spur gear!!!

[Martin P]

ok, i now only have 1 spur gear left out of 5, i striped a total of 3 in 1 meeting, and would have striped another if the stearing didnt come apart.

What is wrong, the pinion looks quite big in comparison to the spur, although i think its a 27 or 28.
I have a corally sp12g3, and have chaecked the ride hieght adjusters at the rear and there absolutly fine, im currently using the ones which say 3. (dont no if that helps)

i striped 3 104's, (one on the meeting befor) and ive striped a 98.
They are all 64dp and looking around it seems 48dp is quite popular, shall i change to 48dp??

Whats wrong, i dont want to enter another meeting untill i have some more spurs, other wise i may hav to go home early :'(

Any advice would be greatly apprechiated

[Mark Stiles]

I run 48dp.

Did you have any hard knocks at all, as these sometimes lead to a damaged spur. Also make sure your mesh is okay; too much play and the gear will strip, too tight and the car will be slower and the motor will get hot.

48dp is much easier to mesh properly, and I've had very few problems with it.

[DA_cookie_monstA]

64dp is REALY picky over gear mesh, and like the above poster, if your mesh is slightly out, and you have a knock, it can damage the teeth on the spur, and then it is a downward spiral from then.

Go for 48dp, a lot more forgiving.

[Martin P]

i think ive meshed it properly, but thats my jugdment, and its usualy wrong ???

I dont recall any hard knocks, but i did have a few small light ones, which i dont think should have made it happend.

What anoys me even more is that i havent finished one race in the championship >:( >:( >:( >:( >:(

Can someone PM me a place where i can mail order some 48dp spurs then.

And what mmpr (i think it is) should i be aiming for??

[Mark Stiles]

You'll be able to get 48dp spurs from most model shops.

mpr depends on what motor you have, and whether you run 4 cell mod or 6 cell stock etc...

I currently run a 12x2 geared at around 40mm/rev. I run orion 3300 cells, and usually have about 150mah left in my cells after 8 mins.

Feel free to come and see me at the next MK meeting. I'm sure jason butterfield, or anyone lese will be happy to talk to you as well.

[PUASHP]

I have experienced some problems with stripping 64dp gears recently and it was down to a rear bearing on the axle.

The bearing was old and without seals and had a lot of play in it.

64dp is VERY critical on meshing so it may be safer to change to 48dp. I have also found some spur gears seems better than others for longevity.

Paul

[jason]

Martin,
I run 48dp and have not head any problems, I would recommend Kimborough spurs these seem th be as tough as old boots.
The most likely cause of you stripped spur is the motor moving forward in a shunt. Make sure the motor screws and your driver are in good nick and replace if necessary so you can nip them up real tight.

Jason

[PDW]

Martin, you may like to check the following:

Motor screws - they should bear down on washers that are NOT shiney, but rather have the natural metal finish. Don't use anodised washers or cups, or titanium washers or cups. If possible, rough up the surface of the washer on some wet 'n dry.

Mesh - place a piece of 80 gramme (laser copier) paper between the pinion and the spur gear. Do the mesh so there is no play. Revolve the gears to get the paper out, et voila - meshed gears!!

Paul has put you straight on the rear axle bearings, I'd just like to add the ride height adjusters - are they the same height on each side (it's been done!!) and are they still a nice snug fit on the torque tube? Any play must be removed.

Lastly, make sure there is minimal play from side to side in the rear axle. You can use the paper trick again. Put a piece of paper between the left-side hub and the bearing, do them up snugly and remove the paper; et voila - correct endplay!

I'd go 48DP myself if you are replacing this stuff - it is much more bullet-proof for 1/12th, and means you can use the stuff for TC too if you run that in the summer. HTH :)

[MattW]

I had some problems last year, all mianly due to the motor moving. I made 2 changes and haven't stripped one since. Firstly i switched brands of gear. RW and Kimbrough seem fine. Then i went back to Torx motor screws. I had changed all the screws on my car (corally) to allen head but you can get Torx screws tighter (careful, i have come close to stripping can screw holes ::) ) and like i say i haven't had any problems since. I have worn a couple out, but this has been down to deformed teeth on a couple of pinions.

[Big Jimmy G]

I used to have the SP12M and had several cases of stripped spur gears. I was using the Corally ones and the seemed to be far too fragile. As soon as I changed to Kimborough ones they lastes far longer.

Onec I also found a small crack in one ride height adjuster (after a bg smash). It was not completely broken but if did allow the axle to move and I stripped several spurs after that. I think it took several meetings before I found the cause.....

My advice is to swap to 48dp, change brand of spur and keep a real close eye on that mesh.

James

[Martin P]

ok, i think i will change to 48dp then.

Thanks for all the replys.

And MattW, was one of the problems actualy changing the screws to allen heads, as i have also done this, and now thinking about it, the srtips have been going on after i change the screws from torx to allen.

[MattW]

It seemed to be around the time that i started suffering, like i say, changed back to torx and no problems.

[PeteMason]

hi was not sure where to put this post me and a few others from batley are thinking of runing 1/12 at the club this is going to sound like a dum thing to ask you guys but we are all new to this can u tell me why u run 4 cells and 6 six cells and what sort of wind motor i should be looking at runing any help would be great also where do i get hold of a 1/12

[Ian]

48dp one's are a lot less mesh critical and the Associated spurs (for the TC3) are commonly available in most LHS's. It also means that you can use the same pinions you use for your TC. That said it is still important to mesh these correctly.

Another cause of destroying spur gears (regardless of pitch) is if your motor moves as a result of either a big impact and/or not tightening it up properly.

[Mark Stiles]

hi was not sure where to put this post me and a few others from batley are thinking of runing 1/12 at the club this is going to sound like a dum thing to ask you guys but we are all new to this can u tell me why u run 4 cells and 6 six cells and what sort of wind motor i should be looking at runing any help would be great also where do i get hold of a 1/12


You can run 4 cells with any modified motor, or 6 cells with any stock motor.

PM sent re a car

[Martin P]

So what size spur gear am i looking for then, what mmpr should i be running.
I al runnig a brm stock motor in a modified can (6 cell obviously) and race at the mk track.
Can i just use any spur gear, or do i have to use ones specialy for a 12th car??

p.s i think my tire size at the moment is about 49mm, but i will have to check this.
Also, is there an easy way to check the tire size, because i use a ruler and i dont think its a very effective way.

[Mark Stiles]

Easiest way to check diameters is with a vernier caliper. (if you have one) Otherwise, use a ruler.

Aim to get a range of pinion and spur sizes so that you can adjust you mm/rev according to tyre diameter. I race 4 cell mod, and tend to run about 40mm/rev (using 12x2 motor). I have 69, 72, 75 and 78 spurs with pinions from 16T to 20T. (I run 48dp gears).

Not sure what rollout you use for stock, but I would definitely say over 40, perhaps 45mm/rev? If you have 3000's or 3300's than runtime shouldn't really be an issue.

While on the subject of mm/rev, what should I be running if I have a peak vantage 9x2? I thought around 35mm/rev?

[Bish]

Martin,

The spur gears for 1/12th are different to some 1/10th spurs that just have screw holes.

I don't know what make of car you are running but next time you come to MK (15th Feb is the next 1/12th meeting), speak to Jason Butterfield, Dave Treacy, Ian Devonshire or myself (and Mark of course). We'll all try and help you out with gearing, measuring your tyres etc.


Bish

[Mark Stiles]

Kimbrough spurs fit all 1/12th cars. I would recommend them for quality as well. (so will most other drivers)