Operation Rat.

[jpmatrix]

The diagnosis... Cadburys chocolate transmission

Well, I wont be racing this weekend as my car is currently dead.

Bought this car at Xmas and have been to 4 race meetings at Torch which has astroturf. 3 of those meetings I raced with a brushed set up and Nimh battery) so I reckon the car has done a couple of hours of running.

I then decided to upgrade to brushless and bought a 2nd hand speed passion esc and 7.5t v2 motor. Installed last week and ran it at the last meeting and the car was a lot faster than previous.

I taken all the precautions namely tightening the slipper until the spring is fully compressed and leaving it for a couple of days and then backing it off.

I made sure the advanced setting on the esc was set at smooth and not aggressive settings. Timing was set at 4.

So today I basically was giving the rat a blat on grass to see that everything is ok ready for this Sunday and low and behold no transmssion to the wheels.

So after fifteen minutes of dismantling I discovered this.....




This is the secondary gear or whats left of it.

Another pic...



The rat... gutted..



Pretty fooked off to be honest. have hardly run it for more than 1 hour with a brushless set up and the transmission melts.

Anyone else had this and is there an upgrade for this gear?

Or I could just burn it

regards

James

[minke]

Powered by a flux capacitor

This is out of stock right now but may be what you need
http://www.tcmodels.net/index.php?pa...mart&Itemid=71

[jpmatrix]

Originally Posted by minke

Powered by a flux capacitor

This is out of stock right now but may be what you need
http://www.tcmodels.net/index.php?pa...mart&Itemid=71

Thank you. So the bearings just fits inside the gear?
Looks different internally or is that the way its macchined out.

[minke]

I've never had to fit one myself, but should be a straight swop. The next time I order from them I'll add one to the cart anyway and give it a shot.

[Tom3012]

Touch wood not had a problem with mine, ran it loads with a 6.5 and 50c lipos so loads of punch, been spot on...?

Question... Why so much grease in your gearbox??

[minke]

My instinct tells me the slipper may have been too tight. Fast acceleration with too tight a slipper could have caused it, though the spur usually goes first. May be a one off.

[nicefrog]

Just run your slipper a bit looser and use the standard gear again, the alloy one has been known to smash. Or outdrive? I think is their name make steel one in the States

[jpmatrix]

Originally Posted by nicefrog

Just run your slipper a bit looser and use the standard gear again, the alloy one has been known to smash. Or outdrive? I think is their name make steel one in the States

It is most likely the cause but I ran the slipper with the lock nut at the very end of the threaded shaft so I couldnt back it off anymore. I checked the slipper pads and I cant see any slippage marks so it obviously wasnt working right.

I definately assembled it correctly. Perhaps the spring is too strong?

What do people do to loosen up the clutch as I already got the nut on the end of the shaft?


James

[Tom3012]

If the slipper isnt slipping when loose then maybe your diff is too tight, id also remove all that greases and only use a bit in the actual diff...

[jpmatrix]

Does anyone know where I can buy a 28t idler gear for the rat?
Or if anyone has a spare then can send me I will pay

Looked at modelsport and they are out of stock.

[Tom3012]

Originally Posted by jpmatrix

Does anyone know where I can buy a 28t idler gear for the rat?
Or if anyone has a spare then can send me I will pay

Looked at modelsport and they are out of stock.

http://www.jespares.com/electric-mod...tegory_id=1297

[jpmatrix]

Originally Posted by Tom3012

http://www.jespares.com/electric-mod...tegory_id=1297

Cheers for that. There was 1 left.

I shall prep and more importantly clean all the gears and diff casing ready for installation.

i am just worried its going to shread it again.

What about the slipper spring, can I squash it in a vice so it will have a bit more give? It seems so stiff to me even when i had the nut at the end of the thread.

[Kusal]

Yes, I always do this for the diff and slipper spring!

[big-ell]

i had the exact same problem shredded the idler when i installed 5.5t brushless setup i squezed the slipper spring with a pair of mole grips and put a drop of loctite on the nut put it back together with the shaft just touching nylon bit went round torch today lasted all day

[jpmatrix]

Originally Posted by big-ell

i had the exact same problem shredded the idler when i installed 5.5t brushless setup i squezed the slipper spring with a pair of mole grips and put a drop of loctite on the nut put it back together with the shaft just touching nylon bit went round torch today lasted all day

Shame I wasnt there. How did you get on at torch? First time there?

There isnt many ansmann buggies there, just me and another member John known as 'MrMagoo' on oople forum. I am pretty new to the scene just been to 4 torch meetings this year since buying the rat at xmas.

Hopefully should be up and running this week so hopefully will see you down there on Sunday.


Regards

James

[Robbiejuk]

I had one go at the players meeting at worksop, but that is the only one I have done in 6 months of racing with an x12 6.5 and high powered lipos.

When you re-build your gear box make sure you remove all of the debris out of the layshaft and diff gear, use a sharp scalpel or a toothbrush (an old one obviously, not someone elses ) and make sure there is no plastic impacted in the gears. Clear all that excess grease out and when rebuilt you should be able to spin the gear box easily with no tight spots.

Just pout of interest how long was the grass you practicing on? And was there any dead grass wrapped around the drive shafts?

[Cameo]

Hang on a minute do nothing else until you read this.

1. The idler gear is like a suicide gear for the gearbox. It's the part that breaks when something is wrong as it’s the cheapest part. Like all metal gear servos have one plastic gear in case something goes wrong

2. My educated guess is the gearbox suffered to much stress and the idler gave up. Possible causes could be
a. The grass was quite long and this caused the car to work really hard to get through it.
b. The slipper is not tight enough causing excess heat build up and melting the idler.
c. both of the above occurred.

3. When you rebuild do the following steps
a. compress the diff and slipper spring (with a set of pliers just fully compress the spring 3-4 times)
b. rebuild the diff, tighten the diff screw to full then loosed off 1/4 of a turn.
c. clean all the diff gears with electrical parts cleaner and toothbrush - do not put any lube back on the gears. (Just inside the diff as the manual suggests)
d. rebuild the slipper and tighten so it has 1mm of thread showing past the lock nut (tighter than you had it)
e. DON'T drive it in long grass where you could stress the gear box out or you will simply break another idler.

Note - HPI do an idler for their Short Course Truck (Blitz) it fits perfectly into this car and is made of a more resilient plastic

[jpmatrix]

Originally Posted by Robbiejuk

I had one go at the players meeting at worksop, but that is the only one I have done in 6 months of racing with an x12 6.5 and high powered lipos.

When you re-build your gear box make sure you remove all of the debris out of the layshaft and diff gear, use a sharp scalpel or a toothbrush (an old one obviously, not someone elses ) and make sure there is no plastic impacted in the gears. Clear all that excess grease out and when rebuilt you should be able to spin the gear box easily with no tight spots.

Just pout of interest how long was the grass you practicing on? And was there any dead grass wrapped around the drive shafts?

well now you mentioned grass and dead grass wrapped around the shafts This may have caused the idler to die come to think of it.

There was a little bit of grass wrapped around the shaft, and the grass was about to 2inches.

Yes, I definitely made sure I cleaned all the residual crap out the gear teeth and box with a scalpal.

Thanks for the pointers.


James

[big-ell]

Originally Posted by jpmatrix

Shame I wasnt there. How did you get on at torch? First time there?

There isnt many ansmann buggies there, just me and another member John known as 'MrMagoo' on oople forum. I am pretty new to the scene just been to 4 torch meetings this year since buying the rat at xmas.

Hopefully should be up and running this week so hopefully will see you down there on Sunday.


Regards

James

hi james had a great day at torch good track nice people. I raced 1/8th truggys before, beating wylie all the time but havent raced since 2007 so a bit rusty out there. i was last in every heat but was heading in the right direction at the end of the day as for the rat very impressed for a £50 kit amazing went on all day without a hitch

regards big ell