Cole Trickle

From time to time, I hear someone talk about radio noise and glitching, because of the use of carbon fibre.

Is this true, or is it just a rumour because of one or two bad experiences compared to the million cars out there with carbon fibre?

popsracer

Cole Trickle;

I had an HPI Pro-2 that would NEVER stop glitching. Two of everything, Motor, ESC, Servo, Receiver. With the antenna down the car would glitch a 10 feet.
I put ALL of my electronics in my Boys Tamiya TL01 and could go to the end of my block with NO glitching what-so-ever.
HPI finally said to send the Car and Radio in for evaluation. I dismantled the Car for parts.
After talking to other people who have or had Pro-2's. Some had the exact same problem with their cars and some have had no problems.
I also called Futaba and mentioned the glitching and the guy asked me if the car had Graphite in it. When I told him what kind of car that I had, he said that "sometime there can be a BAD run of Graphite that will cause the problem". This guy told me he has been in R/C for over 20 years and has seen this problem before, so I'm inclined to believe him.

Cole Trickle

Hmmm. How can it be they still sell carbon cars?

Focus_Racer

I though that real carbon fiber was a electric conductor and could cause problems with some electronics. But yet you see alot of CF chassis, are this electronics too small is some cases to cause problems or is this just a rumor?

popsracer

Guys;

Carbon Fiber IS an electrical conductor. This is the reason for having a chamfer in the battery slots. If the sharp edge of the slots cut through the batteries shrink wrap ZAP, POW, and I've seen it happen.


For the most part there are very few problems.
However as I said, " Once in awhile you get a BAD run of Graphite" This has been confirmed to me by several different people that I've spoken with.
If you ALREADY have a Graphite chassis-ed Car and are not having any problems, Don't worry about it.
If you are THINKING of buying one, ASK some people that have the exact same car if they have ever had problems. I have also heard that 27 mhz is LESS effected by the Graphite than 75 mhz.

Cole Trickle

Nice tip, thanks. Maybe one should ask people with the same car, same radio and same mhz.

coolrcdad

I'm inclined to believe this is a rare problem. A friend with a FTTC3 switched to the composite chassis and solved his longtime glitching problems. No one else I know with the graphite car has had the same problems. This after he bought new electronics and even tried filing the edges of his brushes to see if that reduced noise.

popsracer

Coolrcdad;

I like your user name.
Yes the graphite problem IS rare. The HPI Pro2's had about 20-30% of the Cars with that problem. This I estimate from talking to other racers that have owned a Pro2 at one time or another. I have heard of Zero problems with HPI's Pro3 when converted to graphite components. Some guy online complained about his Losi XXXS glitching when he went to the graphite chassis, but that's the only time I've heard problems with Losi's.

Thanks,

popsracer

Cole Trickle;

I see in your signature "HPI Sport-2" which is basicly the same as the Pro2 but with fiberglass instead of graphite. If you upgrade to graphite, save your fiberglass pieces to reinstall just in case you have problems. There STILL may be some Bad graphite floating around for these cars.

Cole Trickle

Thanks for the advise, but I wont upgrade my Sport2. I've been very happy with it for 2½ year by now, but it's quite worn by now. So just to make it a good shape again will take over 1/3 of the price of a TC3 FT or Mission Carbon. Besides, HPI Europe support us danes very bad now. It's not un-normal, that it take over 3/4 year to get parts.... Bottom line, my car is good, but the support is bad and parts prices are gone to the sky.

Action-RC.com

Also, sometimes the way electronics are mounted can cause glitching. I mounted my reciever with velcro, and it stopped the glitching I had. I mount them all now with velcro, weather Am or FM. The velcro cushions impact, and makes the parts easy to remove for cleaning. Also, some people have had a problem with chassis's that have the antenna wire thread through them, like Losi and Associated do. you can try to wrap the antenna around the tube so it doesn't touch the chassis to see if thats the problem. Personally, I don't think there's a problem with graphite parts themselves. Something has to cause it. Even a piece of metal rubbing on it can cause glitching. Look at nitro cars, when you put the glow ignitor on, the servos glitch till you remove it with cheaper radio systems. I have had some high end radio's do that as well though.

Jack Smash

iTrader: (35)

I custom built an oval pan car a while back and the battery came lose in a bad wreck and the car caught fire so you better believe carbon fibre is a conductor.

-CriMinaL- |RC

The reason your car caught fire was due to the impact of the batteries and ground.. just because carbon fibre is a conductor, that wouldnt cause your car to burn . You pack obviously exploded on impact and caught fire

Jack Smash

iTrader: (35)

Actually the cells shorted out on the chassis and then caught fire a few seconds later. It was kinda cool to watch. Nothing else in the car was damaged and the driver walked away.

-CriMinaL- |RC

ok then ...