Variable speed ?
#8
I have an old Delta lathe that I would like to use. The drawback is the old 4 step pulley system. What is a good aftermarket variable speed DC motor and controler?
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#9
Most folks, me included, use a 3-phase motor and VFD.  Used 3-phase motors, especially small ones, have little value and can be had cheap.  4-pole (1800 rpm) with TEFC frame, and 1 hp rated, are the best way to go, IMO.  1 hp sounds like a lot for a small lathe, but when running the motor at half speed, it’s going to have the same torque as at full speed (constant torque below synchronous speed is typical), and at half of rated speed, it’s only good for half of rated power.  So you upsize so it doesn’t get wimpy when running slow.

Use the step pulleys to select the ratio most suited to the work.  High speed for pen and other small diameter work, low speed for large diameters like bowls.  Then vary the motor speed between roughing, turning, sanding, etc. as desired.  I rarely change pulley ratios on a single piece.

But don’t use a high mechanical speed then crawl the motor at 1/4 speed attempting to rough out a big bowl blank, for instance.
Tom

“This place smells like that odd combination of flop sweat, hopelessness, aaaand feet"
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#10
(09-27-2020, 09:51 AM)castguy2003 Wrote: I have an old Delta lathe that I would like to use. The drawback is the old 4 step pulley system. What is a good aftermarket variable speed DC motor and controler?

Penn State has this retrofit kit for a Jet mini lathe.

It would require making a motor mount emulating the Jet lathe and you would likely wind up using a link belt. I am experiencing a bit of sticker shock as I think that the price has gone up ~40% since the last time that I looked it up.

The price for a DC motor, controller, and mount is high enough that the approach of finding a 3-phase motor with a frame that matches your existing mount. On the other hand, all of the 3-phase converters that I have seen require 220V feed.

I should add that the step pulley is not that big a deal - especially for a lathe that has <12" capacity over the ways. The last time that I bought a new mini lathe, I had the choice of a step pulley or electronic variable speed. I chose the step pulley because there is no electronics to go bad.
"the most important safety feature on any tool is the one between your ears." - Ken Vick

A wish for you all:  May you keep buying green bananas.
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#11
(09-27-2020, 09:51 AM)castguy2003 Wrote: I have an old Delta lathe that I would like to use. The drawback is the old 4 step pulley system. What is a good aftermarket variable speed DC motor and controler?

While restoring my Powermatic 90 I opted for a 3 phase motor with vfd control. Variable speed at your fingertips is hard to beat and can be had at a reasonable price.

Ron
"which plane should I use for this task?......the sharp one"

http://www.breseplane.blogspot.com/
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#12
In the 1990s I fixed up an old Delta lathe with a DC motor and controller and it worked great until the controller's components failed.  Turns out the motor drew too many amps for the controller, but it did work great for a decade of more.  More recently (2013) I did a Powermatic 45 4-speed  with a three phase motor with a VFD but it did take 240 volt single phase current because the motor was a 1-1/2 HP.  I really find this superior to the DC motor.

As has been pointed out, a DC controller can be had to convert 120 volts to 90 volt DC and feed a 14 amp DC motor.  VFDs can be had that run off of 120 volt current but the HP limit is 1 HP.  At lower speeds this can be a weakness.

I suspect that any of the better VFD suppliers like Automation Direct can put a package together for you.  They can also put a DC motor package together but I think that's more expensive these days.  A phone call and conversation will be necessary to get the right components for your needs.
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#13
Kbac makes a dc speed controller and people use them with dc motors from often times free or cheap treadmill motors.

I prefer ac 3ph motors and vfd. Kbac also sells a couple really nice vfds.


Glad its my shop I am responsible for - I only have to make me happy.

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#14
(09-29-2020, 04:04 PM)BloomingtonMike Wrote: Kbac makes a dc speed controller and people use them with dc motors from often times free or cheap treadmill motors.

I prefer ac 3ph motors and vfd. Kbac also sells a couple really nice vfds.
I upgraded my Delta 1460(1954 manufacturer date) a few years back. Changed the 3/4 hp to 1 1/2 hp 3ph. Added a VFD and some additional controls. Had to adjust the motor mount to account for the difference in motor height ( used some hard maple ). Motor cost about $160, VFD was around $200. Control box and etc was around $75. System works great  and I have never looked back.

Greg
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