UltimaX MRB - another mid convertion
 

Hello racers!

There are some homemade kits out there and I wanted to do one myself. Inspired by Fabs and Mr Pink.
First things first. NO 4 GEAR TRANNY:blush:. Wanted to make one myself and I am going to eventually, but just to evaluate. Have seen MR Pinks creation in real life and he is doing really well with it. It accelerates strait on slippery surfaces and turns like nothing else. And on turf, don't need to say more.

I did my transmission differently than him tough. I simply made a hole on the opposite side and reversed the axel. Put in some shims here and there and Volà. The bearing sticks out a 0.5mm. I solved that by making a 6.1mm thick CF fixture with a 10mm alutube inside that holds the bearing in place. Everything is then attached to the motorplate. The bushing are made out of 3*5mm brasstube. The whole motor/motorplate is shifted towards the right to create perfect balance L/R. Seen from behind that is. About 2.1mm shift.
The screws from the lower suspension holder (will be blue alloy soon) are longer and screwed into the brass bulk and from top as well. The lower part of the shocktower (CF of course) will be attached into it as well. Some sort of brace will also be made to support the higher end of the tower. The CF on the gearbox is for supporting the plastic and strengthen it.
Just waiting for the CF sheets to arrive so I can start on the chassi and tower. There will be no top-deck and side by side liposaddles only. http://rsb.se/gallery/files/2/6/4/6/img_1333.jpg
More to follow soon:D.
http://rsb.se/gallery/files/2/6/4/6/img_1334.jpg

Looks good so far :thumbsup:

Thanks:D.

I forgot. I am going to steal your CR2 chassis solution with CF screwed together Jonathan:thumbsup:.

Is there a webcam in my workshop??? Rear end looks similar to the car I am looking at right now but with the motor plate on the other side and a 4th gear (similar to the CR2 idler gear mod).

Question is do I take it to Petit or not?

Alex,

Looks good mate, but I have a question: where does the shock tower go??

Roger:

Of COURSE you bring it !

Thanks Mr Mid Ultima Custom special!

If you look closely, you can see the brass bulk between the upper suspension holder and the rear arm mount. Going to drill 4 holes in that. Going to use 3mm Cf for the tower and mill 1mm off where the upper shock holes are to 2mm. This straitens up the shocks and they clear the turnbukles better. Then I have a solution for another 2 holes a little higher up on the tower for greater support so the transmission does not break easily. The 4 holes in the bulk is not enough I think.

What's great with this tranny mod is the fact that there is very little preparation on the gearing house ones you figured out what spacers to use and what holes to make. Only had to reem up the new opening to 10mm and shims it correctly. If the transmission case breaks it will only take a few moments to make a new one:thumbsup:.

Have another idea too. The Durango Dex410 front shocks are not that much shorter than the Kyosho rears. Perhaps 10-12 mm. Have not messured yet. This could mean lower CG and improved airflow over the wing. Got enough Cf for an optional shocktower....

Transmission finally done!!!:woot:. Some blue option parts to top everything.


Chassis next..
http://rsb.se/gallery/files/2/6/4/6/img_1336.jpg

http://rsb.se/gallery/files/2/6/4/6/img_1337.jpg

Some more done!
 

The result so far. Next up is the fixture part that will hold the lipos and give some more stiffness to the chassis. No topdeck.
There will be 3 of those brass bulks. For adding weight (54grams) and hold the motorcables. The brace from the tranny will be fitted on to that as well for extra support. On top of them I will have a CF for support and looks.
http://rsb.se/gallery/files/2/6/4/6/img_1341.jpg
http://rsb.se/gallery/files/2/6/4/6/img_1340.jpg

Looking GOOD!!!

Im likeing the whole hiding of wires bit, thats one thing that annoys me on these mid motor cars the wires over the cells like that, but hidden away like that is really clever..

When i had my Atomic Carbon S2, the pre-tub chassis i hid all my wires between the cells once and it was soo much more easy than having them up top and i feel "Messy-like"

Good job man! :wub

Happy you like it:D.

I am very allergic to messy wiring. Absolutely hate it and just looks so terrible inside mid-motor cars. Had to sacrifice 8mm of the chassis for it, but it is worth it.
Have some cool ideas for keeping it clean inside later;). New thinking and good looking too.

don't forget the sensor lead!!

Yeah, I know. That little sucker could not fit In those small holes. Do not worry. It will be solved.

Almost finished here. Fitted an extra 2mm cf to stiffen everything up and it does also serve as a lipo retainer. The whole thing is very stable and I believe it will hold together.
Still to be made.
*Batteryposts
*Fine tune the CF with sandpaper and CA.
*a new motorplate that excepts the gearcover without having to cut into it.
*A body and undertray
*Fitting electronics
*Testing the living daylight out of it!!!

Here some pics. Let me know what you think. :D
http://rsb.se/gallery/files/2/6/4/6/img_1343.jpghttp://rsb.se/gallery/files/2/6/4/6/img_1347.jpghttp://rsb.se/gallery/files/2/6/4/6/img_1346.jpghttp://rsb.se/gallery/files/2/6/4/6/img_1345.jpghttp://rsb.se/gallery/files/2/6/4/6/img_1344.jpg

looking very nice indeed. How about slotting the brass blocks at the bottom so the sensor lead can run under there before bolting them down?

Spasiba!

Not really sure how you mean Griff. Please explain further.

just cut the middle part out between the holes so you get one long hole instead of 3 round ones.. then you can slide the sensorcable/plug through and then place the cables.

how hard can it be alex? ;)

Alex, he means like this. Make a slot in the bottom of the block
Gå och lägg dig nu Peter ;)
Promillevarning på ritningen :thumbsup:

Have been over those solutions a couple of times already and there is no space left. First up I did a "tunnel" with 2 CF plates attached on each side of two 4mm*6mm brass U-profile that worked as top/bottom.
The problem was that there were not much material to make the threaded holes. Too week. If I only had a 4*4mm brass. It would be just perfect and a lot more space inside. Could not find that thin. Only 10*10mm:(. Perhaps I will make them myself at a friends house to solve this issue.
My workshop is my kitchen. Only tools available is a Dremel and a hand held drilling machine.

If I want to replace the motor or something else I only have to loosen the two screws on the back bulk underneath. The front only has one screw so it can be turned;)

This is how it looks. Probably going to use thinner cables. This has A LOT of isolation!
http://rsb.se/gallery/files/2/6/4/6/img_1351.jpg

I have to say ive been watching all the RB5 mid conversions very closely, and considering your workshop is your kitchen with very basic handtools, this is a superb effort - over the years ive seen supposedly professional conversions & parts a lot rougher than yours. Very, very impressive.

Looking forward to seeing how it runs now ;)

I meant like hot tuna has drawn, but looking now it would leave no fixing points.:(.