Free Spinning drivetrain

[speedfreak]

Hi guys, I have a suppose tricky question. How do the guys at my club get their drivetrains on their belt or shaft cars to be so free spinning?. One guy has mentioned special exspensive bearings and others generally say a lot of time and hard work....but thats all I ever get. When I say free spinning they literally spin one wheel at the rear and all the wheels keep spinning for about 5 seconds...mine stops as soon as I take my hand off it!Can just see what advantage they have with that less friction.....any suggestions [:^)]

[MAD ANDY]

ball race kits and good grease / lube will help,

i too have seen a ta04 spin on ever......i suggest buying a good quality ball race kit........

what have u got,i can supply u with race quality ball races......not cheap asian inports

 

andy

[Gruntfuggly]

Try taking you pinion off the motor - I bet it'll spin much better then...

[speedfreak]

No...the pinion is def removed.

[speedfreak]

Oh for the record, I have a TRF 415 MSX....that's the car I'm trying to get up to speed. We race on asphalt outdoor track. Using Jaco foams 35 shore wheels. I race in open stock class, std silver can johnson or mabushi with 1500 nicad's. So less friction the better I see

[Gruntfuggly]

Hmmm - I had a Baja Champ that seemed really slow, even with bearings fitted, but I found that there was so much grease around the bearings that it was actually slowing it down. I took all the bearings out, cleaned them with some WD40, removed all the grease and reassembled, and now it runs smooth as you like...

[steviedee]

i never regrease  the bearing when they are fitted it seesm to attrach too much crud around em, and to back up mad andy i've had a few of his bearing kits and they top stuff, not a dud in sight, and with my driving thats great []

[WillyChang]

Oh for the record, I have a TRF 415 MSX....that's the car I'm trying to get up to speed. We race on asphalt outdoor track. Using Jaco foams 35 shore wheels. I race in open stock class, std silver can johnson or mabushi with 1500 nicad's. So less friction the better I see

Not many gears in a 415... []

Belts should be on as loose as possible - loose until they flop. You'll never skip teeth on a 540. There should be some white low-friction belts for 415... but the MSX should already have those, ya?

Degrease all your bearings -- remove the seals & flush out all the grease. Lube with light oil.

Don't grease your unis, degrease them and lube with light oil or run them dry.

 

[speedfreak]

I will give it a try, cant seem to find the clip on the 950 bearings, You mention not to grease the unis, you mean universal joints....I will do that to, I flushed all the bearings in bezine, and used 1 drop of lite oil...I have reassembled the car and I can now literally move it by blowing on it with the shell attached. But from what I have felt and seen at the club with the old racers...their drivetrains are a lot loose!....but any suggestions are taken in and will be tried. Thanks guys!

[bender]

Oh for the record, I have a TRF 415 MSX....that's the car I'm trying to get up to speed. We race on asphalt outdoor track. Using Jaco foams 35 shore wheels. I race in open stock class, std silver can johnson or mabushi with 1500 nicad's. So less friction the better I see

My MSX spins very freely so I can offer some you some tips.

Firstly, there are some misconceptions with regards to free-spin and efficiency, especially when comparing belt drives to shaft drives. Basically, you should only compare your MSX to other cars with the same drivetrain - in other words any of the Tamiya 415 series.

You can't compare free-spin even against other brands of belt drives as there will be differences in component weights, pulley sizes, belt material etc all of which have an impact and can give you a "false reading".

My MSX required only very minor work to get it free running.

1- correct belt tension. This is very important! Running stock or 540 motors you can run the belts very loose which will be a big help. Basically run them as loose as possible without them slipping.

2- Re-lube the bearings. The first thing I do with any new car is to clean all the bearings with shellite to get rid of the horrible crappy grease they are packed with, and then re-lube with a good quality motor oil.

That's all I've done with my MSX and its very free-running, very quiet, and completely reliable.

Incidently, the standard grease that comes in most bearings is not much good at actually lubricating the bearings - it's more of a anti-corrosion lube designed to stop any internal corrosion of the bearing while it sits in storage for however long. That's why I always get rid of it and  put some decent oil in there.

Hope this helps.

[speedfreak]

Cool bender.....I have just ordered some ceramic bearings and diif balls for the msx, I will see what difference it makes. I was refering to a Belt drive, namely a schumacer

[terry.sc]

If the bearings are rubber sealed replace them with metal shielded ones

for less friction, needs a lot more maintenence to keep running freely

though.

You can use ceramic bearings instead, but they are expensive for the

minimal performance increase. Flushing out the bearings and making sure

the belt tension is right (as loose as possible without skipping) will

give the biggest difference

Are the cars that will spin for seconds shaft drive? You will never be

able to achieve that with a belt drive car because of the belt, but

that doesn't make yours

any less efficient. Also the fact their cars spin for a few seconds

does not mean they are any faster on the track as they are spinning

them with no load on the transmission.  Once the transmission is

loaded under power the free transmissions are not necessarily as free

as you would think. For example the Predator buggy was designed so the

bevel gears were most efficient when there was a side load on them,

this meant the wheels would not spin at all. Setting the drivetrain

free usually meant you destroyed the gears very quickly.

The biggest advantage of a drivetrain spinning that freely is to psyche

out the opposition, for example replacing steel diff outdrives with

delrin ones will give you better performance on track, but will reduce

the amount of time the drivetrain will spin for as there is less weight

in the drivetrain. As you are using standard 540s the slight increased

efficency will never be noticed on the track as a freer running car

will give you more duration but not really make you go faster. You

would get a better increase in performance by making sure you have

a decent 540, bedding the brushes in and polishing the bushings in the

motor. Standard 540s aren't all the same.

You could always fit one ways front and rear and add a bit of lead to your wheels. The wheels will keep spinning forever []

[DJTheo]

Terry is right, many racers do the mistake to compare the free wheeling by their hands, which doesn't tell much though about the important real resistance during driving (at load), as the friction varies according to it, i.e. is dynamic.

 As he said you are better of building and mainting the car and motor well instead of spending loads of money on exotic materials and let other racers scare you with their hype and voodoo (guess the loss of confidence is the most important and some clever racers use it)

Cheers

[bender]

Yep, it's amazing the lengths some people will go to to acheive a supposed advantage, only to find out it didn't help at all, or often made their car worse.

One case in mind concerns the oiling (or lack of) bearings in a car. A fellow racer used to amaze everyone with how long his car would spin for. Of course he was never one of the fastest in a straight line, nor did he make great run-time  - which all seemed a bit odd, until it was discovered that he didn't oil his bearings at all, he simply ran them dry.

Now this is great if you want to show off the free-spin of your car, but of course without lubrication those bearings create a lot of friction and heat (and additionaly, wear) so the reality is that the car is much less efficient almost from the start !

 

[speedfreak]

Thanks to all the imput guys. Its not about strategy from my point of view. I am actually talking about a few of them namely all the guys that are on top of their class i.e. the leaders all have that in common, the free drivetrain, apart from their overall experience in years and me, a rookie relatively speaking, I joined the club in December last year, participated in 5 races since then, best position, 4th A group. Best average time achieved over race distance 15.830 seconds versus their best of  14.900, I say I have a fare way to go. Overall points standings at the moment 3rd out of 19 guys in total. The advice I've been getting was very genuine and made sense overall, My first 2 races averages were about 17.200 sec's and since then improved to the 15.800 mark, I think a lot of thats got to do with the change from the evo 4 ms to the trf msx....and pure track running time. Best lap 14.930, lap record 13.900, currently fast guys getting 14.300, me 15.100. My thinking is to have all the right equip in place, eliminate all unknown variables, then take it to the track. But getting imput from you guys out there is very valuable and comforting. Those ceramic bearings and diff balls are on the way....It cost a bit but eliminates a variable. Thank you so much for the imput!.

[terry.sc]

Replacing the bearings with ceramic ones aren't going to make up a

second a lap, maybe a few seconds over the total race distance. There

are much cheaper ways of getting more performance out of your car.

The biggest difference can be in tyres/inserts/wheels. For example

using a harder insert will reduce rolling resistance and give you more

speed, but you sacrifice a bit of grip in the corners (assuming the

inserts match the tyres). Ask the fast guys what tyres AND INSERTS they

are using and use the same.

With a standard 540 make sure you have a good one, they do vary a lot.

Buy a few and see which one us fastest. Run it in properly by water

dipping and polish the bushings to get the most out of the motor.

To go as fast as possible you need to carry as much speed as possible

through the corners, making sure you have the right tyres and inserts

go a long way toward this and then the suspension needs tuning to suit

your driving style. With the MSX there are plenty of things to adjust,

try one adjustment at a time and make a note of what it does. Check the

settings on other cars to use as a starting point, especially roll

centre settings and springs.

Batteries can make a speed difference in stock, using voltage enhanced

cells and choosing batteries with the highest average voltage will get

more speed out of your 540. Having a decent ESC designed with a stock

motor profile (usually a lower operating frequency than for modifieds)

will  also give you more speed.

Lastly your driving style can make the difference. Try and watch what

the fastest drivers are doing with their hands and try and adapt your

driving style to match. For example I am much more competitive with

1/12th scale and buggies than I am with touring cars because I struggle

to drive a tourer as smoothly as I need to, mainly because I mainly

race the other classes and have to try and relearn how to drive my

tourer properly.

Your lap times after 5 weeks are pretty good. I would say there isn't

much wrong there, especially as you are racing against people who know

the track well. More practice will improve your lap times and tuning

the setup should make up the  rest.

[jerrywasaracecardriver]

As mentioned above, run metal shielded bearings, lube with oil not grease. Run the least possible belt tention, and low friction belts. A couple very important steps, and these do make a difference, even if a little, are: Shim everything properly. Make sure side play is a minimum for all rotating parts; diffs, wheel axles, top shaft. Dont shim tight, just get rid of excess sideplay. Too much side play allows a wobble to develope at high rpm, or even at low rpm for some cars, making things not spin as long. The other is, balance your wheel tires. Yes, even with a 540 motor, those tires are spinning fast enough that balancing will help to run smoother, and allow ever so slightly higher rpm. These items too will add to a free spinning drivetrain when spun by hand. Also, a well used car, that is shimmed properly, and everything balanced will spin more freely than a new car with equal preparation. It just takes a while for everything to get seated, wear in, loosen up.  Now, even if having less friction in your drivetrain will not make you go faster[:^)] at least you can also have the psyke out factor.