Busted High Lift prop

[SGNAS]

Last used the high lift 2 weekends ago (and gave it some abuse).

Went to use it today. Gave it a quick lookover and found the rear prop had lost both circlips from the UJ joint on the rear axle, gearbox end.

I cannot think how they would have come off and luckily retained the pin but now need to replace them or change the pin for something different.

Now, they are tiny so where could I get some?

What can I replace the pin with? I looked at the UJs in the XC and SRB and they use a conventional "rivet" for the pin so where do you get those?

Who can think of a good reason why tamiya moved away from using the rivet pins and replacing them with a circliped version?

Hmmm. wonder if there is enough clearance for a split pin

[Rat Fink]

Cost!

The cost of setting up a small part to rivet is high as it would be manual.

Machine the parts, buy the illfitting E clips, drop them in a bag and get the owner to do the assembly...cost dropped!

There are a couple of options Make your own rivets out of mild steel and rivet dollies this could end in disaster if you have no experience in cold riveting and are overly happy with the hammer.

The other choice is not as good looking and that is to drill and pin using hardened steel dowles, drill the outer holes to a clearance (Refer to Zeus Book) and the inner hole to a press fit. This will only work if you have a set of good quality drills which are at 0.1mm sizes (Presto do the best quality for price). Press the pin through the assembly using a small arbour press or put a squared off piece of steel in a drill press and use that.

Trim off what you dont need with a dremel and you can get the whole thing looking neat and flush.

Next time I recon the old brass ones I will take pikkies and post them 

[OCD]

Cost!

The cost of setting up a small part to rivet is high as it would be manual.

Machine the parts, buy the illfitting E clips, drop them in a bag and get the owner to do the assembly...cost dropped!

My driveshafts came factory assembled, with e-clips.  I'm not so sure they went to this to cut cost, I think it's just a 'serviceable' design. Much nicer than the XC D-shafts that are simply rivoted together as the OP mentioned.  Good idea using a roll pin though; hadn't considered that myself.[Y]

Anyhow, I just noticed something peculiar about the rear driveshaft that might explain why you're ejecting e-clips. 

This is the drive shaft in question:

And this is where the e-clips hit the battery![:S]

I casually checked over the assembly and it all seems to be in place, but I haven't heard this complaint from any of the other High-Lift runners.

Has anyone else had clearance issues with the rear driveshaft and battery??

-Steve 

[Rat Fink]

Well spotted Steve

I will check that during the assembly of my runner.

We dropped Riveting in engineering as much as possible because of the handling difficulties and the tooling.

To cnc cut shafts with a groove and Stamped Eclips are much cheaper ways of doing things, especially in todays throw away world.

I have tried to maintain some of the old skills by working in forges making stuff from raw steel with nothing more than a set of hammers and traditional engineering workshops where CNC has not fully overtaken the production. I realy should try and take the Mrs on holidy instead one year!

After 26 years in engineering I have seen a decline in both skills and quality wholly driven by accountants rather than the designer and proddy engineer.

Hence the model building and the love of the older models and of course older motorcycles.

Still to badword with cost when you are in the driving seat of your own build! I have just built a Clod crawler and spent most of Sunday exchanging the scabby old bolts for A2 Stainless.

Gee

 

[SGNAS]

Anyhow, I just noticed something peculiar about the rear driveshaft that might explain why your ejecting e-clips. 

This is the drive shaft in question:

And this is where the e-clips hit the battery![:S]

I casually checked over the assembly and it all seems to be in place, but I haven't heard this complaint from any of the other High-Lift runners.

Has anyone else had clearance issues with the rear driveshaft and battery??

-Steve 

I admit they're close but mine don't touch the battery.

For now I've used a split pin and put this joint at the axle end to avoid clearance issues. It works fine as a "trail" repair (another thing to put in the toolbox!), so I just have to find some teeny weeny circlips[:@]

[OCD]

Wow - in triplicate!  [][]

 

I should clarify that the pin doesn't actually contact the battery when the rig is just 'standing'.  I can however get the two of them to touch it if I put even the slightest pressure on the top of the battery.  I figure this is a pretty good simulation of what happens when you hit any sharp bumps and the chassis flexes. ( Try 'twisting' the chassis while the driveline is spinning - the torsional flex will cause an 'audible' binding in the driveline! [:|]) It isn't hard to imagine that the plastic battery holders 'give' quite a bit, even when used under normal running conditions.

Couple this close tolerance with a little bit of mud and turf, and voila!, goodbye e-clips!![]  I tried moving the set screw as far up the shaft as possible, but no real improvement...

 

-Steve