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Old 05-17-2004, 12:51 AM   #8596
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Hi friends. Greetings from Malta.

DAVE W.

We run GT7s on our cars. I have run other speedos too.

I recently moved the electrics around on my son's TC3 and suddenly got masses of glitches. I tried the usual remedies but nothing worked. i moved them back to their original position and the problem was solved.

Clearly the positioning of electrics is very critical and modern touring cars don't give you much space to play.

One favorite one with TC3s is the aerial wire rubbing and shorting on the graphite but I expect a seasoned racer like you will have already seen to that.

At the risk of being repetitive I am attaching a pic of son's TC3. With electrics fitted this way we have no problems.

regards

Joe from sunny Malta.
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File Type: jpg jan 04 jb tc3.jpg (99.9 KB, 219 views)
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Old 05-17-2004, 06:13 AM   #8597
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JOHNBULL: I was thinking last night, i switched to the GT7 to go to the Snowbirds in 2003. My first GT7 didnt have the external schottky diode mounted on the power wires. I had no problems with that one. The second one i bought for my ASC B4, and it was the same as the previous. As they aged, i had problems with them. Recently, i swapped the first GT7 through Novak for a remanufactured one, along with my receiver. The new GT7 has the external schottky diode. All of my problems were with the first generation of GT7 in both cars, graphite OR composite chassis. This past Snowbirds ('04), my glitching was terrible. The best i could muster was a B main qualifying position. I swapped everything i could think of, including the radio and module, speedo and receiver. So i got the new GT7 and new XXL, bought new crystals for my M8, and installed a brand new Airtronics 94357 for steering duties. I purchased NEW motors too, both stock AND modified. This past Saturday at our local club race, the glitching began, but moderately. A hit here and there. Sunday (yesterday) a few racing friends of mine and i decided to drop out some cones on the tennis courts here in my apartment complex for some practice. The glitching got increasingly worse. (all the steel fencing??) I swapped motors just to see, and that didnt make it any better. I grounded the negative pole of the battery to the chassis with 14g wire... that fixed all the issues... for now. I am so frustrated. I am going to tear the car completely apart, add all composite parts, even in the driveline, to see if that might be the culprit. I have the IRS light drives and Niftech SWD aluminum dogbones along with a titanium Niftech driveshaft. I have moved the electronics around SO much in this car, i have gone through an entire roll of servo tape. I can definitely relate to the GT7 being sensitive to placement in the car! I have HAPPILY raced Novak products since i started racing in '93, and i am seriously considering a change. Keyence speedos anyone?

- DaveW
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Old 05-17-2004, 07:58 AM   #8598
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John > My Electrictronics with my TC3 and the GT7 are almost in the same place, but I have my GT7 turned the other way and i put the receiver on top of the servo.

One thing i will mention about glitching. Are you using a personal transponder? Man those things cause glitching if they are to close to the received. Orginaly I had it on top of the servo and glitch central. I have a JR R1 and I never glitch.

Anyway, I moved it to the front of the car on top of the bumper and BOOM, no more glitching. Just something to think about.

I will try to take a picture and post it here later today.
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Old 05-17-2004, 06:01 PM   #8599
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hey DaveW

if grounding the Neg side of the batt to the chassis solved the problems for now ... dont tear it apart yet .. go get a can of static guard spray and hose down the underside of the chassis and then let it air dry ... I have had to do that a bunch of times to cure glitching when rug racing ... I wouldnt think that outdoor racing would create that problem .. but it might have picked it up from somewhere else .. a carry bag .. or something ... give that a shot ... and yes inside a tennis court the glitching will worsen due to all the fencing around ... ( I am a radio technician for Motorola for my day job )... give that a shot befor going back to the flexy chassis .. also folks at the carpet track here had problems running the ti drive shafts ... created a lot of RF noise .. even with the composite / graphite drive cups ... might want to also try just switching back to the alum one ...

have fun racing

E

Last edited by roddude65; 05-17-2004 at 06:06 PM.
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Old 05-17-2004, 06:25 PM   #8600
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I ran my FTTC3 with a new monster stock lightspeed motor and man was that motor on fire, literally, hot to the touch. We put a temp gun to it and it read +200 degrees, not good at all. I ran a 96 / 33 = 7.3 FGR. I thought maybe I should go to a 7.5-7.8 range to see what happens, still hot but slightly less that 200 degrees, 194. This was at 7.7 (96/31). From the looks of it, I'm going to have to gear this like a mod motor, around the 8.25-8.50 range just to get this at the 140-160 degree range. Nothings is binding, drivetrain is free, I'm running 3300 brand new fukayama batteries and the motor was brand new out the package when I ran it this weekend.

Any usuable suggestions? I contacted lightspeed but I guess there off today

Thanks
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Old 05-17-2004, 06:31 PM   #8601
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Quote:
Originally posted by Mike F
I ran my FTTC3 with a new monster stock lightspeed motor and man was that motor on fire, literally, hot to the touch. We put a temp gun to it and it read +200 degrees, not good at all. I ran a 96 / 33 = 7.3 FGR. I thought maybe I should go to a 7.5-7.8 range to see what happens, still hot but slightly less that 200 degrees, 194. This was at 7.7 (96/31). From the looks of it, I'm going to have to gear this like a mod motor, around the 8.25-8.50 range just to get this at the 140-160 degree range. Nothings is binding, drivetrain is free, I'm running 3300 brand new fukayama batteries and the motor was brand new out the package when I ran it this weekend.

Any usuable suggestions? I contacted lightspeed but I guess there off today

Thanks
Check Your Drivetrain, If its Dragging it will put a Load to the motor. Also If its a Tight track it might get that hot....
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Old 05-17-2004, 06:35 PM   #8602
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Thanks.

Drive train was free. Tight was a little tight. My bud was running everything the same as I was. FTTC3, same lightspeed motors, the only difference was that he was using the 48 pitch gears and I went with 64. His gear ratio was about 7.9 and it was only reading 146 degrees. His driver train was free as well, I know I built his car.
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Old 05-17-2004, 06:36 PM   #8603
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Well, Check ur mesh. If its too tight that can cause it too. Other than that i can't say much w/o it being in my hand. you mgith want to try going Lighter springs too on motor if your really worried
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Old 05-17-2004, 07:01 PM   #8604
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motor mount might be tight, also what esc are you using?
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Old 05-17-2004, 07:27 PM   #8605
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lighter motor springs may help but your springs can also be too light and are bouncing on the comm causing excess arcing. Also, a poor motor lathe cut can cause arcing. Do you use motor diodes?
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Old 05-17-2004, 08:10 PM   #8606
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Default Steering Rack

Hi all,

I came across a slight problem yesterday during the race day. I noticed that the steering rack when it is fully extended to the right-side of the car causes some binding when it returns. I noticed that it takes more force to move right to left. Also I noticed that when going right to left, the servo saver reacts with the extra force needed. It almost feels like there is a bind at that point. I heard that this may be normal.

Has anyone adjusted the turnbuckle length between servo and rack to comensate for this phenomina?
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Old 05-18-2004, 01:03 AM   #8607
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Hi Dave. greetings from Malta.

Yes you are right about the first batch of GT7s. They were more susceptible to glitching. I hadproblems with them too.

However the newer ones, without an internal schottky diode and with the large external one went a long way to improve the problem.

Certainly conditions around the track can have a serious effect on interference, and yes, some speedos catch it all more than others. parked cars in the area, especially with their radios on, are a perfect culprit. Metal railings etc are the enemy too. We have them all at our track and yes we do get some days when the glitching gets worse than others.

I also run a normal schottky diode on my motors. I find it helps.

Regards

Joe from sunny Malta.
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Old 05-18-2004, 07:57 AM   #8608
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Guys, thanks for the ideas! Ill try them and let ya know what works.

MikeF: The armature may have a short in it. It still runs, but gets extremely hot. The Trinity GM3 motors used to do that alot, dead shorting where the wire is wrapped around the arm stack. The epoxy would bleed some voltage, shorting out that side of the stack, the wires getting dark red to black. The motor ALWAYS ran hot, no matter what you did to it. Try swapping the armature with another one to see if that fixes it. If not, the PC board the caps are on may have shorted, but usually you get the dreaded glitch as well. OCCASIONALLY, i have found a bushing not seated correctly in a stock motor. Usually in the can end. If the bushing is cocked at an angle, the arm wont spin well, and cause it to overheat. Maybe a magnet came unglued from the can and is rubbing the armature... look for scratches on the arm and magnet... see if it wiggles loose. Just a few ideas...

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Old 05-18-2004, 08:06 AM   #8609
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RINKRAT: Try swapping the spring in the rack with a firmer one, if you have a metal gear servo. Then make sure the link from your servo to the rack is at a 90 degree angle from the servo arm at neutral. Making sure of this will equal the force left and right on the rack from the servo. This should also bring your EPA for steering REALLY close. If you have an Airtronics M8, the numbers should be in the 70's left and right, with the Losi steering knuckles on the TC3. This is setting max EPA left and right with the car ready to run sitting on your workbench (steering under load). If your servo is buzzing constantly at max EPA, you are doing damage to your servo by having it force the rack too far each direction.

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Old 05-18-2004, 11:50 AM   #8610
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John Bull.

Whats up with the rear camber link positions on your boys TC3??
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