Finding a motor on a budget

286318 Views 173 Replies 62 Participants Last post by piotrsko, 5 mo ago

sukusia

Discussion Starter · Mar 26, 2011 (Edited)

So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.

When looking for a forklift motor:
Get a series wound motor because they have very high torque and handle abuse (over volting) a lot better.
Know the difference between a Spex motor and a Series wound.
When dealing with series wound forklift motors go for higher voltage. (36V may require advanced timing.)
Hp does not directly represent torque (although it does have a factor in its equation).
Get a class H insulation if possible (makes your motor last longer)
Get a motor around 150lbs (Wouldn't risk a motor that's too light, it won't have the oomph you need. a few extra pounds is A-o.k. but a significant amount of extra pounds limits your range)
Get one with a male shaft
A keyed shaft is easier to work with but you can still work with a spline shaft
Try and get the coupler that goes on to your motor when you buy it/rip it out (saves you $$ and time)
When looking for a different motor:
Ac is not the way to go for your first conversion (or do i just have low expectations of myself?)
You can tell if a motor is AC if it is a 1 phase or 3 phase motor
Pancake motors are usually not good candidates for car conversions. (Yeah you saw the one on ebay. They overheat easily)
Golfcart motors are seldom powerful enough for a conversion
Motors specifically made for EV conversions are the best but its gonna cost you.
You do have to look at many factor such as volts, amps (which gets you Hp). Torque is nice to know. Continuous Hp. So many factors!!!

"HP is HP Electric motors and gas engines are rated differently w/r/t HP. And they have different torque curves. But one HP from an electric motor shaft is exactly the same as one HP from a gas engine shaft at the same RPM "- Major

If there is any more helpful hints I'll be happy to add them

Reactions: 2

81 - 100 of 174 Posts

morganharri

· #81 · Jul 8, 2015

I have 36v motor which i have purchased 2 years ago and it is really working very well.

tenthousandclowns

· #82 · Apr 29, 2016

what do you think of this salvage AC motor?
http://www.ebay.com/itm/AZURE-DYNAM...376728?hash=item1ea9002098:g:ioMAAOSwYaFWfE0u

3 phase
25hp
1785 RPM
208v
$500 OBO

what if it was run at 144v instead of 208v, with a curtis 1238?

dcb

· #83 · Apr 29, 2016 (Edited)

tenthousandclowns said:
what do you think of this salvage AC motor?
http://www.ebay.com/itm/AZURE-DYNAM...376728?hash=item1ea9002098:g:ioMAAOSwYaFWfE0u

3 phase
25hp
1785 RPM
208v
$500 OBO

what if it was run at 144v instead of 208v, with a curtis 1238?

you have to go into the wayback machine to find the datasheet for that one:
http://web.archive.org/web/20090806...-drive/documents/AC90_DMOC645ProductSheet.pdf

but 208v is rms, which is really more like 294v dc pack, the datasheet says 312v min.

so look at the first graph, and slide it to the left by 144/312. So that the knee is at ~623 rpm.

Also the curtis is probably a 500 amp controller, so then pull the whole graph down by 500/600.

so the knee will be at about 416 ft lbs (graph is in nm fyi), which puts you at about 50 hp (37kw) at 623 rpm.

with the dmoc and a 312v pack it says it does 97kw at 1500 rpm. but the thing weighs 189kg!

Plus 3 phase controller costs are not cheap. Even with a kit expect lots of time and several hundreds of dollars.

edit: I'm at a bit of a loss as to how a 312v pack and a 600 amp controller is only making 100kw.
edit2: must be a sqrt(2) * efficiency thing.

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tenthousandclowns

· #84 · Apr 30, 2016

mmm..
I really don't know anything about AC motors... maybe I'll stick with DC for now.

dcb

· #85 · Apr 30, 2016

I hear ya, I keep an eye out for a nice DC motor too, but damn these induction motors are cheap ( I have a 4 pole 7.5hp 1765rpm for $100 on the bench that looks about like an ac51 on paper, with 1.4x longer windings, and of course no testing in that sort of environment or hundreds/thousands/??? of satisfied customers), but then the extra requirements start kicking in. It isn't too bad as hobbies go though, keep ya busy for a while

bigmouse

· #86 · May 1, 2016

Those look like nice motors, but the max speed is a bit low and the rated voltage is a bit high. From what I can tell, these were installed in-line with the driveshaft on the hybrid trucks/vans/busses that they came from, so 5000rpm is probably plenty for that. A rebuild of one of these with a high speed balance and some good bearings would probably make for a very nice motor. I can't tell if they're water cooled or air cooled. It looks like there might be a hose poking out in one of the photos?

A repurposed Prius inverter with either my control board in it, or two of Eldis's boards in it make AC motors more feasible for DIY, though not plug-and-play like the DC stuff.

major

· #87 · May 1, 2016

bigmouse said:
Those look like nice motors, but the max speed is a bit low and the rated voltage is a bit high. From what I can tell, these were installed in-line with the driveshaft on the hybrid trucks/vans/busses that they came from, so 5000rpm is probably plenty for that. A rebuild of one of these with a high speed balance and some good bearings would probably make for a very nice motor. I can't tell if they're water cooled or air cooled. It looks like there might be a hose poking out in one of the photos?

Hi big,

Those were made by Lincoln Electric in Cleveland; a NEMA 286T frame. We used one for a project and balanced the rotor and used precision oil lubed bearings and did well over 10,000 RPM, 12k peaks. With modified windings, 350Vdc bus and liquid cooling, it was capable of over 200kW. Those pictured are TENC (totally enclosed non-cooled). And I think the Azure application was limited to like 400A-phase (for member dcb).

Those are real nice motors--- big but nice. Great extruded aluminum frame shell. A shame they used iron end caps. We had aluminum ends made for ours.

Regards,

major

tenthousandclowns

· #88 · May 3, 2016

Ok... why are these ones so cheap?

http://www.ebay.com/itm/Force-Drive...015043?hash=item41a9956743:g:SwAAAOSwv9hW2JFv

AC24LS motor
88.2 lbs
15kw continuous at 4k rpm
35 kw peak

"peak efficiency 85%" isn't that kind of low?

$150 OBO

dcb

· #89 · May 3, 2016 (Edited)

they have a weird output shaft, not insurmountable though, plus you may need a real drive end bearing. And the seller has zero feedback.

Also most folks are looking at scrap tesla motors, etc, these days, spurred on by a desire for more power if you are going to go through all the effort.

I'm sure there is a niche for these, but 3 phase controller (and battery) costs make it worth investing a little bit more in the motor if it means you will get more out of the rest of your investment.

edit: a pic of the dataplate would help, also folks may want liquid cooled, I'm looking at ODP motors myself. This is TENV, enclosed no fan (can add one maybe), not the best for continuous power.

rahulkentonn

· #90 · May 15, 2016

Toyota 4Y engine is the best option. I have heard it is widely available and it is very reasonably priced !

Jbrewer106

· #91 · Jun 19, 2016

major, can you decribe how you modified the windings?

major said:
bigmouse said:

Those look like nice motors, but the max speed is a bit low and the rated voltage is a bit high. From what I can tell, these were installed in-line with the driveshaft on the hybrid trucks/vans/busses that they came from, so 5000rpm is probably plenty for that. A rebuild of one of these with a high speed balance and some good bearings would probably make for a very nice motor. I can't tell if they're water cooled or air cooled. It looks like there might be a hose poking out in one of the photos?

Click to expand...

Hi big,

Those were made by Lincoln Electric in Cleveland; a NEMA 286T frame. We used one for a project and balanced the rotor and used precision oil lubed bearings and did well over 10,000 RPM, 12k peaks. With modified windings, 350Vdc bus and liquid cooling, it was capable of over 200kW. Those pictured are TENC (totally enclosed non-cooled). And I think the Azure application was limited to like 400A-phase (for member dcb).

Those are real nice motors--- big but nice. Great extruded aluminum frame shell. A shame they used iron end caps. We had aluminum ends made for ours.

Regards,

major

major

· #92 · Jun 19, 2016

Jbrewer106 said:
major, can you decribe how you modified the windings?

Basically same or slightly increased copper mass (slot fill) with less turns and increased (effective) conductor cross sectional area. ie. Decrease V/f, increased base frequency.

ATFforklifts

· #93 · Jul 13, 2016 (Edited)

sukusia said:
So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.

When looking for a forklift motor:
Get a series wound motor because they have very high torque and handle abuse (over volting) a lot better.
Know the difference between a Spex motor and a Series wound.
When dealing with series wound forklift motors go for higher voltage. (36V may require advanced timing.)
Hp does not directly represent torque (although it does have a factor in its equation).
Get a class H insulation if possible (makes your motor last longer)
Get a motor around 150lbs (Wouldn't risk a motor that's too light, it won't have the oomph you need. a few extra pounds is A-o.k. but a significant amount of extra pounds limits your range)
Get one with a male shaft
A keyed shaft is easier to work with but you can still work with a spline shaft
Try and get the coupler that goes on to your motor when you buy it/rip it out (saves you $$ and time)
When looking for a different motor:
Ac is not the way to go for your first conversion (or do i just have low expectations of myself?)
You can tell if a motor is AC if it is a 1 phase or 3 phase motor
Pancake motors are usually not good candidates for car conversions. (Yeah you saw the one on ebay. They overheat easily)
Golfcart motors are seldom powerful enough for a conversion
Motors specifically made for EV conversions are the best but its gonna cost you.
You do have to look at many factor such as volts, amps (which gets you Hp). Torque is nice to know. Continuous Hp. So many factors!!!
If there is any more helpful hints I'll be happy to add them

Good job! U seems a master of forklifts..

Mane55

· #94 · Feb 2, 2018

sukusia said:
Good thing I'm not in Europe then.

I am very happy to live in Europe. All calculations are way easier using metric units. You also may check your formula simply checking that the units match.
A few examples:
F=ma so 1N = 1kg * 1m/s^2
P=Fv so 1W=1N * 1m/s = 1 kg * 1m^2 / s^3
And also P=I*U so 1W=1A*1V
Luckily seconds, amperes and volts are the same here and there.
For energy
1J=1Ws and thus 1kWh=1000W * 3600s=3 600 000 J = 3.6 MJ

Karsten

· #95 · Jun 11, 2018 (Edited)

Hi.
Would be nice to get some input on using this Fanuc 10 M dc servo motor to power a light weight Opel Corsa. Theyt apparently have high torque since they are used in Cnc lathes etc. The motor is about 30 years old but was never used.

Any advice would be appriciated.
Thank you.

Product Label Metal

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major

· #96 · Jun 11, 2018

Karsten said:
Hi.
Would be nice to get some input on using this Fanuc 10 M dc servo motor to power a light weight Opel Corsa. Theyt apparently have high torque since they are used in Cnc lathes etc. The motor is about 30 years old but was never used.

Any advice would be appriciated.
Thank you.

View attachment 106818

165V * 12A = 1980W or about 2 hp by the time you get to the shaft output.

I doubt you'll be happy with a 2 hp powerplant in a car.

Regards,

major

Electric Forklift Guy

· #97 · Jul 27, 2018

Mane55 said:
I am very happy to live in Europe. All calculations are way easier using metric units. You also may check your formula simply checking that the units match.
A few examples:
F=ma so 1N = 1kg * 1m/s^2
P=Fv so 1W=1N * 1m/s = 1 kg * 1m^2 / s^3
And also P=I*U so 1W=1A*1V
Luckily seconds, amperes and volts are the same here and there.
For energy
1J=1Ws and thus 1kWh=1000W * 3600s=3 600 000 J = 3.6 MJ

Uh , electric units are metric.
Electricians usually do all the calculations in metric to get Watts and Newton Meters and just hit the old conversion button so "Non-Electricians" can understand what we are talking about.

But every American electrician knows that 1 Electric horsepower is 746 watts.

It's actually a myth that Americans dont know what the metric system is , we are taught it in school , and if we go into any field of science or engineering we use it almost exclusively.

Every mechanic knows that 1/2 inch is 12.7 mm and that if they have a 13 mm bolt head thats stripped a 1/2 inch wrench will grip it a little tighter.

Everyone who changed the oil in a car knows that a liter is almost 6% larger than a quart.

Some products are sold in metric values ( like a 2 liter soda bottle )

Every car enthusiast knows that 100 km/h = 62 MPH

Everyone knows that a meter is 3 and 3/8 inches longer than a yard and a kilogram is 2.2 pounds.

American understand the metric system , we just prefer using the traditional measurements in our daily lives.

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Emyr

· #98 · Jul 27, 2018

What's the conversion between CI and litres?

Hirngespinste

· #99 · Jul 27, 2018 (Edited)

Electric Forklift Guy said:
American understand the metric system , we just prefer using the traditional measurements in our daily lives.

Sure... "traditional" is the best

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Reactions: 1

Duncan

· #100 · Jul 27, 2018

"Traditional" is not too bad for simple stuff

But it's truly awful if you have to do anything remotely complicated!

Reactions: 1

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