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Old 07-12-2004, 09:13 PM   #61
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Originally posted by Palmaris Europe
Yes. But in a corner they only lock to one wheel. A solid axle works great on smaller twisty tracks. If a one-way axle locked completely in the corners under power then why do they not work too good on twisty tracks with a nitro car??
hmmm.. funny, It works best on twisty tracks for me.
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Old 07-12-2004, 09:14 PM   #62
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Here's my theory of belts and oneways. There is no slippage in the one way, it is the tires slipping and the belts actually stretching. One ways are esseentially solid axles with two independant one way bearings. Those belts are like rubber bands and their constantly storing and unloading power back to the wheels when grip becomes available. Since there's two belts for the front drive, there's more stretch, and that means a good supply of traction for the front wheels to the one ways.

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Originally posted by RcRacerX That's why you see all 1/8 scale buggies are shaft driven, the belt wouldn't handle all that power!!! [/B]
I don't agree, what about 1/8th onroad cars? They're all belt! Has anyone mass produced 1/8th onroad shaft car? Probably not because the shaft would most likely break. Granted they use different style motors, but I would imagine that the 1/8th on road cars drive train is under alot more stress than a 1/8th off road buggy, due to the greater traction of the surface.
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Last edited by tomkelley; 07-12-2004 at 09:20 PM.
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Old 07-12-2004, 09:14 PM   #63
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Quote:
Originally posted by moby
I just felt more comfortable with a belt car simply because 1/8th scale on road nitro cars are running on belt. And that to me just means that shaft cars have some problem handling high speed. True or not? You tell me.
True. In the beginning many companies tried connecting the drivetrain to the engine by a tiny shaft on the old 1:8th flat-pan cars. It didnt work then either with their highly under power veco .19 engines hence all 1:8th on-road racing cars being belt driven.

Its the same thing with the current 200mm cars. Shaft drive is proven to be faster but it cant withstand the constant abuse and wears out too fast with the current range of high performance engines. To me this is the wrong approach simply because this is a hobby and not just a sport for the rich. Shaft drive should have stayed in the pull-start cars with low power engines like it has always been.
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Old 07-12-2004, 09:18 PM   #64
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Quote:
Originally posted by Pyramid
hmmm.. funny, It works best on twisty tracks for me.
It has worked for me too on tight tracks but only when the weather was really hotter and traction higher.
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Old 07-12-2004, 09:27 PM   #65
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Quote:
Originally posted by RcRacerX
Here is the most detailed diffrences that I can give you.
The advantages of a shaft driven car is that it is more closely to a direct drive then a belt. A shaft can't stretch our or skip. You can still use a center and front one way with both belt and shaft. The biggest disadvantage with the shaft is torque steer. You don't notice it that much in stock and spec 19T mod, but the few times I have ran a 10 single mod motor in my TC3 if I pulled to hard on the throttle during initial acceleration the car would wonder slightly between the torque steer and me trying to compensate for it.
As far as the belts go, the only advantage I have seen is that they tend to be a little more balanced, and this is from how the motor is installed in the car. With a belt set up, typicly the "Torque wieght" will lean between the front and rear of the car. With a drive the torque wieght will lean side to side, and that is what causes tourqe steer. As far as maintence is conserned, belts usually have more things that can go wrong. See, with a belt you have to make sure it is at the proper tension. Too lose the belt will skip and slip, and the action is like doing a burny.....the tires are moving so fast that your speedometer is reading at 40 mph but your doing maybe 3. so thearetically, the belt is spinning at 20 mph, but the pulleys at the axles arent moving. If you set the belt too tight, then it's causing too much drag and slowing your car down, plus making your eletcronics work harder then it needs to and causing them to get too hot. As with a shaft, they typicly "float" in thier out drives, much in the same manner as the CVD's on the inside part of your car where it meets the out drive.
The only 4wd cars I have are T-maxx, E-maxx, and a TC3. I prefure the drive shaft because of it's reliabilaty. Iv'e seen a few belts on X-rays and Losi's during a race, as well as belts being too lose or too tight and that's what turned me on to the shaft driven car. That's why you see all 1/8 scale buggies are shaft driven, the belt wouldn't handle all that power!!! I may try the XXX4 as soon I get some funds up, but if Associated comes out with thier 1/10 4wd buggy before then I'll get that instead since I'm sure it will be shaft driven. I hope I shown some light on your issues there.
There is a huge difference between nitro and electric.

As for 1:8th buggies - it has nothing to do with power. An on-road car produces more power than an off-road buggy (which requires more torque). The reason shaft is preferred on the buggies is to do with the terrain. With the constant rough ground and jumps the belts would skip and possibly throw off the pulleys too easily. This doesnt happen with shaft drive.
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Old 07-12-2004, 09:36 PM   #66
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yeah i totally agree. Thats why racing 1/8th onroad at a bumpy track could cause belts to break or skip. Regardless, both classes are totally different animals and should be treated as such.
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Old 07-12-2004, 09:50 PM   #67
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Quote:
Originally posted by tomkelley
I don't agree, what about 1/8th onroad cars? They're all belt! Has anyone mass produced 1/8th onroad shaft car? Probably not because the shaft would most likely break. Granted they use different style motors, but I would imagine that the 1/8th on road cars drive train is under alot more stress than a 1/8th off road buggy, due to the greater traction of the surface.
Not entirely correct. On road may have more surface taction. However, imagine running your on-road with twice the diameter tire...imagine throwing it 7ft up in the air and 20ft across the track with the engine spinning at around 30,000 rpm to maintain the attitude.... now imagine that that 3.x kg mass falling slap bang on hard clay...the shock loading will most probably destroy the average on-road transmission. A 1/8 GP buggy will do that lap after lap without bending a single shaft!!!
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Old 07-12-2004, 09:52 PM   #68
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Quote:
Originally posted by Palmaris Europe
Anyway to keep on topic. Belt drive is better

Can anyone tell me the price of belts these days? Havent bought a spare belt for a 200mm car yet. Both my Yokomo's and my Serpent are on original belts. Cant say the same about the gears on the shaft drive cars around here.
I think a better comparison would be belt vs shaft........crown wheel vs pulley!
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Old 07-12-2004, 10:17 PM   #69
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Quote:
Originally posted by moby
Having tried the FW-05R for half a year, i have decided to switch back to belt car.

But my experience with the shaft car was a pleasant one. the maintanance was easy as the drive train was much more straight forward. However i felt that the crown gears worn abit too fast and unpredictably with a powerful engine. Also having too powerful an engine resulted in tire spin as the power was transmitted to the wheels too directly. However this aslo meant greater response from the shaft car. Good or bad? you decide, as it means shaft car can achieve the same result as a belt car with a more powerful engine.

I just felt more comfortable with a belt car simply because 1/8th scale on road nitro cars are running on belt. And that to me just means that shaft cars have some problem handling high speed. True or not? You tell me.

You can get harden gears which are much better than the standard cast ones. After a couple of liters they have shown little sign of wear.
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Old 07-12-2004, 10:22 PM   #70
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1/5 scale use belt and shaft so I don't see why 1/8 on road couldn't use shaft.
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Old 07-12-2004, 10:34 PM   #71
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Quote:
Originally posted by dtm
Not entirely correct. On road may have more surface taction. However, imagine running your on-road with twice the diameter tire...imagine throwing it 7ft up in the air and 20ft across the track with the engine spinning at around 30,000 rpm to maintain the attitude.... now imagine that that 3.x kg mass falling slap bang on hard clay...the shock loading will most probably destroy the average on-road transmission. A 1/8 GP buggy will do that lap after lap without bending a single shaft!!!
Yes your points are valid, I do not disagree with you. I said, they're totally different animals. My 2nd post already noted the belts problem on bumpy surface. Plus you're arguing with me two totally different aspects of drivetrain stress. I'm talking about power transfering effectively to the wheels with traction available. Can a buggy on dirt accellerate from a stand still to 60mph in 2 seconds? Also 30K rpm in the air is a virtually no load situation on the drivetrain. I'm just curious, even though the tires have more rotating mass which adjusts attitude horizontally, Doesn't the buggy also attitude slightly laterally in the air as a result of the drive train spinning?

No point in arguing here, just clarifying ;-) and enjoying the discussion.
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Old 07-12-2004, 10:52 PM   #72
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There have been some comments about torque steer on the shaft cars. Is this caused by the engine crank or the lay shaft do you think. They rotate in opposite directions and depending on the comparitive mass and rotational speeds...............................

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Old 07-12-2004, 10:55 PM   #73
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rjl

Have you had any troubles with your shaft drive being that the motor is on the opposite side.

If any car was going to be affected by torque yours would with very powerfull motors and the location of the motor.
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Old 07-13-2004, 09:30 AM   #74
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Quote:
Originally posted by rjl
There have been some comments about torque steer on the shaft cars. Is this caused by the engine crank or the lay shaft do you think. They rotate in opposite directions and depending on the comparitive mass and rotational speeds...............................

The crank and lay shaft rotation thing doesn't work 'cos there is only one entity generating the torque - the crank.

Torque steer in shaft cars is caused by the longtidudinal orientation of the engine. That is; the torque reaction and the subsequent weight transfer when you hit the throttle, is lateral.
The fact that shaft cars are directly driven would make it more noticeable than it might otherwise be, I'd expect.

A belt car, having the engine mounted laterally, will experience the same torque loads, but longtidudinally. Additionally, the belts are better able to absorb and release the torque loads from a sudden throttle application and it's therefore less noticeable.

Anyway, that's why you have two primary controls on the transmitter - so you can steer as you apply vastly excessive power.
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Old 07-13-2004, 10:02 AM   #75
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Quote:
Originally posted by tomkelley
Yes your points are valid, I do not disagree with you. I said, they're totally different animals. My 2nd post already noted the belts problem on bumpy surface. Plus you're arguing with me two totally different aspects of drivetrain stress. I'm talking about power transfering effectively to the wheels with traction available. Can a buggy on dirt accellerate from a stand still to 60mph in 2 seconds? Also 30K rpm in the air is a virtually no load situation on the drivetrain. I'm just curious, even though the tires have more rotating mass which adjusts attitude horizontally, Doesn't the buggy also attitude slightly laterally in the air as a result of the drive train spinning?

No point in arguing here, just clarifying ;-) and enjoying the discussion.
Yes, when the buggy is in the air there is no load on the engine at all. The hardest load is when the car hits the ground while the engine is spinning 30k rpm. The easyest way I can think of simulating the stresses is to set the cruise on your rc car at speed to maintane it's attitude then try to stop the tires with a clamp on some other device. It is true that on road has several times more traction then off road, but there is more stress on an off road buggy landing a jump then an on road car accelerating out of a corner or off the line. I know that electric is diffrent then gas, that's why power is instantaneous with an electric motor, and an engine has to spool up it's power before it can go, but that's for a diffrent forum. Yet the physics of energy are the same for all.
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