ShadowX

iTrader: (10)

I'm hoping someone can help me with this....I run both a mugen Ninja.21 and also the newer O.S. Speed tuned .21 and have been having problems with stripping out the 3x6mm button head screw that screws into the end of the crankshaft. Ya know the screw that holds the clutchbell to the flywheel. Pretty much the last screw used on the whole clutch system that needs loc-tite added.

BTW I am riding a Kyosho MP9 kit and using the 3x6mm screws that comes with the kit. Everytime I change my clutch shoes or just the opposite while going to tighten down the screw nice and tight the hex screw wants to start stripping right as I am really starting to tighten it really well.

Is there another type of screw I can use here and if so which company? I just do not like the idea of going to Lowe's when I may be able to order some kind of specific screw from a company like Amainhobbies or others.

The screw I am using is Titanium and once again it is a 3x6mm hex screw but the 2mm hole is just too small even using an expensive set of hex screwdrivers.

Thanks in advance. I am so sick of breaking out the Dremel to cut in a score so that I can use a flat head screwdriver to remove it.

Again I would appreciate any recommendations greatly this is getting aggravating.

blade954

iTrader: (23)

I would go to a high quality steel screw i only use ti screws in low end maintenance areas as i find they don't hold up to the riggers of RC racing in areas where you wrench a lot. In the last five years i have not put a drop of loctite and never had a bell come loose....touch wood..

got_nitro

iTrader: (24)

The thread pitch of a traxxas screw is the same as the threads in a o.s crank. In fact, it's the same thread pitch in JR, Futaba, Savox splines too. I usually use a cap head with a drop of blue loctite. Dubro makes nice cap heads that will fit.

Stubbs

iTrader: (58)

I was having the same problem. I finally stopped using loctite. Now I just take a pair of side cutters, and squeeze the threads just a little. It deforms one thread, which makes for a very slight interference fit.

It's basically a mechanical "locker", and gives enough resistance to keep the screw from backing out, nt not so much that the head strips.

triplebvalp

Although, I have never stripped the screw you are referring to, I have used these screws, in other locations, with great results:

http://www.tonysscrews.com/

ShadowX

iTrader: (10)

Thanks. I found some nice steel cap head screws on amainhobbies by a company called "Avant". I don't see why these would not work I mean they are 3X6mm which is the same size that I am using now.....could be wrong but at least they are cheap enough to where I'm not losing out much at all if they don't work....again correct me if I am wrong but they look fine to me.

I'm just now noticing the link for Tony's screws up ahead just now may order some of those as well....because now I'm a little paranoid that the avant screws may not work,lol....knock on wood here as well.

I'll see how they work. Having a nice socket head should make it much easier to really tighten up that screw.

Ruune

+1 on the hardened steel cap head screws. If you use loctite, only use blue/non permanent.

I use cap head screws and hold the flywheel in a cloth with some channel locks, then tighten the piss out of the screw.

ShadowX

iTrader: (10)

Yeah that's the same way I tighten up that screw. BTW should these work for both the O.S. 21xz-b and the speed tuned version?

I'm not allowed to post links yet but they are from amainhobbies called "Avant 3x6mm grade 12.9 Alloy Steel Socket Head Cap Screw".

I should have asked first but it was the only steel ones I could find. Thanks again if anyone knows.

curacing2

It pays to use the 3mm steel screws that have the 2.5mm driver size hole and not the 2mm drive dome headed screws because you want to do them up quite tight and not worry about stripping out the hex shaped hole.

Yep they look like the right ones.

ShadowX

iTrader: (10)

Yep the 2.5mm driver size holes are the ones that I received and they work amazingly. I can use an L-wrench 2.5mm and make sure I have the flywheel wrapped before putting on pliers of some sort and then really tighten that bolt up and don't have to worry about stripping out the head of the bolt...why they do not supply these kinds of bolts with the kit is beyond me...a small button head screw is the worst kind to have for that specific bolt....there is no way that bolt is coming loose ever.

bentgear

Forget the locktite and use a small dab of fingernail polish. Make sure the screw and the end of the crank (threads) are oil/grease free. There is no need to tighten the screw to the point the head starts stripping out, at least not if you have done the prep work.

Ed M.

ShadowX

iTrader: (10)

I'll try out your advice...I'm a guy but hey I still keep a bottle of finger nail polish here and there I have my hidden secrets....but believe me the button head screw with the tiny 2.0mm driver head that comes with the kit is very easy to strip when cranking down on the wrench. I don't strip them all the time but having a bigger 2.0mm driver with a nice socket hole around it makes it pretty much impossible to strip.

motomatt

iTrader: (12)

L-wrenches are most often made from extruded stock. Translation = they don't fit worth ship, and strip screw heads. Use a quality hex driver.

ShadowX

iTrader: (10)

Yeah I do have some expensive hex drivers I just thought it was always better to use an L shaped driver in order to go tighter...but between the force of a quality hex driver and either blue loc-tite or nail polish I think the bolt should be more than tight enough. I'll stay away from the cheap L shaped drivers from on now.

bentgear

Do a good prep job and 2 fingers on a driver will get it tight enuff not to come loose. Had to slot a bunch of them with a dremmel cut off wheel to get them out before I learned.