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Enjoy...http://www.tamiyaclub.com/forum/index.php?showtopic=70644

Interesting design ideas, but I wonder about a few things...I find the belt tensioner as currently designed would add more friction than necessary, making the belt go through two 90-degree bends instead of simply making a down-pointing "V" or triangle of the upper length, and just raising or lowering the apex to adjust tension. I also think the front shock tower as shown will snap off far too easily.

If it was me, and I was going to use a custom belt length, I'd try to mount the battery longitudinally if I was going to all that effort--though that might present problems with the Optima's original steering servo mounting location.

Coelacanth wrote:Interesting design ideas, but I wonder about a few things...I find the belt tensioner as currently designed would add more friction than necessary, making the belt go through two 90-degree bends instead of simply making a down-pointing "V" or triangle of the upper length, and just raising or lowering the apex to adjust tension. I also think the front shock tower as shown will snap off far too easily.

If it was me, and I was going to use a custom belt length, I'd try to mount the battery longitudinally if I was going to all that effort--though that might present problems with the Optima's original steering servo mounting location.

Just buy a KX-One and add Lazer ZX arms.

Kyosho beat him to it and called it the optima mid.

The rear suspension geometry looks as if it would cause problems with positive camber

Well, respect to anybody who makes use out of spare parts. I have a pile of Optima spare parts, some are scratched, bent, stripped, etc...but would work fine for a custom build if cut up and used in new & intriguing ways. I just think if you're going to re-engineer a design, might as well do it logically and improve on the original design, not just introduce new weaknesses in the design elements.

EDIT: Further to my last sentence; the project is considered done and doesn't even have a gear cover. I don't think one could even be fabricated, the way he mounted his custom camber links in that area.

I just think if you're going to re-engineer a design, might as well do it logically and improve on the original design, not just introduce new weaknesses in the design elements

Agreed but I have to say it was done quite pro and looks pretty clean. I would like to see how it performed as a runner.

I don't think his goal was to reinvent the optima mid. I think he was just trying something new. He bent the belt so that it would fit under the tray. I think the project was rather neat even if it doesn't have a proper gear cover.

I think reading through his posts, you got some indication of how it held up (or not). His initial CAD design work was great, but the final execution of the various chassis components' assembly has a number of deficiencies. That belt routing seems to introduce a lot of unnecessary friction; the front shock tower needs to be redesigned or braced somehow, and lack of a gear cover are some areas that must be addressed--at least for an off-road runner.

But like I said, anybody who builds something like that, using spare parts or fabricated parts, does something unique and different, has my respect. Anybody can follow a manual and build box-arts...this kind of stuff takes ingenuity & creativity.

Interesting and different.

Shame about the dodgy printed parts though... ewww!

I think the design is appropriate for the year of the components. My opinion would be to link the rear camber mounts across the back with carbon fiber, and finish up with a molded lexan gear cover.

From one designer to another, great achievement, well done. Now the fun begins as testing will find the faults and redesigning makes for a stunning runner. Leep up the good work.

I find this amazing. Never saw or ever heard about it. Pretty sweet.