Need help hacking a lathe!

[Bill Lantry]

OK, Gentlemen,

I'm back on it. I've gotten pretty far with figuring out this project, but I'm stymied at this point. I thought I had it all figured out last night, but the harsh light of day shattered everything.

Here's the lathe I'm hacking:

http://images.grizzly.com/grizzlycom/pics/jpeg288/g/g0462.jpg

Nice, solidly built frame, halfway decent bearings in the spindle, reeves drive. We all know the problem: lowest speed is too fast. Only solution: VFD and a new, 3 phase motor. I'd like to stay at 2 HP, since most of the better lathes are 1.5 to 2 HP. Based on the VFDs I've found, that pretty much means I need to run 220 into the shop, which I guess I should do anyway. The 110 VFDs pretty much top out at 1 HP. So...

220 to the shop (it's really only a 20 foot run from the main panel in the basement, and I've already got a now unused 220 breaker on the main that used to power the oven). Subpanel in the shop, with both 110 and 220 coming out of it. Here's the VFD I'm thinking will do the job:

http://www.factorymation.com/s.nl/it.A/id.196/.f?category=32

single phase in, 3 phase out. I'm not real clear on how to hook it up, but I can probably figure it out. I figure I can route around the switch on the lathe. Not real clear on how to set speed controls on it, but again, I can probably figure that out. It's $145, so that's inside the budget.

OK, on to the motor. I want to keep the reeves drive... and doing that uncomplicates part of the project. That means I only need to worry about the motor spindle size, which I take it is not universal or standardized. But I can measure the shaft on the existing motor. The real problem:

As far as I can tell, I need a motor that is

3 phase
2 hp
tefc
inverter duty
c-face
about 1700 rpm

and probably a bunch of other variables that I have no idea about. I found this motor last night:

http://www.surpluscenter.com/item.asp?UID=2007092711250329&item=10-1810-A&catname=electric

for 70 bucks, and got very excited. That's a price within reach. it's not tefc. It's not inverter duty (whatever that actually means). And I don't know the spindle would match. So, I go searching for a motor that I think might match my percieved specs, and can't find anything for less than many hundreds of dollars. Am I barking up the wrong tree? How does one go about finding a motor like that for under a hundred bucks? This all started because people said I could pick up a 3 phase motor cheap. HELP! ;)

Thanks,

Bill

[Rod Sheridan]

Hi, you obviously need a motor that matches your original one as far as shaft size, and mounting arrangement.

The surplus motor you indicated, is a C face mount, which looks like what you need. (It's hard to tell from your lathe photo).

The surplus motor however, is open type, and the dust and shavings will get into it. Woodworking really requires a TEFC (Totally Enclosed Fan Cooled) which has a sealed motor with a fan and shroud on the non drive end to blow air over the motor.

You should be able to pick up a surplus motor at a motor shop.

Inverter duty motors are expensive, because the insulation on the windings has to be capable of handling higher voltage spikes from the waveforms produced by VFDs, and cooling on the motor is impaired at low speeds since the airflow is inversely proportional to the square of the fan speed. This requires larger fan, more expensive design and construction.

You will be fine with surplus, conventional 3 phase motor in your application......Regards, Rod.

[Brodie Brickey]

Bill,

I'm not sure that your motor should only be a 1750 RPM motor, but your 'fly wheel' or pulleys could compensate for that. Whatever RPM motor your lathe currently has, is what RPM you should be using.

I originally thought you were going to have problems with the controller, but your input is SINGLE PHASE or 3 PHASE, so you should be good there. I would make sure that you used a heavy enough gauge wire when you moved up to the sub panel. Remember, you will be running this under load for long periods of time. Once you're at the sub panel, leave yourself open for another 220 circuit for DC or table saw later.

having 220 in the shop really opens your options up for old iron.

[David Epperson]

You will also need to stay with the same frame size. At least as far as the C-face is concerned. I'm guessing that this has a "standard" 1750 rpm motor on it? Why not just get a lower RPM single phase motor? Other than you lose the top end RPM. But with the VFD you will lose HP at the low end.

[Bill Lantry]

Gentlemen,

Yep, the present motor is 1725 RPM. Low speed is now about 600... if I could find a single phase 2 hp that turned at around 600, low speed would be around 200, I'm guessing. But I'm not sure such motors are readily available, or I don't know where to look...

I'm curious about the loss of hp at the low end with a VFD... is that generally accepted? And if so, how severe is the loss?

I'm not sure this lathe has anything close to a fly wheel on it... if it does, I haven't seen it. And yes, 220 to the shop would be a good thing: my 3650 could be re-wired for it already, and other old iron tools might actually save money in the long run (famous last words, I know... ;)

It's pretty clear the inverter thing is out of reach. The TEFC may be as well. May have to do the surplus thing, and hope. If it burns out after 6 months, and needs replacement, it would take a couple years before I was up to the cost of a tefc 2 hp 3 phase... ;)

More famous last words... ;)

Perhaps my experience will be only to serve as a counter example to others... ;)

Thanks,

Bill

[Dennis Ford]

The two Grizzly tools I have both use motors that are NOT standard frame size. Your project is very interesting but will probably require some machine work to adapt a standard motor to the lathe. Do you have a machinist friend?

A TEFC motor is desirable but not as critical with three phase motors (no starting switch to foul). If you don't mind blowing dust out occasionally you can get by without TEFC. Blowing out the dust will help with cooling and fire safety.

An Inverter duty motor is not necessary for a home shop lathe (they are very expensive).

[Bob Hallowell]

Bill,
first off That's the same vfd I bought and their tech support is great and will help you out, plus I can as well. As for the remote switches you can buy theirs but they are expensive or I can send you the part nubmers for the ones I got from mcmaster carr.

Next the motor. Most general duty motors lose turque as the are slowed this is true. but you want lose much as you will only be down 20-30 hertz to get 200-300rmps because of your reaves drive can take you to 600rpms.

deals can be found as I bought this motor http://www.baldor.com/products/detail.asp?1=1&catalog=ZDNM3584T&product=AC+Motors&family=Vector%7Cvw%5FACMotors%5FVector&winding=05WGW058&rating=40C+AMB%2DCONT
for $75 dollars used on the bay. You just have to be patient.

I think the most important thing you need to look for is frame size and spindle size and make sure it is a tefc or tenv. Don't over look 1 1/2 hp motors cause belts like ours are probaly going to slip at low speeds before the 2hp motor will. The bigger lathes use poly v J belts.

I bought a 1 1/2 motor but mine is rated at constant torgue to 5hz so I only have one pulley belted at 1000rpm's but as I am drilling out peppermills on lower speeds it is the belt that slips not the motor right now it is not a problem but in the future I might upgrade to the J-belt.

Bob

[Nathan Camp]

I originally thought you were going to have problems with the controller, but your input is SINGLE PHASE or 3 PHASE, so you should be good there. I would make sure that you used a heavy enough gauge wire when you moved up to the sub panel.

One word of warning when you are sizing your drive. 2HP drive is generally 2HP at 220V 3 Phase. You will loose power with only a single phase of input voltage. This will derate the drive.

Back when I used to buy a lot of VFD's my general rule of thumb was to get a VFD one size larger than the motor (that was three phase). In other words, get a 100 HP VFD for a 75 HP motor. Of course, this was a continuous duty application.

For a single phase of input, I'd probable go up two sizes. There are surplus 5 HP units. You can set the maximum amperage in the drive, so you don't burn out your motor. In addition, I would add a starter with an overload.

They do have vector drive VFDs and motors that give a lot of torque at the low end of the speed range, but you can buy a very nice lathe with a VFD on it cheaper.

The manufacturer can tell you how feeding single phase will derate the drive.

Good luck,
Nathan

[Bill Lantry]

Gentlemen,

Thanks for your help so far. Next obstacle:

to make a long story short: I did get the thing apart last night. I don't know if the motor housing is standard. Four bolt holes, spaced at 3 1/4". The biggest worry is the size of the motor shaft. Assuming I can fit another motor into the housing, the shaft will need to be 5/8" in diameter, and extend at least 4 1/4" from the motor.

72660

I need help on this one. Are shafts interchangeable? I've never heard of people worrying about this, so maybe it's not a major issue? I have no idea. It seems odd that the motor specs I've found seldom list the numbers for the shafts? Can I use this shaft in another motor? Am I biting off way more than I can chew?

HELP!!! http://familywoodworking.org/forums/images/smilies/wink.gif

Thanks,

Bill

[Jason Clark2]

Bill, I had this lathe until recently. There is another hack out there that will allow you to obtain slower speeds without resorting to swapping the
motor. You won't get significantly below 600 but it's better than nothing.

Please see the link below:
http://home.comcast.net/~hypot/Projects/LatheSpeed.htm

Jason

[Bill Lantry]

Jason,

Thanks for the link. I already did this, but slightly differently. Instead of drilling, I loosened and repositioned the lever, essentially moving the detent over. This lost me one speed at the high end, but got me down to about 540. The limitation of the reeves drive won't let me go anything below that, as long as that motor spindle is turning at 1725 rpm... :(

Thanks,

Bill

[Jason Clark2]

Bill, That's what I did too but was having trouble expressing it here. I even went so far as to drill and tap holes in the headstock to reposition the lever.

Jason

[David Epperson]

Gentlemen,

Thanks for your help so far. Next obstacle:

to make a long story short: I did get the thing apart last night. I don't know if the motor housing is standard. Four bolt holes, spaced at 3 1/4". The biggest worry is the size of the motor shaft. Assuming I can fit another motor into the housing, the shaft will need to be 5/8" in diameter, and extend at least 4 1/4" from the motor.



I need help on this one. Are shafts interchangeable? I've never heard of people worrying about this, so maybe it's not a major issue? I have no idea. It seems odd that the motor specs I've found seldom list the numbers for the shafts? Can I use this shaft in another motor? Am I biting off way more than I can chew?

HELP!!! http://familywoodworking.org/forums/images/smilies/wink.gif

Thanks,

Bill
First off, no. Motor shafts are not "interchangeable" as such. But 5/8" shafts are not that uncommon. The 4-1/4" dimension just might be more of a problem. I'd have to find one of the motormakers catalogs with engineering tables to verify this, as well as the bolt spacing - used to work with them all the time, but that was then.
Can you use the shaft in another motor?....short answer is probably not. Just about the only possible exception would be in a motor of exactly the same frame size made by the same manufacturer..And even then there is no real guarantee. OEM motors can quite often be made to proprietary dimensions. But it could just as well be a standard offering. Longer shafts are not often used in high side load applications like this, as it's harder on the shaft bearings.

If you have an interest in having a solution made, and have access to a machine shop, you could probably build a c-face bearing holder and belt drive your Reeves drive input - and put step pulleys on both the motor and the input shafts. Which would solve quite a number of speed limitation problems.

Also the fix that Jason posted looks promising.

[Dick Strauss]

Bill,
They do make 1140 rpm motors but these are even harder to find than the 1750s.

Bill I'm in the same boat. I've been having the same difficulties finding the motor. I want variable speed and reverse on my Delta 1440 lathe. I have been looking for a 3ph inverter duty motor while maintaining the same 5/8" shaft. I may end up replacing the pulleys to match the shaft on a new motor since I really won't need the reeves drive any longer with the VFD.

Bill and Jason,
Hmmm, it sounds like a few people followed my directions for the speed mod on their reeves drives. I did it on my Delta 1440 (46-715) about a year ago and got it down below 200 rpms. I'm glad to hear it works on the Jets and Grizzlies too although it sounds like it isn't quite as effective.

I ran across this site when looking for adapter plates. Here is a link showing specs for various bases so that you know how to adapt from one to another:
http://www.baldor.com/pdf/501_catalog/22_access.pdf

[Brian Weick]

To make life easier,,, and much better - why reinvent the wheel. Buy a 1-1/2hp rated induction motor- 3ph and then get a Variable frequency drive and the problem is not only solved - you have incredible amounts of options with this set up. If you can't find a shaft diameter on the new motor to match the pulley (which i doubt you will have a problem) you can buy an adapter, or have a machinist make you one ($20-50$). In my opinion; that lathe was designed that way based on specifications of the motor's RMP to torque parameters and balance/weight ratios on the entire frame ~ when you start tampering with that , you may run into some problems along the way. This is only my opinion Bill, I know it may set you back $300 for everything but - it would be well worth it. you can always keep the existing motor if you ever decide to sell it, and keep the 3ph motor/VFD setup with you for the next one.
I hope you fix your problem Bill:confused:
Brian

[Jim Kountz]

I wonder why you couldnt just add a third pulley like a drill press does? Mine goes all the way down to 210 and up to around 3000. Its just a third pulley on a pivot point. The motor would have to hang somehow like on a contractors saw in order to keep tention on the belt but thats not a problem. Something to think about....

[Dick Strauss]

Jim,
That is a really good thought. However there really isn't enough room for the third shaft (holding two pulleys) without going to a delta or triangular belt arrangement. The third (middle) shaft would have to be able to pivot as well to take advantage of the reeves drive. You would also need to make a new cover for pulley assembly to keep the sawdust out of the reeves drive system. It's definitely doable if you got a very good friend that happens to be a machinist.

I think the vfd route is still easier and might be cheaper if you had to pay to have the parts machined.

[Jim Kountz]

Well heres what I was thinking about, not sure exactly how all this would come together but heres the basics. If you mounted the motor under the lathe like many older ones are then ran from the motor to a middle pulley then on up to the lathe with a second belt. All the pulleys would of course be 4 step pulleys. The middle one if done similar to a drill press, would simply be a stub shaft on a pivoting arm. This arm would have to be mounted very securely and for that I thought about a metal plate of at least 1/4" in thickness bolted to the leg assembly in such a way so as to keep it in line. The motor could be mounted on a simple hinged platform that kept the tension on the belts at all times yet easily released to change speeds. If the motor was of the same rpm as my drill press and the pulleys the same size, I should be able to go from about 220 to around 3000 rpm. The only part you would have to have made would be the pivoting shaft again using one from a drill press for a "pattern".
Im going to look into this further and who knows I might come up with something that actually works!! (dont hold your breath!!)

[Bob Hallowell]

Jim,
for they lathe you have and the setup you have and the swing you can get away with a 1hp vfd and motor and probly only have $200 in it. Plus it would be easier and you would love it. you could keep you step pulleys to rough tune your speed but unless you are rough a big bowl you could just mostly keep it in you middle range. I have mine running 10hz to 130hz. But I only use one pulley.

Bob

[Jim Kountz]

Jim,
for they lathe you have and the setup you have and the swing you can get away with a 1hp vfd and motor and probly only have $200 in it. Plus it would be easier and you would love it.

Bob

You're probably right Bob, I havent abandoned the VFD route by any means Ive just always wondered if the three pulley setup would work and why its not a more common thing on lathes. I think I'll keep on eye on the bay site for a motor and see what develops there.

Jim

[Dick Strauss]

Jim,
I don't think these drill systems are designed for as much hp as we would like to use. Delta and PM both have reeves drive based drill presses that use a 1750 rpm motor and get shaft speeds in the 200 rpm range. These machines are in the 1 hp range. I know the Delta has two speed ranges but the PM has one. You may want to start there by looking at these two products.

http://www.powermatic.com/Products.aspx?nav=ByPart&ClassID=332168&Part=1792800

http://www.deltaportercable.com/Products/ProductDetail.aspx?ProductID=15684

[Jim Kountz]

Hmm thats a good point there Dick, something to consider for sure. My drill press doesnt use a reeves drive so I didnt even think about that. I think for my smaller lathe a 1hp motor however would be fine, I cant really turn anything real large anyway. With that said I have been looking into these VFD's and I think Bob has the right idea with them. I like the idea of soft start too, that would be really nice and safer too all around.

[Bill Lantry]

Well, gentlemen,

After many phone calls, it's back to the drawing board. Can't find a compatible motor with a long enough spindle, nor even a spindle extension long enough to work. Now I have two choices:

1. Keep my eyes peeled for a compatible motor. Not keeping my fingers crossed.

2. Think about ditching the drive pulley on the reeves drive. But I'd still need a pretty long spindle... :(

Looks like I'm dead in the water for now. The multiple pulley idea's a good one, but I'd lose the swinging headstock, and limit the size of blanks I could turn. Darn.

Thanks,

Bill

[David Epperson]

Looks like I'm dead in the water for now. The multiple pulley idea's a good one, but I'd lose the swinging headstock, and limit the size of blanks I could turn. Darn.

Thanks,

Bill
Well maybe not. Only if you hung the motor below the bed. Bracket it above the headstock and you're still in bidness. :D
Or.................Here's an "out of the box" thought. Mount your "second set" reduction pulley to the fan end of your existing motor and drive that with another motor. You will have to install an isolation switch to disconnect the "primary" motor while you do that though. Otherwise it will just drag the secondary motor down acting as a generator. In fact you could clutch the connection between the two and just select your speed range by selecting which motor runs the system. There are some two speed hoists/cranes that use exactly this type of system.

[Christopher Hunter]

I have the same Lathe and same problem !!!!!
Here is a thought -how about calling Grizzly and seeing if their new Lathe( with the VFD) head stock could be baught to replace the old one and mounted onto the old bed?
I thought about this a few months ago but never made the call.
It would be cheaper then buying the entire new one and it is the same height.

Just curious---
--Chris

[Bill Lantry]

Chris,

I made that call. Spoke to a very nice, helpful gentleman. No such luck. Darn!

Thanks,

Bill