My Ultima ST EP Type-R BNIB project with 3D printed "CF" parts.
 

I thought to separate this project from my GP Ultima project, so here is it.

Today i received pretty rare package from Germany.

Kyosho Ultima ST EP Type-R, brand new in a box. It isnt even assembled. All the parts bags are sealed as well.

Attachment 2267581

So, whats the plan? I´m not actually 100% sure. But im going to replicate it to my PC and 3D printing most of the parts, so i can get a nice beater for boring days.

I started from the obvious part:

https://hitecmods.kuvat.fi/kuvat/RC/...ng/_medium.jpg

https://hitecmods.kuvat.fi/kuvat/RC/...ng/_medium.jpg

And ready to print:

https://hitecmods.kuvat.fi/kuvat/RC/...ng/_medium.jpg

Does someone remember about these cars, that was the too long wheelbase the problem on the slippery tracks? Because i could easily shorten it a little. And yea, Ultima RB5 and RB6 and SC seems to use the same looking chassis with slight differences.

Im currently printing the first prototype. The PLA print didnt adhere to bed properly, so i swapped to CF/PETG, lets hope the dimensions are correct.

Edit: So far so good. Just finalized the printing. Havent cleaned up the supports, as i just wanted to see if everything lines up.

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=mediumhttps://hitecmods.kuvat.fi/kuvat/RC/20200609_011843.jpg?img=medium

This is just a "draft quality" print, so forgive the quality.

And just a quick mock up with front and rear parts.

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

So, its seems that it was a success at first print. I have already designed the battery holder strap, battery holder post, rear bulkhead and some other parts. These are all Type-R EP specific.

Printed some other parts. Rear bulkhead (UM-305), battery stay (UM-304), my own design front chassis (UM-107) and servo holder.

Test fitted some parts, its still good to go. I´m suprised that the first chassis prototype has so good fitment. Durability is still a big question.

All plastic parts you can see here (except the steering servo ofc) are 3D printed:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

Now that i have this real Type-R on my hands, i can see that the Type-R UM-105 rear suspension holders does have some degrees of anti squat, where the Racing Sports versions doesnt have any. I need to update my design files for that part.

Just finished assembling the kit. I thought not to assemble it at all but yea, it was a real joy. It was nice to see how big improvement the Type-R version of this car was, when compared to Racing Sports. The general quality on the parts is also unbelievably good. All seals and rubber parts were still good and the plastics haven´t dried up.

I assemble the car almost fully like the manual says, but i swapped the plastic collars on the suspension arms to aluminum ones and shimmed the arms with 0,25mm shims. I also swapped the servo saver plastic bushings to ball bearings.

Couple of pics:

Anti-squat:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

Assembling the Twin Cap Pro shocks:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

(And yes, i didnt attach the suspension lower ball joint ends to the suspension shafts with those pliers. I wrapped the suspension shafts to vinyl gloves to give a needed grip to install the lower ball joint ends without pliers).

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

The quality of these shocks still amazes me.

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

ProLines:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

These are the updates i made:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

Whole car pictured:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

Anti-squat visible:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

Rare sticker set?

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

The set even included the colour correct (Type-R) spray colours:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

For some reason, they included brand new hitec SP-560 Electronic Speed Controller. This seems to be the best car ESC hitec offered that time, if i red the lineup correctly:

https://hitecmods.kuvat.fi/kuvat/RC/...jpg?img=medium

Okay, here are some things that i realized when inspecting this Type-R.

- The slipper spring seems to be the same spring that newer Ultimas (RB5/6 etc) use in ball diff.

- The slipper design is same between the EP/GP (the aluminum parts).

- Evolution suspension arm inner hinge pins are just basically a right length shock shafts (for those who are looking for replacements).

- Servo saver aluminum shaft/spring/nut assembly is just the same as newer Kyosho DBX (for those that are looking for replacements).

- Ultima RB REAR shocks SHOULD be the right length for the front end.

- Ultima RT5/RT6 REAR shocks SHOULD be the right length for the rear end.

- If i calculated properly, the main diff gear is 52T, so unfortunately its not a direct upgrade from Ultima RB5/RB6 that use 55T gear.

- Idler gear 26T is the same as Ultima RB5/6, so you can upgrade that to UMW718 aluminum idler, or use stock RB5 or 6 idler.

I just ordered the whole RB6 gearbox/rear chassis (rear motor version). Im making a custom rear chassis, so it can use RB6 gearbox covers, diff etc, so the replacements are easier to get. I will release everything in thingiverse once i test that everything works.

To be continued...

Edit: Spur gear, chassis, transponder stay released:

Spur:
https://www.thingiverse.com/thing:4484164

Chassis:
https://www.thingiverse.com/thing:4462223

Transponder stay:
https://www.thingiverse.com/thing:4462295

Stock rear chassis (for CNC):
https://www.thingiverse.com/thing:4462232

Edit: Also lot of other parts released, check out my thingiverse profile! https://www.thingiverse.com/jiipeee/designs

Here are some of my parts combined for this chassis in one picture. All is not visible as i didnt had time to search them from my library. But the progress is pretty good, this model should print out nicely.

https://hitecmods.kuvat.fi/kuvat/RC/...png?img=medium

The whole custom rear end package will be:

- Custom rear chassis plate (i doubt that the RB6 rear chassis plate wont fit, but i will ofc test it first).
- RB6 gearbox, ball or gear diff, with plastic or aluminum idler gear and aluminum input axle.
- RB6 slipper system, if the ST:s spur gear quick release system cannot be 3D printed.
- Longer than stock dog bones (because the stock ones are too short for the narrower RB6 diff output axles).
- Im not exactly sure about the motor mount plate. I think it needs to be custom made from 2mm aluminum plate but we will see once the parts arrive. You could ofc use the stock RB6 motor plate.

Im also ordering the RT6 suspension arms to see what mods are needed to be made to make them work as a replacements for this chassis, as the original ST:s arms are getting harder and harder to find. Because the RB/SC/RT front bulkhead hinge pin measures the same 40mm width than the ST, its easy to modify my bulkhead design to make them fit. Those will be great replacements on the front. I dont know about the rears yet, as the whole suspension arm mounting is different in RT6.

Still waiting the RB6 rear mount gearbox and rear chassis plate. I also ordered a set of RT6 suspension arms and RB6 aluminum front suspension mount (that part that you can turn around to adjust kick up angle).

Once i see how the RT6 lower suspension arms compare against the original ST:s arm, i will make the decision if i will make retrofit front and rear end to ST. Im getting some doubts if im crazy or not to try when trying to breath life to chassis this old. This particular car (in GP version) just gave me so many enjoyable days when i was a kid, that i would love to see other peoples Ultima ST:s come back to life with the work i´ve done. At least in the forums there hasnt been so much interest. I know its a chassis that suffers understeering in some situations, but in EP version it should be easily fixable. I already uploaded a main chassis to thingiverse that´s 2mm shorter than stock (i actually uploaded the stock wheelbase version as well). I cant wait to see how the -2mm version handles. Im going to print both versions and i will be testing those against each other.

Alright, took a little break.

My custom RB6 transmission conversion released. With this set you can swap the stock Type-R transmission to an stock rear mount RB6 transmission and use those diff parts. With this you will be able to use gear/ball diffs, gears that are still available and RB6 slipper parts. Future proof upgrade.

Enjoy:

https://www.thingiverse.com/thing:4735706

Holy shiiii....

I just drove the first meters with the "original" Type-R in snow. I paired the Hitec SP-560 with my old Marui Hunter Mabuchi and it was slooooooooow. But drove so well, its just so different car than the Racing Sports version.

So after that test, i paired my Robitronic brushless esc with Robitronic 4000KV brushless motor and used my NiMH battery pack from my Kyosho Blizzard and then came the holy shiiiii... moment.

Its insane how fast it is. Easily much more faster than my original ST GP. And it still drives so well. The only thing that holds it back is the original Pro-Line tires. They are so soft that they literally rip of from the wheels if i go full throttle. I ordered tougher Schumacher tires for it.

Anyways. Here some pics for you about the latest improvements for my EP beater chassis.

Ultima ST EP Type-R "3D printed", with my modified shock tower mount to accept the RB6 transmission and spur gear. Also in the pic is my latest version of the motor mount/input shaft bearing holder.

https://cimg6.ibsrv.net/gimg/www.rcu...a523c84ca4.jpg

https://cimg7.ibsrv.net/gimg/www.rcu...53a01450ef.jpg


https://cimg1.ibsrv.net/gimg/www.rcu...77323f82a9.jpg


I still need to design a slipper for this, because the RB6 slipper feels too expensive for me.

So, heres the latest retrofit kit for Ultima ST to accept RB6 transmission:

https://cimg9.ibsrv.net/gimg/www.rcu...7c5ea91e83.png

https://cimg1.ibsrv.net/gimg/www.rcu...5562cf055e.png
https://cimg2.ibsrv.net/gimg/www.rcu...fede85785a.png

There has been some design changes here and there. I made some space to the motor mount so the stock RB6 slipper could be used if wanted, i also made recesses to small 3mm nuts, etc. I could also do some weight saving stuff, because the first print from carbon fiber filament didnt bend at all (which is a great news, because motor mounts are usually made from duralumin.) I could probably even shave more out from the material as its really a rock solid.

Pics:

https://cimg9.ibsrv.net/gimg/www.rcu...fe79dc57cc.jpg
https://cimg0.ibsrv.net/gimg/www.rcu...a0b669535c.jpg
https://cimg1.ibsrv.net/gimg/www.rcu...1a2d57c74f.jpg
https://cimg3.ibsrv.net/gimg/www.rcu...a8e47ce163.jpg
https://cimg4.ibsrv.net/gimg/www.rcu...c033be3cdc.jpg
https://cimg2.ibsrv.net/gimg/www.rcu...63fadd1005.jpg

Just released my modified V3 chassis. https://www.thingiverse.com/thing:4462223

V3 is the latest. Read the changes from v2 version from the thing page.
https://cimg2.ibsrv.net/gimg/www.rcu...8546ea7c0c.png
https://cimg3.ibsrv.net/gimg/www.rcu...8953cd0e8c.png
https://cimg5.ibsrv.net/gimg/www.rcu...f780e54c18.pngAlso other mods coming up (retrofit package for kickup change.) I modified some stock Ultima ST parts, so they accept the RB6/RT7/SC7 front hinge block:

https://cimg8.ibsrv.net/gimg/www.rcu...2f9f9f32ab.png


This offers some interesting possibilities. These parts have compatibility with stock Ultima ST front lower arms and also RT6/SC6 front lower control arms.(Prototype parts pictured):

https://cimg2.ibsrv.net/gimg/www.rcu...f08c844c0b.jpg
https://cimg3.ibsrv.net/gimg/www.rcu...3a08326175.jpg

Here is a short clip about my 3D printed Kyosho Ultima ST Type-R EP project. I have tried to print everything possible. Even the oil filled shocks are 3D printed. (In video the 950 weight oil is used and its way too stiff):

Click to open:

https://hitecmods.kuvat.fi/kuvat/RC/...4_125124_1.mp4

Straight link if that doesnt work: https://hitecmods.kuvat.fi/kuvat/RC/...4_125124_1.mp4