lee82gx

iTrader: (1)

hehe..sometimes the discussions get heavy...
there is always something to discuss and something to debate.

but at the end it's all about driving and having fun...looking forward to more runs with the TC3 and brushless..

Horatio

Does anyone know the all-up weight of the rotating parts down the middle of the car ie, spur, adapter, bearings, spacers, shaft, and drive pinions etc? And to what extent these rotating parts counter the torque produced from the armature of the motor?

Also I imagine the RPM of the armature is part of the equation somewhere along the line - the mass is probably multiplied by it's RPM to calculate it's force. Whilst I would guess the mass of the centre drive train is probably more than the armature, as there is a considerable (but variable) reduction ratio between the motor and the centre shaft, the armature will always be spinning very much faster than the drive train.

What you guys are saying is very interesting. I have my own ideas about what could be going on, but I'm not entirely convinced that my theory is correct or most sound based on 'proper' physics.

I know some may feel this subject is a little 'anally retentive' but it would be great if the 'boffins' here could figure it all out and finally agree on the best 'theoretical' layout

As regards enjoyment, no-one enjoys racing minature motorsport more than me and if they did, I'd shake their hand Regardless of which side their motor was on and EVEN if they drove a belt driven car

Boomer

If we're talking about mass, rotation and the force they are creating acting on the chassis and batteries - I think that we may need to see how much different it acts with a Mod (heavier arms, thus more force) and a stock (much lighter arms. . .)

I've rarely run mod. I don't enjoy it too much (except in my L2 where it's a blast! ) so I only know about stock. I've never found too much torque steer or chassis roll with stock - perhaps because of the lighter armature.

What kind of motor did you do your testing with?

lee82gx

iTrader: (1)

well if u want to take it a little further,the rpm(when it's constant) of the motor does not produce a torque on the chassis.when the speed is constant,the whole car is considered as a SINGLE rigid body.
only a change/acceleration of the rotation produces torque.
this is countered(opposite direction) by
1.the moment of inertia of the drivetrain(normally constant)
moment of inertia is about
2.drag of the drivetrain(which might be constant,but might not also)

so the torque(not motor output torque)but inertial torque(ie angular accel x motor's moment) - moment(drivetrain) - drag = car roll.

car roll would then be product of it's own moment of inertia that is a function of it's weight distribution.

Horatio

Sorry speediphatt, my previous message crossed with yours! Basically your little experiment with you missus's kitchen scales demonstrated in real time what happens when you boot the throttle from a standing start. Trying to calculate it would have probably taken many times longer!

What this basically means is that we can conclude that AE got the battery/motor/electronics confiuration right!!

So why are all these guys who are running chassis with the motor on the 'wrong' side feeling a reduction in torque steer etc? Is it such a subtle effect that people are simply imagining performance gains that aren't there? Or are these chassis' performing so well in other ways that this is improving times etc rather than it being anything to do with the torque steer issue?

Don't flame me - I'm just thinking aloud

lee82gx

iTrader: (1)

to concur that AE thinks they got it right,u can check with the NTC3.
weight is also placed on the left side.

i dont know too much about the those cars which are on the opposite side of things...
it's very difficult to even know how much torque steer is actually produced or if it's produced at all.
furthermore...u'd be staunchly defending ur car no matter which side the battery's are on,so what can we say about that?

Horatio

Ahhh, thanks for this. I knew my physics was a bit rusty

So does this mean that the RPM difference between the Drive Train and the Armature doesn't actually have an effect on the chassis roll - ONLY the angular acceleration x the armature's polar moment of inertia - the drive train - drag?

Horatio

Fair enough.

Though from my point of view, I drive more than one type of car anyway and I wouldn't defend a chassis just because it's one I happen to use. Regarding this subject, I'm only interested in the logic behind changing from a AE chassis to an aftermarket one which changes everything around without really explaining or justifying why. I'd have to know why first before parting with lots of £££ ($$$). As it happens, I'm thinking of getting decent chassis for my TC3. Look like the motor will be staying on the right afterall

Horatio

Good point, one which had been overlooked. As it happens, most people I know who had complained about the TC3 Torque Steer problem raced modifieds on fast, open tarmac circuits. I suppose it figures that as they accelerate far harder, there is a much greater difference between highest and lowest speeds around any given track. With stock it's all about keeping up momentum, speeds are lower but more consistent - thus torque steer is less noticeable.

Speedie

When I did my little crude test I was using a monster stock. What I didnt think would happen was that the weight measurement was back exactly to where it started no more than a second after hitting the throttle. As far as weight being different. It shouldnt be not if the car is balanced. The only thing that should be different is the more dense mass of the batteries compared to the more spread out mass of the electronics. I dont have a mod to test but it makes considerably more torque so Id assume that the initial torque to the chassis would increase also.

R/C Anonymous

iTrader: (1)

i like the batteries on the right side cuz theres usually more right hand corners then left....what ya guys think about that one?

protc3

iTrader: (13)

yes but the left hand corners are usually more technical

R/C Anonymous

iTrader: (1)

meh ...busted....the debate is over already

protc3

iTrader: (13)

if you aski me,all you need to eliminate tourqe steer is a rigid chassis.try taking the upper deck of of a warpspeed and tell me it doesnt tourqe steer.when i did the bmi chassis i didnt try to reinvent the wheel.i just wanted to make a highly adjustable car for an excelent price.you can buy 2 of my chassis for the price of all of these other companies and it performs as good or better than any of them.my kit is extremely stiff and has been proven under alot of track conditions.i have heard alot of bad stuff about some of these other ones.i have run modified and stock in my car and it has absolutely no tourqe steer.

Brian McGreevy

iTrader: (10)

The Warpspeed car does not have torque steer. Rob Love, Chris Doseck and I can all attest to it, as we have all run killer modifieds in our cars on high-traction carpet with foam tires.

I thought we were done knocking each others cars?