DIY Electric Car Forums banner

Finding a motor on a budget

301K views 175 replies 63 participants last post by  Banks1234 
#1 · (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
 
See less See more
#2 ·
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. Correct me if i'm wrong on these.
Hi suk,

Not bad :) Here's a couple of comments. Refer back to your #1 post for quote context.

(36V usually is too low)
Not necessarily. Many 36V motors work out well for guys on 72 or 96V systems, some even higher. That usually requires advance (shifting the brush position).

A heavier one is o.k. but it limits your range
Unless you go way overboard, I doubt you need to worry about a few motor pounds subtracting from your range.

Hp from an electric motor is not the same as Hp from an Gasoline engine
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 :)

Regards,

major
 
#155 ·
Hi suk,

Not bad :) Here's a couple of comments. Refer back to your #1 post for quote context.



Not necessarily. Many 36V motors work out well for guys on 72 or 96V systems, some even higher. That usually requires advance (shifting the brush position).



Unless you go way overboard, I doubt you need to worry about a few motor pounds subtracting from your range.



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 :)

Regards,

major
Hi Major,
One thing that I have a hard time to understand. Many folks on this site are suggesting to use a forklift DC motor to replace the original combustion engine. But as you say, an electrical motor HP and a combustion engine HP is the same... So, if I want for instance replace a 100 HP combustion engine and look at the 100 HP electrical motors outthere, they are a lot bigger than the typical forklift DC motors. And for some reason, these forklift motors are not showing the amount of HP they are providing on any nameplates that I looked at. So, how can you size a "good" forklift DC motor to fit your expected output power?

Thanks,
eSharo
 
#4 ·
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.
 
#5 ·
I have a local motor service place near me and they have quite a few motors 'in stock'.

Often a dead motor is brought in and found uneconomical to repair or the turn over time is too long and so a new or recon motor is sold in exchange. The dead one is then repaired when work is quiet and place on the shelf for sale. Occasionally they have also repaired motors and the customer never returns for it, some are even paid for and abandoned.

So it is worth asking and you should get a rebuilt motor with a warrenty on the work.

However, the other way is to find a fork lift breaker. They will often remove running motors and sell them with no more warrenty then that it spins on 12V. You may then, if is is rough, be taking it back to the repair shop to have it rebuilt anyway. But you could also be lucky and get a really good one that require only a clean and new brushes and bearings.
 
#6 ·
I am going to make this thread a 'sticky'.

Please post concise useful hints and tips, maybe with helpful images, here to help members and keep the 'is this one any good (with photos)' and the 'chat' about them in the other sticky thread please.

Thank you.
 
#9 ·
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
Anywhere where the "metric-sytem" is used; there is no use of the word Horse Power, it is a forbidden-word in the Euro-Union, to the extent, if a student doing an exam uses the word ,horse-power he automatically voids his answer!!!!!!!!!!!! Some examiners were willing to fail your whole "paper" in Europe during the "changeover" to metric.
 
#11 ·
Anywhere where the "metric-sytem" is used; there is no use of the word Horse Power, it is a forbidden-word in the Euro-Union,

COBBLERS!

The demon word - Horsepower - is frequently used - the only problem is that there are lots of different -horsepowers-, SAE, DIN, PS

I have taken numerous European technical papers - and set a few - and I have never heard of anybody being penalized for using the word - horsepower

Mind you if you tried to answer a technical question in horsepower instead of Kw I would have marked it wrong - just as I would have if you answered a distance question in Roman miles

Have you ever tried to do any serious engineering work in the Imperial system?
It's bloody hard - Rotary Slugs for example

during the "changeover" to metric.

I remember the UK as the last country in Europe to "changeover" - but that was over forty years ago!!
 
#12 ·
I was threatened in England just after the "changeover" to metric, just before starting a Marine Engineering exam, and again in Canada when starting a "Stationary Engineer's" exam also. But; I guess nobody in both countries "cares a damn" which you use theses days!! In England most "speed signs are in both! Here in Canada there was talk about doing the same, posting in both MPH and KPH.... In a lot of calculations it is easier to use metric, but that is the only advantage I can see.
 
#13 ·
Hi Electro

In a lot of calculations it is easier to use metric, but that is the only advantage I can see.

Just try to calculate driveshaft resonant frequencies in Imperial! - nevermind anything difficult

The real advantage is that SI is a designed set of measurements so that everything keys together

This is a major advantage when you are trying to understand what is going wrong

Imperial is a set of almost random units related to the size of somebodies foot and the width of a horses arse thousands of years ago
 
#14 ·
The horesepower we use for electric motors here in Europe is rather straightforeward.

it´s 1,36 horespower roughly in a kw.
all other horsepowers (EPK, IPK etc) are long forgotten, though they might be used by vague merchants to whip up the power (just like speaker-watts)

But type-plates are reliable enough to stick to the */1,36 to use in your calculations.
 
#15 ·
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.

I have always wanted to build a EV but I dont have the knowledge of the motors or the electrics involved. After reading many posts here I think I may be able to do it with help from all of you. I have mechanical skills I did a engine conversion on a Rx7 to chevy 4.3l v-6 4bbl , 700r4 trans. So here is where I am now. I posted this earlier ,I'll paste it here with the link to the pics. Any advice, info comments WELCOME.:)
04/29/2000 DAY ONE

Went to local junk yard this morning and removed the motor and all controls from a Nissan forklift model CWP02L25S , with a GE dc 9.9 kw 43.5 volts 1000 rpm motor GE part number 29010-8G200. $ 75.00 . Seven hours of work time from removal start till home in garage. Turned the motor shaft by hand it spun free no binding or noise. Will test it with 12v in the morning, after I find out here if it will not damage it only using 12v to test it. I am really psyched , still looking for the donor veh, not sure which one to get , either a S10 or a Ranger. I have read here that the S10 is better because of the way the motor mounts are located and it is a eaiser fabrication because they are not off set like the Ranger. Also the S10 has a better made 5 spd manual transmission than the Ranger.
Pics http://s1237.photobucket.com/albums/ff466/UNED2GETBENT/
 
#18 ·
If I may assume that speaking about the front, you are meaning the Drive End (i.e. the part where the shaft exits that is going to be connected to the gearbox, and NOT the part that house the brushes) AND we can assume that the motor is wired standard, then your drawing would be correct.

Regards
Dawid
 
#20 ·
Re: Finding a motor on a budget 2 motors available

I have 2 electric motors made by Polaron & marketed under the name of Nelco. It has a peak torque of 60kw. It was originally developed for medium sized buses & large vans. They have never been used to my knowledge but have been in sotrage for a while. 2 links below give some info close to the motors I have. If interested I can send pics and maybe work out a deal. You can call email me at wud10inc@yahoo.com.

http://www.coopercontrols.co.uk/components/motors.htm

http://www.coopercontrols.co.uk/components/n200ml.htm
 
#21 ·
OK, I'm a Noob. I have an industrial electric motor that is rated at 10HP, 240V A/C 3 Phase. It weighs a heck of a lot, well over 100 lbs.

I also have a 10KW generator, again 3 phase and 240 volt. (This thing weighs a TON!!!!)

How would these two motors compare to one another and would either of them be suitable for an electric conversion powerplant?
 
#22 ·
OK, I'm a Noob. I have an industrial electric motor that is rated at 10HP, 240V A/C 3 Phase. It weighs a heck of a lot, well over 100 lbs.

I also have a 10KW generator, again 3 phase and 240 volt. (This thing weighs a TON!!!!)

How would these two motors compare to one another and would either of them be suitable for an electric conversion powerplant?
Hi Vik,

One is likely an induction motor and the other an alternator (synchronous machine). Neither would be a good choice for a rookie EV builder. AC motors require inverter type controllers typically costing more than DC converter controllers. Standard 240VAC machines mean battery pack voltage on the order of 300VDC. This increases the cell count, and cost of associated equipment for the battery like management and charger.

Regards,

major
 
#23 · (Edited)
Just made an ebay purchase of a 3-phase AC motor rated as following

Motor label specs:
Water cooled
keyed shaft dia=.75" x 2.6"
Torque 22.2Nm
Speed 4500rpm
Voltage 54.5
Current 136A

Hoping I can push the voltage higher and get enough torque for my 1800 lbs of 83 VW Rabbit. At least its water cooled, I thought that was worth the $500 purchase price. That shaft size and the fact that it is keyed much like my FB4001A is also nice:)

Steve
 
#24 ·
To see how much that motor can be overvolted, you need to know the voltage / frequency ratio of that motor. This can be calculated if you know what the base speed of the motor is. That should normally be the speed (in rpm) where the torque would start to fall off. Using that speed and knowing how many pole-pairs the motor has, would allow you to calculate the frequency needed to achieve base speed, and thence your v/f ratio.

Good luck with your build
Dawid
 
#27 · (Edited)

So I just bought this rolling junior dragster and plan to convert it to electric. The motor that seems to fit is a 48 volt Brush-Type Permanent Magnet DC Motor from Electricmotorsport.com. The battery would be four
PC625 Odyssey drycell batteries. All my research says I should also buy a controllor. Can you tell me why I cannot just use an appropriate on-off switch to turn on the motor? Okay, so I checked around and found that there are no simple mechanical switch that won't weld contacts at this DC wattage. So what is the way to go?
Tropes
 
#28 ·
The things I have seen mose is people will basically cut a normal section out of their main cable and add a plastic box and a handle to it. so that way it is like a giant removable section between the batteries and everything else for an emergency "kill switch" if you will. I saw a few people do it on youtube that way. I think the white zombie may be that way. I could be wrong tho...
 
#37 ·
I have two. One connected to the old Kaylor adaptor plate for the VW. Sweet setup but best only for the lightweight buggy or kit car. Not for high speeds either but they do work. Can't over speed these puppies either. They may also make a nice DC generator for folks. I have some stuff on youtube too.

http://www.youtube.com/watch?v=2UtQuiiWAks
What are the specs on the motor you are using gottdi?
 
#32 ·
If you mean with 'power converter' a regular 12Vdc to 110Vac inverter, I would guess: yes. BUT. They normally are not much higher rated than 1 kW maybe some up till 3 kW. Just enough to power a washing machine. Or a bike. But more important: How are you going to control the power? It's just on or off.
 
#36 ·
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
I have just purchased a slightly used K91- 4003, 72 volt motor for my junior dragster conversion. Is anyone here using this motor and if so, what are you using for battery, controller, throttle,contactor?
Tropes
 
#40 ·
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.
 
#41 ·
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!
 
#42 ·
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.
 
#43 ·
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 .
 
#45 ·
Re: 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 .
CW- S1 to battery; S2 to A2; A1 to other battery terminal.
CCW- S1 to battery; S2 to A1; A2 to other battery terminal.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top