Intro and YZ10 Project

[Rally Classics]

Hi guys, been lurking here for about a year now. I was big into RC in the late 80's and raced a bit on the local level. Won a couple weekly races here and there but mostly just had fun. I spent more of my time racin' a 2wd buggy - Ultima, which went thru many transformations from stock to Hot Trick Everything, to mid-motor, to graphite chassis. Enuf about the Utima though...

I 'progressed' into 4wd buggy after saving up my part-time wages and picked out a Yokomo. I raced it twice and crashed it in practice, hard. I swapped out the front A-arms and went back into action. The car was still jacked up and I saw why. The backbone had separated from the chassis. After that I but it in a box and never touched it for 24 years?!? Good lord I just got old.

Anyway I stripped down the car and began searching the internet for old RC stuff and thats how I ended up here. Had I started here I would have shared the teardown process but instead you get spared the gory details. At least everyone car see it go back together.

This is where it's spent the last year. I ordered new belts and cleaned up everything. Not to the extent of some I have seen here, but I also started out with a car I built instead of an ebay find.



I added a couple more countersunk holes to the chassis and will be glueing and screwing that back together in the next day of so. I'll add those pics as I take them.

[Rally Classics]

Here is the chassis, I had to use the dremel and a sanding disk to remove the decades old super glue. I don't remember if the super glue was per the instructions, or per my emergency fix but it still needed to come off.



Can I add a top deck like some of the Worlds Cars I have seen? Can the top deck still be used in conjunction with the spine in the picture above?

[stickboy007]

I have seen pictures of 870s with a top deck and a spine, so there's no reason why you can't do it. Strangely, my 870 has a top deck but no spine. I'm not sure why, though. The spine doesn't appear to do anything other than act as a mounting point for the belt tensioner (although I suppose it may reduce flexing along the long axis, to prevent belt skipping), but you can also custom place the tensioner on the upper deck with a bracket or something.

[Rally Classics]

I think you said it exactly, the rigid spine added strength to the chassis and kept the belt from skipping. Thats why I stopped driving it and boxed it up.

[stickboy007]

However, I don't suspect you need that top deck exactly. If you have a dremel, you can fab one pretty easily from a carbon fiber plate (which are easy to find on eBay). That should be more rigid than the fiberglass deck and may even obviate the need for a spine...

[jwscab]

yes, the spine added rigidity; as per the factory installation, you were supposed to super glue it down, as well as add a few small screws and nuts.

You can leave it off and run a top plate for sure. You can make it from black G10 fiberglass or carbon fiber, 2mm is probably fine, but 2.5 or 3mm is probably better.

You need to get longer 2mm screws, and look up 'jammin' top brace' for yz10/870c for the right shape, the jammin upper brace had the font extend out to help brace the front shock tower. The way this was designed, you didn't need to modify your bulkhead caps. Later yokomo cars actually had holes in the caps for the top plate. So whether you drill hole in the bulkhead caps, or use long 2mm hardware in the existing holes, that's up to you.