dpatterson26

iTrader: (6)

I am looking for suggestions, Tonight I was running my foam car with a LRP speedo and Novak 13.5 motor. I was on the track checking my end points and never even make a lap. I went to pull the car off of the track and it smelled hot. I started to diagnose and found that the motor had melted 2 of the 3 segments and was about 180F on the can.

I pulled out my 17.5 rubber car with a different speedo/motor and ran it in the first qual and it was about .4 tenths slower. Didnt think nothing of it. Went out for the 2nd qual and made 4 laps. The car just stopped. I went and got the car and it smelled hot. I pulled the motor apart and had the same thing happen.

I bought a brand new novak 17.5 motor and plugged it into the rubber car. The motor would act like it would go 2 steps forward and one step back. Plugged it into my foam car and it would go intermidantly. I put the motor into a totally seperate car and it worked just fine so it eliminated that motor being bad out of the box.

Has anybody ever seen or experienced this? Did I have 2 speedos go bad on the same night by coincedence?

Drillit

can that blue stuff go into 'brushed mode'?

rezenclowd3

iTrader: (17)

Nope. Your best bet is to call LRP and Novak.

mugler

iTrader: (3)

dpatterson26, yes I have experience the same. Have you been free revving your motors, running them with no load??

That will ruin your brushless motor very very quickly and a bad BL motor will very quickly ruin a good BL speedo. Usually free revving will ruin both simultaneousely., that's what happened in my case. What's more you are lucky you have not ruined your 2nd 17.5 motor because a bad BL speedo can also ruin the BL motor as well but less likely.

Send both of the motors and both ESCs in for repairs. If you are lucky one of the motors or ESCs may be still good but it doesn't sound like it.

Finite Racing

iTrader: (1)

how does free reving damage the motors, any technical details. Are the ESCs in question sensored? i would have thought they would have protection for over reving cos i could imagine that the motor would end up going so fast that the sensing circuit cracks up and starts putting current into the motor out of timing. This is an interesting subject which every BL owner will want to know about!!

dpatterson26

iTrader: (6)

I have not free revved either one of them. Neither motor has been out of either car for quite a while. The highest temp either one has ever seen is
185 degrees. The thing that really gets me is the fact that it was two different motors and two different speedos in two different cars.

Steve Weiss

Sometimes we see situations like this and it occurs for a number of reasons:

A.) LRP ESC has no provision for motor thermal shut down. If your motor is running hot, the ESC will not shut down because of it.

B.) The LRP has an electronic timing advance function commonly referred to as the "Power" setting. Running this setting on very high levels such as 5-8, can cause more current draw, heating, and seems to increase the liklihood of some sort of failure especially when coupled with high gearing like most people seem to be accustomed to.

When using these timing settings it is important to use a lower gearing (smaller pinion gear) in conjunction with them due to the higher current and RPM that they induce into the motor.

dpatterson26

iTrader: (6)

Thanks for the input Steve, both Speedos are set on the default settings. I have ran this set up in the rubber car since july. Just bouth my 2nd lrp speedo and installed it two weeks ago.

Drillit

Glad to hear you're gettin' help on this

Gives you time to set up a J-CAR!

dpatterson26

iTrader: (6)

Do you have a speedo I could borrow?