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Doozie870
04-18-2007, 09:56 PM
Im looking at the 2-1 reduction belt drive graupner has,(scrapped the twin 700 gearbox) does anyone think this belt could stand a reversal of the pulleys for a 2-1 overdrive? still planning on running twins BTW. :confused:

SJFE
04-18-2007, 10:01 PM
Depends on the with of the belt IMO. I had 4 diffrent belt drive nitro cars. The wider the belts where the longer they lasted. If you use a tentioner to keep every thing tight..and the belts are beefy..I see no problem

Doozie870
04-18-2007, 10:11 PM
Sounds good, the twin motor gearboxes became very awkward trying to line up with the prop shaft, a lot of weight got real high in a hurry lol. I think this will give more flexabilty in motor placement.

SJFE
04-18-2007, 10:25 PM
The drivleline should be real smooth and forgiving in chop also. If i remember correctly Mugen had the best belts. It may be an option for you. You will have to size them up.

Fluid
04-19-2007, 08:14 AM
Belt drives were tried in race boats over a decade ago and were found to be very problematic. One friend set-up one of the first BL motors on a belt drive and went through belts quickly - belt heat was one of the problems in the enclosed mono he raced.

Running a drive in a boat is far different than in a car. The sharp vibrations propogated every time a prop blade hits the water stress the belt more compared to the relatively smooth forces in a car. If the drive is somehow "smoother" in a boat it could mean belt slippage - precursor to belt breakage.

I'm not certain why you think that belt drives would be easier to set up than gear drives. Modern belts may be better than in the past, but my buddy tossed his belt drive after a year and went back to gears. Try it if you want - but we know that gears work.

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Doozie870
04-19-2007, 09:44 AM
The main reason for concidering it was, not having to reverse the motors (pinions forward) to get ccw rotation back, I may retime them to run CW, thanks for the input.

SJFE
04-19-2007, 12:04 PM
Mr Fluid...Do you know of any one who has tryed a ball diff or slipper to relieve some of the stress put on the grears?

Fluid
04-19-2007, 07:26 PM
No one who was successful doing it. Adding parts to an already complex system just begs for additional problems.......KISS. ;)


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ReddyWatts
04-19-2007, 07:42 PM
Dang SJ, I think you just got blessed. J/K

brooks93
04-19-2007, 10:55 PM
Mr Fluid...Do you know of any one who has tryed a ball diff or slipper to relieve some of the stress put on the grears?

by doing that you would save the gears but, you are also going to lose power to the prop since water puts more load on a motor then tires do on a car. Plus the prop is unloading and loading up again depending on the water conditions. This would cause the slipper to melt because its going to be slipping alot. A ball diff might work better then a slipper but, then you woudl have the same problem with lose of power to the prop and the loading and unloading.

I have ran gears on everything for 6cells to 32 cells. With the right mesh you shouldn't stripping gears. I don't run them anymore because it is one less thing I need to worry about failing in my race boats.

I have also tried a belt drive with 1/2" wide belts. I actually cause more drag then just plan gears. I also noticed that the belt was only good for about 3 or 4 runs do to them stretching.

Doozie870
04-20-2007, 12:53 AM
Got the picture, so belts are out, I like low maintenance, it would be so much easier to double the power, if the shaft was protruding the same on each side of the motor, maybe the next time someone special orders some motors,they could add this feature to the specs. :o