Kyosho Mantis EP FWD build

[EvolutionRevolution]

Great thread, thanks for taking the time to document it this thoroughly

I'm thinking this is one of the designs that were actually NOT done by kyosho engineers themselves, but bought off someone else's - the famous "b-grade" cars (like Raider, Rocky, etc...). I've always been told K always had this dual "sourcing" strategy...!

I'm not entirely sure about that. Most of those (including the Ultima Racing Sports series) use different bearing sizes and just slightly differently sized internals compared to the first-tier Kyosho cars (making parts swapping a pain). This one is in the same category as the 2WD Spider, 4WD Pure Ten Alpha and Lazer ZX5/TF5 RTR cars: worse quality materials and simplified designs but compatible parts. Basically entry-level cars that can be upgraded to something better.
In the Mantis' case I suspect a fully upgraded FWD car will perform close to or maybe even better than Tamiya's FF-02, which is really the only other comparable car (mid-motor FWD with space frame chassis).
The GP FWD Mantis was actually developed further than the EP version, and was raced in Japan (there's also a very cool Mini version).

[Mr. ED]

Comparing the mantis chassis to tamiya, I think some of the modular m-chassis are a closer match of concept. Or, and that might be a fun project, the twin daggers. A gearbox with motor in the front and rear, lazer or optima mid suspension, maybe some wheel wideners, and some big wheels and tires!

[EvolutionRevolution]

Comparing the mantis chassis to tamiya, I think some of the modular m-chassis are a closer match of concept. Or, and that might be a fun project, the twin daggers. A gearbox with motor in the front and rear, lazer or optima mid suspension, maybe some wheel wideners, and some big wheels and tires!

FF-02 is a lengthened M-03 with touring suspension

So, getting the motor mount as a spare part quickly turned out to be impossible, as it doesn't seem to have been released separately Therefore I bought an incomplete Mantis chassis some time ago:

Another thing all incomplete cars appear to be missing are the actual body posts (which also can't be found as a spare part, unless they use a number that doesn't start with "MI"). So I'm not sure yet how I am going to mount one of these two beauties:

But, motor plate:

This is attached to the car using four screws, two of which go through an additional plastic part to which the spur and pinion cover mounts. Since I will use a spur adapter meant for another car instead of the original spur gear, I will need to modify that part. So I put everything together and marked the area I had to cut away:

So, how to do that? The plastic is fairly soft and cuts well with a X-acto knife, but I needed to get a start for the circular part:

Hand drill to the rescue. Of course I managed to chop off the wrong bit when I started cutting That gap you see in the central circular bit? Shouldn't be there...:

Some progress:

Yeah, starting to look like it:

[EvolutionRevolution]

Test-fitting everything:

Things fit quite tightly in some places. Better:

I also properly countersunk the holes for the screws:

Now with a spur:

But not all is rosy :

The spur hits the plastic part. And it's a two-fold problem:

Because the spur hits the plastic part, the spur adapter does not reach far enough into the plastic part. Disappointing, because I really want to use the spur and pinion cover as I think it is part of the character of the car.

However, let's try something:

A 2 mm thick spacer and three 0.3 mm shims between the gearbox and the pin holding the spur (adapter). It even puts a bit of tension on that pin, keeping it in place when removing the spur adapter. Would that do it?

Malediction! It's just not enough!

But. There quite a bit of side-to-side play on the layshaft in the gearbox. What happens if I shim that out?

Success! A veritable miracle! It fits (barely)!

I will still sand off about a mm from the plastic part and the spur/pinion cover to obtain a less tight fit, but this is great.

Now I still have to modify the spur adapter so it can use the 2 mm diameter pin instead of a 1.5 mm one, and fit a whole lot more spacers and a 5 mm e-clip to secure everything in place. This also means that building the ball diff is becoming a top priority.

[Mr. ED]

Do you have a manual, or other picture showing the body mounts?

[EvolutionRevolution]

Nope. They should screw onto the mounts from the side, and the mating surface of those mounts is molded in the shape of a 8-pointed star (a bit like a cartoon sun). I suspect that if they are available separately they'll have a number starting with 9 or 90 (as do most of Kyosho's general purpose parts)...

[Mr. ED]

Sorry, I can't help you there. I've never even seen mounts like that.

[EvolutionRevolution]

Found an ebay auction (WAY too expensive for a used chassis) that shows the body posts:

http://www.ebay.com/itm/Used-Kyosho-EP-Mantis-Pure-Ten-Touring-Car-Chassis-FREE-SHIPPING-/121578678920?hash=item1c4ea76a88:g:XUYAAOSwo6lWHVhd

[clm]

I /think/ after a bit of google-fu the bodyposts are mi-5 or mi5

[EvolutionRevolution]

Thanks.

Nothing on Ebay right now, so I'll have to keep looking.

Just a warning: This site supposedly has them in stock, but according to what I can find about them on the web they say that for every single item on that webstore and do not actually have stock for many of the items. Instead they take your money, and make you wait for months. So I guess I'll be skipping that store.

Edit: Found another store that had the part in stock and shipped internationally and looked trustworthy, so ordered it together with something else I needed. Let's see how that works out.

[EvolutionRevolution]

Fixed the wrongly cut out bit on the part that goes between spur and motor plate:

Last Saturday I also received the swing bar set:

Instructions:

I paid about twice the original price for this; this option is somewhat hard to find (there's one on Ebay now). I was afraid the swing bar could not be used together with the shock mount set, but fortunately Kyosho took that into account. This option also fits the Mantis Mini.
I will fit the swing bar to the rear of the car, as I've read it really helps with handling. For this I need to remove the rear shock tower and replace two of the screws by longer ones (right side of picture):

But before I can do that, I have to assemble the swing bar. Parts:

And assembled and attached to the shock tower:

It was somewhat hard to attach the mounts to the tower under the right angle, as they tend to rotate with the screws when those are tightened.
Sliding the shock tower with attached swing bar into place was a bit tricky. Attached to the car:

The next step is adding the balls to the suspension arms. Parts required:

[EvolutionRevolution]

Attached to the arms:

And with the links added (forgot to take a picture of the parts required for them, oops):

I wasn't very fond of how free the suspension moved at this point, so I reamed out the inner hinge pin holes. Frees it up a little, but still rather tight.

Some parts of the swing bar set remain:

Then, I decided to assemble the shocks as far as possible at this point.

Parts included in a single Mini Inferno rear shock set:

I started off with assembling the pistons and shock caps:

I'm using the stock pistons indicated in the instructions. Two spare e-clips are included, of which I needed one because I folded an e-clip when trying to install it.

Assembled:

Then the shock bodies followed:

I think the o-rings may have been upgraded compared to older sets, but am not sure.

And eyelets:

Assembled and together with spring perches:

I then inserted the pistons into the bodies:

[EvolutionRevolution]

Normally I'd fit the eyelets to the piston rods and fill the shocks at this point, but instead I decided to test-fit the shocks onto the car:

This revealed a problem. The shocks come with long eyelets, but for proper attachment to the car they need short eyelets. The touring shocks would have come with these, but Kyosho replaced them by the other size for the Mini Inferno. I tried Ebay to no avail. My Tour Force manuals show these parts as belonging to the shock set, with no separate part number. Then I remembered I had some eyelets left from the swing bar set:

Those will do. At this point I stopped work on the car and decided to wait for more parts to arrive.

[EvolutionRevolution]

Edit: Found another store that had the part in stock and shipped internationally and looked trustworthy, so ordered it together with something else I needed. Let's see how that works out.

Well, while I've since then received another part I still needed, the body posts and the other part still haven't shipped...a week later . Makes you wonder why a company would set up a fancy website with an advanced online ordering system accepting international orders...thankfully I paid with Paypal.

[Mr. ED]

After seeing the pics, I don't think it should be too hard working around those rare body mounts.
Same for the long shock ends. You could just chop them to the right length.