$20 2.5 HP DC motor for crazy HV experiments

M

Matt Gruber

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Joined
Feb 8, 2007
Messages
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Location
New Smyrna Beach FL
Big prize
(u can gloat)
if u make a successful EV with it.
Drawbacks
NEED 95-130vdc CONTROLLER(maybe adapt from a treadmill?)
6750 rpm
.

SEE CAT # 10-1783-A
SURPLUSCENTER.COM

4"x8"
1.5 HP @95vdc
weighs 10#
18.5 amps

They have a 3450RPM for $60 too.
 
Yes, I've seen similar motors from treadmills. Really beefy looking.
With the upward trend in battery voltages, it may be applicable if one could find the right controller.

I suspect most treadmill controllers won't work because they're SCR based and need AC to function. It wouldn't be that hard to re-FET a brushed controller to work at 130v or so.

Another idea that's been mentioned before is to get a cheap 12 to 120v inverter and a big car battery. Control would still be an issue (unless on / off is OK). 12v to 120v inverters have the FETs in them already, so it would be concievable to convert one to PWM for variable speed control.

If you had a sine wave output inverter, a standard treadmill speed control would work.
 
My brother and I had a conversation just yesterday about using a treadmill in the opposite fashion... for a homebrew dyno.

Not sure about all the specifics, but we figure a good load on the motor that wont burn up, an ammeter and a DVM with peak hold might be a start.



:?:
 
A halogen light bulb should make a pretty good load. Two or three 500 watt bulbs can take all the power your setup can dish out. A 300 watt bulb is good for smaller setups. I'm not sure how badly resistance changes as they warm up, but a voltmeter and ammeter will give you all the information you need.
A very important piece of information to know with a dyno setup is motor rpm. Knowing motor rpm, no load voltage, loaded voltage, and output current you can derive most of the information you would want to know.
Joe
 
A treadmill motor would make a good dyno generator. I've seen them used for windmills before.

Lightbulbs would make a great load. Hair dryers might be good too.
Ideally you'd want to vary the load continuously. It might be challenging to come up with an electronic way to do that. Maybe one of those gigantic 1930's rheostats.

A car alternator might be good too, since you can easily control the loading with the field voltage.
 
NickF23 said:
with nimh, high voltage is easier. saves the complication of parallel strings. 120 volt of subc cells. could crack out 30 amps if you wanted them too! reasonably cheap aswell. do you reckon u could gear it down?
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my bet would be to run it w/off the shelf 60-72v controller for 2500-3900, then use bypass boost for long empty roads. with mx500 rear wheel & sprockets top speed 45 mph at 6700

Fechter
can we reduce timing to lower the speed range? will it increase power at lower V?
 
Leeps said:
A halogen light bulb should make a pretty good load. Two or three 500 watt bulbs can take all the power your setup can dish out. A 300 watt bulb is good for smaller setups. I'm not sure how badly resistance changes as they warm up, but a voltmeter and ammeter will give you all the information you need.
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I feel somewhat vindicated that there is at least someone else that shares the view that halogen bulbs make for a nice compact resistive load. Cheap too, much less money than a 500W power resistor. The appeal for me has always been that you don't need to sink light, less heat to contend with.

Over at the PA I was ridiculed by some when I suggested using these for regenerative braking. :cry: That wouldn't be where you heard it, is it? Not like it's an original idea but it would certainly help the healing process.
 
A light bulb really is a power resistor that gets so hot it glows when you look at it. They get hot, very hot, it still needs to be delt with. The high temperature is a plus and minus at the same time. Being that they run hot normally you dont have to heat sink it, theres a huge temperature differential they shed the heat out of brute force so to speak. The downside to this is that the huge temperature swing makes for a sharp increase in resistance as the bulb lights up. If your not looking for precision then who cares, its a cheap easy load to set up. With a dyno its not the best thing, but with an ammeter and a voltmeter you get your information anyways. Perhaps a couple bulbs set up with switches to take them in and out of parallel could give various loads and more data points.
Actually for regenerative braking i think it would make for a better feeling brake. At low speeds the resistance is low and can give more braking torque at low speeds, then at high speeds the resistance goes up. This would give a more constant braking torque, well more constant than a normal resistor. The hot fragile bulb would have to be dealt with.
Joe
 
Matt Gruber said:
Fechter
can we reduce timing to lower the speed range? will it increase power at lower V?
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No, retarding the timing will just make it into a space heater.
Rewinding the armature would do it, but that's a time-consuming PITA.
The brushes and commutator are also limited in how much current they will take. If you rewind for a lower voltage, the current would need to be higher to get the same power, and that might put you over the limit of the brushes.

Modding a controller to take 150v might be easier. New FETs, freewheel diodes, main caps and a pre-regulator for the control circuitry.

I wonder if any of the treadmill speed controllers would work. Most of the ones I've seen wouldn't, but there might be some that would. Anything that uses a SCR would not work.
 
Over at the PA I was ridiculed by some when I suggested using these for regenerative braking. :cry: That wouldn't be where you heard it, is it? Not like it's an original idea but it would certainly help the healing process.
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Dr. Lemmiwinks may be able to help you resolve your hurt and anger the way he helped me recently. His is tough-love therapy, but it worked for me :)
http://endless-sphere.com/forums/viewtopic.php?t=396&postdays=0&postorder=asc&start=0
 
if weight is any indication of quality and power, the 36#
Cat # 10-2190 $59.95 2.5 HP 130vdc is the one to get. 3450 rpm 18 amps. "treadmill duty"
it has ~10-15# flywheel that should be removed imo, so at ~21-26# net, it could be a killer.
 
I'm pretty sure that's the motor I used - hard to tell since they don't have it anymore but the specs match my motor and I got it from them in '07 for $35 shipped. It works ok (after applying workaround) with a MSW inverter and SCR but I'm sure it would work better with a PSW inverter.

I screwed up and went w/ a 12v inverter/battery so the battery could see peaks near 80a...I should've went w/ 24v but I'll upgrade eventually.

gloat..hah...it works, that's good enough. ;)

edit; I wish I would've seen this thread when it was started. :lol:
 
Sometimes great threads perfectly relevant to what I am doing now happen to have been started (and ended) long before I ever joined. :lol:

I still think there is great potential in these motors, especially with the easy high-voltage packs now possible with LiPo and stuff. :) Also with the handy Recumpence reduction drive, or other versions.
 
Isn't there something fundamentally wrong with the whole idea of a treadmill motor?

You take motor power, and human power, and add them together to get... exactly zero.

Maybe that's why they are on the second hand market.

Nick
 
Actually, I think they're there because people are fundamentally lazy, and most of the people I know who bought treadmills to get their expanding bodies back into shape ended up just letting the thing collect dust in a corner. Reasons given are usually "it's too hard", "no time", "no time because I'll miss my TV shows", "it's boring", "I get tired too quickly", etc.

Almost all of those have easy fixes, but the reality is that they're usually just excuses not to even try.

That said, what I would actually do with a treadmill if I were to design one or rebuild one is to setup the belt to drive a *generator* with a variable charging current into a battery array. The load presented by the generator could be varied by the settings on the control baord by the person exercising so that they can have an easy time of it or a hard workout, and they could then use that power generated to run a light or two around the house for a while.

Or, they could run a TV or radio or whatever from the power while exercising, and require enough of a workout to run those devices from it or they don't get any entertainment. :)
 
Sometimes great threads perfectly relevant to what I am doing now happen to have been started (and ended) long before I ever joined.
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If I had seen this thread in '07 I'd have a lot more miles on it by now but it's also kinda cool that it's like 3yrs later, I didn't see the thread until recently, and I'm still first (AFAIK). 8)
 
REdiculous said:
Sometimes great threads perfectly relevant to what I am doing now happen to have been started (and ended) long before I ever joined.
Click to expand...

If I had seen this thread in '07 I'd have a lot more miles on it by now but it's also kinda cool that it's like 3yrs later, I didn't see the thread until recently, and I'm still first (AFAIK). 8)
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nice job! congrats!
 
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