Ear plugs in drive cups

[craigs1977]

It all started when i replaced dog bones (flm) in standard drive cups.10 mins of run time spat a bone out.So i replaced drive cups (flm) which seem to lock the dog bones in place.Had no problems since but still have another set of (flm) bones and standard drive cups for my t Im building.Ive read on (HBF) that some of the guys use spongee ear plugs in the drive cups that equalise the dog bones and should stop them from coming out.Im am going to give it a go and see how it works.Has any one else tryed this?.

[monster]

I have tried this method before but on 1/8th scale and I used o-ring or small cut of fuel tubing. However, I do have grommets in my FG ball drive cups and seems it's doing the job so far. Good luck with your experiment and let us know how you went

[suzukiboy]

I have a set of Phatdad dogbones and they came with dental pads to put in the cups, the ear plugs should work fine.

[speedy_vl]

I've also read that a lot of people are using Killer RC suspension limiting straps, which appear to fix the problem as well.

[main_event]

Originally Posted by speedy_vl

I've also read that a lot of people are using Killer RC suspension limiting straps, which appear to fix the problem as well.

Why don't you just use stock HPI cups - they are stonger then FLM and you will no longer have the 'bone popping out' problem

The cups are something HPI did right

[Global_Warmer]

I use PHATDAD drive shafts and have half an ear plug behind each end

[speedy_vl]

Sorry to disagree but i was constantly spitting the dog bones out with the HPI cups, and it's starting to do it again with FLM cups and PhatDad dog bones now that the pins are slightly worn.

[MONAROMAN]

Originally Posted by speedy_vl

Sorry to disagree but i was constantly spitting the dog bones out with the HPI cups, and it's starting to do it again with FLM cups and PhatDad dog bones now that the pins are slightly worn.

If you have a massive amount of preload or stiff springs on the rear it tends to spit them out, the dog bones should be close to level and the rear end should not sit too high, I have seen blokes with the described setup spit dogbone after dogbone, the best way was to "lower" the rear end a little and problem fixed.

I have had a baja for 2+ years now (actually 2 bajas) and have NEVER spat a dogbone, its in the setup.

[monster]

Originally Posted by MONAROMAN

If you have a massive amount of preload or stiff springs on the rear it tends to spit them out, the dog bones should be close to level and the rear end should not sit too high, I have seen blokes with the described setup spit dogbone after dogbone, the best way was to "lower" the rear end a little and problem fixed.

I have had a baja for 2+ years now (actually 2 bajas) and have NEVER spat a dogbone, its in the setup.

+1 for the set set up.

My Baja has been running for almost 18months and never lost a dog bone. I'm using DS meaty dog bones with stock HPI drive cups. The DS dog bones are a little twisted but the HPI cups are still like new I am yet to try the FLM bones.

[MONAROMAN]

For almost 3 years now all I have run are HPI HD bones and stock cups. I have run this setup with stock 26 CY and Zen's, ESP fullhouse 30.5cc engines, Allanach reed 26's, plastic and alloy cars, stock and RR steel gearing. If you don't land on the throttle then even the stockers are alright. I just don't get the whole DS, Phatdad, FLM crap. IMO its for those that can't drive (sorry to offend but IMO its true) use some common sense and the stock stuff is fine, I have never been one to ***** out when it comes to the throttle or getting 20+ ft of air, if its setup right and you can drive with common sense then you will spend more time driving and less time fixing.

[speedy_vl]

I didn't mean to cause a stir i was just sharing my experience with the stock setup. I dont know if i have an issue with my sotck cups but they will not keep the dog bone in them at all. I recently replaced one of my damaged FLM cups with a sotck one when i was tuning my 5T after putting on a new pipe, and it would keep spitting out the dog bones in a matter of seconds, no high speedruns, crashes or jumps just running on the lawn to try and get the tune right.

Im not trying to cause an argument but the stock stuff just doesn't work for me, i've just checked my 5T and it sits fairly level across the rear arms.

[monster]

Its ok mate, we are not arguing here. We're just basically sharing info/experience that might help others in the future.

If you're running stock lower arms check those arms for flex, too much flex will lead to popping dog bones too. Check your preloads too, should be around 20mm or less IMO. While you're at it give the whole back end a good check.....;o)

[speedy_vl]

Running RPM rear arms under a 2 tanks old, beats me they just wont stay in there for me.

[MONAROMAN]

Originally Posted by speedy_vl

Running RPM rear arms under a 2 tanks old, beats me they just wont stay in there for me.

spewin!!!!!

[redline]

I have never had this problem either with stock driveshafts and stock cups with RPM arms.

I have seen these used before http://www.elcon-models.com/products...6conicalspring

As monaroman said, too much preload on the shocks will do it (this is also a good way to snap the end off the shock shaft).