ESC help for a newbie

[Cola_]

I've been lurking around for a while now and need a bit of help finding a speed controller for my go kart project.
I'm looking at getting a forklift lift motor and I'm not sure on what I need in an ESC.

The motor runs on 48 volts, with an 8.8 Kilowatt output.
I know that i'm going to need some hefty batteries to power it but I'm more concerned about finding the right speed controller since I'm new to this.

I've been looking at the Alltrax AXE4834 and Kelly Controller's KDZ48200 but i'm not sure if those are what I will need. (I assume that the motor is brushed but I would have to get more information)

I've read through the stickies and a few other posts about people using forklift motors, but I would like some personal advice if I could get it.

If anyone knows of better (or cheaper) controllers for a newer builder, feel free to suggest

Thanks, Cola_

 

[chancer]

I dont know about all the electric stuff... but I used to drive electric forklifts, and this sounds like a cool idea. The ones I used to drive had Full speed in forward and reverse. So to brake you just switched directions. Cool.
But what I am imagining as really cool is hauling A$$ in reverse in a kart then turning the wheel and hammering it in forward doing one of those Tactical driving 180s in a go kart. If you can figure how to get this kart built.... Fun Fun Fun.

 

[itsid]

Holy mother of Current Batman, that is one hefty motor right there...

Now, quick math, shall we?

8.8kW OUTPUT

Assumingly, around 80% efficiency best, about 75% at average

So let's round this up to 12000 Watts electrical input (just to be on the safe side controller wise)

that'd be 250 Amps of constant power the ESC should be capable of.
(no, peak power does NOT count I'm afraid.. )
they will get hot, very hot.. enough to burn... and no warranty will cover for that!

So Alltrax AXE4865; not AXE4834! ( the Alltrax SPM-48400 would be a cheaper match )
Or the Kelly KDZ48650.

And yes, that IS expensive; sorry.

And of course you will not ride full throttle all day, but peak power is usually measured in seconds before the controller runs hot (likely 30secs )
32 seconds and the controller will be gone forever if it doesn't have a thermal fuse that is.

Oh.. the kelly do have thermal protection (IDK about alltrax) still I wouldn't go below 400A rated power, since it'd be a pain if that kicks in too early

'sid

 

[Cola_]

Holy mother of Current Batman, that is one hefty motor right there...

Now, quick math, shall we?

8.8kW OUTPUT

Assumingly, around 80% efficiency best, about 75% at average

So let's round this up to 12000 Watts electrical input (just to be on the safe side controller wise)

that'd be 250 Amps of constant power the ESC should be capable of.
(no, peak power does NOT count I'm afraid.. )
they will get hot, very hot.. enough to burn... and no warranty will cover for that!

So Alltrax AXE4865; not AXE4834! ( the Alltrax SPM-48400 would be a cheaper match )
Or the Kelly KDZ48650.

And yes, that IS expensive; sorry.

And of course you will not ride full throttle all day, but peak power is usually measured in seconds before the controller runs hot (likely 30secs )
32 seconds and the controller will be gone forever if it doesn't have a thermal fuse that is.

Oh.. the kelly do have thermal protection (IDK about alltrax) still I wouldn't go below 400A rated power, since it'd be a pain if that kicks in too early

'sid

Thanks for the quick reply!
I think that I'll end up getting the Kelly controller if anything, but I'm going to have to save up a bit more before I can get one.
I could always try and make my own, but I don't feel like dying anytime soon...

 

[itsid]

Loool;
I know that feeling

but don't worry to much .. think about 50ct per Amp to make your own;
to get an idea what you'll have to spend making your own.
@ 600 Amps (as we talk about here...) that's still about 300 USD.

okay, that includes maybe a few spare parts and shipping fees for digikey etc .. but still... it wouldn't be cheap.

'sid

 

[machinist@large]

.....okay, that includes maybe a few spare parts and shipping fees for digikey etc .. but still... it wouldn't be cheap.

'sid

Uhmm Alex?

At a former employer, someone on high found a Digikey catalog, and declared that they were our new source for PLC's, proximity switches, cabling, etc.

The fun began when parts started to fail in the 80 to 85 day range from start up,and got much more interesting when the "Made in Germany" decals started peeling off of the "Made in China" decals.

Try explaining why you lost your on several jobs to the same on high type because the only way you could make the machine run was by replacing all the magnetic reed switch type proximity switches with the Allen Bradley equivalent for four times the price, plus the labor to do it, plus all the bad press you get I'm such cases....

 

[itsid]

Well Pat..
as always, keep your eyes wide open.

If you buy a part you don't know from a company you never heard of, it's likely something you'd never wanted in the first place

Not a single part I bought ever failed me (and the first batch I got in 1998 or so, shipped with a paper catalogue! a bazillion times the weight of my smd capcitors I ordered )
(small padded envelope would have been enough... I got a 12 lbs box!)

What did happened though (of course) was a mishap of mine every now and then, ordering the wrong part (say correct specs, wrong size or something);
but frankly, I never bought any part that's the cheapest in their list of options.
For two reasons:
1) I don't need reels of 1000 pieces.. I need say five maybe ten
2) if an individiual price is close to the bulk price, then it's likely something fishy going on.
You cannot look inside, and most of us would never return a 75ct part and pay 3 bucks shipping to do so.
So... mid price segment, known maker and/or known seller whenever possible.

in the end, that's the cheapest solution (at least for me since I always payed overseas shipping anyways;
doing that twice for a 50ct article isn't exactly a smart move, right? )

'sid

PS I don't actually like reed switches too much, one was too close to a motor and got triggered whenever the driver powered up to 2 amps since I don't like my hands close to a moving axis, it took me two weeks to find the cause.
precision mechanical switches (for the basics) or optical gates are my weapons of choice for cartesians ever since; reed switches only for fun projects
(and no, that's ONLY my personal preference, not advice!)

 

[HelloYOU]

I've been lurking around for a while now and need a bit of help finding a speed controller for my go kart project.
I'm looking at getting a forklift lift motor and I'm not sure on what I need in an ESC.

The motor runs on 48 volts, with an 8.8 Kilowatt output.
I know that i'm going to need some hefty batteries to power it but I'm more concerned about finding the right speed controller since I'm new to this.

I've been looking at the Alltrax AXE4834 and Kelly Controller's KDZ48200 but i'm not sure if those are what I will need. (I assume that the motor is brushed but I would have to get more information)

I've read through the stickies and a few other posts about people using forklift motors, but I would like some personal advice if I could get it.

If anyone knows of better (or cheaper) controllers for a newer builder, feel free to suggest

Thanks, Cola_

The AXE4834 conroller has active current limiting and temperature foldback protection. It is more than enough for your needs and would be the correct controller to get for your application. DO NOT get the Kelly controller. You will regret it as they are garbage Chinese made that will fail often with spectacular results.

If you have any other questions then let me know.

 

[Cola_]

Quick update.
Haven't made much progress because we've been quite busy.
We've been running around to pneumatic pump and electric motor shops in our area looking for a spline shaft to fit the darned motor.
As we've expended most all of resources in the pre-made spline shafts, I may have to attempt modeling a shaft and sending the files to get a custom shaft for it. (We have access to a 3D printer, so we can test our files physically before sending them off, don't worry!) I have CAD experience but a spline is a pain in the butt for an amateur! (I'm already working on modeling the frame)

If any of know where I could find a 10 splined shaft with a diameter of ~.67in, it would help us out immensely. (I need to measure the diameter again to be sure)

I also think that speed controller-wise, a better option for us is the Alltrax AXE4844 http://www.electricmotorsport.com/ev-parts/controllers/alltrax-axe4844-24-48v-400a.html
We don't intend to be running it full speed constantly and we probably won't use the full 48v that the motor can put out. (Well, maybe sometimes )

_Cola

Have some images of what we've done so far: