DIY Bowl Lathe Project

[Greg Wittler]

Hi all,

while I am in the process of turning a 2 car garage into a woodworking shop, a lathe was going to be one of my lasts purchases (was planning on waiting until a possible Powermatic sale Nov 2010 if it is anything like last year) as I already have a lathe albeit it is a small one, and last week the president at my work asked if I wanted to pull any parts out of this 2 kilowatt laser before sending it off to the scrap heap. So I yanked out a pritine Baldor 7.5HP motor (was powering a water pump) and a Mitsubishi Inverter/VFD. First I was thinking can't run a 3phase motor at home unless I use a converter, but since the stuff was free, the coverter would be the only high $ part as for the last 6 months, I have been thinking about building a heavy duty bowl lathe and was wonding if it was worth considering or should I forget it and sell the stuff on CL. Here are some pictures:

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Some of the Motor specs: Volts 208-230/480
Amps: 19-18/9
RPM: 3450
60HZ 3Phase Class B

Thanks,
Greg

[Eric Kosanovich]

Greg it would be nice to see how it goes if you do it Good luck

[Dick Strauss]

Greg,
7.5hp is definitely more than you need. Most lathes use 3hp or less but 5hp should be plenty to turn a very large bowl.

Once you get above 5hp, there are very few VFD's that don't require a 3 phase input (due to the current needs at 220V I assume). This means that it will be hard to find a way to power that motor (short of a true phase converter). You may want to consider trying to trade/sell the motor and VFD so that you can get something in the 3-5hp range.

Good luck with your project!

[alex carey]

Well first you should think hard about where you really want to go to work on making your own big lathe, its not a small undertaking. But if you do really want to then you should probably get a smaller motor. 7.5 if pretty dang big, I have 2 hp and can turn 20" bowl pretty easily. I guess 3 hp would be better for me but I don't think I'd need anymore than that. If you plan on turning really big a 5 hp is probably all you would ever need.

Keep us posted on your ideas. A couple other people have done this and we always love to watch and comment. Lot of good advice here.

[Jeff Nicol]

I am sort of in line with the other guys on this. You can get two types of phase converters, the true full power converter using a separate motor (Rotary Phase Converter) to create the 3 phase or a static phase converter that would give you 2/3 of the full power of the motor. The Rotary converter is the expensive one, ENCO has them on sale right now and one that would work for you is just under $1000. The static phase converters are on sale too and the one that would work for you is $200. Since the rest of the stuff is at no cost to you so far the $200 is not a bad out put from your wallet to get started. That being said you may be able to sell the inverter and the motor on Craigslist or another outlet in your area. If you can find a place that sells motors and controlers they may help you sell them. To buy them new it would cost you about $1500.00 or more so if you could sell them or trade them for a 3hp and an inverter that would use 220V single phase input you would be farther ahead.

No matter have fun and we hope to see a great creation soon!

Jeff

[curtis rosche]

from what i have seen in my searches of bowl lathes that are homemade, and asking around, here is one thing you could do with that. make a lathe bed out of some angle iron and an Ibeam. and then use the motor as the headstock. the bearings on a 7.5hp motor are heavy enough to let you use the motor shaft as a spindle. just thread the end of the motor shaft. and if its not long enough, put an adapter over it to make it longer. the vfd will give you the speed control you need. if you do this you wont have to think about making a spindle and getting it machinces and getting bearings and the rest of that stuff.