Finding a motor on a budget

286313 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

41 - 60 of 174 Posts

Duncan

· #41 · Feb 13, 2012

Weenam said:
A query I have is finding a source for a forklift motor. Other than purchasing a wrecked forklift I have seen information about picking them up from servicing and repair places. However if a motor is being thrown out then surely it is not going to be worth salvaging for using in an electric car conversion. If it won't work in a forklift any more then to me it follows that it is only suitable as scrap. Please any advice gratefully received.

Hi Weenam
Forklifts can live for a very long time - long enough to outlive their spare parts supply

There are lots of parts on a forklift from the batteries to the hydraulics to the controllers - any one of them dying on a ten year old machine can make it not economical to repair
This results in a lot of forklifts being scrapped - the motors are still fine
Some of these are kept as spare parts - but forklift motors are robust - spares are not needed very often
So forklift motors become scrap metal

I got real lucky on mine, it had just been refurbished when the forklift was scrapped
$100 - its bigger than I would have chosen but more torque is good!

josmeijer

· #42 · Feb 13, 2012

It is not impossible that those firms find it more profitable to replace the motor with a new Chinese or salvaged motor.
Yet, in my opinion the best place to get it (and where I got mine) is from a firm that sells and maintains forklift trucks.
They usually take in the old when they sell a new one and the majority of these is wrecked.
I asked them to look out for one and I paid their time to disassemble it.

epyon

· #43 · Aug 4, 2012

Finding a motor on a (cheap)budget

The motor I got is off of a utilty cart that had a 9" inch Ford rear end an a GE motor . I took A2 an S1 and hook them together . I put A1 to pos an S2 to neg and ran forward ....great . A1 to neg an S2 to pos ... still forward , not good . What do I have to do to make the motor run backwards an forward for the cheap ? The motor really looks good in there with the driveshaft an cool looking motor mount I made , and I'm not rich .

josmeijer

· #44 · Aug 4, 2012

A1 and A2 are the rotor connections and S1 and S2 are the (serial) field connections.
So if you connect A1 to the battery and S1 to A2, it should run one way if you connect S2 to the other battery pole, and the other way with S2-A2 interconnected and S1 on the battery.
If that trick doesn't work, I fear there is some massive short cirquit in the field winding or in the wiring.

tropes

· #45 · Aug 4, 2012

Re: Finding a motor on a (cheap)budget

epyon said:
The motor I got is off of a utilty cart that had a 9" inch Ford rear end an a GE motor . I took A2 an S1 and hook them together . I put A1 to pos an S2 to neg and ran forward ....great . A1 to neg an S2 to pos ... still forward , not good . What do I have to do to make the motor run backwards an forward for the cheap ? The motor really looks good in there with the driveshaft an cool looking motor mount I made , and I'm not rich .

CW- S1 to battery; S2 to A2; A1 to other battery terminal.
CCW- S1 to battery; S2 to A1; A2 to other battery terminal.

josmeijer

· #46 · Aug 4, 2012 (Edited)

Re: Finding a motor on a (cheap)budget

tropes said:
CW- S1 to battery; S2 to A2; A1 to other battery terminal.
CCW- S1 to battery; S2 to A1; A2 to other battery terminal.

if I´m not mistaking I said the same, , though phrased a little differently .

But after some close reading (wich I didn´t do the first time) I found that you changed the polarity of the battery and left the field alone.
So there is probably nothing wrong with the motor.
What you should do, is changing the polarity of the field, (swap S1 and S2) en never mind the polarity of the power source to change direction.

McRat

· #47 · Aug 4, 2012

Forklifts:

It is seldom the motor that retires a forklift for good, it's the battery + one other problem, often the transmission or hyd pump or circuit board. The battery is the most expensive part, often over $5k. I've never had a motor failure, but other issues.

I feel guiltly, but I have perhaps "given" away 3 forklifts in my life. Scrap value.

Look on Craigslist, a busted electric forklift is often dirt cheap after you subtract the resale value of the battery. The batteries are often over 2000lb, mostly lead. Scrap batteries are 30 cents US a pound, so over $600, and the lift can be had for $500. What's the catch? A forklift weighs 4500+ lbs. You must pick it up in person.

josmeijer

· #48 · Aug 4, 2012

McRat said:
Forklifts:

The battery is the most expensive part, often over $5k.
(....)

A busted electric forklift is often dirt cheap after you subtract the resale value of the battery. The batteries are often over 2000lb, mostly lead. Scrap batteries are 30 cents US a pound, so over $600, and the lift can be had for $500. What's the catch? A forklift weighs 4500+ lbs. You must pick it up in person.

You should get them in Holland, I pay 1,8k€ (roughly 1,4k$) for a 24v set of 700AH tubular batteries (and real good ones, I bought them in 2000 and they still have approx. 90% of their initial storage capacity by daily use).
So for a 48v forklift that would make 2,8k.

Batteries are seldom really dead. If you buy the forklift with batteries that need replacement you stilll would get a couple of miles out of them after thoroughly loading (and refilling with distilled water) so if you can get it anywhere in the neighbourhood you could still drive it to your garage if you´re lucky.
Nevertheless I would still recommend paying the firm that scraps the thing to unmount the motor at a reasonable price so you are not left with 4100 tons of scrap, and they can still sell it for roughly the same price so everybody happy.
I don´t now how regulations are in the US but here lead-acid batteries are virtually worthless, as nowadays they only accept empty ones that are cleaned from any trace of sulphuric acid and you have to dispose of that acid in a legal way so any profit on the lead is eveporated on advance.

See less See more

tropes

· #49 · Aug 4, 2012 (Edited)

Re: Finding a motor on a (cheap)budget

josmeijer said:
if I´m not mistaking I said the same, , though phrased a little differently.

series motor connection.

See less See more

epyon

· #50 · Aug 6, 2012

I have a shifter that can shift two poles at a time (I want to keep it simple) . If I cant just switch neg an pos , how should I hook up this switch ? A2 switches or S1 ? Will A1 get pos and not get switched ? Can I just switch S1 an S2 between a pos an neg and then just let A1 stay pos an A2 stay neg ? Can the motor be sent to a motor shop an made to just run in series so I can just swap the poles ?

Electrical wiring Wire Electrical supply Cable Technology

See less See more

tropes

· #51 · Aug 6, 2012

epyon said:
I have a shifter that can shift two poles at a time (I want to keep it simple) . If I cant just switch neg an pos , how should I hook up this switch ? A2 switches or S1 ? Will A1 get pos and not get switched ? Can I just switch S1 an S2 between a pos an neg and then just let A1 stay pos an A2 stay neg ? Can the motor be sent to a motor shop an made to just run in series so I can just swap the poles ?

Rich or poor, if you want reverse, I think you should invest in a controller that has reverse capability.

epyon

· #52 · Aug 8, 2012

It doesn't mater if it's the best controller money can buy , If I can not use the motor or hook it up right . I'll just go out side and check it after the sun goes down a little .

major

· #53 · Aug 8, 2012 (Edited)

2

tropes said:
Rich or poor, if you want reverse, I think you should invest in a controller that has reverse capability.

With series motors reversing is accomplished with a contactor set not in the controller. Or some lower voltage/power systems like golf carts will use a manual multipole selector switch. Here is how it looks in the circuit:

Ref: from the Curtis manual.

See less See more

tropes

· #54 · Aug 8, 2012

major said:
With series motors reversing is accomplished with a contactor set not in the controller. Or some lower voltage/power systems like golf carts will use a manual multipole selector switch.

Thanks Major. Would you suggest using a contactor or manual switch without a controller?

major

· #55 · Aug 8, 2012

tropes said:
Thanks Major. Would you suggest using a contactor or manual switch without a controller?

I don't understand the question. You need the controller for speed control. The reversing contactor (or switch) is outside the controller. The manual type of reversing devices may not hold up well with voltage in excess of 48 or with currents exceeding 200 amps regularly. And they are a PITA to string large cables to where you can reach them. Reversing contactor sets can be located near the motor and controller and activated with a signal switch. Contactors also come in higher voltage/current ratings.

I don't suggest running any motor (in an EV) without a controller.

epyon

· #56 · Aug 8, 2012

Controller was bad and I just needed to switch the S1 an S2 to get reverse , switch the field not the rotor . The utility cart the motor came from had a tool box with engines on it an could push a car every night . I seen it do that before he stop paying his taxes . It can go to the body shop now that I see the basic parts work .

Snakub

· #57 · Feb 13, 2013

Anyone ever use or thought about using a brushed dc elevator motor? Where could I find one?

Electric Forklift Guy

· #58 · Feb 18, 2013

Duncan said:
Hi Weenam
Forklifts can live for a very long time - long enough to outlive their spare parts supply

There are lots of parts on a forklift from the batteries to the hydraulics to the controllers - any one of them dying on a ten year old machine can make it not economical to repair
This results in a lot of forklifts being scrapped - the motors are still fine
Some of these are kept as spare parts - but forklift motors are robust - spares are not needed very often
So forklift motors become scrap metal

I got real lucky on mine, it had just been refurbished when the forklift was scrapped
$100 - its bigger than I would have chosen but more torque is good!

Yes , the large majority of electric forklifts that get scrapped have good motors and controllers in them

The main reasons electric forklifts get scrapped is usually from mechanical issues , or you have a "Receiving Manager" who refuses to believe you when you tell him the battery is bad.

Its rare to scrap one out for a bad motor or controller....we have a "rebuild industry" for these components and its not that expensive for us

To give you an idea , I can get a Curtis 1244 controller for $150 dollars as long as I have a core to trade in.

And the GE EV-100 controller . the most expensive part on that to replace is the oscillator board ( $180)

My company used to have a 5 acre "junkyard' for forklifts and I can tell you that almost all of the electric trucks were DRIVEN into the yard.

Anyway , to get back onto the subject

Even if the controller or the motor is bad you can still trade it in as a "core" to a rebuild company ( Like Flight Systems or M and M Motors ) for a rebuilt one and its a lot cheaper than buying a new one .

See less See more

Electric Forklift Guy

· #59 · Feb 18, 2013

josmeijer said:
A1 and A2 are the rotor connections and S1 and S2 are the (serial) field connections.
So if you connect A1 to the battery and S1 to A2, it should run one way if you connect S2 to the other battery pole, and the other way with S2-A2 interconnected and S1 on the battery.
If that trick doesn't work, I fear there is some massive short cirquit in the field winding or in the wiring.

In the jargon of electricians "S" is for "Stator"

Electronics technicians would label it "F" for "Field".

I really wish electronic technicians and electricians could standardize symbols and names better

Im an industrial electrician so I have to deal with both sets and it irritates the hell out of me sometimes

Its almost like speaking two different languages that are distantly related, like Italian and Latin.

These two sentences mean exactly the same thing

" I need the in-line reactor in series with the stator"

" I need the induction coil in series with the field "

And it doesn't stop there

"E" is "V"

Snubber is a filter

"Lagging Power Factor" is "Negative Phase Angle"

" Contactor " is " Power Relay"

And I swear to God I feel like strangling the son of a bitch who came up with some of the electrical terms the computer nerds use.
( So now its Italian, Latin and Ebonics.)

See less See more

major

· #60 · Feb 18, 2013

The industry standard for marking the terminals on DC motors used in forklifts, industrial utility vehicles and golf carts in the United States was and still is, I believe, as follows:

A for Armature (connected internally through the brushes),

S for Series field coils,

F for Shunt or Separately Excited field coils.

41 - 60 of 174 Posts