Mod of the year (at least for me!)

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dfurlano

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Many thanks to TomServo who sold me a kit to convert my Turncrafter pro lathe from a 5 speed to a variable speed! (click pics to make them larger)

This is not a simple parts swap but with a little skill and some decent tools I was able to do this in about 6 hours.

Photo of the front. I now have a forward and backward switch (kewl) and a speed knob (currently without a knob).



This is a photo of the back. The black box is a motor controller. I may need to add a fan after I use it for a while. On the right is the new motor in a plastic tube that I had laying around. The motor is actually for a tread mill and was not covered. Again I may add a fan on the end at a later date.



This is a belt and gear photo. I had to bore out the center hole of the gear assemble and mill a keyway in the new motor shaft. Also had to do small modifications to the motor mount.

 
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It was inexpensive (to me) but you need to work with Brian (tomservo) on what you want. Brain mentioned that the motor runs from 30-5000 rpm's although I do not know that I can expect because each configuration is different.
 
Dan: glad to hear it's working for you - I love modding a good tool into a great one.. I think I mentioned it once, but it bears repeating - don't switch directions while the setup is on! Even if you have it at the lowest speed (even if the motor is stopped). I think that's how I toasted my "cheapie" controller before I got these industrial models.

I finally got my set of HSS chisels from HF - turned my first pen using a skew properly today, and I must say I like it! You should see how I rigged up a tool rest - I bought a banjo to use with an offboard toolrest setup to turn bowls, and i'm using the BANJO as a tool rest :)
 
OK, Tom, can that be done for a Jet also and how much money are we talking about... also what does it entail for those of us electronically challenged... [:(]
 
heh, I told Brian that all I was capable of doing was pluging the power cord into an outlet... anything beyond that was something I didn't want to try. Brian wired and labeled EVERYTHING so all I had to do was to unplug the forward/reverse switch to get the wires inside a box. Worked first try.

Originally posted by Old Griz
<br />OK, Tom, can that be done for a Jet also and how much money are we talking about... also what does it entail for those of us electronically challenged... [:(]
Click to expand...
 
Dan: can't wait to hear how it turns for you. I'm working on getting more of the speed controllers at a reasonable price.

Griz: Depending on what I can get the controllers for, I'm shooting for about $100 for a kit. It would include the controller, speed "dial", forward/reverse switch, and motor. Some of the controllers may come in a housing, in general I would say that they will just be a little circuit board mounted on an aluminum "L" shape (how they come). The one I sold Dan is just like mine at home - rated to 1/2HP without being cooled, 1HP with cooling (generally just a heatsink). I will wire everything up, solder the terminals to the wires, and put heat shrink tubing on whereever possible. Dan wasn't sure how he wanted to setup the switches and everything, so I just made all the wires "plenty long".

Installation is as simple as mounting the motor, mounting the pulley on the motor, and making a housing of some sort for the controller. If you plan on really demanding some power from the lathe - more than 1/2 HP I made a wood box (still only partially completed) for my motor and controller, mounted them on a hinge and I can remove the hinge pin and move the motor and controller behind the lathe to turn with the headstock reversed. I'll try and get a picture when I do this tommorow to buff my pen in the hat pen.

I've been using one of these treadmill motors on my lathe (and frankly since switching to chisels for turning, it has absurd power availible) and have been very pleased. I assemble the system and set the low speed setting as low as the motor will turn. The motor brushes are replaceable; however, these motors are $10 from surpluscenter.com so replacing the brushes would likely cost the same as a new motor.

(http://www.surpluscenter.com/item.asp?UID=2006022701500123&item=10-2167&catname=electric)

It all fits in a flat rate box, so $8-9 to ship. I'll post in individual classifieds when I have one or more ready to go.

 
I tried it on Sunday.... very nice!!! Now I need to get used to adjusting speeds... worth every penny. Also runs much smoother then the orginal motor...

Thanks.
 
This sounds interesting, but one question. I know that on the VS Jet Mini, you still need to move the belt depending on which speed range you want. Is that still necessary with this setup?
 
No belt moving is required. I have not played much with the motor controller but you can adjust the min/max speed to what you like.
 
I have a TCLPRO so this is VERY interesting, thanks for posting!
This is a belt and gear photo. I had to bore out the center hole of the gear assemble and mill a keyway in the new motor shaft. Also had to do small modifications to the motor mount.
Click to expand...
Hmmm...[:(] I certainly don't have the tools to do that. Will there be an option for a motor with pulley/gear pre-installed?
 
Huzzah: pretty much - the original controller I had was from a treadmill.

gerry: these controllers will allow you to run the motor as slowly as it possibly can turn - mine and dan's seem to be able to run about 30 RPM, although his was able to run a bit slower, maybe 20 RPM. As you can imagine, there wasn't much torque availible at that speed. I can part a tenon with the spindle running about 45 RPM. It really depends on how aggressive you want to be.

Ron: I'm not sure. I'd need to source one, but it's certainly possible. What size belt does the TCL Pro have? I could definitely find a single speed pulley, a multi-step one might be harder to find but could be doable.
 
Tom,
I have the same lathe as Dan does, so whatever you gave him would be the same for me....okay wait a minute, I read your post again and now it appears you didn't supply the pulley? Just the motor and controller, right? So where do we get pulleys?

Okay, so another question is: why not just use the stock motor with an AC speed controller? Probably won't be able to do reverse, but I'm not concerned with that. The big advantage of course is no motor/pulley/mounting problems. Sorry for all of the basic questions, I'm just try to get a feel for what all needs to be done.

Thanks,
 
Chuck: brake resistor? I'm not really following - the problem is that if the motor is spinning, it will act as a generator and feed power back into the controller. I've turned it off and switched from F to R while it was spinning and other than it stopping much faster (dumping the current into the controller) the controller was no worse for wear. It's not something you should do every day, or if you have a 12" bowl blank chucked up. There are reverse-while-running switches availible, I will look into them.

Ron: making an AC motor VS has two basic requirements... a VFD (variable frequency drive) and a 3 phase motor. a cheap VFD on ebay will run about $150 (1/4 of retail) and a 3 phase motor could be anywhere from $50-300. Any other kind of A/C motor speed control is frankly dangerous and will reduce the availible torque to almost none... and has no provisions to maintain the motor at a constant speed.
 
Thanks for the info Tom. I'll keep watching this topic for more installation details.

Dan, would you please provide more details about your pulley installation and motor mounting - those are the two hurdles I'm most concerned with.

Thanks,
 
Motor mounting only requires you to drill holes in the motor flange and grinding out two spots in the orginal motor mount. Make sure you put tape over the openings in the motor casing so that you do not get any metal chips inside the motor housing.

I used the original pulley but you will need to bore out the diameter to fit the new motor shaft. I have a mini mill and a rotary table and thats how I did the boring. You also need a keyway if you use the original pulley. Again I used the mini mill. You can get another pulley but you need to figure out how it will mount on the motor and if you need to replace to drive pulley to be the same diameter.

I am really tired right now so if this does not make sense let me know.
 
Thanks Dan, I think I know what you're saying... enough to know that it requires some metal working and I don't have the tools nor expertise to do that.
Thanks guys, I'll have to pass on this.
 
I think you can find a pulley that works without any mods to the shaft. I just have not looked that hard since I had the tools.
 
For the TCL Pro:
The belt is 0.25" wide and 24" dia.
The pulley shaft is 0.675"
The pulley steps measure 1.15", 1.50", 1.85", 2.20", 2.50"

Dan, or someone, please check my numbers, it was a bit awkward to maneuver the calipers.[:I]
 
Thanks, ron! I'll look this morning, I hate going home then leaving when the post office opens :)

Now is that the pulley shaft for the motor or the headstock? .675 is a weird size or is it metric?

dan: i see, it's a poly vee belt.. I'll have to check with a bearing shop
 
Actually, the belt is 24" around (not it's diameter). By measuring the front side of the pulley, I agree with Dan that the shaft is 0.629". Yes, these measurements are from the motor pulley. Tom- thanks for not giving up.[8D]
 
I know that you shouldn't put a variable speed controller on a soft or slow start motors cause it will ruin the motor. They make a device for your router that if it is instant on you can use to convert to variable speed. Why could you not use that to accomplish the same thing?
 
Steve: the router speed controls are made to use with "universal" AC motors - those are a/c motors that have brushes. You certainly could use a universal motor and router speed control to do this - my lathe came setup this way originally when I got it... myself, I can't stand the racket a router makes. Add to that, it would be running at less than 5% of it's rated speed. Router motors don't have a lot of torque, they generate their horsepower by spinning fast.. You would be talking about running a "1.5" HP / 18000 RPM router (12A/115V) at 10% of it's rated speed - and that would be at "full" lathe speed. running it at 2% of the rated speed - 360 RPM - and I can't imagine getting more than 3% of the rated power - .045 HP. I doubt it would last long under that kind of abuse.

The "RSC" claim to work with DC motors but based on the research I've done, it seems they put a half-rectified AC current in "DC" mode. No way around this because they use a device called a triac. What it boils down to is that at best you'd be feeding it about 68% of the power it would get with real DC.

These controllers are a bit more intelligent than the typical "RSC" - they can regulate the motor speed under load (within limits). I'm looking into some that can even have speed sensors used in conjunction to further boost the torque at low RPM. Also trying to get my hands on PWM controllers and "regenerative" drives. A regenerative drive can be reversed in operation - the excess power is dumped back into the AC power line. A PWM drive - the most expensive type - can run the motor at (nearly) full torque at any RPM - but you can cook your motor right quick too.
 
Has anyone looked at whether this would fit in a Delta Midi Lathe? As for the stepped pulleys, I would think that the additional adjustments would allow more torque at the lower RPMs by allowing the motor to spin faster, and then gearing down.

JimQ
 
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