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Old 05-05-2011, 11:31 PM   #1771
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I find that to be a disappointing reply. You might as well say that some play in the end links of the swaybar on your real car doesn't matter. To me, your desire for high quality and precision build up just went out the window. Ah well, life is full of disappointment.
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Old 05-06-2011, 02:16 AM   #1772
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I find that to be a disappointing reply. You might as well say that some play in the end links of the swaybar on your real car doesn't matter. To me, your desire for high quality and precision build up just went out the window. Ah well, life is full of disappointment.
really ?? I think you are over reacting slightly. bmi products are of the highest quality especially compared to the other offerings available right now. like i said before if it is excessive slop the pieces need replaced. when new there is no slop .
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Old 05-06-2011, 04:11 AM   #1773
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Parts break down over time and get sloppy; stop hitting shit, it'll last a bit longer.
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Old 05-06-2011, 07:02 AM   #1774
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I find that to be a disappointing reply. You might as well say that some play in the end links of the swaybar on your real car doesn't matter. To me, your desire for high quality and precision build up just went out the window. Ah well, life is full of disappointment.
UMMM, ok. The point was that if you have a size on size fit, it will bind. When you have a .0005 of an inch oversize ball detent, it has partial contact so the verticle play is exagerated from limited contact verticlaly. This is not a quality issue. What i was stating is that it is not worn out if you have slight play on the vertical axis. There is no quality problems on our end so there really isnt any corrective action needed. I guess you cant please everyone. Oh well.
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Old 05-06-2011, 11:55 AM   #1775
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I find that to be a disappointing reply. You might as well say that some play in the end links of the swaybar on your real car doesn't matter. To me, your desire for high quality and precision build up just went out the window. Ah well, life is full of disappointment.
Er... My car has a bunch of rubber bushes in the sway bar giving it all the movement it wants in almost any direction. When the car rolls, some of that movement is taken up by moving the rubber, not preventing the roll.

On the BMI, the system is pre-loaded so that the clearance in the ball joints is taken up in any direction. The side springs are not level, so they act by pushing down on the pod plate. the weight of the car acts on the ball joints as well taking up the clearances. Once that pre-load is in the system, any clearance is controlled such that as it moves, there is no 'free' play in the system as the suspension operates.

I don't know any moving system that doesn't have some free play in it in order for it to work, except pre-loaded rolling element bearings. In my road car those bearings are all pre-loaded, but in my RC car none of them are. Are you saying you don't use rolling element bearings in your RC car because they have some play in them? They all do, since it is impossible to pre-load them accurately using plastic parts.

The BMI ball joints are very good. I wish Jason would make one to fit the centre of other link cars like the 12R5 and CRC - they would be much better than those standard parts!! Just a thought...
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Old 05-06-2011, 05:50 PM   #1776
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UMMM, ok. The point was that if you have a size on size fit, it will bind. When you have a .0005 of an inch oversize ball detent, it has partial contact so the verticle play is exagerated from limited contact verticlaly. This is not a quality issue. What i was stating is that it is not worn out if you have slight play on the vertical axis. There is no quality problems on our end so there really isnt any corrective action needed. I guess you cant please everyone. Oh well.
You are right, you can't please everyone. On my personal 1/12Th cars, there is no play in the pivots, because I take the time to hand fit each one. It's part of good prep, but on this car it's not possible. Having raced 1/12Th for 30 odd years with a wide variety of cars, I find this a little strange. This car has been used, but it doesn't look like it has been used much. The center pivot has approximately .2mm of vertical play, is that within your acceptable tolerance? And the instructions and the website show pivot balls and pivot cups for the side pivots as 2 part numbers, do you buy them separately and press fit them yourself or is there another part number I am missing? I am not trying to rag on the car, or pick a fight and get flamed, I have never worked on a BMI before and this is different. Thanks.
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Old 05-06-2011, 07:27 PM   #1777
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The pivots come with the pivot balls installed. All that needs to be purchased is the pivots.
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Old 05-06-2011, 07:33 PM   #1778
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BTW, Everyone has a view of what is acceptable to them. Some like to pinch, squeeze or sand parts. I have heard of all sorts of tricks to fit different parts from ride height adjusters needing a small dink put in the to remove slop out of them for the pod cutouts being to big, to others needing to be sanded. I try my best to offer the highest quality. A lot of time is spent in the manufacturing of our cars and we hold extremely tight tolerances. We have had a lot of success this way.
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Old 05-07-2011, 10:18 AM   #1779
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Someone here used an o-ring to hold the suspension parts together thereby eliminating the slop but still allowing completely free movement. He said the o-ring came off during a race and he could not tell the difference... I think Jason has done his homework.

The tricky part about the ch12 in my opinion is getting the carbon flex plates on the NFE adjusted perfectly for preload and droop. There's some snake charming involved.
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Old 05-07-2011, 12:51 PM   #1780
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You are right, you can't please everyone. On my personal 1/12Th cars, there is no play in the pivots, because I take the time to hand fit each one. It's part of good prep, but on this car it's not possible. Having raced 1/12Th for 30 odd years with a wide variety of cars, I find this a little strange. This car has been used, but it doesn't look like it has been used much. The center pivot has approximately .2mm of vertical play, is that within your acceptable tolerance? And the instructions and the website show pivot balls and pivot cups for the side pivots as 2 part numbers, do you buy them separately and press fit them yourself or is there another part number I am missing? I am not trying to rag on the car, or pick a fight and get flamed, I have never worked on a BMI before and this is different. Thanks.
I too have raced 1/12 for 25+ years. I can tell you that if you do not have some play in the frond end it will not work. It's kind of like trying to mount the body without play, you need some play to make it driveable, if not it will dart and be too sensitive. Remember these are not real cars and the setups do not cross over. Oh yea I have worked for Indy car teams and NHRA Teams and we even have play on some parts of those cars also.

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Old 05-07-2011, 02:47 PM   #1781
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Someone here used an o-ring to hold the suspension parts together thereby eliminating the slop but still allowing completely free movement. He said the o-ring came off during a race and he could not tell the difference... I think Jason has done his homework.

The tricky part about the ch12 in my opinion is getting the carbon flex plates on the NFE adjusted perfectly for preload and droop. There's some snake charming involved.
That was mine...I've had my car since IIC of last year so the pivots have had a bit of wear and loosened up. The car still drives very well. As I recall from my 1/10th scale days on the EV10 the saying was that the front end really didn't start working well until it got sloppy.
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Old 05-07-2011, 05:46 PM   #1782
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I too have raced 1/12 for 25+ years. I can tell you that if you do not have some play in the frond end it will not work. It's kind of like trying to mount the body without play, you need some play to make it driveable, if not it will dart and be too sensitive. Remember these are not real cars and the setups do not cross over. Oh yea I have worked for Indy car teams and NHRA Teams and we even have play on some parts of those cars also.

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Hey Steve I agree, but I was talking about .2mm of play in the center rear pivot ball, seemed like a lot to me.

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Old 05-07-2011, 06:06 PM   #1783
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Hey Steve I agree, but I was talking about .2mm of play in the center rear pivot ball, seemed like a lot to me.

Lonny
Yea, you are probably right. At times I get play with different parts that I don't think should be there but most of the time I don't notice a differance.
However hand fitting everything all the parts is the way to go....
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Old 05-07-2011, 07:26 PM   #1784
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Handfitting $300+ kits? Especially when these manufacturershave been designing kits for how long? I don't understand the mentality. A tad bit of massaging here and there.....okay. But you go handfit the kit of your choice, I'll stick with BMI.
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Old 05-08-2011, 03:21 PM   #1785
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.2mm is going to be from wear. We normally have about .002-.003 of vertical play due to the distortion you get of the leading edge of the ball detent when pressing the balls into the housing. If i did not offset that, the balls would bind slightly. This would be an issue as the car would feel tweaked. The slight bit of play seemed to be a better route as it does not hurt performance in any way.

The variables i chose to stay away from are these tiny, overstressed coil springs. There are many variances in wire diameter,coil pitch and spring length that do in fact play a huge role in performance. Any variance and your car will have an unbalanced feel as the spring progression and spring rates will vary. It will still drive but is not a variable i wanted to deal with. If you want to go over each manufacturers car with a micrometer, you will find plenty of variance. We on the otherhand hold extremely tight tolerances on all of the parts we make. Everything literally falls into place.

All the manufactures cars seem to work fine but i guess for some reason, i cant have any variance even when i have an explanation of why it is there. Its like you feel im blowing smoke.lol I guess if i was one of the other manufacturers it would be acceptable. Oh well, it is what it is.
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