Re: [CAD_CAM_EDM_DRO] Monarch 10EE lathe

Marcus, list, et al:

I have a 10EE with an Ahha! control setup. I left the original acme screws
and use the half nuts for carriage travel. I can switch it back to manual
control pretty easily. Mine is the motor generator style spindle drive. I
have a spindle encoder so I can cut threads.

> It sounds, from what I've seen of the machine specs, that this machine can
> take a reasonable cut if asked to.

The spindle drive has only "reasonable" power. You should consider
calculating horspower requirements for this cut.

> Ward, if you were to set up a 3" dia bar of 4140 with a positive rake
> carbide insert cutter 0.032 nose radius, and did a 0.100" deep test cut,

3"

> from the chuck jaws, could the machine take it without strain? (I'm not
> asking you to do it, just if you think the machine is capable of it)

No way. I have cut a lot of 303 stainless. the most I cut was .050" on the
diameter. I wouldn't even try that depth of cut on an interupted cut.
feedrates approximately: .050" depth of cut, 3"/min feedrate at 500 rpm
(diameter about 2.5") All number from memory, job complete about 6 months
ago. I was shooting for SFM of about 250. I stalled the spindle repeatedly
and trashed a number of carbide inserts in the process. 4140 is much
tougher than 303.

> Would you feel comfortable roughing down a square 4x4 bar 6" long to 2.5"
> diameter round over 5" with it if you had tailstock support?

It is do-able at maybe .025"- .050" depth of cut. The cnc doesn't get
bored.

> Would you still do it if you couldn't get tailstock support?

It REALLY sucks to have the workpiece loosten in the chuck to the point
where it comes loose. interuppted cuts are horrible that way. Ask me how I
know.

> Would you feel sympathy for the machine if you had to do this more than

once

> or twice a month?

I would cry for the machine. Really. I love my Monarch. I work it hard,
but I try hard to treat it with respect.

I WOULD NOT feel 'comfortable' with an interupted cut of that
severity at that kind of feedrate/depth of cut/ spindle speed on my machine.
the cross slide will dance and the the carriage will wiggle. It gives me
the creeps thinking about it.

> Would this machine make a decent platform for 2 axis CNC?

yes.

> Could the DC spindle motor be used as a servomotor (with an encoder, and
> servoamp) or are servomotor guts completely different from this rig?

This is not a servomotor in any sense of the word. It is a huge open frame
antique DC motor. It actually works very well, but it doesn't have the kind
of horspower or torque at the spindle speeds you need.

Just my .02$ worth. Your mileage will vary. I tend to be conservative with
feedrates/ depth of cut / spindle speeds. I hate destroying a tool on a one
off job when I didn't figure in any tooling costs.

Ron Knittle starbird at warwick dot net aka Starbird Prototypes