SpeedySST

iTrader: (6)

Thanks guys! I appreciate the help especially considering the outdoor season is upon us!

Touring Jr.

iTrader: (6)

Hey Guys, Just raced @ our local club yesterday and still working out some bugs. Car pulls right under hard acceleration and I cant really find any problems in set up or chassis tweak. Could the steering servo be the problem? I will admit I am running a cheap hk metal gear unit. Is the torque of the brushless motor creating torque steer?

charlie_b

iTrader: (1)

Sounds like a droop or maybe even a spring tension issue. Check both and see whether they are even from left to right.

cosmo1974

iTrader: (3)

But why is there more lateral weight transfer
This is the thing I am having trouble visualising

As mentioned before:
If D2 gets less (and nothing else is changed), Wheel Rate gets larger:
---- Wheel rate = spring rate * (D1/D2)² * sin (a)
This seems to indicate the opposite, so there are other "forces" at work here which I need some educating on

For example, is the Roll Centre getting LOWER, and the resultant force (increased leverage) outweighing the INCREASED Wheel Rate (I just dont know)

komkit

iTrader: (6)

You don’t really get torque steered on a belt driven cars. First thing you want to check is a set screw on your pulley and spur adapter. Makes sure they are tight.

Are you running diff front and rear or rear diff and spool up front? Check the diff makes it doesn’t slip under heavy acceleration. If you are running one-way makes sure it’s still a “One-Way” not two-way.

Normally when one of those above happened to me the car generally pulled to the left though. I have had a front belt flipped on me one time and it pulled to the left. Not sure what would caused it to pull to the right.

Touring Jr.

iTrader: (6)

Thanks Komkit,

I am running front spool and rear diff. Rear seams to be smooth and tight I think? When I hold the tires and push It with my thumb I cant turn it. But if a loose rear diff causes a pull( or push per say ) to the left I guess that doesnt apply here anyway?

tomracing

wheel rate has nothing to do with weight transfer.
wheel rate is like a spring rate but transfered to the wheel center.
so if it tells you the force per wheel travel.

the total weight transfer is calculated as
weight*lateral acceleration*cg height / track width

so reducing the track width increases weight transfer

Outtacontrol58

iTrader: (92)

Huge Question, I just got the TC, my Lipo battery does not fit the chassis because its hitting the purple aluminum piece on the other side of the motor mount (sorry i forgot the name). do i just shave it to where it wont fit or will this mess the chassis up because it connects to the upper deck. THanks and i cannot wait to run it! I am running the 40C SMC lipo

SpidarX

iTrader: (3)

Most people just shave off about 2mm from the underside of the mount.

cherry2blost

iTrader: (1)

+1 just sand it down by hand don't use a dremel too messy

cosmo1974

iTrader: (3)

Thanks.
Do you have a reference to the formulae, and how it is derived

Touring Jr.

iTrader: (6)

Charlie, When you say spring tension you are talking about ride height correct?

Thanks for your feedback.TJ

Outtacontrol58

iTrader: (92)

Thanks for the reply! I will get to sanding

tomracing

okay small physics summary:
basically it is the reaction in the outside tire to the lateral acceleration on the mass at height.
not taking into account gravity only lateral acceleration we take the sum of the moments about the inside tire central contact point.
sumM_insidewheel=0=mass*lat_a*cg_height - Fouterwheel*trackwidth
so
Fdue to lateral G= mass*lat_a*cg_height/trackwidth
to get it into mass units do F/gravity

to get the total weight on the outside wheel you would start like this:
sumM_insidewheel=0=mass*lat_a*cg_height - Fouterwheel*trackwidth + mass*gravity*0.5wheelbase
and bring out the Fouterwheel again.

and finding the inside wheelload would be sumF_vertical=0=Foutside+Finside-mass*gravity
Finside=mass*gravity-Foutside

hope that makes it a bit clearer

to get these kind of things easier may i also advise either of these books
-competition car suspension by allan staniforth (simplified and easy to read)
-race car vehicle dynamics by milliken&milliken (more complicated but the best book though not in SI-units)
-fundamentals of vehicle dynamics by thomas gillespie (complete basics)

smk

iTrader: (2)

Hi,

Just got my cyclone TC world edition and I want to prepare it for a race on saturday. Could you please let me know what should I take into consideration when building the KIT? Should I do something different , is there any tip you can give me when building the car?

Also , I will use a 13.5 motor , and I want to gear it to 4 - 4,5 , could you please let me know what Spur/pinion will fit? Also will the 48p spur/pinion will fit , and if yes , what combination of spur/pinion will I have to have to gear it at 4 - 4,5.

Thanks