"M" Head

I am looking for a Bridgeport M head

-- hd_74al

Reply to
hd_74al
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I am looking for financial independence.

Reply to
Stephen Young

Umm, have you ever used one? One of the greatest improvements on my Bridgeport was cobbling a J head in place of the M head. The range of speeds is too high for the use of boring heads and fly cutters, and there are rigidity problems with that type of cutter, too. But, your machine may not have room for a J head, if it's not as big as a Bridgeport.

Jon

Reply to
Jon Elson

Just the head? The whole machine? Where are you?

I have a complete machine. Runs great. It's a nice "little" machine. It's now a spare as I found a J Head machine for a nice price.

Located SE MN.

Jeridiah

Reply to
jw

The range of speeds is too

???

Too fast for fly cutters? Strange comment. When machining aluminum, I run my fly cutter @ maximum head speed, in my case, 4,200 RPM.

I'm not convinced there's such a thing as "too fast for fly cutters", depending on the diameter of the cutter in question.

Harold

Reply to
Harold and Susan Vordos

Hugh? 4200 rpm with a 3 inch flycutter. Wow, 1000 SFPM machining alum. Isnt that a bit fast?

Reply to
Chuck Sherwood

1000 SFPM? I get 3297 SFPM for a 3" dia flycutter at 4200 RPM.
Reply to
BILL MARRS

It's much more than 1,000 SFPM, and no, it's not a bit fast. It works fine. You don't have any of the problems of machining steels when machining aluminum. You can run table travel at full tilt and get a decent finish. I generally rough somewhat slower, depending on the job at hand. I'm more limited by the 2 horse motor on my Bridgeport than anything else.

I don't recommend such speeds for steel.

One need not run a large diameter fly cutter at all times. There are times when a small circle works miracles, coupled with excessive RPM. Surface speed remains reasonable, but feed can be increased tremendously. That was the secret to my success when I used to modify electronic connectors for Univac. Faces could be machined without chipping by running a carbide single point tool revolving in a small circle, no larger than 1/2", at top speed.

Harold

Harold

Reply to
Harold and Susan Vordos

To all the funny guys: I need an "m" head to retro onto another roun

ram mill. Just the head will do. Ya! two twin blondes and financia freedom would be good , but I would probably burn out my other head

-- hd_74al

Reply to
hd_74al

Yikes! I'd hate to have anything go wrong - I don't dodge bullets real well. Running a fly cutter with a 3-4" diameter, the chips come off red hot and smoking (not quite on aluminum, but definitely on steel) at 660 or maybe 1125 RPM.

With the cheap flycutter I have, it is so out of balance the whole machine would start to shake if I tried running it at 4200!

Jon

Reply to
Jon Elson

He must be using carbide, I guess. I use some Mo-Max cutter blanks, and there is a limit to how fast you can go with that.

Jon

Reply to
Jon Elson

Body is fairly well balanced, so I don't have any issues with vibration, and, yes, I use carbide, although not exclusively. Still, you can't run that way in steel, but in aluminum, it works great. I think I mentioned that. There's really nothing to worry about----not if you use good sense. The body of brazed carbide is soft enough for the set screws to deform the shank. They don't slip under load, so the tool's not going anywhere. If I'm doing it wrong, I've been doing it wrong all my life, and I don't have any negative stories to relate.

The hard facts are fly cutters are limited to proper machining surface speeds when materials dictate. Otherwise, they'll take anything you can throw at them.

Harold

Reply to
Harold and Susan Vordos

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