take some closer pictures of the knob and take some measurements, especially shaft diameter. It may well be a collet knob but it is hard to see.

Sent from my SM-G900V using Tapatalk
 
The reason that it looks like a Variac knob, because that's what is behind the panel. Have not seen a knob like that with a screw on the top. A side mounted allen set screw is the deal. You will probably have to modify a replacement knob by drilling a hole in the top.
 
Guys, this is what they look like.

Myford-Knob_zpsqzcpbu8c.jpg
 
Here is a better close-up of the OEM knob.



It really does not seem to match any of the other knobs on that control panel so I strongly suspect that it came as part of the variac itself. I would look at the variac for the manufacturer's name and model number and see if they have replacement parts available. You could also contact Myford: they do have a web site.

If those two sources do not pan out, then electronic supply places like Digi-Key, Mouser, Newark, Arrow, Allied, and the like can be your best source. There are many companies that make knobs for electric and electronic controls. But you will need the details like the shaft diameter, method of attachment, overall diameter of the knob, etc.



As shown at link below, upper left corner of the separate electrical cabinet. Don't need the pot, just the knob. And yeah I know most any knob would do but something approaching the original design would be nice.

Machinery Values, Inc. - 5'' Swing 12'' Centers Myford MG12-HPM OD GRINDER, HYD. TABLE, AUTO INFEED, PLUNGE, RAPID, SPKT (Ref No: 154115)

It reminds me of the dial on a 1930's radio channel dial...
 








 
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