Help Controlling brushless

[Sumilidon]

Hello all,

Another meeting, another failure to finish as I've crashed and broken something. So I am needing some advice on a steady approach to improving my driving.

Generally, the fault is in me - my driving experience is minimal and the car is very quick. This leads to a failure to break in time or generally as I'm still trying to set the car up - a loss of control.

I also have quite an indelicate touch (forward 100%, turn 100%, no middle ground).

Currently I am running:

Xray T2 009
13.5T EZRun Brushless motor
35A EZRun Brushless ESC
5000mah, 35C Lipos
Code 2.4ghz transmitter (with the little LCD screen)
45 Shore foam tyres all round

I also have the D/R on the steering limited to 70% which I find helps in the corners

I am getting this VRC simulator adapter so I can try and get used to more delicate use of the controls, and I think swapping to my steer wheel would be beneficial as I am having issues with braking with the stick transmitter.

Therefore, some answers on th following would be appreciated:


If I set the ESC with the throttle D/R at 100%, then turn the D/R down, will this reduce the top speed?
If this does limit the throttle, do I need to take any considerations regarding to the demand put upon the motor / ESC?
The back end of my car loses traction on acceleration - I have the ride height at 4mm across the car and the suspension is at stock level - any suggestions to retain traction at the rear? (this is primarily when breaking or accelerating whilst turning)


Any help much appreciated

[colmo]

Start here:

http://www.petitrc.com/reglages/xray/SetupSheetsXRayT2009.htm

Touring cars really do need proper setting up, on a setup station, so ask someone at the club to do that for you. If you have a setup station, I suggest getting someone to show you exactly how to use it! The Xray manual is considered a superb reference for setup in general.

I'm pretty sure ride height should be a minimum 5mm.

For radio setup, set your D/R to leave you enough lock to make the turns. To calm down the steering more, set some negative exponential (set on the radio) on it.

On the ESC, turn all the punch and timing settings to minimum if the car is too quick, and you can learn about the midrange of the throttle band with negative exponential on that too.

[dale]

The best things to do while learning are

1. Make the car slow. Ideally your club will have some sort of 'stock' class aimed at beginners such as 17.5 turn motors. If not, then turning the throttle end-point (EPA) down will reduce your top speed and make it easier to drive. The motor/ESC should be fine doing this; I did it to my girlfriends car when she first went to brushless and found it a bit fast. You'll still have lots of acceleration though, which is ideally why you want a slower motor.

2. Get lots and lots of practice, ideally outside of race meetings so you don't have to contend with other cars. You'll also get a lot more runs done on a practice day.

Good luck and stick with it! We were all beginners once, complete with all the crashes and erratic driving. 12 months from now you'll look back and be amazed how much you've improved.

[Sumilidon]

Thanks guys.

My 13.5T motor does not have an option to reduce the timing, however I also have an 8.5T and a 5.5T with a couple of 60A ESCs (EZRun) to go with them (damn you ebay auctions). Both of these can have their timing adjusted.

Should I be swapping over to one of these so I can reduce the timing therefore?

[sosidge]

No, because the 8.5 and 5.5 are both much faster, even with the timing turned down.

As Dale has mentioned, turning down EPA on your transmitter is one solution. The simplest one is to buy a slower motor.

I wouldn't rate a 13.5 EZRun as exceptionally fast, but it is fast enough to need throttle control. 17.5 isn't that much slower to be honest, but it is the slowest EZrun motor apart from their crawler motors. Tamiya put a slow silver-can brushed motor in their kits for a reason.

Practice is very important. If you are very inexperienced, just driving around a car park with a few cones laid out (or manhole covers as corner apexes) is a good start. Remember, they say slow is fast for a reason.

The build of the car is also very important. Don't worry too much about the team driver setups, concentrate on building the car right to kit settings (and that means making sure everything moves freely and is set evenly on both sides). Tyres are 90% of the performance, if you are on the wrong ones, or they are worn out, you will never get anywhere.

Once you have the car built so it runs in a straight line, and turns evenly left and right, you are well on your way to being a competitive racer. It takes time, but it is worth it, because the satisfaction of a good race (and that doesn't necessarily mean winning) is a buzz I still enjoy after 20 years.

[Sumilidon]

Would reducing the D/R also work?

I ask because I'm also going to try my steer wheel more but it's fairly basic and has no EPA function, only D/R

[sosidge]

You don't usually have d/r on the throttle side. That is the steering setting.

[frst]

when i used to race (a long time ago) i used a softer rear tyre (30r 40F?)

this made the car more stable under accelleration, also removing the rear anti roll bar if you have one fitted

and laying down the shocks kind of slows the cars responses to an "indelicate touch"

i've been trawling this forum, looking to get back into rc after a long break, and really am looking forward/dreading these sort of situations again! lol

[Sumilidon]

With the rear tyres should I be looking at a 26mm with 0 offset or a 30mm with a 2 mm offset?

[dale]

With the rear tyres should I be looking at a 26mm with 0 offset or a 30mm with a 2 mm offset?

Very few people run foams anymore. You'd probably be better off with a set of Sorex 28JBs (assuming you're racing on carpet), they'll be the only tyres you'll need and will last forever. It will also mean you can run a more 'normal' setup from one of the team driver setup sheets.

[Sumilidon]

They mostly run foams at Barley Mow. To my knowledge there is nothing preventing the use of rubbers - so long as they don't have spikes.

If using these rubber tyres, would the rear need to be a softer compound or would 28 be suitable all round?

[dale]

They mostly run foams at Barley Mow. To my knowledge there is nothing preventing the use of rubbers - so long as they don't have spikes.

If using these rubber tyres, would the rear need to be a softer compound or would 28 be suitable all round?

Same compound all round with rubbers.

With foams you'd normally have either a wider rear tyre or a softer rear tyre as you tend to get lots of steering. Plus run a much stiffer front spring.

[frst]

...and make sure your front diff (if fitted) is tighter than the back one

[Sumilidon]

Well first race since changes and a big difference!

I didnt get the new wheels in time so put some old rubber wheels on the front and the foam at the back. I also had the throttle set to 65%. The result was very little oversteer (some understeer but mot much) and i eventually finished a race. In fact i finished all the races.

Even when the front diff went too loose and i had to use the ansmamm are2, the lack over overster and overall improved control was major improvement.

Cracked a c hub on the mi2 however in a collision with something, i jave a spare.

Next step, put the 35 foams on the back, 45 foams on the front and gradually start raising the throttle limit.

Ta for help