John Stranahan

iTrader: (27)

If one side of the chassis is low when it comes off the tweak station, then adjust both collars on that side down to get the ride height correct. Then redo the tweak. I have seen cars like this. You get better at doing the adjustments after some practice.


If the side to side weight balance is off on a Losi.

GP3300's are about 1 ounce heavier than ultra metals or stock metal hydrides. On a Losi XXXS You can compensate for this extra weight by mounting the transponer on the Losi like on a TC3. To the side of the servo. One racer at our track was doing this. There is just enough room. Also mount the electronics on the Losi on the outboard edge. With stock metal hydrides this is not neccesary. If the car is not up to minimum weight you can add ballast or steel screws to the light side of the car in the place of Aluminum screws. I took and relieved the Losi chassis slightly so that the battery bars did not touch the center tunnel. This prevents glitching and also moves the battery slightly inward if you use a foam spacer to hold it there. The chassis is slightly conductive and arces on the battery bars. At least put tape there.

timc

Ok this is what I found when I weighed the car. 3000 SMH batteries. I set ride height at 4.5 all the way around. Visually, the front shock collars were equal height, same with the rear. Using 2 scales and a level block the same height as the scales.

LF: 9.7 oz RF: 13.9 oz LR: 14.1 oz RR: 11.1 oz

As you can see, the RF and LR appear very heavy. This indicates to me that maybe the chassis is warped. I doubt it though as this car is 1 week old (XXXS+). Also, my first Losi had the same issue with level ride heights showing a severe tweak on the MIP station. I never weighed the corners though.

I then began to adjust collars to get side to side weights the same. I could not get it spot on but got close. If I set got the fronts equal, the best I could get in rear was about .4 oz apart. And vise versa. (Obviously every time I adjusted 1 end, it affected the other when I rechecked that end.

I would up with the following weights: LF: 11.5, RF: 11.9, LR: 12.5, RR: 12.5. I then put it on the tweak station for curiosity sake and tweak was perfect. Next I rechecked ride height. LF was 2.5 mm higher than RF and LR was 2 mm higher than RR! You could easily see that the right side was sitting lower than left side. Shock collars left to right were probably 2-3 turns different.

Now I’m guessing that I’m missing something here, just not sure what. I just built this car. I measured all shocks and fronts are equal, rears are equal. Arms are very free. Green springs front, rears are blue.

Not sure what to check next???

John Stranahan

iTrader: (27)

timc-Your car is just slightly heavy on the right front from your scale readings. Probably no need to move weight. You get about .2 ounces of error from shock friction.

Your right Front and right rear chassis height are too high just because you have lowered both of these collars too much. If you raise these two shock collars the same ammount the right side of the chassis will lower without upsetting the scale readings a lot. Then put it back on the scales and make the front wheels read the same. It should only take a small movement of the collars on the scales. 2mm off means you have turned the collars way too much. Alternatetively used the method that Popsracer posted with a block on the tweak station.

Also make sure that the shock ends are in the same holes left and right on the top and bottom.

gotpez

If only one corner or one side was heavy, it would appear to be a weight distribution problem, but based on the fact that you have two heavy wheels at opposite corners, it really sounds like a tweaked chassis.

Have you taken the wheels off and put the chassis on a perfectly flat surface to see if it is flat?

Jeff Gilligan

timc

John S-
I'll try that but I think I did last night. And when I lowered the the one side back down, my tweak (and scale measurements) are way off again.
I will double check the shock mountings. I actually thought of that on the way to work this morning. I'll feel pretty stupid if that's it!
Thanks

bigd4343

Im still looking for concrete track settups for my tc3's if anyone has any....im going to call associated's # to see what i can come up with.
thx bunches and good racing to you,
Darrell

popsracer

John Stranahan;

I didn't think of the shock mounting being off on one side. I guess it was so simple, that I over looked it as the possible cause of the problem. should have as I have done it before but caught it during set-up check.
Hopefully his problem will be as simple as that.

timc

John S & Pops-
Thanks for your input guys. I thought I'd share what I found and what solved the problem.
First I pulled shocks to remeasure and check for free arms. All was well. (And yes, I did have side to side shock mount locations the same). I then reset everything back to level ride height and tried Pops method for adjusting tweak. I put the rear on the scales, front end on a block. I was able to even the rear with a 1/2 turn 1 way on 1 side and 1/2 turn the other way on other side. I then removed the block and put the front on the scales. Less than 1/2 turn was needed to get close to even. Rechecked rear without block and it remained very close.
When I rechecked ride height, it was less than 1/2 mm off left to right. IMO, this method works very well.
When I rechecked it one more time it was way off again. Lo and behold I had 1 wheel quite badly bent. Changed wheels and it was good again. Guess setup wheels might be a good investment after all. Final confirmation on MIP station showed level tweak.
Thanks again guys,
Tim

elnitro

iTrader: (1)

What setup wheels do you guys use? Will the Yok ones fit any car? Thanks.

popsracer

I use the Ofna set-up wheels, but I'm not too fond of them. The O-rings are not as tight of a fit as I would like and the Hex area is very shallow and hard to line up sometimes.
(remember I set my shock lengths within .0005 thousandths).
The Yokomo set-up wheels look better.

Also, the more power you put into a chassis, the more critical your set-up becomes.

timc;

Glad you fixed your problem.

Boomer

you mean 5 thousandths, right Pops? (that's .005)

.0005 thousandths is .0000005 . . . sorry, just can't leave it be!

I only get mine to the hundredth - .0x

John Stranahan

iTrader: (27)

I thought I would mention a couple of things that help you set tweak on scales. First set the ride height at three corners. The ride height can be correct and the car seriosly out of tweak though. I adjusted such a car last night. On a new assembly start with collars even left and right. This eliminates most of the tweak.

If your car is on the scales and you lower the front and rear shock collars on the same side of the car you will not change the scale readings or the tweak much. You will just jack up that side of the car and mess up the ride height.

If the left front is light, then the RIGHT rear is light as well. You have to add load to these two wheels without jacking the car up unevenly. At the front move the left front collar down 1/6 turn. If you are not even yet, move the right front collar up 1/6 turn up. If you are not there go to the rear, but now move RIGHT rear collar down 1/6 turn and then left rear up 1/6 turn. Repeat. Does not take too long with practice. 1-2 minutes. If you were way off at the start recheck ride height. This is usually not neccesary as you make very small movements of the collars normally.

I use and recommend this same method on a tweak station.

popsracer

Boomer old Buddy;

Been doing machining all of my adult life. .0005 is 1/2 of a thousandth SO, .001 - 1/2 = .0005 and yes I set my shocks to that tolerance. Takes a little extra time and effort, but that's how seriously I take my set-ups. (Digital Calipers help) If I need to measure in mm, just push a button on the Calipers to convert back and forth.
Guess I should have said .0005 inches?

See you at Rev,

JDM_DOHC_SiR

iTrader: (31)

I use Yokomo's and Take Off's

They do the Job.

-Dave

429racer

iTrader: (19)

I have seen setup wheels but man are they expensive just do basically do one thing ($45).