If my controller is limiting my speed would the stock GE 7hp make any difference? Also what about the RFF motor, would that also be hampered by the controller?
Dave this is really interesting. Refer to the spread sheet I sent you on tire diameter and plug in 23 inch tire.
Look in the 10.35 row. then read the 30 mph column. About 4540 RPM then look up the same RPM in the 12.44 Row. Gregs real world results track perfectly.
The control limits RPM to somewhere south of 4500 RPM
Greg Try The MM again I believe we GOT IT
Rodney
Yes the controller is limiting RPM no matter what motor.
Now that you have the power up, time to fool the controller with a MM or hi Speed Magnet.
I will Email you a spread sheet on Tire diameter vs Gear Ratio = motor RPM.
If any one else is interested Email me. rodneyadiehl@aol.com
Are we having fun?:confused2:
Rodney
Having fun hereā¦
Just got back from pinewood derby. My E4 is charged. Time to see if I can burn out my T4.:eek:
You have kids that young?
Grandkidsā¦
Believe it or not. This is my first real test of MM1/2. I was always playing with the MM1-22.
E4 7hp runs 34mph with no other changes.
Iāll probably us the MM20% to keep from blowing motor.
iāll bet you guys all a bear the mm wont help . the motor is a shunt motor . the motors natural rpmās is a relationship between the armature magnetics and the field magnetics . on a shunted motor if you lower the current on the field side the motor well spin faster . on most controllers once we raise the speed limiters we then lower #7 down to reduce the current in the field winding and produce more rpmās .
those of you that have lowered #7 , have you wondered why reducing current is making it faster ? this is the reason .
we do give up some torque in the high end but the motor well spin faster.
greg , I believe (though I havenāt tested) that is why when u add more current( # 4) your cart is slowing down . if you could lower #7 , the ratio between #4 and #7 would change and you would get more speed .
if you cant then you either need a motor designed for more rpm (rff) or you have to change your controller.
you can give the other ideas a try but I suspect you wont see much if any improvement.
Try speed limiter at 150 or less, stock 5 or 7 can stand 5000 RPM. If that doesnāt work back off max armature amps or adjust minimum field.
There is no #7 on a T3. Maybe this is why it only lasted a year. Greg, your up.
http://www.fsip.biz/Documents/GL3Tech.pdf
pages 30 thru 33
If this turns out to be the case Then the ball lands in Daveās Court to cripple field current:juggle to allow 5000 RPM
MM will still be needed to get past speed limiter.
Rodney
[quote=kinghappy;29252]iāll bet you guys all a bear the mm wont help . the motor is a shunt motor . the motors natural rpmās is a relationship between the armature magnetics and the field magnetics . on a shunted motor if you lower the current on the field side the motor well spin faster . on most controllers once we raise the speed limiters we then lower #7 down to reduce the current in the field winding and produce more rpmās .
those of you that have lowered #7 , have you wondered why reducing current is making it faster ? this is the reason .
we do give up some torque in the high end but the motor well spin faster.
greg , I believe (though I havenāt tested) that is why when u add more current( # 4) your cart is slowing down . if you could lower #7 , the ratio between #4 and #7 would change and you would get more speed .
if you cant then you either need a motor designed for more rpm (rff) or you have to change your controller.
you can give the other ideas a try but I suspect you wont see much if any improvement.[/quote]
he can change the tire diameter and gear ratio to get around the speed limiter so in this case the mm is not needed . he says #7 shows a value of 4 , can it be changed ?
I believe what Rodney is getting at. May be a hard RPM limit.
He has already gone thru the full range of those parameters. Max RPM at present is a bit south of 4500 rpm.
It was very interesting - when he programmed in different gear box ratios the performance followed the spread sheet exactly. The speed followed a fixed RPM depending on the ratio he entered into the controller.
Email me and I will send you a spread sheet.
Rodney
Rodney this is now above my pay grade, but looking at the info you sent re the T3 maybe you can explain what they are talking about in this section I found.
Section 2.1.4.a Field Weakening
This function allows the adjustment of the field weakening level in order to set the top speed of the motor. The function is enabled when the armature current is less than the value set by Function 24 and the accelerator input voltage is greater than 2.9 volts. It is important to note that this function is used to optimize motor and control performance, and this setting will be determined by GE and OEM engineers at the time of vehicle development. This setting must not be changed by field personnel without the permission of the OEM.
I will retest the MM tomorrow and report back, you also mentioned setting the speed limiter to 150 or less but I donāt see that function. Is that position#7?
Greg
Iām sorry this was a response to Dave. At this point in time leave your setting at 255.
Can you get the MM to try with your present settings?
If it works were good to go. if it does nothing KH has it nailed and Dave will come up with a solution to reduce field current.
This is an interesting project we thank all of you for hanging with us as its a GREAT educational experience.
There is a ton of unpublished knowledge out there that is Proprietary Secret Squirrel ****. The Professionals keep it to them selves and charge an arm and a leg for servicing and modifying our carts.
This is an open forum and the knowledge we gain and share benefit fellow owners
Rodney
Rodney math seems correct.
My suggestion of getting tach data is moot. Motor rpms can be calculated from speedometer readings, gears, and controller settings.
If always limited to 4500rpm, what else can it be?
In my mind the tach is the main read. We will find out when greg goes back with the MM. If it doesnāt change any thing then KM has it nailed and maybe you can sell some of those heavy duty wire wounds.
Will test the MM tomorrow and report my results. Would Marlon have any ideaās regarding adjusting position #7 for 4(cts) to a lower or higher setting?
Dave would you have any suggestion with adjusting the MM regard my test? Not sure if I should play with the adjustment one way or the other either on the low or high end?
Thanks Greg
i havenāt been able to contact Marlon for 2 months. Anybody know anything?
1 Like
[quote=spider445;29262]Will test the MM tomorrow and report my results. Would Marlon have any ideaās regarding adjusting position #7 for 4(cts) to a lower or higher setting?
Dave would you have any suggestion with adjusting the MM regard my test? Not sure if I should play with the adjustment one way or the other either on the low or high end?
Thanks Greg[/quote]
Last I heard it read 1/2 at 22mph. As long as it switches to 1/2, good to go.
If anyone thought a different model would be better, or you needed more test equipment, Iāll be glad to help.
My field weakening project is in early testing. No good news yet. Hope to test further tomorrow.
[quote=OLD HOUSEBOATER;29258]He has already gone thru the full range of those parameters. Max RPM at present is a bit south of 4500 rpm.
It was very interesting - when he programmed in different gear box ratios the performance followed the spread sheet exactly. The speed followed a fixed RPM depending on the ratio he entered into the controller.
Email me and I will send you a spread sheet.
Rodney[/quote]
If you think it will add clarity, be glad to make him a plug-in tach for testing.