View Full Version : RB5 mid

Mr. Pink
05-07-2009, 08:38 AM

Here is my converted kyosho rb5 in the making.
I have managed to modify the gearbox with reverse rotation.
Rear shock tower and tower mount is stock.


/Mr. Pink

Alex H
05-07-2009, 08:46 AM
Yes, here you are:). Cool project. Good luck with it. Sure it will run well. Saw you in action at the Nordics with you Lazer. Congratulations to a A-main spot!

Mr. Pink
05-07-2009, 08:58 AM
Some electronics installed...


/Mr. Pink

05-07-2009, 09:14 AM
nice work, looks fab mate. i think you can say your a perfectionist. :)

05-07-2009, 10:43 AM
The 1st version of the x6 had a problem where the torque caused on power created lift in the rear. With your gear box, does on-power cause the front to want to come up (good) or push down?

Alex H
05-07-2009, 10:49 AM
The 1st version of the x6 had a problem where the torque caused on power created lift in the rear. With your gear box, does on-power cause the front to want to come up (good) or push down?

The Rb5 has got a lot of rear grip so maybe it wont be an issue.

Mr. Pink
05-07-2009, 03:32 PM
Tested the car today at our local track (green hill) with 100% astroturf.
I do recognize the rear rb5 suspension. Still alot of grip.
It behaves much like normal buggy. On power gives alot of rear traction.
I think the weight distrubution is much like stock rb5 but now the yaw-moment of inertia with the mid-setup is lower and the car changes direction like a mid-buggy should.:p
It is very easy to drive and handles bumps much better than expected.
I am very keen to test the car on a low-grip track as soon as possible.

/Mr. Pink

Thomas P
05-07-2009, 06:14 PM
I agree the car was ace to see IRL!! it will be the future @ our track

Mr. Pink
06-07-2009, 10:30 PM
Attempted to make a body + undertray today out of soda bottles.

The result is not top notch but it will do as a prototype.:blush:




07-07-2009, 08:11 PM
That looks fantastic, well done ;D

07-07-2009, 09:21 PM
Is the wheelbase as original? Just looks long to me?

Mr. Pink
07-07-2009, 09:33 PM
No the wheelbase is ~1cm longer than original.
I hope the combination of low inertia and longer wheelbase will give a stable but quick car.

Edit: Put the car on the scales and mesured a total weight of 1520g.
The distrubution is 63% rear and 37% front.

/Mr. Pink

07-07-2009, 10:46 PM
How did you make the bodyshell with soda bottles?

Mr. Pink
07-07-2009, 11:02 PM
I am using the same method as one of my racing buddys.

Simply a mold out of wood and the bottle acts exactly as a shrink-wrap when heated with a hot air gun.

Mr. Pink
08-07-2009, 06:46 PM
And a painted body...

Maybe the color is not to everyones liking but I like cars that stand out.:p


09-07-2009, 01:13 AM
Stupid question but, what size and brand of bottle did you use, im struggling to get one big enough for my custom car. Yours looks great btw!!

Mr. Pink
09-07-2009, 08:43 AM
I am using 1,5l coca cola bottles.
But before cutting the bottle apart to wrap around the mold I drill a small hole in the cap and pump up a pressure with a bicycle pump. (around 2 bar) Then I carfully go over the bottom end with the heat gun to smoothen out the bottom end. This gives me a little more plastic to work with.

09-07-2009, 12:44 PM
It wouldn't be very expensive to have a decent shell made form polycarbonate if you where to make the mould yourself .. ....

Nice job on the car BTW ....

10-07-2009, 11:21 AM
hi .. nice work there :D

what did u have to do to achieve the reverse gear rotation?

Alex H
10-07-2009, 11:25 AM
Its not reversed at all. The motor is positioned the same as usual. Same rotation as normal. Just on the other side of the gear box.

Mr. Pink
11-07-2009, 07:23 PM
Managed to run a couple of packs today with the car.
I flipped the rear wishbones to get the rear wheels as far forward as possible. This gave me only a few mm longer (instead of 1cm) than original and hopfully better weight distrubution. (Now F 36% B 64%)

It is very easy to drive and the only major drawback found so far is that I built it 2-3 weeks to late. (the week after the Nordic CC):cry:

Below: Som pics of the "Panther" side by side to the rb5 SP.
/Mr. Pink

13-07-2009, 10:59 PM
How much for 1, I was trying to do something similar but your proto is amazing. Pm me witth details plz

23-07-2009, 07:30 PM

I'm trying same kind of modifications, but i'm using the original chassis, after little 'Dremelizing'!

But, unfortunatly, it's not so easy to reverse the spinning direction of a BL motor... What's why I've asked Mr Pink to show us in detail the gearbox modifications.

My prototype:







Mr. Pink
23-07-2009, 07:54 PM
Here's som detail pics of my conversion...

What you need to do this is an extra gear-case half to cut out the bearing holder closest to the spur-gear, a 5x11 bearing, and some spacers (~8mm)








The last pic showing a prototype garcase that I made before.
On the left half i cut down to the same level as the rest of outside of the gearcase. On the right i drilled up to 11mm (used a reamer from the outside) The original inside diameter in the gearcase is 11mm in the location that the 5x11 bearing will sit. The bearing holder from the extra gearcase half is cut flush to the same level from the other side. The screws and motor-plate will center everything up nicely.

/Mr. Pink

23-07-2009, 08:04 PM
Thanks a lot Mr Pink!
I'll try that tomorrow! :woot:


Mr. Pink
24-07-2009, 08:01 PM
Also the gearcover is possible to re-use with a few small adjustments...



/Mr. Pink

24-07-2009, 11:55 PM
haha johannes how dirt-tight is that gearcover :p:p

27-07-2009, 09:22 PM
Hats off to u guys....... AMAZING:D:D
I cant even hang a toilet roll holder so I think I will leave my RB 5 as is for now:D
but I would buy one if avaliable;)

16-08-2009, 04:56 PM
Some details on PetitRC:

Sorry, in french... You can PM me if you want some details ;-)

Mr. Pink
28-08-2009, 08:07 PM
Made a new paintjob today.
This is the third paintjob on this car and the least ugly of them.:blush:

However I managed to get 6:th overall at the Swedish Nationals last weekend. It was the first race ever with the mid so I am very satisfied.:p
The track was very slippery but the car was still very easy to drive. Just needed a little bit softer throttle finger.

31-08-2009, 10:16 PM
you used a carbon body and upper deck.
Where does this comes from? Made them yourself?

Also, could you show some more detailed pictures of the reversed (=mid-placed) gear box?

Mr. Pink
01-09-2009, 05:58 PM
I bought some 4.25x11.875"CF-sheets from http://fullforcerc.com/.
2mm and 3mm. Then I drew everything on the computer using autocad.
Printed it all out on a regular printer in 1/1 scale. Made sure that the printer was calibrated and then glued the paper onto the sheets.

First I drilled all the holes and made sure they where all aligned and then cut out the pieces using a manual hand saw. Then of course CA-seal and sand the edges.

This saturday the car went trough its second race.
This was the track. A lot of mixed surfaces.
I ended up third which is my second time ever on the top-third placement.
So I am very pleased so far with the performance...:thumbsup:

Lowie: I think all gearbox pitctures shows everyting already. Is there any specific part of interest?

/Mr. Pink

Mr. Pink
18-10-2009, 08:12 PM
New body again...
I never seem to be satisfied but it I think they are getting better and better.;)


I have now attended two races since the last uppdate. The first one outside on clay/dirt with the worst result sofar. The other one was indoor on carpet wich was a completely different story... This car is so easy to drive and I ended up in a total 3:rd out of 21. I cant wait to the next race.:wub

18-10-2009, 08:32 PM
defo your best shell yet :thumbsup:

stampede vxlboy
18-10-2009, 09:38 PM
nice work

18-10-2009, 10:03 PM
Totally awesome car mate :thumbsup:

Big G
19-10-2009, 10:04 AM
I don't think the motor is spinning the same way as the wheels still. You need to add another 'cog' to make it do that. What you've done is make the motor spin the same way as originally (assuming it was hanging off the back, I'm not familiar with this car sorry).

wheels/diff spin clockwise
idle gear spins anti-clockwise
spur clockwise
motor anti-clockwise

I have done the same with a T3 in the past, but couldn't get the motor to spin the same way as the wheels at the time so it's somewhere in the back of my garage right now.

When I first turned the gearbox 180 degrees the motor required wiring up to the speedo the opposite way which of course made it run like a dog. even after a adjusting the timing it still wasn't right so I put the spur shaft out the other side of the gearbox and turned the motor round so it ran the same way as before, but still spins the opposite way to the wheels.

The conversion looks very tidy though :)

Mr. Pink
11-11-2009, 08:37 PM
I actually don't think it is an disadvantage to have a 3-gear transmission.
I "mirrored" the tranny just to be able to run sensored motors.

Compared to many other mid-conversion I have seen, my car have both the motor and battery pack about a full cm closer to the rear axle. The chassis is on the other hand 1 cm longer in between the suspension mounts compared to a stock rb5. But with the flipped rear wishbones and shimming of the rear hubs the total wheel base is now just about 2~3mm longer than stock. The wheight distrubution is almoast the same as the stock rb5 so the only "change" really is the change to a lower yaw and pitch-Inertia.

And there is also no extra wheigts added to this car whatsoever.

Since last uppdate two more indoor races hav been attended.
Both ended upp at 2:nd place.;)
Wich happens to be my best 2wd result ever.

/Mr. Pink

13-11-2009, 02:44 PM
My MID RB5 is working well also: qualified 17th at last french cup of champions, my 2nd B main in 2WD, after last French national, also with the Mid.

But I will not continue, I definitely prefer touring cars...

If anybody is interested in my prototype, I'm selling it. Of course with all parts to build it back in standard configuration ;-)

Contact: vincent.cavard@wanadoo.fr


13-11-2009, 05:13 PM
Hello Frere,
do you have any pictures of your mid-car?
You can also mail them to me if you prefer that (at ludodg_AT_gmail.com)

20-11-2009, 08:28 PM
Hello Lowie,

Did you get my Email?

20-11-2009, 11:35 PM
yup, i did ... sorry but family-related issues makes that my head is in very non-rc-mode at the moment.

Mr. Pink
30-12-2009, 09:04 PM
The second chassis is being made for a friend of mine.
This one vill be able to take the old trackpower lipos and it has a little different topdeck.


Mr. Pink
04-01-2010, 11:10 PM
Finished conversion no.2
It is a real pain to cut CF by hand. But I am satisfied with the result.

/Mr. Pink

07-01-2010, 02:52 PM
Thats hot.
Really good custom build.

Mr. Pink
20-01-2010, 09:32 PM
Experimenting with the soda bottle bodywork.
I managed to get some "negative" curves this time by using another mold ontop of the main one and press down as the heat is applied.

I admit it is not a beautiful creation. But the bottles are cheap and the mould easy to modify...http://www.oople.com/forums/attachment.php?attachmentid=11525&stc=1&d=1264022568

21-01-2010, 02:20 AM
looks good with the air intakes but the back looks too much like an x6 or whatever they are called :P :thumbsup:

21-01-2010, 09:26 PM
Experimenting with the soda bottle bodywork.
I managed to get some "negative" curves this time by using another mold ontop of the main one and press down as the heat is applied.

I admit it is not a beautiful creation. But the bottles are cheap and the mould easy to modify...http://www.oople.com/forums/attachment.php?attachmentid=11525&stc=1&d=1264022568

I like it....
Can you please give us some more details about how you do these????
A tutorial would be good.......

21-01-2010, 09:29 PM
looks good with the air intakes but the back looks too much like an x6 or whatever they are called :P :thumbsup:

Well of course its gonna have the same lump at the back to cover the motor, so will all the mid motors will have a bulge

Mr. Pink
07-02-2010, 11:54 AM
Got tired of continually breaking the rear shock tower and made a new backplate. I have also made a stabilizer bar attachement out of zx5-lazer parts. Stabilizer yet to be tested...

But at last practise I converted into the original narrow rear end. It felt alot quicker around the corners and I think I will test this setup at the next race meeting.;)


Mr. Pink
07-03-2010, 01:04 AM
Experimenting with a 4-gear tranny with idler.

The kyosho idler meshes perfectly with a 21 tooth pinion.

Will be tested tomorrow.


Mr. Pink
14-06-2010, 05:42 PM
Some updates...
Now with motor centring from the rb5sp2.

Some pictures.

Söderhamn . 4th position

Nordic Championship Norway. ended up 10th
(Car no 2 in this picture)

29-06-2010, 12:11 PM
Some updates...
Now with motor centring from the rb5sp2.

Some pictures.

Söderhamn . 4th position

Nordic Championship Norway. ended up 10th
(Car no 2 in this picture)

Hey Mr Pink, any new pictures of the car with the motor centering kit from the SP2?

Did you update the rest of the rear suspension with the SP2 parts too?

The RB5 seems to run awesome in mid-motor configuration. I'm currently running mine without the idler mod but it seems to run fine without it. Car has TQed and won the Amain in the last 2 local races I ran with it.

I'm wondering if the motor centering kit makes a significant difference and if you run an extra idler?

Mr. Pink
01-08-2010, 05:50 PM
Oh Sorry for not replying to your post BloodClod.
Didn't notice it until now...:blush:

Yes the centering does actually the car a lot.
I do not have any pictures of it now but I basically cut the spacer in half to make it fit the "wrong side".
And it is the sp2 suspension together with the longer shock shafts. Ran Ghea 3x1.2 pistons all around.

The car did its best result this far yesterday during the Swedish nationals.
Qualified 3:rd and ended up 5:th (ended 4:th in all thee finals)
My car is the blue and silver one.

I still consider myself as a novice driver so I am very satisfied with my result.:p

Edit: I tried the idler once indoors but I have only raced the car with the standard 3-gear.
Another funny thing is that in Norway (Nordic championship) I did my best two qualification rounds on an slippery whet track.

Some of my racing friends yesterday joked about on what I have done to my car to make it go so fast and they came up with that I have somehow "bewitched" it to go fast...:cool:

07-08-2010, 05:13 AM
Where do you measure the front/rear weight balance from? is it the center point of the chassis from front to back?

Mr. Pink
07-08-2010, 07:38 AM
It is the front to back weight ratio.
I use a set of scales and weigh the car as it is. Then I support one axle (front or rear) and let the other axle rest on the scales again.

Then to calculate the % of weight on that axle it is


Mr. Pink
20-08-2010, 11:35 PM
For those who's interested...

I will attend the European championship in Vienna with my rb5 mid. ;)

03-09-2010, 04:47 AM
Hey Guys,
A few fellow racers suggested I should post some pics of my conversion.

This is version 2. It offers - 4 fore/aft positions for stick pack, currently tweaking for a saddle pack, adjustable servo fore/aft, adjustable gearbox height, adjustable roll-center via hinge pin holders, easy adjust upper camber link holder (no need to remove ball cups), pivoting upper deck to better support tower in crashes but allow the lower chassis to flex, all standard parts are off the shelf RB5, delrin four gear box.

Only had it running for a week or two, the RT5 version is awesome that I've been running for quite some time. Enjoy!


03-09-2010, 07:31 PM
we can't see your pics...

03-09-2010, 10:37 PM
we can't see your pics...

I'll try again...:confused:

If it still doesn't work, go here -


Edit: Still not working it appears, happy to send them to somebody if they can post them for me?


Mr. Pink
26-02-2011, 08:43 PM
Short update...
I have been racing a lot with my mid and have been for the most of the time placed top 3, but no win until today on carpet...:D

Have played around a little with with BB shocks but the old shocks work best indoors. I now use 350 oil and ghea 3x1.2 pistons all around and springs is lime green at the front and dark green at the rear.

The suspension geometry is sp2-spec but with the 54mm shock shafts in the rear.

02-03-2011, 07:17 PM
Where did you win?

Mr. Pink
03-03-2011, 04:49 PM


03-03-2011, 04:52 PM
got some recent pics we can have a browse at :D??

03-03-2011, 05:41 PM
Me and my 2 smäll kids (2 and 4) where there. I spoke to a guy with a rb5 and next to him was a guy with a mid engined car. Was that you?

Mr. Pink
03-03-2011, 07:34 PM
I think it where 3 home converted cars at that race. I suspect you spoke with Lars Hägerman with his mid converted losi XX.

Some pics.


04-03-2011, 09:09 AM
Thoose homeconverted cars are fast, i did feel some slow cornerspeed on my tamiya at the Norrtäljetrack compared to Johannes car, i couldn´t push it harder even though i tried.
I need to do something for some faster pace...

Nice to see you win, you really deserves it!

Mr. Pink
29-03-2011, 06:57 PM
Have made some further results with the car. I have now won all the 3 remaining races in our indoor series.
But I did not manage to win the total. :( (2 points short)
However it felt really odd to dominate a race. :confused: Everybody else where just slower and I simply ran at my own pace.:cool:
Here is the A-final 3 from the final race in the series.

Mr. Pink
09-08-2011, 12:46 PM
New adventures with car. I have attended the Worlds and other outdoor events with a regular RB5 but decided to try out my mid car at our home track Green Hill. I built the car for this track so the result was good. Ended up at second place.

This is the last A-main with the winner Mikael Johansson not running after winning A1 and A2.


The car got a new body and a new position of the rear tower as far forward as possible. I will update with some close up pictures as soon as possible...

10-08-2011, 12:23 PM
My videos seem to pop up like mushrooms everywhere :thumbsup:

Good driving Mr. Pink!


Mr. Pink
05-09-2011, 06:52 PM
Thanks Joel!

Well here are the pictures I promised to post.
First is the new body style. Of course inspired by the PL-bulldog.
Next is some close up pics of the new position of the rear tower.


Last is a pic on the top-deck for the lazer zx5 FS2 made from 3mm CF.


Mr. Pink
25-10-2011, 06:03 PM
Chassis no:3
My first "order" finished for delivery.
Did some updates on the battery tray.


Mr. Pink
06-01-2012, 01:02 AM
Yes... I am crazy.

I got my self a cnc mill and here is my first prototype of my mid conversion in 3mm fibreglass. This material cost about 1/5 to 1/6 the price of CF. Perfect for prototyping.

06-01-2012, 01:05 AM
Very cool! I quite like the fibreglass - gives it a bit of a retro feel :woot:
Home CNC hey - will have to remember that :)

Mr. Pink
06-01-2012, 01:34 AM

I really like this machine. Bought it from a guy who designed and put together about 10 mills of this design in his spare time.