Predator Eater

[Functional Artist]

I picked up a (supposedly) slightly used ME-0709 electric motor

It's for a powerful, off-road capable kart (I told ya 'all Challenge Accepted

It's rated @ 8hp (or 19hp peak)
...so, it should be able to "kick" most Predator's azz(es)

It seems to weight about the same as a 6.5 Predator
...but, has waaaaaaay more continuous horse power
...& the peak hp is almost (3) times higher

Product Description
The ME0709 (ME1908) is a Brush-type Permanent Magnet DC motor. Light weight, high efficiency design. Designed for 24-72 VDC battery operated equipment. Capable of 300 amps peak and 125 amps continuous. Totally open, fan cooled motor. Similar in performance to the Perm-motor 132 and the Lemco or Lynch LEM-200 motors.

Specifications
Power: 8 cont-- 19 pk hp
Voltage: 72 Volt rated
Speed: 3700 rpm @ 72v unloaded
Size: 8" OD, 6.5" long (w/o shaft)
Shaft: 7/8"x 1-3/4", 3/16" key
Weight: 36 lbs.

Ima thinkin', Ima gonna power it with (3) 24V 50AH modules from a 2014 Chevy Volt
...& now, I'm lookin' for recommendations on a 72V speed controller, to control it

It came with an old 48V Altraxx controller
...but, I wanna run 'er @ 72V
...so, Ima probably lookin' for a Kelly controller

Ima thinkin' the KDZ 72401 (~$300.00) should do the trick
https://www.kellycontroller.com/shop/kdz/

It's a bit "over sized/rated" (400A peak for a 300A peak motor)
...so, it should never have ta work hard (it's better to work smarter than, harder)

 

[EpsilonZero]

That Kelly should work fine as would an Alltrax SR if you wanted to stay with Alltrax. The motor has quite a low RPM rating and is brushed, but very good torque. What do you want your top speed to be? What frame are you using?

 

[Karts of Kaos]

what do you think it was originally on?

 

[Functional Artist]

That Kelly should work fine as would an Alltrax SR if you wanted to stay with Alltrax. The motor has quite a low RPM rating and is brushed, but very good torque. What do you want your top speed to be? What frame are you using?

Well, a comparable Alltrax controller (SR-72400) is listed at $635.00
...whereas the Kelly controller (KDZ 72401) is $299.00 (with regen)

Plus. I'll need a contactor 72V 400A ($69.00)
...so, $750+ all together, going with Alltrax stuff
...or, under $400.00 using Kelly components
Um...where's my calcumlator?
* The KDZ 72550 Kelly controller, on my electric motorcycle, is very powerful & has worked great for a few years now
...so, I'll stick with 'em

Also, please explain, in excruciating detail, why you say "The motor has quite a low RPM rating and is brushed, but very good torque."
(many of us want to know more about these motors & you seem ta know a bit about them)

Target top speed:
Well, ta "beat up on" or "eat" them Predator's, I'd say we need ta do at least 30 ta 40 MPH (on a semi-smooth surface)
...& for off road use, we'll need 'er ta be geared kinda low (maybe something like 7:1, depending on wheel size)
...but, I still wanna have enough torque ta "walk away" from them "off the line" or "coming outta turns"

Frame:
IDK, I haven't put much thought into it's design, just yet

IMO, ya gotta figure out your performance goals, first
...next, choose the "main" components (motor, controller & batt pack) ta (hopefully) meet those goals
...then, ya can get ta designing a frame, that'll hold everything & can (again hopefully) handle the "stresses" that will be imposed upon it

 

[EpsilonZero]

Also, please explain, in excruciating detail, why you say "The motor has quite a low RPM rating and is brushed, but very good torque."
(many of us want to know more about these motors & you seem ta know a bit about them)

The motor is good for 3300+/-250RPM. That means your top speed is going to be limited compared to an equivalently geared motor that can reach a higher RPM. My ME1719 is rated for 5500RPM and it can hit that RPM the way the kart is configured, for instance. That is up to a 2450RPM difference between the motors. At a 7:1 ratio with 12" tires that missing RPM is worth 12.54MPH of top speed. However, 7:1 is way too low anyway... if you were running 12" tires and got 3550RPM@72v, your top speed would only be 18.16MPH. This isn't a tiny MY1020 style motor. The motor has a good torque rating (.20Nm/Amp) so you can "spread out" the power with proper gearing; I run 3.67:1 with my ME1719 rated at .143Nm/Amp to give you an idea. You could theoretically do 34.67MPH with the same gearing as my kart (which is good for 55@5500RPM as it sits).

Being brushed, you're going to have to do maintenance perhaps every 1500 hours and you'll need a reversing contactor or a controller that has it integrated. I don't like brushed motors for my purposes and wouldn't personally spend too much on them.

Target top speed:
Well, ta "beat up on" or "eat" them Predator's, I'd say we need ta do at least 30 ta 40 MPH (on a semi-smooth surface)
...& for off road use, we'll need 'er ta be geared kinda low (maybe something like 7:1, depending on wheel size)

Pretty much any Motenergy you'd put on a kart is going to "beat up" on a Predator if you don't undervolt it. It is just more complicated in some ways and costs more. I doubt you will even need to change the gearing for off-road; it never mattered with my kart. You have full torque from 0 RPM.

 

[Functional Artist]

what do you think it was originally on?

The guy I got it from said that it "was used for less than 50 miles in an electric motorcycle conversion project"

He didn't come right out & say it but, the way he talked, I don't think they got 'er goin'
...or at least, not going "too good"
...& the twist throttle that came with it, was just a cheap Chinese scooter throttle, that was wired to a cheesy DIY circuit board (IDK why?)
...but, I don't think that worked either, 'cause the (1) wire that came off of it was cut, real short

 

[EpsilonZero]

Frame:
IDK, I haven't put much thought into it's design, just yet

How about one that puts at least two of the Volt batteries up front ? Maybe between your legs. I have one of my Headway modules up front on mine, but that's all I can fit. I think the Volt batteries look kind of cool anyway... maybe incorporate that into the design. The weight distribution would improve steering too.

 

[TheGlamourousOne]

Like it but my targeted speed is 0-100