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mgs781
10-05-2005, 11:49 AM
Hi,

Based on advice given on this forum, I bought a Rocket motor and 8 cell pac. I ran the car 5 time with the slipper gear tightened up all the way but still slipping too much. Last night I was running the car for 15 minutes when it died. The motor was hot, I put my temp gauge against the opening in the chassis and is read 145F. I took the cover off and placed the temp gauge against the can and it read 250F. The motor is junk, but do these things really only last a few runs? I am going to get a 3Racing motor mount and heat sink, Do I need to buy a supply of Rockets. I am not ready to go brushless yet.

MGS

WhoMe
10-05-2005, 12:00 PM
While I have no expierence with the Rocket. You might end up saving if you just save your ducks and get a brushless combo.

WeatherB
10-05-2005, 12:23 PM
I have no experience with the rocket either, but did you break in the motor before running it in your car?

mgs781
10-05-2005, 12:37 PM
What kind of breakin does a $10 motor need? Brushless is cool, but you need to replace all electronics, which is atleast $200.

When the slipper isn't slipping, the car is really fast with the Rocket.

MGS

WhoMe
10-05-2005, 01:27 PM
Your absolutly right. When you get a new motor its usually a good idea to break in the brushes somhow. Some people just run it with no load..(that means not in the car with no weight to move) on very low voltage for five minutes or so. I use the water break in method. In where you hook your motor up to a charger that has a motor run feature; hit the motor at 2 or 3 volts and dip it while running into a cup of water. Let it run in there for 1 or 2 minutes untill the water is alittle cloudy and remove it. Clean it out with motor spray and oil the bearing or bushings. Then your good to go. However that may not be why your motor is going nuclear. Try ajusting your gearing..you may be geared too tall or too low.

P.S. Definatly consider getting a heatsink if you dont already have one and maybe even alittle fan in there. My X-speed got really hot too.

mgs781
10-05-2005, 02:13 PM
So you submurge the motor in water while it is running low speed for a few minutes. Cool, I will give it a try.

When I was a kid, I had several RC cars with brushed motors. I ran the crap out of them and never broke-in a motor. Never cleaned anything and never had a motor fail like this. Have manufactures forgotten how to mark motors?

mOOsE
10-05-2005, 04:56 PM
no, its just the ype of motor you are using combined with how you are using it. Most rc motors need to be broken in but can still run without that process. On my rocket motor, I break mine in at 4 volts using bushing oil, and a very light oil on the comm to get the brushes seated. Your rocket should have lasted longer but the key to any of the 400 motors is cooling. The half8 is a large vehicle to move for any of the current brushed motors on the market. I might also suggest either dropping a cell or two to reduce wight or go with a lipo battery. That will significantly reduce the weight and should allow the motor to cool a bit. Maybe drop your pinion gear one tooth also

mgs781
10-05-2005, 05:04 PM
OK I just ordered two more Rockets and will try to break in these. Does anyone have a step by step procedure? I would like to see what different methods people are using, I guess I already have two methods.

Thank,

flipside7
10-06-2005, 05:29 PM
i noticed, with my xmods, when you are running a good amount of jiuce, things tend to get a little more tricky, when im doing high speed runs, the motor stays cooler than if i drift, or say run a windy course, so i was thinking i should gear it lower. wrong, because it even gets hotter if i reduce the load, or even run the car mid air in my hand.

so its cooling all the way. vent your body, alum heatsink (heatsinks for microprocessors work best, look funny) also you could look for cooling fan for micro proc., and they can be as small as 3/4 inch.

if you fix your slipper, your car will move through the air more when compared to the rpms of the motor.

does that make sense??

to break in motor, -
just enough water to submerge the motor
drop motor in water
hook motor to 2 AAs ?(polarity dont matter)
run until water looks greyish
oil the ends of the motor's shaft and bearings
thats it


i dont think break in is the culprit, but once you solve, motors will last better with better accel and spd.
i run 7.4v lipos- in my xmod, and it getsHOT , it leaves heatsink marks when you accidentally touch it, and the endbell lights up almost bright enogh to read by, and ive had that motor installed for 2 months, no break in. so yours hould last a LOT longer with your voltage

46u
10-08-2005, 08:56 PM
I have the X-speed and I broke it in using commutator drops on two AAA cells under no load. With an alloy motor mount and heat sink on 8 cell pack it gets pretty hot. I have found when checking temperatures on the motor it all depends where on the motor you check. Anyhow my heat sink was about 240 degrees and the case and vent holes where around 180 so to me that shows the heat sink is sucking up the heat. My stock RX unit gets about 145. Now take in consideration I am running on grass that has not been cut in two weeks (which here in the south it grows like a weed) and the concrete driveway about half and half.

All so it is a good idea to let the motor cool down in between runs as well as let the battery pack cool down before charging and after charging. The only reason I got the X speed is for what I can get the Rocket and shipping I can get the X speed cheaper and from a place I was getting other parts. So far I have only made one run do to the weather.