stripped out rear spool [Archive]

Thump Wallop

09-07-2008, 06:58 PM

Hi All,

When I was building the truck, I thought that there might not be the correct amount of preload on the pinion/spool, I left it for the time being as I knew I wasn't going to be doing any tortureous driving to start with. I am considering adressing this sometime though befor I give it a beating, I am just a bit unsure of where to get some shims, and also what the correct backlash should be.

Scott, you mean use TL on the little bolts that hold the diff cover on or the ones holding the axle together?

Thanks and regards

ruffryder

09-07-2008, 07:13 PM

I use a little threadlock on everything to be safe.
I stripped a spool and RC4Wd replaced it no problem.
I was waiting on a reply email and they just sent one...pretty good by me!
Only problem is,i stripped that one too.I had a high lift diff that i locked and put in its place.
I think either the material used should be changed or have a grub screw fitting(probably easier)

JEFF THE JET

09-07-2008, 07:14 PM

Yes the spools are weAk i upgraded to the full spool

twisted77

09-07-2008, 11:31 PM

well I cant find any upgrade options for this axle on the site.

Thump Wallop

09-08-2008, 05:57 AM

Guys,

That is a bummer to hear about the stripping of spools....fools and their spools huh :-)

I am not sure that the material is weak, but I am convinced there is too much backlash on the gears. Whenever the truck starts shuddering under load, the backlash becomes a VERY important factor, there needs to be some play, but too much play and the gears will not mesh, they will try to climb each other. Another way to help relieve some of this is to have synchromesh in the gears, whether this is feasible in small gear like this is questionable.
I am going to try and shim the pinion a bit and see what happens. I really dont want to strip a spool, and I need to know there is some reliability in what appears to be a simple design.
As soon as I have made some progress, I will report back.

JEFF THE JET

09-08-2008, 11:42 AM

well I cant find any upgrade options for this axle on the site.

part # x-0236...full spool:D

Thump Wallop

09-08-2008, 01:57 PM

Weelllllll, looks like I spoke too soon.

A light run this afternoon and suddenly one wheel is not biting the dirt properly....I understand what you guys were talking about now...I thought you were referring to the ring gear getting stripped ...! But noooo it is the splines inside the spool that are stripping....and mine is proper stripped....damn.

Edit to add:

What is the difference between the std trailfinder spool and part X-0236?

Having a look at them, they seem exactly the same?? *scratching head* I thought a full spool would have meant axles locked in the spool?

Does anyone know what the grub screw is for on the trailfinder spool....seems superfluous to me. I think I might try and drill a hole down to the shaft and see if I can lock it in place... I dont have F-350 diffs lying about. LOL.

ANOTHER EDIT:
I drilled and tapped a hole for a 3mm grub screw, and dremeled a flat spot on the axle, put some threadlock on the grub screw and tightened it all up again, I doubt this will be a lasting job, but it may be a good solution if it does last.

Andy

ruffryder

09-08-2008, 07:04 PM

Andy,was it the right rear drive shaft that stripped? Thats the one i had go twice.
I never worked out the grub screw either.It does nothing as far as i can see.
I dont have the tools to make it go all the way through like you did,but its the obvious solution when you see it.Thats why i mentioned it in my first post.It seems like the idea was there when it was being made but they stopped half way through :(
The driveshafts could do with a triangular fitting rather than splines to beef it up a bit.

Thump Wallop

09-08-2008, 08:23 PM

RR,

Nah, it was the front right. I am not sure why, but it must gone over a period of time, wasnt sudden, with any audible grinding or anything.

http://img.photobucket.com/albums/v290/Cathurga/RC/BustedSpool.jpg

Here is the handiwork I have done, I also dont have the tools to do the job properly, my tap set was a wal-mart/hyper special that got about halfway through my drilled hole and then started stripping it! So I sacrificed a grub screw to finish the tap, slow work, but eventually got it done. I have no grinding bench or a decent vice, so I did my best to grind a flatspot and ultimately over did it a little....went about 1/4 way through the shaft, and not straight either. The axle turns over the grub screw, and I assume will eat the shaft away to the point where it all twists itself in two. The front right can now turn about a quarter turn before the grub stops it. Half-job Bob strikes again. Whaddya do when you have limited resources huh? :-)
Anyways, took it out for a night time dusty rock crawl, and it came out fighting, so we'll see how long it lasts.
In the interim, I mailed Mike and they are going to send me another spool.
They really are re-writing the books on customer service over there, and I hope there efforts are profitable, I really would like to see them succeed in this very competitive market. The products are mostly good.

I agree with you on the driveshafts having something stronger than the splines, but essentially it means something else up the line is gonna break. Judging from the website, new gears for the R2 tranny are cheaper than the new spool so it makes sense to have the gearbox go *!!%^ than the diff gears.

Andy

JEFF THE JET

09-08-2008, 10:08 PM

ruffryder

09-08-2008, 11:10 PM

Good idea on the triangle but i: Beat on mine and no problems other then the axle breaks every now and then...i have to remind myself.....this is a great trail truck!!!! Not a rock crawler....thats why i got the diablo....:d

my first spool failed on the test run in the lounge after building it.Running the truck over the plastic parts box.
I was running a Novak Goat brushless and swapped it for an Integy 35t brushed as i thought it may have been the torque of the Goat system,but it really shouldnt happen

Thump Wallop

09-09-2008, 04:46 AM

Jeff,

Could you be more specific when you say the axle breaks?

Thanks

scubadaveojr

10-01-2008, 12:18 PM

when i was having the problem, i just took some cold weld and placed them togther and they hold perfect. i dont think they will slip now. and when i need to replace the spool its self i just soak it in paint thinner or naphtha.

Thump Wallop

11-17-2008, 08:57 PM

Hey All,

I am resurrecting this old thread, because the demon has reared it's ugly head again. I have now stripped the other side of the axle I repaired a few months back. This means that the above repair held out longer than I expected!! Yay for me.
I did buy another spool and shafts, but before I just replace, I would like to try and salvage whats left of the old shaft :-) ...until it well and truly craps, I will not write it off!
D, in the post above you mentiond cold weld, is it this stuff you are talking about? http://proseal.supergluecorp.com/64600.html
You seem to indicate that if soaked in naphtha it will give eventually....the above product tries to tell us it is impervious to everything...
The issue I have is that the bearings cannot be removed from the shaft for replacement if you cannot get them apart...is yours still holding out?
I might try another tap and die effort, but the other side of the spool already has that threaded hole that has no purpose, and I would hate to strip that while trying to drill the last bit out.

If I install a new shaft (read: If I ever give up on the old one) is there any preventative measure that could be taken to avoid stripping it again? Maybe squeeze something in there between the splines that will give it more strength....apart from cold weld that is :-)

Thanks again all.

Regards

scubadaveojr

11-18-2008, 02:33 AM

use some cold weld and make them all one. lol..... that is what i did and it made a better back end. also it is much more stronger for when you hit the tight spots.

ruffryder

11-30-2008, 10:00 PM

BACK TO THIS THREAD AGAIN!:(
Thought i was getting intereference today...til i realised the truck was running on 3 wheels and shuddering all over the place.
I dont think splines are the answer for a fixed diff.Theres way too much load on the axles for small splines.
Are there any plans for a revised drive to make it stronger?

scubadaveojr

12-01-2008, 02:47 AM

glue the axles into the tack gear. that will make it nice and solid. trust me. lol.

Thump Wallop

12-01-2008, 09:25 AM

Yeah,

I used 2 different types of glue to do mine. The one was steel epoxy and the other was a steely putty, we will see how long they old out for. I used the old axles so that I still have a spare set of the old ones do give up. It is pretty useless having those splines on there, definately not designed to hold up against a 55T motor and low gear....only thing is, if that is stronger, the next weakest link can only be in the gearbox. Having had an R2 in pieces, I am fairly confident that it is able to stand up to some abuse, so it should be ok. At some point the drive train has got to be stronger than any torque you can put through it...

Andy

spiros

12-01-2008, 10:04 AM

I was wondering myself why they used splines on the spool. Yes, you have to make it so something gives, but a) why not put a stiff slipper and b) why make something that has easy access as the failsafe ie stong plastic hex wheel nut. Anyway i would definately change the splines and use something square or rectagonal (see pic). Sorry for the awfull design , took me 5 minutes to do

scubadaveojr

12-01-2008, 10:15 AM

use some cold weld, that is what i used and man it kept every thing nice and tight, no problems. also for the spline issue. you want to go with more surface bite, which a hex would be nice but you would spin that still too.... there are thoughts on making it into a triangle and or a square. the more surface the better of a bite. lol.

spiros

12-01-2008, 10:25 AM

The hex was for the wheel nut, but anyway what i've seen with crawlers generally is that they don't incoporate any kind of failsafe in their design, this is not rc4wd specific, this is a general thing. I can understand why , but something will eventually give. I.e on an axial10 just by looking at it i say either the hexes or the transmittion will fail. If it's the hex it's ok , if it's the transmittion is a fuss to do .There is generally the misconception that stronger is better, that's not always the case , you have to design it so you are the one directing the stress to the weakest part you want to brake, something cheap and easy to repair.

scubadaveojr

12-01-2008, 11:01 AM

if you look at the end of these...
http://rc4wdstore.com/product_info.php?cPath=60&products_id=775
http://rc4wdstore.com/product_info.php?cPath=60&products_id=776
they have some what a fail safe. but you are correct with the "stronger is not always better" part, i think that the have a strong fail safe that might need to be toned down a little, i was thinking the rod were the hex lines into the 12mm hex, that is simple and can be replaced with out having to tear the rig apart, just take a tire off and replace it, but there are so many places and things you can do. lol.

spiros

12-01-2008, 01:48 PM

If you're on about the recess just before the splines start , it's actually part of the machining process, it's not a failsafe design. They're using a bullnose cutter.
I think whatever failure in the axles is time consuming to repair. All 1/10 buggies used to, and continue to have quite strong plastic hexes. This is easiest to replace. I'm gonna get some and try them off.

scubadaveojr

12-01-2008, 02:24 PM

i think you are right... let me look around and see what i can come up with.

ruffryder

12-01-2008, 03:26 PM

.... there are thoughts on making it into a triangle and or a square. the more surface the better of a bite. lol.

I said way back about using a triangle design.
It`s got to be the best solution.I dont see any reason for "give" anywhere on the drive train.Unless someone is running some stupid wind brushless through it,the drive train should hold up to the slow crawler mtors,even with a lot of torque.
I have had three diffs fail on me now,and each time it wasnt through doing anything over stressful.
Yesterday was pretty frustrating as i was only running a short time before it failed.
Im lucky enough to have another trail finder to fall back on,but i dont always take both.
For me to drive out for the day with my son and have to come home after a short time coz a diff failed for no real reason would have really..........i wont say anymore:D

scubadaveojr

12-01-2008, 03:33 PM

ok.... well i am sorry to hear all that.
i am only throwing suggestions out to ya... not calling you out. lol.
just make sure you lube them and if that doesn't work i think there might be some thing binding in the system to cause the problem to keep coming back. i am a very hard driver and will bind my systems up to the point were they stop my 60 turn motors and i have no problems. also when you strip out the tack gear check to make sure the ends of the axles that have the spline on it are still some what sharp and you are not putting in a 65% end into a brand new end, that will also cause some stripping to keep coming back.

ruffryder

12-01-2008, 03:49 PM

They`re lubed and theres absolutely no binding there Dave.
Its happened on both trucks.
Everything spins freely with no motor installed.
I even cleaned the trucks with an air hose at the end of the day,and the free spinning wheel ballooned the tyre!:D
Being told to glue it back together isnt the answer.Its not an airfix kit :p
When ive replaced them,ive used high lift diffs and shafts,so its not recurring in the same place.
So two trucks with four axles and three diff failures its costing me.

edit:
I wasnt having a pop at anyone either,just saying that im not the only one with this problem,and its been happening for a while now

scubadaveojr

12-01-2008, 03:51 PM

i am not saying the gluing them is the right way but i am saying they are working on it.... trust me. as for the gluing thing. when i stripped mine out and did not want to buy more, i gut got some cold weld and then i was set.... never had any problems and still running them. i know that they splines are some what weak but they are working on making them better.

roborg5000

12-01-2008, 04:04 PM

phill005

12-01-2008, 04:19 PM

Fixing it with glue is only a quick fix, it can still brake down I know from experience.
I had the same problems on my t-rex but I am in a position to machine new ones, I made two flats opposite each other in stainless steel axles, a tight fit in the slots, with a 2 mm rod to center the shafts through the stainless locker, and now no problems.
I guess my weakest link now is where the pin goes through the rear axle to hold the hex, you have to have somewhere to give, and it's much easier to replace a shaft than a locker.

http://i247.photobucket.com/albums/gg123/phill005/Complete.jpg

Phill

spiros

12-01-2008, 04:33 PM

Just noticed this long thread. Sorry to hear about your guys problem. I havent had a problem with mine yet but, I think Dave has the best solution for a temporary fix.
I really dont think splines are the way to go on these unless the teeth were deeper. We need a hardened shaft with a flat spot to shove into a female slot in the spool.

I do agree, there is no need for splines unless this was a telescopic shaft. Plus you require quite tight tolerances for splines that small so cannot develop much slack.

Machining wise is not that difficult even on the diff gear side to make a male/female slot. You probably end up with rounded side ends but really doesn't matter. Not the best design to use two side flat shaft but i think it'll be better than this

scubadaveojr

12-01-2008, 04:48 PM

agree ^ i think that is going to be a strong solution.

sloppy

12-01-2008, 05:58 PM

why not just get rid of the tamiya style spline all together.. and use a rectangle setup like the WK and axial use it seems to hold up fine..

ruffryder

12-01-2008, 08:22 PM

Im sure it will get sorted.It`s just a lil frustrating at the moment.
Ive ran buggies and tourers on and off over the last 22years,and when a company brings out an updated part,it usually comes with the words "after getting feedback from team drivers".
What i like about this company is they ask,and listen to the buyer.
All the changes/updates are from customer feedback.
You Have to admire that!;)

Xoltar

12-03-2008, 01:19 AM

does this happen .. no matter what tranny or motor you have ?

im wondering that this happens with .. which motors or torque etc ?

can you guys post the motor and tranny you using ?

most i think use R2 but .. which and which motor ..

i dont know if it has something to do but .. anyway im interested

-------------------------------------------------------

so you guys say threadlock doesnt work ...

and putty ?

Thump Wallop

12-03-2008, 06:17 AM

Hey all,

A little update on my WELDING of the shafts (I posted this a little earlier in the thread). The rear was fine, and seems to be holding up ok, the front I had a prob with. The shafts need to have the exact fit in the spool otherwise the dogbones at the ends do not fit into the outershafts and this will cause some binding when at full lock. I have one that was ever so slightly out and the binding starts when at full extension. I have not run it yet but it seems that maybe the servo will not push the steering to full lock so I might get away with it. I am rebuilding the truck like new, and it is always cool to have a shiny new toy...again :-)
To the suggestions of a slotted shaft, let the makers read and understand, this is DEFO the way to go....I will be acquiring them if it happens....
Regards
Andy