EMP Motor

Volt_Ampere · 05-05-2016, 06:56 PM

The field map for my Alltrax is not human readable. I have looked at it with an editor.

Helirich · 05-05-2016, 08:41 PM

So JohnnieB, Are you saying that a DCX controller could have multible field maps for the same motor, but a XCT will only have one? That would make sense because when I asked for a map for my motor, the only question from Alltrax was "what motor". I sappose the rpm imput on a PDS could help also.

mjroman20 · 05-05-2016, 11:35 PM

Johnnie's pretty much spot on with that explanation. One thing to add however to the lower field current. While typically lowering it produces more rpm the result is a loss in torque possibly to the point where the motor is unable to provide traction under loaded conditions so take caution there as well. As for the heating..most motor manufacturers generate a plot that characterises the motor. The plot usually shows the maximum limitations not always the peak efficency. Operating current ratios below this curve results in poor commutation between brushes and armatuer stack causing excessive arcing resulting in excellerated brush wear and overheating.

JohnnieB · 05-06-2016, 07:48 AM

Quote:

Originally Posted by Volt_Ampere

The field map for my Alltrax is not human readable. I have looked at it with an editor.

Thanks for that info.

Quote:

Originally Posted by Helirich

So JohnnieB, Are you saying that a DCX controller could have multible field maps for the same motor, but a XCT will only have one? That would make sense because when I asked for a map for my motor, the only question from Alltrax was "what motor". I sappose the rpm imput on a PDS could help also.

Yes, the DCX could have multiple field maps for the same motor, and perhaps there should be, but that doesn't mean multiple DCX field maps actually exist for the same motor. From what I can tell, only one field map exists for each make/model motor and there is some overlap with the same field map being used for more than one make/model motor.

The XCT could also have multiple field maps for the same motor, but it might be smart enough to adjust to differing applications and one may suffice.

Quote:

Originally Posted by mjroman20

Johnnie's pretty much spot on with that explanation. One thing to add however to the lower field current. While typically lowering it produces more rpm the result is a loss in torque possibly to the point where the motor is unable to provide traction under loaded conditions so take caution there as well. As for the heating..most motor manufacturers generate a plot that characterises the motor. The plot usually shows the maximum limitations not always the peak efficency. Operating current ratios below this curve results in poor commutation between brushes and armatuer stack causing excessive arcing resulting in excellerated brush wear and overheating.

A Field Weakening Limitations Map appears to plot the motor manufacturer's lowest acceptable efficiency points, so peak efficiency would be somewhere above the minimum values plotted. If you run the motor at values below the plotted minimums, severe overheating can occur.

The field map I'm running does weaken the field considerably below the motor manufacturer's recommendations and my motor does run hot, so it won't last as long as it would if it ran cooler, but I accept that fact as an unavoidable consequence for obtaining a higher RPM from the motor.

skipsmith521 · 05-09-2016, 09:45 PM

EMP motor was shipped today...should have it by end of week.

Can't wait to get everything installed.

Should get the field maps in a day or so...

Sent from my Nexus 6 using Tapatalk

skipsmith521 · 05-16-2016, 10:26 PM

Quick update...

Got the EMP motor today and had someone install the motor.

I should be getting the cart back tomorrow... Will let everyone know how things go with the EMP motor.

Sent from my Nexus 6 using Tapatalk

skipsmith521 · 05-17-2016, 09:04 PM

After almost 4 weeks without my cart, finally got it back today.

The 3 month old DCX controller had fried and Alltrax covered it under warranty with a new XCT400 controller.

So, since I was going to put a new controller on, i thought let's upgrade the old motor on my DCS cart since it was all apart.

Contacted EMP and got an aftermarket motor built for my cart. After all the details I provided EMP about my cart and requesting 23 mph... they targeted 24mph for me.

Used GPS today and the cart ran at 23-24mph. I guess EMP knows what they are doing.

The 23-24mph is with the turbo turned off.

Sent from my Nexus 6 using Tapatalk

05-05-2016, 06:56 PM	#11
Volt_Ampere Gone Wild Join Date: May 2012 Location: Rio Verde, Az Posts: 7,183	Re: EMP Motor The field map for my Alltrax is not human readable. I have looked at it with an editor.

05-05-2016, 08:41 PM	#12
Helirich Gone Wild Join Date: Sep 2015 Posts: 572	Re: EMP Motor So JohnnieB, Are you saying that a DCX controller could have multible field maps for the same motor, but a XCT will only have one? That would make sense because when I asked for a map for my motor, the only question from Alltrax was "what motor". I sappose the rpm imput on a PDS could help also.
Helirich Gone Wild Join Date: Sep 2015 Posts: 572

05-05-2016, 11:35 PM	#13
mjroman20 Gone Wild Join Date: Apr 2015 Location: Pennsylvania Posts: 378	Re: EMP Motor Johnnie's pretty much spot on with that explanation. One thing to add however to the lower field current. While typically lowering it produces more rpm the result is a loss in torque possibly to the point where the motor is unable to provide traction under loaded conditions so take caution there as well. As for the heating..most motor manufacturers generate a plot that characterises the motor. The plot usually shows the maximum limitations not always the peak efficency. Operating current ratios below this curve results in poor commutation between brushes and armatuer stack causing excessive arcing resulting in excellerated brush wear and overheating.

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05-09-2016, 09:45 PM	#15
skipsmith521 Gone Wild Join Date: Dec 2015 Location: Texas Posts: 526	EMP motor was shipped today...should have it by end of week. Can't wait to get everything installed. Should get the field maps in a day or so... Sent from my Nexus 6 using Tapatalk

05-16-2016, 10:26 PM	#16
skipsmith521 Gone Wild Join Date: Dec 2015 Location: Texas Posts: 526	Quick update... Got the EMP motor today and had someone install the motor. I should be getting the cart back tomorrow... Will let everyone know how things go with the EMP motor. Sent from my Nexus 6 using Tapatalk

05-17-2016, 09:04 PM	#17
skipsmith521 Gone Wild Join Date: Dec 2015 Location: Texas Posts: 526	After almost 4 weeks without my cart, finally got it back today. The 3 month old DCX controller had fried and Alltrax covered it under warranty with a new XCT400 controller. So, since I was going to put a new controller on, i thought let's upgrade the old motor on my DCS cart since it was all apart. Contacted EMP and got an aftermarket motor built for my cart. After all the details I provided EMP about my cart and requesting 23 mph... they targeted 24mph for me. Used GPS today and the cart ran at 23-24mph. I guess EMP knows what they are doing. The 23-24mph is with the turbo turned off. Sent from my Nexus 6 using Tapatalk