Brushed writeup for Paul

Paul has asked me to do a little write up for care/ maintenance of your G2/ 4 cell car after he had his faith restored in brushed at the weekend... so here goes!

Running in a G2
The idea of running in a motor is to ensure that the designed tolerances are achieved before bringing the motor up to race speed. In particular the brushes.
What you are aiming for to achieve a fast g2 motor is well seated brushes.
If the bushes have a smoother finish inside then this will give a low friction surface for the comm. to rotate around.
On a new G2 motor the brushes are only in contact with the comm. over a small area at each corner of the brush. They are made like this so that each brush can find its optimal seating position. Better electrical connection is achieved when the brushes are worn down to the extent that the entire brush is in contact with the comm. The brushes on the G2 motors are very hard wearing. Pretty much every time anyone has complained about having a slow g2 I have had a look at the brushes and they are not run in. I have had occasions where a motor has had hours of running and the brushes have experienced little or no signs of wear.
To overcome this I run my motors in on the bench at 3 volts with wd40 on the comm. until the brushes are seated correctly. This can sometimes take up to an hour so not a job for the track. It is also wise to use a cooling fan to keep the motor cool as heat will have a negative effect on the strength of the magnets.

Keep it clean
I have seen many cases of motors clogged with carpet and dirt. This will definitely slow your motor down and make it get hot. After meetings and sometimes during, it is wise to blast your motor out with brake cleaner and then compressed air. Once this is done, oil the bushes and it is ready to be run again.
As the brushes wear, the comm. will become coated in the carbon that has been worn off the brush. This creates a high friction surface. So in between runs once the motor has cooled, get a cotton bud coated in brake cleaner, rotate the motor clockwise and press the cotton bud onto the comm. Repeat this until a fresh cotton bud comes out of the motor clean.
Once the motor is clean, just before your run, spray a small amount of wd40 onto the comm. and rotate the back wheels by hand. Do not rev the motor. Put the car on the track and for the first 2 laps or so, do not use more than half throttle as any more than half throttle will cause the motor to arc and burn off the wd40. When you are ready to start your run, you will notice a significant increase in power as a low friction film will have been created between the brushes and the comm.


Cell maintenance
Maintaining your cells properly is of paramount importance to having a quick car and a long lasting pack of cells.
After a meeting I always go through this routine:
• Discharge cells at a high discharge rate (20A in my case) to 1v per cell – the high discharge current will maintain the punch in the cells by lowering the internal resistance thus allowing a higher current flow.
• Equalise cells on smart tray (or similar) to 0.9v per cell. – This ensures each cell is at the same voltage before charging so that one cell doesn’t peak before the rest.
• Charge up to 1500MAh for storage – cells lose voltage over time and if the voltage drops below 0.9v, irreversible damage can be caused to the cells. So it is best to store the cells with some charge in.
At the next meeting:
• Discharge cells at a high discharge rate to 1v per cell.
• Equalise cells on smart tray (or similar) to 0.9v per cell.
• Charge cells at at least 1C.( If you are charging a 4600Mah pack, 1C will be 4.6A). With my Intellect/Ener-g/Powerboy 4600 cells, I charge them at 5.5A for qualifying and 6A for finals.
The higher the charge current , the more punch but the less run time you will get.

Once you have raced repeat the steps from the start again. I have been using the same cells for a year and a half now and they are still going strong.

This is just my take on how to make your brushed car faster. Some people may do things slightly different, but I hope it helps some people to have more fun racing on a budget rather than forking out for a brushless system.


I hope this has helped dispel some of the myths surrounding the brushed class to enable people to enjoy some close competitive without having to fork out for a brushless system.

This is just my take on things so feel free to contribute

Karl

A good write up but still an awful lot of hassle compared to a brushless lipo system where there is no messing about with charging or running in and brushed I am afraid to say isn't a budget class considering the extra need for balancers or dynos etc for the care of the batteries and motors.

Its not racers who follow these steps who I have a problem with it's the racers who start taking g2s apart and fiddling then as there is no real way of quickly and efficiently scrutineering the motors.
Some may say it doesn't happen but it really does and that's not a level playing field as the slow speeds of g2 racing put such a high premium on power and speed. This is true to an even larger extent on the bigger tracks like ardent.

All that said if people did just follow this guide and not take it too far then g2 racing would be ok.
This is a damn good guide for anyone who wants to race g2.

P.s anyone know how to make a g2 last more than a meeting on 7.4v 2s lipo as us f1 guys are struggling alot and it's expensive

Brilliant write up Karl and i can see by the vote page what do you run that the G2 has the highest vote with 44% so that is speaking volumes in itsself thanks again for the write up mate

Yeah that vote is quite out of date tbf.

I think there has been to much scare mongering about G2's and the dry up of Nimhs that is totaly unfound just take a peek at the jap sites. people are going brushless people are still old school not every youngster is going to be able to go brushless lipo for his first car.
My faith was restored after a few tips with Karl and before you all jump lipo lipo lipo i have a brushless set up as well but still enjoy now runing the brushed system so each to there own.

LOL the point is it is CHEAPER for a youngster or a newbie to buy brushless/lipo kit now than it is to do brushed and be much more competitive with say a £20 1s lipo than buying the very best matched cells,balancers, and chargers and then having to learn what and how to get the best from the cells when all you do is plug in a lipo and charge, use then repeat....... simples

OK its this simple choose G2 nimh or lipo no one is , ah dya know what feckit these threads are getting to be like a stuck record selling me dave and going GT at least its level racing !!!

Neil you got your gt running now? Where the pics at?

Yes mate ready for the track might be up this weekend