Alltrax vs Curtis NEED HELP

General Discussion about electric vehicles.
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futurerel   1 mW

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Joined: Dec 11 2017 12:35pm

Alltrax vs Curtis NEED HELP

Post by futurerel » Jun 09 2018 12:50am

OK... I'm building an E-kart to go at least 60mph. I bought an Alltrax SR72450 controller, sw202 selenoid, 5k throttle today. The problem is I will have to mount everything after receiving it which will cost more money in materials. Then I came across a Curtis controller already mounted on a heatsink plate, neatly done with copper bars and with all components needed on eBay for under $600 (link listed below). I'm wondering which controller would be better for my setup and is it worth keeping the Alltrax and mounting everything up or return the Alltrax controller (which costed me more) and buy the Curtis controller? Will I get the same power and efficiency out of the Curtis as I would out of the Alltrax? THANK YOU FOR YOUR RESPONSE AND HELP!!!!!

https://www.ebay.com/itm/CURTIS-Control ... SwT-FZCD7c

Kart Weight with everything besides the motor: 120 pounds
Rear tire: Mojo 7.1/11.0-6
Gear Ratio: 2
Motor Sprocket: 18t
Axle Sprocket: 36t

Battery Setup: 2x 40V 18.4AH 736WH LITHIUM LIFEPO4 96 A123 26650

Motor: 72v Motenergy ME-1003

futurerel   1 mW

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Re: Alltrax vs Curtis NEED HELP

Post by futurerel » Jun 09 2018 1:04pm

anyone?

futurerel   1 mW

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Re: Alltrax vs Curtis NEED HELP

Post by futurerel » Jun 10 2018 8:18am

i guess this board is dying out.... no one comments anymore =-(

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eee291   10 kW

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Re: Alltrax vs Curtis NEED HELP

Post by eee291 » Jun 10 2018 10:00am

This board is very much alive and doing fine.

No One is replying because your question is about DC Controllers. Which in my opinion are DEAD.
If you want to discuss DC Motor Controllers go to the Golf cart or DIY Electric Car forums. :lol:


Brushless and AC motors have a lot of advantages over pure DC motors.

In all the time I have spent on this forum I haven't seen anyone even talk about DC Controllers or Motors.

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Chalo   100 GW

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Re: Alltrax vs Curtis NEED HELP

Post by Chalo » Jun 10 2018 10:23am

If both controllers are rated to carry the voltage you're using, then whichever one can supply more current could potentially give you better performance.

The Curtis controllers I've used in the past featured automatic plug braking on closed throttle. That wasn't too big a problem when I used a freewheeled drive chain, but with direct drive, it was incredibly annoying. I don't know whether either of your prospective controllers has automatic braking, but I wouldn't recommend it.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

futurerel   1 mW

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Posts: 11
Joined: Dec 11 2017 12:35pm

Re: Alltrax vs Curtis NEED HELP

Post by futurerel » Jun 11 2018 6:34am

Chalo wrote:
Jun 10 2018 10:23am
If both controllers are rated to carry the voltage you're using, then whichever one can supply more current could potentially give you better performance.

The Curtis controllers I've used in the past featured automatic plug braking on closed throttle. That wasn't too big a problem when I used a freewheeled drive chain, but with direct drive, it was incredibly annoying. I don't know whether either of your prospective controllers has automatic braking, but I wouldn't recommend it.
thank you

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methods   10 GW

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Re: Alltrax vs Curtis NEED HELP

Post by methods » Jun 11 2018 2:23pm

Power = Volts * Amps
Power = Volts squared / resistance
Power = Current squared * resistance

You have fixed voltage
You have fixed resistance

Any controller which will tolerate your maximum voltage will work
The power rating of the controller in relation to the duty cycle you will use it is critical

Peak Power
Burst Power
Continuous Power

Where peak does nothing but first-impress people and overheat motors.
Where Burst Power is what you are really after... maybe the 30 second or 2 minute rating
Continuous Power rating almost always lands at your motor - so likely either controller can overheat it in continuous use

If you are pinching pennies... get ready to go work a few shifts at Starbucks.

DC sucks because it has all sorts of... sigh... issues.
Like inefficiency

You can no doubt hit 60mph
Can you sustain it?

Is there going to be enough average speed to cool your motor or are you going to need another $50 for a fan, ducting, and controls?

Do you have a good ratio between your voltage, motor KV, gearing, and tires?
DC controllers do not run "advance" like you see on brushless... they can simply PWM a DC current to make it less than FULL BLAST
(in most cases - certainly with the Alltrax)

How is your braking?
I hear you calling out some real specifics... like a given tire... and I hear Value being engineered first (budget)
What are you using for brakes on this 120lb + 150lb rider 60mph skin peeling machine?

Is it a machine that can roll and do you have a roll bar?

For track use or on the street?

Making a good kart starts with experimentation. It really does not matter what you start with because where you end will be totally different than where you start. You will spend more money.

-methods
Increasing battery voltage and controller current limit will result in a non linear experience

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