3 phase coming soon

[J Tiers]

Well, I picked up an older Roto-phase converter today for an acceptable outlay, so now I have a bunch of work ahead.....

I'm looking at what machines can benefit the most.

The first candidate is the drill press, since it came with a 3 phase motor, and the multi-step motor pulley fits that motor, but not the one on it now. I'll have to figure out how to get a 70 lb Crocker-Wheeler 1 HP cast iron motor up to the top of a 7 foot high DP, but that should be do-able. I can probably crank the head down to an accessible height.

Then I have another 3ph motor that should fit either the lathe or mill.. I'm thinking lathe, for reduced chatter and torque pulsing.

It SHOULD make a goodly difference with the lathe, does anyone have a "before and after" testimony they can share on that?

[Evan]

I don't think you will see much if any difference on the lathe with already two drive belts and the jackshaft in the system giving compliance and flywheeling.

[J Tiers]

I know what you are saying, but it is surprising how much chatter seems to be directly or harmonically related (at least by ear) to the 120Hz line torque frequency.

Even if it is damped a bit, it still should be a "driver" for the system.

Well, I'll see fairly soon, I suppose.

[Evan]

I don't know what the difference is but on my SB9 I get absolutely no indication of hum or torque ripple from the drive.

[Milacron of PM]

Dangit J, I thought by your topic title you were either getting true 3 phase from the power company (for free of course ), or had conjured up your own Phase Perfect ! RPC....yawn.....

[JPR]

or making your own (not so free). It does include an Ingersoll-Rand rotary screw air compressor with enough capacity to run several home shops.

[Bill Pace]

, does anyone have a "before and after" testimony they can share on that?[/QUOTE]

I recently went the VFD route to gain 3ph on my 12x36 Birmingham lathe,---primarily to get the variable speed it offered, but I also was really hoping for an improvement in the 'laddering/moire??' effects I was experiencing ---rather badly at times!. So, not only did I gain the variable speed, which is SOOO fine, I also gained a marked improvement in the finish I'm able to get. Has really surprised me,--- I would have been happy with with much less. Also got quieter. smoother running thrown in.

[Evan]

I've been thinking on it some more Jerry. You may well see a difference if hum from the motor is telegraphing through the work bench to the lathe through the mount and table. My lathe is mounted on a wooden bench with thin sheet metal cover and that should provide good damping so I don't have that issue.

My milling machine is a different matter altogether. I have a DC treadmill motor on it with a cheap SCR controller and it produces so much hum that you can feel it throughout the machine. It is having a very detrimental effect on the finish. One of the first things I need to do is to switch to a high frequency drive.

[J Tiers]

Dangit J, I thought by your topic title you were either getting true 3 phase from the power company (for free of course ), or had conjured up your own Phase Perfect ! RPC....yawn.....

Yawn perhaps, but you tycoons have 3phase already.... us peons gotta make our own.

I considered making a variety of the the phase perfect type inverter system, I have access to an adaptable device, it has an appropriate output that would only really need some mods to the controller, but for that I'd have just got a VFD.

This cost about what a static converter would, and runs more stuff than one VFD.


Evan:
I have a similar benchtop to yours, 2" of wood with a metal top, so I don't think it is straight vibration. We'll see.

[Wirecutter]

or making your own (not so free). It does include an Ingersoll-Rand rotary screw air compressor with enough capacity to run several home shops.

I like the part where it says:

At idle speed, the Air Pak will produce 100 PSI at 60 CFM.

What a bargain!

-Mark