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View Full Version : FOUND: Good Source for DC motors



rbertalotto
12-26-2014, 07:08 AM
A while back I converted my JET 12 X 36 BD lathe to DC / Variable speed drive. I was able to buy a new Baldor 3/4HP DC motor on Ebay for $90. But this was a few years ago.

Recently I wanted to convert my Wood Cutting Bandsaw to DC drive also so I could use it for cutting metal. A search for good quality DC motors was showing well over $200 for a 3/4HP unit.

But then I tried AMAZON. They sell 1/3, 1/2 and 3/4HP AMARINE motors for extremely good prices and if you are a PRIME customer, no shipping charges and you get it in two days.

http://www.amazon.com/Permanent-Magnet-Motor-1750rpm-Tenv/dp/B00KARD85C/ref=sr_1_3?ie=UTF8&qid=1419594752&sr=8-3&keywords=dc+motor+3%2F4+hp

I ordered a 3/4HP version on Friday morning and I had it on Saturday. Not sure how they can get something this heavy to me this fast...for free.

For a control board I went to Surplus Center and used a 90/180 VDC controller:

http://www.surpluscenter.com/Electric-Motors/DC-Motors/Motor-Speed-Controllers/90-180-VDC-SPEED-CONTROL-W-POT-11-2269.axd

The motor cost $179 and the control $82. All I added was an ON/OFF switch. If you are powering a lathe you might want to add another switch for FORWARD / REVERSE.

This motor looks exactly like the BALDOR motor I have on my lathe. Same exact size and footprint.

My research has not found anything close in quality or cost. Please let me know if I'm wrong as I have a couple more machines I'm going to convert as budget allows.

BTW, I was using a Treadmill Motor on my bandsaw and it would stall on 1/8" steel or 3/4" Aluminum with a top quality bi-metal metal cutting blade. With the same blade, with the new motor, it cuts these materials and thicker like a hot knife through butter! As fast as I can push the material iot cuts it. I just cut up some 1" Aluminum like nothing. VERY pleased with this modification.

Thanks!

dalee100
12-26-2014, 09:18 AM
Hi,

I've been finding Amazon is highly price competitive for many of these industrial type items. They have been getting more of my business lately.

Dalee

Doozer
12-26-2014, 10:03 AM
DC motors are not worth messing with once you realize the benefits of 3 phase motors and vfd drives.

--Doozer

olcop
12-26-2014, 11:06 AM
DC motors are not worth messing with once you realize the benefits of 3 phase motors and vfd drives.

--Doozer

Very true---if you have 3 phase power. Most of us don't and don't want want to go to the extra expense for a static phase convertor or a RPC.
olcop

olcop
12-26-2014, 11:10 AM
Hi,

I've been finding Amazon is highly price competitive for many of these industrial type items. They have been getting more of my business lately.

Dalee

Agree wholeheartedly, been using them for a while, very price competitive and the free shipping ain't nothing to sneeze at either.
olcop

Jon Heron
12-26-2014, 11:12 AM
Very true---if you have 3 phase power. Most of us don't and don't want want to go to the extra expense for a static phase convertor or a RPC.
olcop
You dont need 3phase power with a VFD, single phase goes in and 3 phase comes out to the motor... A thing of beauty!
http://www.ebay.ca/sch/i.html?_from=R40&_trksid=p3984.m570.l2632.R2.TR3.TRC1.A0.H0.Xsingle +phase+vfd&_nkw=single+phase+vfd&_sacat=92074
Cheers,
Jon

MaxHeadRoom
12-26-2014, 11:56 AM
My research has not found anything close in quality or cost. Please let me know if I'm wrong as I have a couple more machines I'm going to convert as budget allows.

Thanks!

You may find a benefit from using PWM drive instead of SCR type, the PWM offers quieter and smoother low rpm control.
KB & Baldor offer them and they often come up on ebay but the PWM types are scarcer.
Max.

rbertalotto
12-26-2014, 04:17 PM
You may find a benefit from using PWM drive instead of SCR type, the PWM offers quieter and smoother low rpm control.

Wish I knew more about this stuff. All I do know is I've been running my lathe now for over 6 years with the DC motor and the Surplus Center drive and it has been wonderful. No low speed issues what so ever. And loads of power. Being a belt drive lathe, the belts will slip long before the motor can stall.

tc429
12-26-2014, 04:38 PM
I ran DC on my lathe and CNC bridgeport for a long time... but we have used quite a few of these little drives at work- they were only 99 bucks 2 yrs ago, can run single phase 120 to 3 phase 240 in and still get 240 three phase out- next on my to-do is put the old ac motors back on and run these type drives at home...smooth control, braking, hard to beat.
http://www.automationdirect.com/adc/Shopping/Catalog/Drives/GS1_%28120_-z-_230_VAC_V-z-Hz_Control%29/GS1_Drive_Units_%28120_-z-_230_VAC%29/GS1-21P0

MaxHeadRoom
12-26-2014, 06:16 PM
Wish I knew more about this stuff. All I do know is I've been running my lathe now for over 6 years with the DC motor and the Surplus Center drive and it has been wonderful. No low speed issues what so ever. And loads of power. Being a belt drive lathe, the belts will slip long before the motor can stall.

I was not implying it would not do the job, but there is a noticeable difference with PWM, the SCR drive 120Hz ripple can be noticeable when running low rpm, often more of a audible thing.!
Max.