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Old 12-12-2010, 02:56 PM   #1
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Default Xray T1R/EVO brushless,lipo conversion by [email protected]

Hello. This was mainly a school project but I hope I will have some fun with it and maybe it will be helpful for someone.

http://www.facebook.com/album.php?ai...3&l=121c841103
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Old 12-12-2010, 09:40 PM   #2
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hey you are from slovakia eh, the land of xray ! it must be easier to get parts? i see that you used solidworks to design your modifications. i too use solidworks. personally i would have went for saddle pack lipos instead of a stick laying on one side, but thats your choice. i designed my own diff cup which were longer than stock so that i could use TOP photon CV joints on kawada sv10 alcyon2. That chassis was designed by you?
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Old 12-13-2010, 08:08 AM   #3
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Not really. The price and ability to get parts is similar. But the good thing is that they are organising events on their really quality tracks but I havent been there yet I havent used saddle pack because I dont have it and wanted this configuration. I was able to machine it on lathe and mill so it wasnt problem. If you mean bodywork. I designed the older one and it worked as pattern for this one.
But still there is one thing about what Im worrying. Dont know exact name for it but left and right wheels arent equally loaded but right and left car side is equal. Its caused by the motor position. Its more backwards and outwards than it should. I cant change its position along so I will have to mill those motor spacers again.
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Old 12-13-2010, 09:11 AM   #4
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Use stick pack across chassis under front belt. You'll have to make belt tensioner that will help you get a little bit more clearance over lipo so belt won't rub on it. Throw away idea of spacing motor (you can't really make it better with spacers, only worse).
I did only use T1 (very first version) for fun once with saddle lipos but was considering stick pack so I had idea how to sort out issues.
With stick pack across chassis you're able to play with weight distribution and balance more. I would also recommend to try make new chassis (probably narrower).

To spares for Xray - T1 spares are hard to get anywhere, fortunately we've still got some (though missing central pulley which I've got damaged) in stock for our local racers (or me if I'll decide to run my T1 again )
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Old 12-13-2010, 10:37 AM   #5
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Why spacing motor is bad? Its only few millimeters and its quite strong. I have done some tests in house and didnt realise any problems of this matter. The only problem that I realised were jumping front wheels in turns under throttle. But its of T1R construction and im unable to solve this

Anyway I saw some version with battery across but I dont like it because there is an increasing risk of battery damage during race. And also you get a weight more backwards than you would like + those problems with front belt. New chassis would be cool but it needs alot and serious changes to car and its not worth of time I think.
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Old 12-13-2010, 10:59 AM   #6
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Why spacing motor is bad? Its only few millimeters and its quite strong. I have done some tests in house and didnt realise any problems of this matter.
Because you're getting your car out of balance when it has perfect position of motor. Maybe it won't be major difference on the track but I wouldn't mess with that. You've got car that actually allows to center motor so why don't take advantage out of it?

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The only problem that I realised were jumping front wheels in turns under throttle. But its of T1R construction and im unable to solve this
Stuff your cvds with graphite or moly grease - it will reduce chatter to some degree - with current cvds it's present in all cars.

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Anyway I saw some version with battery across but I dont like it because there is an increasing risk of battery damage during race. And also you get a weight more backwards than you would like + those problems with front belt. New chassis would be cool but it needs alot and serious changes to car and its not worth of time I think.
I don't really think you'll introduce big risk of damaging of cells, chassis is very wide anyway so that will take all beating . To weight position actually it's much closer to weight distribution it was designed with - remember that car used NiMH saddle packs which were much heavier than current lipos. So you'll still be missing some weight from old time cars Anyway it should be just ok with lipo in rear in across the chassis.
Yeah you can ditch new chassis idea (quite a lot of preparation and need of good material) and just stick with what you've got.
It shouldn't be big deal for you to make small ballbearing holder that will push front belt a bit higher so you'll get actually better clearance over battery after making all those spacers, bulkheads mods and battery holders.
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Old 12-13-2010, 11:09 AM   #7
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I actually cant measure how is the car unbalanced in that way but I assume thats a few grams difference. My idea is to mill 3 mm from motor spacer and add 10 grams of led on servo and it should be perfectly balanced - says CAD software
Battery across isnt really good protected. I think its a risky because big part of it is out of carbon plate and too close from wheels.
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Old 12-13-2010, 11:26 AM   #8
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Originally Posted by [email protected] View Post
I actually cant measure how is the car unbalanced in that way but I assume thats a few grams difference. My idea is to mill 3 mm from motor spacer and add 10 grams of led on servo and it should be perfectly balanced - says CAD software
Maybe left to right overall but not left to right at front and rear axle respectively. In current conventional designs battery is supposed to balance motor, but in your car there is nothing to balance what you moved outwards. I hope you get what I mean.

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Battery across isnt really good protected. I think its a risky because big part of it is out of carbon plate and too close from wheels.
Wheels aren't really issue, only problem that can happen is ground scratching - on carpet it can introduce some handling issues in turns and on asphalt also can scratch case. Anyway as far as I remember it didn't hit ground sooner than chassis when I was trying to fit it in.
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Old 12-13-2010, 11:40 AM   #9
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I know what you mean. But with changes im planing it shouldnt be a problem. I simulated that configuration on PC. But as I dont have 4 scales I cant measure it in real. In T3 you have motor more outward but less backwards so the main difference will be mine CG placement more backwards than its in T3. And also I forgot that I simulated version with across battery and couldnt get any good configurations of electric system. In this version of car I think I made a very good electronic placement.
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Old 12-13-2010, 10:02 PM   #10
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Quote:
Originally Posted by [email protected] View Post
I know what you mean. But with changes im planing it shouldnt be a problem. I simulated that configuration on PC. But as I dont have 4 scales I cant measure it in real. In T3 you have motor more outward but less backwards so the main difference will be mine CG placement more backwards than its in T3. And also I forgot that I simulated version with across battery and couldnt get any good configurations of electric system. In this version of car I think I made a very good electronic placement.
here is my saddle pack car, with same layout as your xray, see how i modified the battery to be close together, and they never leave the side of the chassis.



the lipo is so light, and the weight is so centered, that i dont have to run anti roll bars anymore. The motor and the batteries are now passing through the center, unlike in the old saddle pack design. previously with stick or saddle pack Nimh, i have to add really thick antiroll bars to prevent roll. now days if i place any roll bars, i lose grip. becuase it rolls much much less now. i feel this will work on your car also becuase of the centered motor layout.
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Old 12-13-2010, 11:52 PM   #11
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what happened to your lipos??
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Old 12-14-2010, 03:03 AM   #12
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what happened to your lipos??
i removed the hard casings and soldered the center connectors together, so they now form a compact ,rigid and centralized unit !
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Old 12-14-2010, 10:46 AM   #13
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1. I dont have saddle packs.
2. I have different car
3. I would never do something similar to my battery. Thats just too much of risk.
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Old 12-15-2010, 03:15 PM   #14
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Load difference between wheels across is 7g so 14g overall unbalanced.
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Old 12-15-2010, 05:23 PM   #15
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Load difference between wheels across is 7g so 14g overall unbalanced.
you mean in what setup ?
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