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Old 10-15-2009, 02:17 AM   #1
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Default Belt or shaft & gear diff or Ball diff

In My opinion after test both type

Belt or shaft

Shaft
Good point
1- low Maintenance
2- high top speed
3- Not complex
4- heavy duty
5- free run without any Resistance

Weak point
1- non

Belt
Good point
1- non
week point
1- high maintenance
2- lower top speed
3- complex
4- Resistance its like (drag brake 10%)

gear diff or Ball diff

gear diff
Good point
1- Can handle high torque
2- Very heavy duty
3- Low maintenance
4- Handles easily with all brushless motor

Week point
1-Slightly heavier

Ball diff
Good point
1- little lighter

week point
1- Can't handle high torque
2- Loosening (slip)
3- high maintenance
4- Sometimes crying with some brushless motor
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Old 10-15-2009, 02:40 AM   #2
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This topic has been covered just once or twice already...

http://www.rctech.net/forum/search.php?searchid=6199991

You miss the main reason why there are no competitive shaft cars - torque steer.
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Old 10-15-2009, 03:27 AM   #3
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You miss the main reason why there are no competitive shaft cars - torque steer.
How come shaft drive offroad (1/10th 1/8th) cars aren't affected?
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Old 10-15-2009, 04:41 AM   #4
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you are wrong about the shaft giving more top speed than belts. It's the opposite. Ask Hara.

If you belts are tensioned too much, it will cause a loss of top speed and a bit of " drag brake", otherwise it won't.

as for the gear vs ball diff, I agree in general, ( the s400 diff was a great idea, same for the durango) but some racers like to have the possibility of giving a little slip to their diff or like to adjust it without opening it. Fot offroad gear diffs will become the norm though I guess.
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Old 10-15-2009, 05:01 AM   #5
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Originally Posted by dontfeelcold View Post
How come shaft drive offroad (1/10th 1/8th) cars aren't affected?
Bumps and jumps, comparatively low grip and soft suspension mask it.
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Old 10-15-2009, 05:27 AM   #6
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Quote:
Originally Posted by sosidge View Post
Bumps and jumps, comparatively low grip and soft suspension mask it.
Funny enough my off-roader goes in a dead straight line when used on hard surfaces.

There must be more to the equation.
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Old 10-15-2009, 06:39 AM   #7
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Quote:
Originally Posted by Metla View Post
Funny enough my off-roader goes in a dead straight line when used on hard surfaces.

There must be more to the equation.
Still has soft suspension and comparatively low grip, doesn't it? Unless you have put touring springs and touring slicks on it too?

The torque effect is obscured because the soft springs soak up much of the energy before it reaches the tyres. The tyres have less grip and a softer carcass so cause less of a reaction to inputs. The large, heavy wheels on a buggy also create a large gyroscopic effect of their own, encouraging the car to run straight.

You can notice the torque effect in touring cars. Just a little kick to the side on power, just a hint of understeer turning in one direction. And no, I haven't noticed the effect in a 4wd shaft buggy.
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Old 10-15-2009, 07:59 AM   #8
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ALERT-[Possible Rhetorical Question]
The the last year a shaft driven gear diff TC won a National Championship?
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Old 10-15-2009, 08:09 AM   #9
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Quote:
Originally Posted by imjonah View Post
ALERT-[Possible Rhetorical Question]
The the last year a shaft driven gear diff TC won a National Championship?
Are you asking when was the last time or are you making a statement?
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Old 09-04-2010, 08:30 PM   #10
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Quote:
Originally Posted by sosidge View Post
You miss the main reason why there are no competitive shaft cars - torque steer.
You know, the thing that bothers me about this supposed torque steer is that before there were shaft driven cars, they were all belt driven.

So wouldn't one think that after "all the testing and racing that all these pros would do before releasing a car" that they would notice this "torque steer" off the bat and stick to belt driven cars? I.e. - not even bother releasing the shaft driven cars???

And also, BEFORE there were ever ball diff cars, every single one of them was "gear diff". My Tamiya Grasshopper had a gear diff. I wouldn't have thought of "paying extra" for them now.

The reason ball diffs came around was that gear diffs would spin the inside tires in a turn = the same way in a real car. This is why they outfit sports cars with a "limited slip differential". The ball diffs act the same exact way. So I really don't understand why people are going back to gear diffs AND "spools" at the front of the car...
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Old 09-04-2010, 08:34 PM   #11
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I think the opposite. Belts have more torque steer and tweek faster.
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Old 09-05-2010, 01:58 AM   #12
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Quote:
Originally Posted by M3Armand View Post
You know, the thing that bothers me about this supposed torque steer is that before there were shaft driven cars, they were all belt driven.

So wouldn't one think that after "all the testing and racing that all these pros would do before releasing a car" that they would notice this "torque steer" off the bat and stick to belt driven cars? I.e. - not even bother releasing the shaft driven cars???

And also, BEFORE there were ever ball diff cars, every single one of them was "gear diff". My Tamiya Grasshopper had a gear diff. I wouldn't have thought of "paying extra" for them now.

The reason ball diffs came around was that gear diffs would spin the inside tires in a turn = the same way in a real car. This is why they outfit sports cars with a "limited slip differential". The ball diffs act the same exact way. So I really don't understand why people are going back to gear diffs AND "spools" at the front of the car...
You have to put the developments into historical context.

Back when the ball diff was created, electric cars either had no diff at all, or a completely unsealed and truly "open" gear diff. The cars also has a lot less power. The lightweight, easily adjustable ball diff was an improvement.

Now, we have sealed gear diffs filled with silicone fluid to create a tunable limited slip effect, and ample power in almost every class.

Advantage gear diff again.

Shaft drives (in touring) again came from an era when there was a lot less power. Shaft drive is more efficient, especially compared to the small pulley belt drive systems popular at the time. But a shaft drive car never won the worlds. Put any reasonable amount of power in there and torque steer will happen. This makes the car unpredictable and inconsistent between left and right turns.

Advantage belt drive again.

Spools are silly, but they make the cars run well when we don't yet have a diff that can have a very strong limited slip action at the front. Perhaps the new generation of gear diffs with 100k-plus oils in them will consign the spool to the history books as well.
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Old 09-05-2010, 07:31 AM   #13
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Belt or shaft

Shaft
Good point
1- low Maintenance
2- high top speed
3- Not complex
4- heavy duty
5- free run without any Resistance

Weak point
1- non

WRONG ! i remembered cars like the yokomo SD SSG and HPI Pro4 would always break the front bevel gear when you hit anything , becuase the bevel gears have no "give".
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Old 09-05-2010, 08:27 AM   #14
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Ball tranny and belt diff
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Old 09-07-2010, 01:32 AM   #15
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Quote:
Originally Posted by Metla View Post
Funny enough my off-roader goes in a dead straight line when used on hard surfaces.
There must be more to the equation.
My ON-ROADER shaftie goes in a dead straight line , it dont think torque steer is much of an issue with Brushless Motors.

Ive taken some big hits in the shafty without breaking bevel gears.
HPI Pro4 were known for some brittle/weak plastic parts, why else would there be a recommendation to 'boil' gears before use in the PRO4 forum !!!!
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