Is there a conversion kit

Chuck Ellis

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Tellico Plains, Tennessee
to convert the Jet 1442 from the Reeves Unit to Electronic Variable Speed?

I would love to upgrade to the 1642, but the price is way far out of my budget, plus I would probably need to upgrade
some or most of my accessories to fit the 1 1/4" spindle... so not an option.

I've just ordered a new set of motor spindle pulleys for mine... the left pulley has cracked and wallowed the keyway out to the point that it won't slide on the motor shaft... this will be the second set of pulleys I've put on in the last couple of years, plus I've replaced the spindle pulley's once also... I'm thinking there may not be as much stress on the pulleys if I could put the 3phase DC motor in that I think most EVS systems run on... if it requires 220 voltage, also may not be an option... I'm not sure if my breaker panel will take 220 without additional wire run. At any rate, I would have to have a qualified electrician do the wiring as my hair is too short now to curl.
 
I doubt there is anything official...

However, its basically its just a 3 phase motor and a VFD. It looks like you can get the parts third party for around $200-300 so not cheap but less than a new lathe (probably less if you aggressively shopped ebay/used motor stores). You'll have to do something with the sheaves (pulleys) and possibly some mounting bracket changes as well, but I'm not quite familiar enough what the layout on that lathe looks like to really know. The other consideration is that most of the variable-speed latheshave 2 or more pulley settings so you can have a high (and mid) and low ranges so you keep the torque for larger items at lower rpm. The 3520 has 2 speeds but its 2HP so with a lower HP motor it might be nice to go to three pulley settings if you end up with many unbalanced bowl blanks in that collection there.

You can definitely get 1HP VFD's, going larger than that they start to get a bit more rarefied..

You could piece it together with a 1HP motor and matching VFD:
http://www.surpluscenter.com/Electr...s-Base-Mount/?page_no=1&fq=ATR_Enclosure:TEFC
http://www.surpluscenter.com/Electrical/3-Phase-Motors/Variable-Frequency-Drives/

Or buy a motor/vfd package looks a smidge cheaper (although the surplus center motor is a continuous duty and reversable leeson so its likely a better motor - I'm not familiar with the Brook motors):
http://dealerselectric.com/115Vinput_230Voutput.asp

I did find one place with 1.5HP 110v vfd drives:
http://www.vfds.com/variable-freque...ut+Voltage_a-n-21=115V@@Rated+HP_a-n-17=1.5HP
or ebay up to 2hp:
http://www.ebay.com/itm/110V-VARIAB...694?pt=LH_DefaultDomain_0&hash=item2a1bd2d656

Most electric motor shops should be able to put this together as well, and they might have a used 3 phase motor that they can sell cheaper if you're lucky and look around some.

The key with VFD's is to match the amp draw of the motor to the VFD size (and the motor plate voltage needs to match the vfd output as well).
If you can match the frame mount of the motor to what you currently have that will likely be the easiest to swap out.

I haven't actually programmed a vfd myself yet, but looked at the instructions on a couple once when considering them for a project and it didn't look all that hard.

I think the real answer is to figure out how to charge more for your work so you can use the sales to pay for that spiffy new lathe and a new circuit to the shop ;)
 
Chuck, I have a Nova 3000 that was converted over to a 1.5 HP Baldor 3 phase, and then had a VFD added to control the motor. (I should add all this was done by a previous owner, I bought it as is.). The Nova 3000 is an 8 step pulley as it came from the factory, with the Baldor it can start at zero from any of the belt positions. Big deal. In reality, even with the motor/controller, you need several of the belt positions (maybe not 8, but probably 4 or 5). Here's why: the motor has so little torque when running at the lower frequencies it's useless. I'm not an experienced turner, but I can tell if you run it at less than maybe 35 Hz you don't have enough torque to do much besides sanding (and I'm fairly certain you could stall it doing that). So even with the electronic speeds, you would need a step pulley with a few speed options on it. I understand that's why on the larger lathes the motors are often 3 HP, and even then they have a one or 2 belts changes for different tasks. Back to my lathe, the guy who did put a fair amount of work into it. The original motor was a C face (I think) and he made a platform to hold the 56 frame Baldor and hook it to the mechanism that lets the motor tilt for belt changes. He hooked all this to a (surplus?) GE industrial VFD and it actually worked really well. But the motor itself is about $300 (new), plus the VFD, plus whatever changes you would have to make to mount it. It can add up to a sizable chunk, and in your case you would still have to deal with the Reeves drive.
 
I thought it might be possible to just entirely replace the reeves setup with a pair of pulleys? The motor side for sure, but can't really tell from the manual how the spindle is configured (and you'd need to do both sides). It seems that it ought to be possible even if you just had to file a couple of flats (or drill some dimples) for some set screws to catch on (the number of set screws shall be three and three shall be the number of set screws, two would probably work :p).

Looking at the setup if you made a mounting bracket lower down (or an overhead bracket even maybe) for the motor and then mounted a stepped idler pulley where the motor currently is you could swap the steps on the outside without having to get to the inside of the lathe which seems like it would be a pain given how its laid out.

Fred is right on the torque issue, but the 3 phase motors do have a better torque curve than single phase so its not tooo bad, I can stall the 3520 even on the low speed pulley in the 200-300rpm range when roughing a large blank pretty easily though, not quite as easy at 600rpm :D.

DC motors have an even better torque curve so you could probably skip the stepped pulleys with one of those. I wasn't seeing a new setup that would be in the right HP/speed range for under $400+ so that seemed like it probably wasn't a good deal. However, ebay to the rescue again - check out this article for some ideas: http://www.cnccookbook.com/MTLatheDCMotor.htm - that's for a metal lathe, but the idea seems pretty solid. Looking at ebay for "Treadmill Motor DC TEFC" I see some in the $40 range. You'd still need the speed controller but it looks like sub $200 for the whole setup if you shop it a bit. A google search for "treadmill motor wood lathe" turns up a bunch of hits. For the DC motor you'd want an enclosed, continuous duty permanent magnet motor I think (anyone who knows more criteria I'm interested to hear them :D).

Surplus center also has a large collection of pulleys: http://www.surpluscenter.com/Pulleys/Finished-Bore-Pulleys/
 
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