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Old 01-07-2008, 06:37 AM   #931
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when i accelerate (high throttle) the back side move/ slide to side. is it because of tyre alignment or diff slip? how tight should be the diff ?
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Old 01-07-2008, 06:55 AM   #932
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Sounds like tweak.

Best bet is too borrow a tweak board, put the car on it and check. If it's not right, undo all the top deck screws, and then with the car on a flat surface, tighten them back up. Then re-check on the board.
If your still off, alter the shock collars slightly to compensate. IMO Tweak is a far more important setting to get right, than having equal side to side ride height. Hence why I always set the shock collars for correct tweak first, then set the ride height. (Set the collars first for tweak, then adjust them equal amounts for the ride height).

However, there shouldn't really be more than 1turn of the collar difference between the shocks when setting the tweak. If there is more than this, try again with the top deck.

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Old 01-07-2008, 07:16 AM   #933
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i dont really understand tweak problem. can explain.
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Old 01-07-2008, 07:26 AM   #934
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Tweak occurs because the car is made from 2 chassis plates, and these can then mis-align with impact or from being built wrong. This causes the chassis to act differently in different directions.

To remove tweak, just loosen all the top deck screws and tighten them back up on a flat surface, just like is mentioned in the above post.
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Old 01-07-2008, 07:38 AM   #935
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Originally Posted by Matt Pocknell View Post
Tweak occurs because the car is made from 2 chassis plates, and these can then mis-align with impact or from being built wrong. This causes the chassis to act differently in different directions.

To remove tweak, just loosen all the top deck screws and tighten them back up on a flat surface, just like is mentioned in the above post.
Tweak can also come from weight distribution on the chassis. With heavier electronics on the left rear (e.g. a brushless set-up), it can put differing pressures onto the tyres (this, IMO, is effectively tweak).

By adjusting the collars to equalise the effective "pressure" displayed, the tweak is elminated.

I've tended to find that when running B/l, I need to adjust the collars of the car to componsate a little for the extra weight on the Left rear, versus my brushed gear.

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Old 01-07-2008, 08:44 AM   #936
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Quick request: Can someone list all the parts needed to build a 2nd diff. Thanks
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Old 01-07-2008, 09:29 AM   #937
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Quick request: Can someone list all the parts needed to build a 2nd diff. Thanks
http://rcmarket.com.hk/index.php?cPath=51_98_120_176
but some parts was sold out,
next lot around next week end arrive .
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Old 01-07-2008, 11:30 AM   #938
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Anyone know the lb rating of the yellow and blue springs that come in the 416 kit?
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Old 01-07-2008, 11:56 AM   #939
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Red - 11.86
Yellow - 13.33
Blue - 14.08
White - 14.82

Units:lbs
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Old 01-07-2008, 11:58 AM   #940
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Red - 11.86
Yellow - 13.33
Blue - 14.08
White - 14.82

Units:lbs
Thank you!
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Old 01-07-2008, 12:16 PM   #941
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well speaking of tweak,

all you want is that your car has equal amounts of grip left and right.
so, since grip is a nice formula; F = N* c where F is your grip, N is the tire load and c is the friction coefficient of the tire. when putting traction control on your tire actually you are making this c higher and thus giving more grip.
if the left tire has more grip than the right tire the car will be going sideways or turn when trothle is applied .
so that can come from many things, tweak, non-equal spring preloads and so on...

when your setting up your car do it in this order:

1 detweak your car using the method described a few posts above

2 balance your car using a balance tool like from xray. make sure your car has equal mass on left and right side, so if your running BL you'd have to add a little counter weight to the battery side

3 next, and this is kind of important, you should get equal loads on your tires.
disattach your four shocks from the suspension arms and leave hanging them on the shock tower
place a setup block under the front suspension. make sure its in line with the front tires. then you lift up the rear end with a 2mm imbus or anything with a sharp tip, make sure you lift it up in the center of the rear. now look at the distance between the tires and the setup board. if things aint equal you have to adjust your REAR downstop screws to get them equal. so if things are correct, your left and right tire come off the surface at the same time.
do this with the front suspension as well. this way you equalize the front suspension too.

4 now comes the tricky part
attach your front shocks and make sure the front suspension is settled by pushing down the front shock tower exactly in the middle a few times. now again get your 2mm imbus and lift the rear up again and again look if the tires come off equally. if not you'd have to adjust the FRONT shock collars. adjust them equally, so for instance if the rear left tire comes off earlier, you'd have to turn the left front shock collar counterclockwise and the front right shock clockwise. do this in small steps so you can get the front of the suspension precisely right.
in this way you use the rear suspension as a measuring device as it is totally straight because you've just straightend it with your downstops.

now attach your rear shocks and disattach your front shocks, turn your car around and do the same trick again

if you want your car to perform at its best you should do step 1, 3 and 4 before every run. this way you always have a balanced car.

tip, sometimes the uptravel of the suspension is not correctly achieved. sometimes the shocks are too short and act as a downstop instead of the downstopscrew. so if you're changing your cars downstop , check if the shocks are long enough for your new downstop setting. i had allot of trouble with this on my xray T2, untill i switched to TRF dampers, DUHHH

this setup tips for me were the difference between spot 9 in competition and top 3.

good luck!

Mark

Last edited by Markiempje; 01-08-2008 at 03:08 PM. Reason: grammer...
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Old 01-07-2008, 12:19 PM   #942
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Default recommendations please

i'm looking for suggestions for recommended file or tool to prepare the graphite chassis plates. and what grit sandpaper?

the last time i had to prep one, the edges of the battery slots were uneven. would a wider flatter file be better?
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Old 01-07-2008, 01:54 PM   #943
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i'm looking for suggestions for recommended file or tool to prepare the graphite chassis plates. and what grit sandpaper?

the last time i had to prep one, the edges of the battery slots were uneven. would a wider flatter file be better?
I just use a round file, run quickly up and down the battery slots (Hara does too... see here Hara Cyclone build guide). I have seen on here that someone used a Dremel sanding drum bit, and just rotated by hand. Was the same diameter as the cell, and seemed to work really well.

In terms of chassis edges, I use some 400 to start, then 600, and then 1000 (if I feel like it). All used wet, as thats the best way to avoid getting too much carbon dust everywhere.

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Ed
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Old 01-07-2008, 01:57 PM   #944
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Anyone
Quote:
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Quick request: Can someone list all the parts needed to build a 2nd diff. Thanks
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Old 01-07-2008, 02:23 PM   #945
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Anyone
Well, all the part numbers are in the manual, but as I'm a little bored...

TAM9804373 Diff Joints (L and R)
TAM9804374 Diff Screw and nut
TAM9949299 Diff Spring
TAM51287 Diff Plates x2
TAM9949300 Diff Thrust bearing
TAM53030 850 bearing x2
12x 3mm diff balls

Personally, I'm now using JAAD 3mm ceramic balls (JDRDB300 for 10) and ceramic thrust bearing (JDRCT0206) in my diff, and it is ubber smooth. It's properly tight, but I can still spin the opposite wheel... very good

HiH
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Last edited by TryHard; 01-07-2008 at 03:01 PM. Reason: should have been 12 balls not 10!!!!
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