New motor installed.

[MillwrightMike]

Well I changed it to 4 pole and the it did correct my rpm's but I did not see any difference in speed. I'm still averaging 22 mph with a 23 every now and then.

http://i1255.photobucket.com/albums/...918-122200.png

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[MillwrightMike]

Originally Posted by JohnnieB

Wrong. Set to 4-poles and see what happens.

The XCT uses motor RPM as well as Armature Amps and Throttle % to implement the field mapping, so by misinforming it that the motor is spinning at 2300 RPM when the throttle is at 100% and the motor is drawing relatively few Armature Amps, it thinks the situation calls for more torque rather than more RPM and ups the Field amps rather than lowering them. Basically, the XCT is running your motor in the torque mode all the time, so it will never operate at high RPM.

Attached is a 5-second snapshot of a data log (Several columns deleted so it will fit on single page) where my cart had just accelerated up fairly steep hill to a relatively level area and maxed out at 27.5 MPH due to the pack voltage drop while climbing the hill.

Note my Field Amps are 1.1A to 1.2A. What Field Amps does your data log show when you are running at top speed???????

What program are you using to show your monitor? It looks much cleaner than excel.

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[Volt_Ampere]

Looks like you only have 41V at the motor. Field current and motor voltage are limiting your speed - not RPM limit.

[MillwrightMike]

Originally Posted by Volt_Ampere

Looks like you only have 41V at the motor. Field current and motor voltage are limiting your speed - not RPM limit.

So how do I fix that?

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[JohnnieB]

Originally Posted by MillwrightMike

What program are you using to show your monitor? It looks much cleaner than excel.

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Quattro-Pro - I published the selected print area of spreadsheet to a PDF file, then opened the PDF file in Adobe Reader and used the snapshot feature to save to clipboard, then pasted into MS Paint, cropped and saved as a JPG.

It sounds more complicated than it really is and you can do the same thing in Exel. Back when I was a working stiff and had to use M$-Office, I used Excel's Publish to PDF features quite often. Now that I'm retired, I avoid using Microsoft and Intel products as much as possible and practical.


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Your Field Amps are still in the 5A range, which is keeping the RPM down, probably more than the pack voltage being down to 41V is.

By accelerating slowly to top speed, the pack voltage won't drop so much and the cart will reach a slightly higher top speed, but only about 8% at the most. (44.6V - 41V = 3.6 ... 36 / 44.6 = 0.08 = 8%) That would be about 1.8 MPH.

Gotta find out why the Field is only being weakened to 5A.

With 5A of field current, my motor will only spin about 3500RPM while with 1A of field current it will spin at 7000RPM. Our motors are different animals, but the principle is the same.

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What is your measured tire height?
What is the max inflation pressure stamped on the sidewall?

Are you running with Turbo ON?

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If I PM you my email address, will you send me the raw data logs (.CSV file) with the poles set to 8 and with the poles set to 4?

[MillwrightMike]

Originally Posted by JohnnieB

Quattro-Pro - I published the selected print area of spreadsheet to a PDF file, then opened the PDF file in Adobe Reader and used the snapshot feature to save to clipboard, then pasted into MS Paint, cropped and saved as a JPG.

It sounds more complicated than it really is and you can do the same thing in Exel. Back when I was a working stiff and had to use M$-Office, I used Excel's Publish to PDF features quite often. Now that I'm retired, I avoid using Microsoft and Intel products as much as possible and practical.


----------------
Your Field Amps are still in the 5A range, which is keeping the RPM down, probably more than the pack voltage being down to 41V is.

By accelerating slowly to top speed, the pack voltage won't drop so much and the cart will reach a slightly higher top speed, but only about 8% at the most. (44.6V - 41V = 3.6 ... 36 / 44.6 = 0.08 = 8%) That would be about 1.8 MPH.

Gotta find out why the Field is only being weakened to 5A.

With 5A of field current, my motor will only spin about 3500RPM while with 1A of field current it will spin at 7000RPM. Our motors are different animals, but the principle is the same.

-----------
What is your measured tire height?
What is the max inflation pressure stamped on the sidewall?

Are you running with Turbo ON?

-----------
If I PM you my email address, will you send me the raw data logs (.CSV file) with the poles set to 8 and with the poles set to 4?

Sure thing but I'm not home at the moment.

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[JohnnieB]

Originally Posted by MillwrightMike

Sure thing but I'm not home at the moment.

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PM sent - whenever you get a round tuit.

[Jwc1621]

Either of you guys have any more info on this subject? I'm trying to figure out whether to go with a D2 or a B2. I have a 42v TXT w/ Alltrax 48400, 22" tires, 5" lift and a backseat. I am just cruising around the neighborhood on pavement with no hills to mention. I was getting 26mph before I blew up the stock motor and would like to get something similar. Is this going to be possible with a B2?