New Optima Build: Project CYANide - Finished!

[Hcp22]

Can’t you set up the hex in a lathe and chip of few mm from the hex? I remember that we have some problems with Lazer, that It was too wide with some tires back in early ninety’s. So we chipped of 2mm on each hex to get inside the 250mm regulation.

[Coelacanth]

Can’t you set up the hex in a lathe and chip of few mm from the hex? I remember that we have some problems with Lazer, that It was too wide with some tires back in early ninety’s. So we chipped of 2mm on each hex to get inside the 250mm regulation.

That's exactly what I plan to do. After hours of eBay searches, I've been unable to track down any 12mm hex drives that are less than about 5mm thick. 3mm thick would be perfect. The complicating factor is the front CVD axles aren't cross-drilled for pins, so the hexes have to work with the press-fit style of axles. I have a pair of hexes that I plan to operate on today, hopefully they'll be able to press-fit properly on the front axles...

[treehugger]

i think and im talking from experience if you shave that much off there wont be enough of the cones shoulder and the wheel will wobble ..just saying good luck though, but I attempted doing that for my tf2

Paul

[Hcp22]

I never had that problem with the wheels wobbling on the Lazer, but you have to tighten the nuts hard. And it’s always a risk doing this as Paul say.

[Coelacanth]

You're both right, of course. Doesn't anybody make a 12mm hex that's thinner than 5mm that would work??

If not, I'll go ahead with the shave-down and hope for the best. If I could get the 2 hexes down to 3 - 3.5mm they would be perfect, and my front track would be perfect too.

[Mr. ED]

I think I have a pair of shaved hexes that came with some 2nd hand car; so I have no idea if it was bought like that or modified by the previous owner.

I think the pressfit was stillok but I did notice I had to pay attention which wheels I put on: if the hex cut-out in the wheel was too deep I had to put a 1mm thick washer between the hex and wheel. Tamiya wheels for example have deeper cut-outs than kyosho ones and the edge of the wheel would rub the axle carrier if I forgot the washer.

[losiXXXman]

Coelocanth.. I believe HPI did at one time, now that I think about it. I was trying to put wider front arms (TA01) on my Mini and use Ta02 hubs and blocks to stay in "mini" width. I remember someone pointing me to some HPI slimline hexes to help that situation. I'll see if i can find more on it....have to look for it in that "other" forum...


Coming up blank, but I know I found some once. They were purple and PRICEY IIRC. BUT, is the issue with the street wheels and tires? If so, doesn't HPI make those vintage touring wheels in a few different offsets? If yours are super wide +6 or the wide +3 mm, you could slim it down by using the other offset wheel..IDK, you may already have that wheel.

Another thought, Mr Ed. may be able to help with this. I think he said somewhere that he had used optima rear hubs to widen an Ultima...perhaps you could go to an Ultima hub that would narrow it up??? I have some if you need them too..

[GJW]

[Mr. ED]

Coelocanth.. I believe HPI did at one time, now that I think about it. I was trying to put wider front arms (TA01) on my Mini and use Ta02 hubs and blocks to stay in "mini" width. I remember someone pointing me to some HPI slimline hexes to help that situation. I'll see if i can find more on it....have to look for it in that "other" forum...


Coming up blank, but I know I found some once. They were purple and PRICEY IIRC. BUT, is the issue with the street wheels and tires? If so, doesn't HPI make those vintage touring wheels in a few different offsets? If yours are super wide +6 or the wide +3 mm, you could slim it down by using the other offset wheel..IDK, you may already have that wheel.

Another thought, Mr Ed. may be able to help with this. I think he said somewhere that he had used optima rear hubs to widen an Ultima...perhaps you could go to an Ultima hub that would narrow it up??? I have some if you need them too..

I'm confused . Which side needs narrowing, front , rear or both? Slim hexes with conical fit for the front: PM communcation ongoing. Ultima rea axle carriers: may work but will require shorter dogbones. That would reduse the total width in the rear about 10 to 12mm I estimate

[Coelacanth]

Thanks GJW, I just bought a set of those on eBay.

Mr ED: I'm mainly only concerned with narrowing the front track a bit. Going from 5mm hexes to 3mm ought to be perfect.

[Coelacanth]

I haven't been able to do more to finish building the chassis as I'm still waiting for parts to get through the mail--bloody holiday lag!

I had some spare time so I tweaked the suspension and took some more on-road body shots. I didn't want to fab rear shock tower extensions or buy shorter rear shocks as the shock travel was only about 5mm too long, so I took apart the shocks and inserted a 3mm plastic spacer inside to limit the travel. That pretty much got the rear control arms to sit the way I wanted, especially considering the low height of the HPI vintage series tires & wheels. The fronts were already setup how I liked.

Armed with a bag of assorted width Tamiya [3mm I.D./5.5mm O.D.] spacers, I tweaked the shock mountings so that the shock adjuster rings wouldn't rub against the towers and would move freely. The cheap black plastic spring retainers were upgraded with a beautiful set of 3Racing Kyosho V-One/RRR spring retainers. This was practically the ONLY set of spring retainers I managed to find; nothing else fit properly.

To Do List: Install some 3mm Kyosho hexes to narrow the track a bit; replace the 62.5mm Optima-length CVD bones with 60.5mm bones, as the 62.5mm bones press all the way into the outdrives with max shock compression. This will also help suck in the rear track a bit.

[Coelacanth]

Pics of chassis thus far...

[Coelacanth]

Until I receive an upper chain guide, there's not much to do except tweak things. But today (thanks to GJW's suggestion), I received a set of thin 3mm Kyosho 12mm hexes, and those were just perfect! They narrowed my front track by approximately 4mm. The front tires now fit just inside the fenders, and look quite realistic. Now, I just need to swap out the 62.5mm rear CVD's for 60.5mm ones, and the rears will hopefully look close to perfect too. On-road-wise, things are coming along better than expected!

I also received that Dirt Burners final pinion gear, and can confirm that it's an exact replacement for the stock OT-41 gear...it's noticeably heavier and made of steel. Was I ever lucky to snag that off eBay! It's practically impossible to find OT-76 hard final pinion gears anywhere!

[Coelacanth]

Since it's damn near impossible to find an original Optima bumper in decent shape (at least without breaking the bank), and the aftermarket Kydex repros looked pretty clunky, I figured I could come up with something better. After some measuring and a general idea of a sleek, simple design, here's what I came up with.

It just needs a bit of time in the oven to form an angle and mold it over the round bump in the skid-plate. I plan to drill a couple holes so I can add heavy foam onto it for on-road use.

[CNA75]

Fantastic build! Really looking forward to seeing this pan out, particularly with the offroad wheels and body (when you get round to it)....