7LikesG-Force Motor Checker
12-03-2014, 07:08 PM
#64
Can you test with the motor connected to the esc or would that damage the esc?
12-04-2014, 09:42 AM
#67
Things I've learned:
The 40 degree mark is 62 degrees of timing on a Tekin 17.5, which means 17 amps when free spinning.
I dialed it back to 45 degrees and only 3 amps free spinning amp draw on the checker. Maybe that's why that thing was such a dog.
My LRP X20 17.5 is actually advanced some 5 degrees past the claimed number on the insert, but it had one of the least variance between the three poles. Even so, it was drawing less than 2 amps at 40 degrees advance showing on the meter.
All timing is not created equal, and older motors have much less timing built into them than new ones. My old Trinity Duo 17.5 was timed at 45 degrees with the endbell cranked to the stop, but spun pretty high and only drew 2 amps on the checker. Setting my Orca RX3 to 45 degrees drew over 6 amps, and it didn't seem happy with it. The Orca RX3 seems to want less than 40 degrees.
On the other end of the spectrum, my Team Powers 17.5 only drew 6 amps with 60 degrees of advance. It seems the wind and core construction of the motor counts for more than I thought.
Modified motors get so much more out of a given amp draw. 2 amps of draw on my 4 turn gives me over 35,000 rpm.
Check your bearings. One of mine was gummed up with track detritus, and you never would have guessed by looking at it.
The 40 degree mark is 62 degrees of timing on a Tekin 17.5, which means 17 amps when free spinning.
I dialed it back to 45 degrees and only 3 amps free spinning amp draw on the checker. Maybe that's why that thing was such a dog.My LRP X20 17.5 is actually advanced some 5 degrees past the claimed number on the insert, but it had one of the least variance between the three poles. Even so, it was drawing less than 2 amps at 40 degrees advance showing on the meter.
All timing is not created equal, and older motors have much less timing built into them than new ones. My old Trinity Duo 17.5 was timed at 45 degrees with the endbell cranked to the stop, but spun pretty high and only drew 2 amps on the checker. Setting my Orca RX3 to 45 degrees drew over 6 amps, and it didn't seem happy with it. The Orca RX3 seems to want less than 40 degrees.
On the other end of the spectrum, my Team Powers 17.5 only drew 6 amps with 60 degrees of advance. It seems the wind and core construction of the motor counts for more than I thought.
Modified motors get so much more out of a given amp draw. 2 amps of draw on my 4 turn gives me over 35,000 rpm.
Check your bearings. One of mine was gummed up with track detritus, and you never would have guessed by looking at it.
12-04-2014, 09:51 AM
#68
Based on what I know of brushless ESC's it should be okay, but I will unsolder my motor a bunch of times for the $200 I would be risking by powering it up. The MOSFETS in ESC's are tough and hard to overdrive, but it's just not worth the risk. The only check I could recommend in good conscience with the car ESC hooked up would be checking the hall effect sensors. Just unsolder the wires to do powered tests, it's not hard or time consuming.
12-04-2014, 07:22 PM
#71
the old competition electrics turbo 30's had a fan to check amp draw. you attached the fan to the drive shaft and powered it up. might try that. as long as the fan is balanced and in a shroud. i watched a guy cut himself pretty badly from a fan blade coming off while he was holding it. its a good idea but can be dangerous if not done right. maybe make a mount to hold the motor and cover the fan. dont know if it would work with this setup.
12-04-2014, 08:14 PM
#72
the old competition electrics turbo 30's had a fan to check amp draw. you attached the fan to the drive shaft and powered it up. might try that. as long as the fan is balanced and in a shroud. i watched a guy cut himself pretty badly from a fan blade coming off while he was holding it. its a good idea but can be dangerous if not done right. maybe make a mount to hold the motor and cover the fan. dont know if it would work with this setup.
I guess I could re-position the motor to face the opposite direction and place a fan on the end. To contain the fan from damaging me or others, I could simply get a tupperware box, cut a round hole on the side and slide the motor shaft through. Place the fan blade on, seal the top, and power it up.
12-04-2014, 08:39 PM
#74
I guess I could re-position the motor to face the opposite direction and place a fan on the end. To contain the fan from damaging me or others, I could simply get a tupperware box, cut a round hole on the side and slide the motor shaft through. Place the fan blade on, seal the top, and power it up.
