hey guys, im having problems with my ct4s belts. my problem is not with the front belt, but rather the side belt connecting the rear to the front drive train. now the first belt went after 6 tanks from new... not happy. so then i bought a new belt, $27AUD and the tensioner $35AUD, to hopefully solve my problem... now, only after 2 TANKS, the new belt stripped!!! what is going on. any have any idea on how to stop this? i never used to have problems with other belt driven cars i owned..
any help please

I sent you an e-mail. Hopefully that helps with the problem. If not contact CEN and see if they can fix your problem.

there are others there will like to see a solutions to this problem why not post it here ?????

I really didn't have a solution but I had some suggestions.... Here is what I put in the email....

How loose is the side belt? I have had my car almost a year now and I have never had to change the side or rear belt. I have had to replace the front (main) belt about 3 times due to the 25T pulley being ground down on the left side so lossing the left side support causing the belt to slip off. But your side belt should not be stripping out. If your belt is tight, look at the 17T pulleys. The groves in them might not be deep enough for the belt groves and causing your belt to slip. If thats not the problem I would contact CEN and talk to one of there reps and see what they can do for you. Contact Mike...
Mike
[email protected]
714-792-1923 ext: 105
there is his email address and number with his extention. He helped me out on a package I received. I ordered the brake up-grade and it didn't come with the brake disk. It only came with the pad. I contacted him and he sent me a new part with out any questions or returning the other package. Also if you can send me pics. so I can see what might be the problem. I wish I could help you out more. Let me know what you find out.

Thomas

just a thought guys...

belt tension is normally related to by deflection of the belt, given a certain force. how much deflection do u guys, who are having no problems, have on ur belts?

say... how much the belt moves, if u put a relatively heavy standard part of the car on it?

ive never been a fan of belt drives, but if they can be made reliable, i would be more interested in the ct4.

It could be possible that your sidebelt is too tight. Like the previous person said make sure the pulleys are in good condition and make sure they are not too tight. They just need to be tight enough so they don't slip. The side belt you can run pretty loose. I did have a problem once when I mixed up the pulleys and put the wrong one on and that caused some problems. You should make sure that you have the correct pulley in the right place too. Hope that helps.

I have replaced all my belts and now I'm having problems with my brake not moving back to the nutral spot when the brake is applied. Any suggestions on what I need to do to fix this.

the pulleys were both fine, and they were the correct ones from the factory, and they only go on one way. since last post i stripped a 3rd belt, with belt tension very light, then i replaced the pulleys, as im running out of ideas, and them, with a new belt, no change, stripped in 2 tanks. ive given up. i made my own drive system for the side belt using hpi pulleys and belt. runs a thrid pulley inplace of the tensioner to remove slack and to guide belt aswell. see how it goes the next time i run it. i am also going to try and get a longer belt to use for the side belt, with the use of 2 25t pulleys instead of the standard 17t's.
last belt driven car i ever get...

ok, whilst i was at it i fitted the copetition drive train kit cause i wanted more acceleration. now with my new custom drive set up in place of the side belt, took it for a run and it runs like a dream. im using 2 hpi 17t pulleys, hpi rear belt, and i modified one of the original cen 17t pulleys by drilling the centre out and fitting 2 ball bearings in, and put it in place of the old tensioner so it acts like an idler....works a treat. havent had a problem yet and i dont think i will. the hpi belt is a much better quality then the cen. here are some pics..

Looks like a good modification if you are having trouble with the side belt. Good Work!!!! Sorry I couldn't help with the belt problem. But I am still wondering why your belt slipped. I don't have a tentioner on mine and it works great. I have never had to change out the rear or side belt yet and I have had my car fora year this July. It seems that all parts are not machined the same way. Some part my be shorter; longer; or not wide enough to fit properly. But, good job on getting the problem worked out!!!

I changed my servos out and everything is fine just one thing though now my large belt is rubbing up against the steering servo.

put some washers, a few mm thick in between the servo mounts and the servo, this will move the servo out, away from the drive belt, should do the trick

hello again. i dont know what it is with me and cen drive belts, but since my modification to the side belt (still works a treat), my rear belt has started to strip aswell. so this time i didnt mess around, i just made a custom tensioner for it straight away, and used another hpi belt instead. i used the same tensioner as the front belts, bent the wire into the required shape, and drilled and countersunk the chassis, and mounted the tensioner. havent run the car yet as im waiting on some other bits, but i can see that it will have the same success of the side belt mod. if anyone is interested in more information or pictures, please let me know

I have since done the upgrade aswell. But had to add another tensioner as the HPI belt i received must have been a little longer than Raap51's belt.. I have also done the Genesis Metal gears Mod as metioned on another post on this site..



I have also replaced the 16t plastic gears that come with the compitition package with 17t metal ones. I ended up using one of those plastic 16t gears as a runner/guide for the side belt mods.



These are the same units as the 17t metal side gears but u have linish/grind the side of the gear down so the bearing and cir-clip can fit on. When u see the old 16t ones and the metal ones side by side u will see how much u have to grind down. Its about 3mm. The metal gears have also taken up all the slack in compitition drive belts. I know rear is 177t, front - dont know... The front belt tensioner has been wound right off aswell, leaving no adjustment. The tension on the belt is perfect - maybe a little tight - but the car still rolls quite freely and shows no signs of energy being eaten up by the belts at that tension. The whole driveline is solid! Finally!

I have set this car up as a drifter aswell, some say this puts more stress on the cars belts, some say less, but since doing these mods all belts are holding up strong. I've had to replace the front belt only because an acorn from a tree got wedged in and sorta locked the front up a bit.. The only other problem im getting now is the clutch bell seperating from the pinion gears. I have just installed a new bell that i soldered up to give extra strength. Alloy tig welding will probably be better tho as solder doesnt stick to alloy.. If it breaks again, im just going to replace the entire engine/clutch/bell with somthing else with a more solid setup.. And more hp!

Havent done much other mods to it. Just an exhaust, futaba steering servo and drift wheels/tires.

Interesting but I don't think I would recommend your modification if your racing or dragging it appear to add a lot more weight to your car then most people would want. I'm still using my acceleration kit and I'm using a smaller faster motor. My car is doing fine. Plus you need to take those rubber tires off and replace them with some foam tires. Those rubber tires will have you sliding all over the place.



HAy has anyone seen the new CT5 from CEN?

I dont see how it would add too much extra weight. Yeah i suppose the Genesis Metal gears weigh a bit more than the plastic ones, but the other drivetrain mods would be be almost unoticable in weight difference. The 17t metal gears are not that heavy compared to there 16t plastic cousins.. But anyhow, i dont race, and dont know what the race scene is like. I guess, if your a super RC nerd, every half a milligram counts, but, i think the reliability factor far out weighs what CEN gives u out of the box or in the compitition kit..

The foam tyres i have are great for corners and top speed stuff. But i have the Yokomo drift tyres on it for a reason. I like drifting.

And yeah, i have seen the CT5 kit.. Not to sure on the differences.. But i bet theres no metal gears..

nice work there - good to see some progress on a long running problem

what pinions are u using out of interest?

and as for the weight of the gears - i noticed it a bit on my funfactor, but like u say, if u dont race then reliability is the most important issue. surprised that we havent heard of more people using the genesis spurs - they seem indestructable.

I just use the Cen 14/17 clutch bell/pinion gear.. Know of any others that work? I tryed fitting an old clutch bell/gear from an OS12 that was in a mates Kyosho V1s. It fit on, but the pinion gears were too thin.. Can the FunFactor bell have 2 pinions fitted to it? Or is it 1 gear only?

oh man dont get me started on pinions... lol - im about to try the hyper 10 steel pinions and bell along with an associated m12 threaded bell for the genesis pinions.

isnt the 14/17 a bit light on the mesh for 1st gear? better to have a difference of 4 teeth on the pinions as well as the spurs isnt it?

yea cen do threaded 2 speed bells, but finding pinions that dont wear to quick that will fit it is a bit tricky ie not alloy pinions.... ive used hyper 7 2 speed steel bells and gears on my MT with a bit of shimming and messing with the engine mounts, but for a ct4, ur best off with cens 1 piece 14/18 steel bell, or try the hyper 10 stuff if u can find em, ofnas pinions are a lot harder than cens. having said all that - if the associated bells work ok with the genesis pinions, then that gives the option of a 17/21 steel bell, which would give u a little top speed back if thats what u want.

typically i just sold all my excess pinions and seven cen 2 speed threaded bells on ebay...

no doubt i will be spamming pics etc of what works and doesnt when all the bits finally arrive. theres a big pinion discussion in here somewhere that covers loads of options, could be in the "28 in a funfactor" thread somewhere.

the kit has 16t pulleys which will alloy you to have a faster take off as well as speed the lower the teeth on the pulley the faster and quicker you will be.

I haven't had any problems with my plastic spur gears at all.

OK - this has been a long time problem with the ct4's.. But after some research i have found replacement belts for all 3 belts on the ct4s.. Some modifications may be needed as shown previously in the post.. The belts are -

Rear Belt
ONFA NZ10 - stock # 38070
Length - 177mm - cen part - 177mm
width - 4.5mm - cen part - 3mm
Teeth - 59


Side Belt
HPI # 87007
Length - 174mm - cen part - 171mm
Width - 4mm - cen part - 3mm
Teeth - 56


Front Belt
HPI # A726
Length - 405mm - cen part - 402mm
Width - 5mm - cen part - 3mm
Teeth - 135


I havent actually received the belts yet, but i've ordered them. You can buy the belts from here
http://www2.omnimodels.com/cgi-bin/woi0093p?&C=CLF
http://www.towerhobbies.com/listings.html

The HPI front and side belts will have tensioners so they should take up some of the slack given by the slight changes in lengths between the Cen and HPI belts. The qaulity of the belts are also 10x that of the CEN belts! Look at the last photo's teeth!!

The rear belt has to be spot on. The Onfa belt is exactly the same length as the Cen part - so in theory - this should work also! Im not sure on qaulity - but from the photo it doesnt look too bad... Anythings gotta be better than those Cen rubber bands!!!

I really hope this is the end of the ct4s belt problems!!

These belts may also work on the rear of a ct4s.

HPI A848
Length - 180mm
Teeth - 60


Tamiya TRF 414 #49175
Length - 177mm
Teeth - 59

great work on the updates and mods.. this will help me if i run into these issues with the CT5.
Timmahh

OK, the OFNA 177mm belt fits on the rear of my cen which has 17t metal pullys. All though i think the belt quality is the same as the Cen rear belt. I have fitted the HPI 180mm 60t belt to the rear with a tensioner as belt qaulity is much better. click [link=http://www.rcuniverse.com/forum/m_4334981/tm.htm]here[/link] for details of mod.

The HPI 405mm front belt replacment is a little long. But, i will try fitting another tensioner in front of the one thats all ready on it. I think it will work, just need some time to do the mod.

And the side belt mod is bullet-proof!!

geez...i havent been on this site for ages, i had no idea my thread kept on going. well i didnt do enough research when i got back into RC, and as a result i bought the cen CT4S since it looked the goods. well i had so many problems with it, and the car was just a hasstle to drive, and very expensive to maintain due to poor quality parts. this belt problem was only one of the problems i had with the car, and after spending over $600 on it not including purchase, i decided to cut my losses and sell it, and buy a car with much better build quality. i bought a HPI RS4 18SS, and this car is far superior to the cen, and to this day have not had a problem with it, couldnt be happier. all my local hobby shops cant even give the CEN's away, some even dropping prices by hundreds, they want them gone, and arnt stocking the cars in future...
i hope you guys dont have the same misfortune i did, but for a next car maybe consider something with a bit better build quality