Tamiya mini cooper
Question on ball diffs. I'm building an M03 using the TA03 ball diff. Normally I would set up a ball diff (I mostly run 2wd electric offroad) so that when you are holding both outdrives stationary you could barely turn the diff gear with your thumb. That amount of slip is usually in the ball park to start. When I set the TA03 that tight, the diff action was also much tighter than I'd usually see. Since you seem to have to take half the car apart to adjust this thing once it's in there, I'd like to get it right the first time....
Any advice on setting it up? TIA
Any advice on setting it up? TIA
Tech Regular
iTrader: (3)
What springs do you guys run in M03?
Tech Master
iTrader: (8)
Bear in mind also that there is only one way of building the TA03 diff - and that is with the bolt fully tightened - the spring washers are what generates the tension so follow their orientation exactly. If you try and overtighten the bolt, all you will do is strip the thread in the outdrive. The TA03 diff does feel a lot tighter than a typical RC ball diff (because of the design), but it works well in the front of a Mini.
Tech Elite
So if I'm interpreting what you are saying, there is no adjustment? If I bottom the threads (haven't tried to do that, because the diff feels very tight to me without bottoming it) then the amount of slip is determined only by the flex of the Belleville washers? That doesn't sound right. I've built plenty of diffs with both Bellevilles and springs to load the diff, and I've never seen one where you'd bottom out the thread and nut. Of course, nothing on this car is like anything else I've ever built...
Both sosidge and I have given you the same advice. This really is the way most Mini gurus will tell you. You might want to check out the rc-mini website also.
TRF White Springs?
The TRF 54000 Damper Set comes with two sets of white springs, one has a yellow mark, the other a blue. Which is the harder set? And are they the same poundage as the flouresent yellow and blue ones? Never been able to figure this out.
Terry
Terry
Tech Elite
There are a bunch of different spring sets, but usually within the set the red ones are the softest and the blues are the hardest. comparing the spring rates between the different sets or types is confusing at best.
Tech Master
iTrader: (8)
Gary, while sosidge and I have had differing opinions on some things he is dead on here. As you said, you are new to Minis, so you will soon find that much of your experience will not transfer over.
Both sosidge and I have given you the same advice. This really is the way most Mini gurus will tell you. You might want to check out the rc-mini website also.
Both sosidge and I have given you the same advice. This really is the way most Mini gurus will tell you. You might want to check out the rc-mini website also.
Tightening the nut all the way down is not enough ! The diff will Work its way loose Quick..... You need to add Ofna diff lock lube carefully to the balls and rings and blue loctite to the bolt/nut threads... Make sure no oil gets in there, so your diff will stay tight. It will act like a slipper spool, and will be sensational exiting turns. Mine got oiled up a bit over time, but can still pull hard out of turns. I built it like Sodidge said at first, and it came loose way too fast. The diff lock lube/loctite combo is necessary, trust me.....
When only One front tire is on the ground, you will diff out if you don't use the lock lube. You can try setting up your Car so your front Tires stay on the ground at all times, but that might prove itself very difficult....
Tech Elite
There are any # of refinements in building techniques. I personally like using ceramic diff balls and polishing the diff rings. This doesn't make the diff work any better, but seems to make it go longer between rebuilds.
You can also put shims on the diff screw. Leaving one of the small belleville or cone washers out will give you a supertite diff. All of these "tricks" will give slightly different diff action.
I've tried quite a few ways to build the diff, but have always returned to stock with antiwear grease and loctite on the diff screw. Good luck and Minis are fun.
Last edited by Granpa; 11-27-2012 at 08:37 AM. Reason: spelling
Tech Elite
Frankly, I do not see much if any diffing in a TA03 ball diff. Assuming, of course, the diff is in good shape.
What I found was that, with no lock lube, when I turn too tight and punch it at the same time, I would get diff slip noise and no forward pull . With the lock lube, no noise and forward motion. When Racing mini, you have to sometimes be Off line to make passes and avoid accidents, and traction on both front Tires might not be there all the time, but with the lock lube it seems that you never loose traction. As far as setup to keep your front Tires on the ground, I found that soft front springs(tamiya red) and raising the radio throttle trim a bit(to keep the Car moving) gave me the best results. Right now I also run red springs in the rear, and I need to keep the Car's momentum going so I don't bottom out, even with 6mm ride height(fairly high compaired with other cars running 4mm or less)...
What I found was that, with no lock lube, when I turn too tight and punch it at the same time, I would get diff slip noise and no forward pull . With the lock lube, no noise and forward motion. When Racing mini, you have to sometimes be Off line to make passes and avoid accidents, and traction on both front Tires might not be there all the time, but with the lock lube it seems that you never loose traction. As far as setup to keep your front Tires on the ground, I found that soft front springs(tamiya red) and raising the radio throttle trim a bit(to keep the Car moving) gave me the best results. Right now I also run red springs in the rear, and I need to keep the Car's momentum going so I don't bottom out, even with 6mm ride height(fairly high compaired with other cars running 4mm or less)...
I think "diffing out" means the unloaded wheel takes all the torque, therefore leaving the one on the ground with no drive.
What you described is diff slip and that can happen anytime not only going around corners if your diff is too loose. The lock lube you mention probably acts as a friction enhancer compensating for the diff being loose.
The fact that you have this happen when you turn "too tight" would have me checking the driveshafts for binding. Without any other change, swap to ECS driveshafts and the problem will go away. Otherwise you'll just wear diffs prematurely.
R/C Tech Elite Member
iTrader: (10)
There's nothing quite like an obnoxious ripoff of a classic paint scheme! I think this is better than my pink phase... Also, please note the eternal struggle going on at the top right corner of the first picture.
Niznai, I already got losi lcd's in my m03, and I still need the diff lock lube so the diff would stop unloading on me......