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  #61  
Old 23-11-2011
rcaddict rcaddict is offline
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It should'nt lean at all when it jumps, the center shafts rotate in opposite directions.
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  #62  
Old 23-11-2011
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It should'nt lean at all when it jumps, the center shafts rotate in opposite directions.
No, they don't.

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  #63  
Old 23-11-2011
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both your top yellow arrow, and your left blue arrow need to be flipped around.
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  #64  
Old 23-11-2011
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Originally Posted by rcaddict View Post
both your top yellow arrow, and your left blue arrow need to be flipped around.
How can you flip the top yellow around around, its fixed to the same shaft as the lower yellow arrow so MUST spin in the same direction.

That drawing is 100% correct, try looking at it again and realise that the top gear is connected to the front centre shaft only, and the bottom gear is connected to the rear centre shaft only.

Heres a diagram similar to above but showing where the gaps are and will also show which gears are the driven ones.

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  #65  
Old 23-11-2011
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both your top yellow arrow, and your left blue arrow need to be flipped around.
They can only be flipped around if all the arrows were flipped, thus resulting in the shafts rotating in the same direction, as before.

The gear near the spur drives the rear driveshaft, and the gear opposite to the spur side drives the front shaft. And both the "yellow" gears always rotate in the same direction.
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  #66  
Old 23-11-2011
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I wasn't talking about the torque making the buggy lean. I was thinking about the weight of the motor making the left side heavy. But then, I looked again and it's no more unbalanced than a 511X.
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  #67  
Old 23-11-2011
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Originally Posted by sim View Post
I wasn't talking about the torque making the buggy lean. I was thinking about the weight of the motor making the left side heavy. But then, I looked again and it's no more unbalanced than a 511X.
Motor on one side, servo, ESC and receiver on the other. Presuming 50g, 80g and 20g respectively, that's maybe 40-50g heavier on the motor (190-200g) side. A lightweight motor would even it out a bit.
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  #68  
Old 24-11-2011
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It does look a bit unbalanced on their demo unit, but they were using a club transponder on the motor side. A personal transponder can fit right on top of the servo. The 511 has components in pretty much the same places, so it shouldn't be a worry.
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  #69  
Old 24-11-2011
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So if the shafts don't run in opposite directions, what's the use of all the extra gears in the centre? It's not a diff, it's not something magical spell or device from Harry Potter to make things fly very controlled and unrealistic while in mid-air, and so far the only things we do know about it is that it adds weight to the car and it's rotational mass, plus the gears make the drivetrain less efficient. Way to go
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  #70  
Old 24-11-2011
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Look this picture long enough and you might notice that there is no extra gears. Look where the gaps are.
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  #71  
Old 27-11-2011
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Look this picture long enough and you might notice that there is no extra gears. Look where the gaps are.
I don't see what you mean. They could have used one bevel gear at the spur and one bevel gear at one single centre shaft if both shafts are to run in the same direction. Splitting the shaft into two pieces and adding two gears makes no sense to me. The reason why they're on the car, the offset of the shafts, could easily have been removed in the design.

It would be more useful carrying around your spares inside the car so you have them with you when needed than using them in the drivetrain and having them wear down while you carry them around in your car
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  #72  
Old 28-11-2011
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We already discussed the reason for not going with the single shaft one page earlier. The four gears do look like a lot of extra friction and complexity but it is really just one extra gear contact point compared to the Awesomatix tourer. It's certainly more maintenance than previous designs, but if it works on the track, it will have a following. I'm not so convinced by the sideways stick pack design though. That does seem a step backwards as competitors are getting slimmer and slimmer with great results.
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  #73  
Old 28-11-2011
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I think with 4 gears gears don't wear so quickly. If this gearbox works properly maybe next TRF car has same kind of layout and gearbox with saddelpack lipos.
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  #74  
Old 28-11-2011
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To reduce roll in high grip situations, there's always the option of using a shorty lipo across the back, much as you can in a X6.
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  #75  
Old 28-11-2011
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Quote:
Originally Posted by sim View Post
We already discussed the reason for not going with the single shaft one page earlier. The four gears do look like a lot of extra friction and complexity but it is really just one extra gear contact point compared to the Awesomatix tourer. It's certainly more maintenance than previous designs, but if it works on the track, it will have a following. I'm not so convinced by the sideways stick pack design though. That does seem a step backwards as competitors are getting slimmer and slimmer with great results.
I doubt that with the right gears (right size and shape, good mesh, right alloy steel, machined perhaps instead of cast) you'd need two additional ones. There are many cars that don't need 4 gears for a system like this, right? It's not the 5 grams that bother me, just that in my eyes they did something that wasn't necessary.

And perhaps it's also a bit of disappointment that it's not a 'new' and 'innovative' feature Tamiya designed, but just two gears added to the car...
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  #76  
Old 28-11-2011
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Originally Posted by Origineelreclamebord View Post

And perhaps it's also a bit of disappointment that it's not a 'new' and 'innovative' feature Tamiya designed, but just two gears added to the car...
To my knowledge, there are not too many 10th scale off road race cars with this layout and shaft drive...
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  #77  
Old 29-11-2011
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Quote:
Originally Posted by Origineelreclamebord View Post
I doubt that with the right gears (right size and shape, good mesh, right alloy steel, machined perhaps instead of cast) you'd need two additional ones. There are many cars that don't need 4 gears for a system like this, right? It's not the 5 grams that bother me, just that in my eyes they did something that wasn't necessary.

And perhaps it's also a bit of disappointment that it's not a 'new' and 'innovative' feature Tamiya designed, but just two gears added to the car...
Yes, in an ideal world with no budget constraints, using expensive bearings packed full of balls, with machine cut gearboxes and gears ground from hardened steel, all to extreme tolerances, you could support that layshaft on just one side and run the centre shaft straight through. That is true.

This car has less gears than the DF-03 and although there were many complaints about that car, few if any were related to extra friction or gearbox maintenance. It's just that the early pictures on this one got people all excited about counter rotating shafts, centre diffs and flux capacitors, so when it turns out that they were just gears, feelings were hurt and hearts were broken.
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  #78  
Old 29-11-2011
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Interesting solution, rather like one of the possible ways of building the Awesomatix touring car, and evocative of the classic Tamiya 4wd chassis. Puts the motor in the ideal orientation for getting the power down, but also hangs it out off the side of the chassis
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  #79  
Old 30-11-2011
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Quote:
Originally Posted by sim View Post
Yes, in an ideal world with no budget constraints, using expensive bearings packed full of balls, with machine cut gearboxes and gears ground from hardened steel, all to extreme tolerances, you could support that layshaft on just one side and run the centre shaft straight through. That is true.

This car has less gears than the DF-03 and although there were many complaints about that car, few if any were related to extra friction or gearbox maintenance. It's just that the early pictures on this one got people all excited about counter rotating shafts, centre diffs and flux capacitors, so when it turns out that they were just gears, feelings were hurt and hearts were broken.
True, maybe a center diff is overkill on a 1/10 scale electric car, but there is no doubt in my mind that the leaning TRF502 of Pisa would have benefited from counter rotating shafts. Man that thing tilts to one side everytime you hit the throttle in mid air. I've seen it with me own two eyes.
Everybody knows flux capacitors are too big to fit in an R/C car. They havent been able to shrink that technology down to 1/10 size yet. LOL!
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  #80  
Old 30-11-2011
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Quote:
Originally Posted by rcaddict View Post
True, maybe a center diff is overkill on a 1/10 scale electric car, but there is no doubt in my mind that the leaning TRF502 of Pisa would have benefited from counter rotating shafts. Man that thing tilts to one side everytime you hit the throttle in mid air. I've seen it with me own two eyes.
Everybody knows flux capacitors are too big to fit in an R/C car. They havent been able to shrink that technology down to 1/10 size yet. LOL!
The 502 and other shaft cars lean to one side because of the longitudinal motor, not because of the centre driveshafts.

The moment of inertia of the driveshafts is insignificant; they are relatively lightweight; slender; have their acceleration cushioned by a slipper clutch and rotate 4x slower than rotor in the motor.

How many times does the DB-02 design need to be explained before people understand why it is the way it is???
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