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Old 02-18-2003, 10:49 AM   #31
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Default Gotta GREAT discussion going on here

Guys;

This is really a great discussion going on. If anyone can learn something from this, then we have accomplished our goal.

John Stranahan;

I have really learned alot from the Electric Motor Dyno discussions on the Hobby Talk board.

Seaball;

I hope all of these discussions clarifies the proceedures and terms for you. Properly checking and adjusting your chassis can be a huge advantage over the average racer. Once you start moving up in the ranks, it becomes mandatory.
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Old 02-18-2003, 10:55 AM   #32
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Popsracer-I am talking about touring cars as well. I understand how you are using the block. 1/4 turn on a shock collar is about .007 inch of movement, not very much. Both my Losi XXXS and TC3 had some chassis twist after a few months of use. Hard to notice by eye. Having all four tires on the tweak station will correct for this, using a block will not. The tires loads will be twisted just like the chassis when using blocks. (I note that you do untwist the tire load when you then put the fourwheels on the station as the last step). If the chassis and other suspension components have perfect symmetry the blocks will work just as well. Thanks for the note on the hobby talk board. Interesting discussion over there.

seaball-I see your point about droop. If you set droop using a ride height gauge (reading at tire lift minus reading at ride height) moving the shock collars will affect the droop reading. You are changing the reading at ride height. Not sure if you could see a small change, as a lot of the ride height gauges are stepped in millimeters. 1 mm = .039 inch, and you have to eyeball the tire lifting. If you set droop using the supplied gauge in a TC3 or Losi you won't see a change in the gauge reading when adjusting shock collars on the tweak station unless you change it a lot. I aggree the actual droop will change a little.

Last edited by John Stranahan; 02-18-2003 at 12:05 PM.
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Old 02-18-2003, 12:57 PM   #33
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Thanks to all who have tried to unconfuse me I think i understand things now.
I think I will get hold of some set up wheels would it be ok to use say aerodish wheels with no tyres?
And use the block method.
I will try both ways of adjusting the car, diagonally opposite method and side to side method.
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Old 02-18-2003, 12:59 PM   #34
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John- I know what you are saying about using the block, but you must keep in mind that in full size racing the chassis should already have the weight distrubutd evenly if the chassis man knows what he's doing. The same is true in r/c except very few racers actually try to distrubute their weight evenly. With that in mind, you must also realize that you can distrubute weight AND check tweak with scales, but you can only check tweak with a tweak station. So therefore, you must have a point of reference or a "control" point if you will... With my method of using the tweak station (which is also the way the instructions read I believe) you are seting the front tweak relative to the chassis level, and then the rear tweak relative to the front. This way any chassis twist or weight unbalance is compensated in the rear shock preload (which by the way isn't actually preloaded on an r/c car)

While we are discussing weight distribution, I'll share that I have been working on a method of using the tweak station to check for equal weight distribution. I simply marked my chassis in the rear exactly centered between the rear arm mounts and started to drill a hole. I didn't drill all the way through which left a dimple. Now I need a pin with a flat mount like the Hudy pins to set the car on the stationary end of the station. Then I can use a 10mm block under the chassis on the other end and see which way the chassis teeters to adjust weight dist. Now I just need to figure out how my method will be better than purchasing the Hudy pins...
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Old 02-18-2003, 01:05 PM   #35
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Quote:
Originally posted by mike_Webb
So if you are looking at the front of the car on the piviot then you adjust only the front shocks? I thought that if say the front right is to low then you adjust the Rear Left Shock to help the Right Front. and so forth.... then flip it around so that the Rear is on the Pivot Block. I think I saw this in a article that Pavidis did back in a magazine about tweaking the chassis
Mike, you should have a 10mm block under the rear when doing this- then you adjust the front to level the pivot. Now kick the block out and adjust the rear to level the pivot back up again. Are you seeing the result? Adjusting the front (w/block in rear) makes the front relative to chassis flat> kicking the block out lets you adjust the rear relative to the front which is now relative to the chassis. You never turn the car around.

If my explanation isn't clear I suppose I could take some pictures. I never claimed to be a scholar of communications...
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Old 02-18-2003, 01:39 PM   #36
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I see what you are saying Jason..

Thanks
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Old 02-18-2003, 05:47 PM   #37
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When you set ride height you have to make some decisions. Usually you get three corners of the chassis to touch the ride height gauge with a light drag fit at the desired ride height. The fourth is going to be a little off unless your car happens to be perfectly flat. I have not seen one like this. You have already accomplished what using a block on one end of the car will accomplish. You have already made the decision as to whether a corner on the front or a corner on the back is going to be off a little. Now set the tweak.

If you put a block on the front of the car and have the rear on the tweak station and adjust the rear first then all of the chassis twist problems will be compensated for at the rear. In other words you have made the rear suspension points uneven by adjusting the rear collars first like bigdogracing suggests. Now if this is your intent then the method is as good as not using a block, just has an extra step. I would accomplish the same task by setting ride height at two front corners and one rear corner first then adjust the tweak. This also is the way that they adjusted the Transam cars and Champ cars that I observed on the corner weight scales in the paddock area at the Houston Grand Prix. One little ruler bolted to the side of each front corner on the champ cars to set the ride height, all four wheels on the scales.

Last edited by John Stranahan; 02-18-2003 at 05:54 PM.
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Old 02-18-2003, 07:03 PM   #38
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When I put the electronics in my car, I weigh everything and try and get the chassis weight as balanced as I can. Before adjusting anything.

Todays electronics are getting smaller and lighter and if your batteries are on one side (like a tc3) that would require adding weight to the oposite side.

Then I set the other settings.

Rod
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Old 02-18-2003, 07:32 PM   #39
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I'm sorry John, but I don't agree with you. What if the tires aren't exactly the same size? What if you have a wheel that is slightly warped? By considering all of your variables that are possible, it only sounds reasonable to use a known control for a reference point. Adjusting the tweak so the chassis is as parallel to the surace as possible is the best way to eliminate all variables.

Trust me when I tell you that a chassis man on a full size race car would love to be albe to eliminate variables as easily as we can. Don't confuse setting up full size cars to r/c cars- it similar, and the geometery is tha same, but the conditions call for different methods sometimes.
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Old 02-18-2003, 07:51 PM   #40
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If the tires are not the same size you want to compensate for this on the tweak station with all four tires on it. If you set the car up with setup wheels and then put on wheels and tires that are not all the same size the tweak will be off. If you are worried about wheel warp then rotate the wheel and check tweak again. The tweak station is not that sensitive, so wheel warp does not seem to be a problem for me. I aggree that you want the chassis as parallel as possible to the ground side to side, but if you use a block on the tweak station you immediately transfer all the chassis flatness problems to one end. It might be better to divide the chassis flatness problem between front and back which I do by adjusting both front and rear collars. I also agree that There are many ways to achieve the same end.

I do use setup wheels and corner weight scales to to get the weight right in the chassis. The tweak station is not sensitive enough to do this well. I have photos of arranging weight in the chassis and setting tweak on the TC3 Assembly Tips, Factory Team Kit thread.

Last edited by John Stranahan; 02-18-2003 at 09:12 PM.
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Old 02-18-2003, 08:04 PM   #41
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Default chassis twist problems

Quote:
if you use a block on the tweak station you immediately transfer all the chassis flatness problems to one end.
If you have a KNOWN chassis tweak problem, wouldn't it be better to correct this BEFORE attempting an adjustment on the Tweak Station.
Unless you have brand new or freshly trued tires, I would leave them out of the equation. Better to use setting discs. (For tweak checking)

Last edited by popsracer; 02-18-2003 at 08:08 PM.
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Old 02-18-2003, 09:07 PM   #42
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It's not usually possible to flatten a molded chassis. I was, however, able to flatten a heat distorted TC3 chassis with a special motor support block. Photos on page three of the thread I mentioned above. The tolerance for flatness of a molded chassis is about 6-10 thousandths inch when new. Probably a little more when used. No need to throw it away. You correct for this problem when you set tweak.

Last edited by John Stranahan; 02-18-2003 at 10:09 PM.
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Old 02-19-2003, 08:09 AM   #43
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Default ballest vs. tweek

I still say ballast is going to be the most important adjustment for handling tweek on a touring car. When the weight transfers front to rear or left to right on an improperly tweaked car it is uneven ballast which will cause the car to accellerate with a shift to one side or an uneven turning radius. Get as close to even ballast as possible and then adjust ride hieght, this would be the easiest and most effective way for handling tweak, assuming that nothing else has failed significantly, like unequel spring weights, or a very uneven chassis.

IRS makes a great scale system, maybe even some of the ones at Staples or Office Depot would work if placed on each corner. I've also heard of harness systems that hang the car from the centerline, or the opposite method from that is to notch two holes in the front an rear bottom of the chassis at even distance and centered, then try to balance car when placing it onto two rounded of nails (this balances left to right) nailed into a board at the proper distance from one another. If anyone tries this method maybe send me a picture of their set up.
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Old 02-19-2003, 10:25 AM   #44
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Hi guys. Greetings from Malta.

I once saw a set of corner weight scales advertised in an American RC magazine, just like the ones we use on real race cars.

I e-mailed the company advertising them as I was interested in buying a set, and still am, however they never replied.

Does anybody know who manufactures them and what sort of price they go for.

I'm still interested.

Regards

Joe from sunny Malta.
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Old 02-19-2003, 08:13 PM   #45
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Default SCALES...

YES!,
YUR N LUCK DUDE.HOLESHOT RACING HAS A SET.I WILL GET U THEIR ADDRESS OR/AND PHONE NUMBER AS SOON AS I RELOCATE IT FOR I HAVENT CALLED THEM IN QUITE A WHILE.
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