Desire RcRacing Scorpion

[RogerM]

I have had quite a few PMs and mails asking about this mid motored converstion for the RB5 and now am in a position to pass on some details.

The car came about as a result of trying to extract the maximum performance from a mid motored 2wd; a car that would be equally at home on low grip / greasy surfaces as ultra high grip surfaces whilst providing sublime drivability in those conditions we typically race.

Here are some images of the production car as they will cover more than a 1000 words can. Some better quality and more detailed images should be available in a few days once the website is live.




The original design brief was a simple one;

1) Use the minium of bespoke components, maximum use of RB5 kit parts and keep all 'wear items' stock Kyosho parts

2) Provide optimal weight distribution and transfer without extra ballast

3) Variable stiffness chassis to tune for different grip levels, as at home on slippery as well as grippy surfaces

4) Maximum amount of geometry tuning options whilst providing a stable base for those that prefer to "just drive it"

5) To be able to remove the transmission and also change the antisquat with less screws removed than stock RB5 whilst utilising the Kyosho gear case


Additionally the option of quickly converting to rear drive when the conditions required it was to be included, something that whilst hard to achieve without compromising the mid motored application has been achieved.

The conversion is now ready for supply and has been proven on a large range of track surfaces and conditions. More details to follow as soon.

[tsan]

hi Roger. The tags in your post were a little messed up. (all I got were incorrect links)
I'll repost them, if you don't mind.

[RogerM]

Thanks Tim, more haste less speed!

[MikePimlott]

Nice work Roger,
Glad to see its finally here

[RogerM]

Been a long time in the making Mike but as I said to you at Silverstone I wasn't going to post any pictures till it was ready for general release.

Have a go next time you see me (or one of the other drivers already lined up) mate, would be interested to hear your feedback.

[jasonrcb]

Mike feel free to have a go with mine also,although both mine and rog's are the same car im running the full sp rear end,see which car feels best

Though mine is all new and shiney hey rog

[RogerM]

LOL ... I like the lived in look of mine. When you have put as many laps on yours as I have mine well see how they compare

What Jason meant to say is that we are trying the different combinations and options Kyosho so kindly provided for the rear end of the Scorpion.

Hopefully there should be quite a few more around the tracks VERY soon.

The car has been proven on multi surface, astro, grass, carpet and dirt. All this with limited setup change required, one of those cars that most people should be able to pick up and run the stock setup anywhere.

[RogerM]

double post

[caneye]

Roger - this is using the standard Rb5 3-gear diff?

[RogerM]

Transmission uses the RB5's gear case and internals unchanged (other than flipping the diff around) and adds an external idler gear to give the correct rotation, not just overall but in our opinion of the spur / slipper assembly for superior control in the air ... basically you get for free similar to what you would if you fitted the brass flywheel to an X6 transmission.

[caneye]

Originally Posted by RogerM

Transmission uses the RB5's gear case and internals unchanged (other than flipping the diff around) and adds an external idler gear to give the correct rotation, not just overall but in our opinion of the spur / slipper assembly for superior control in the air ... basically you get for free similar to what you would if you fitted the brass flywheel to an X6 transmission.

ah thanks .. that was not obvious in the pics. more pics of the diff assembly & rear toe plate pls

[RogerM]

You can see the idler at the bottom of the gear cover in the 6th picture. That is a very early attempt at cutting the gearcover, now we remove much less material and that leaves the idler much less exposed.
Work on a bespoke gearcover is on going, hopefully be ready for release very soon.

[Northy]

Originally Posted by RogerM

Transmission uses the RB5's gear case and internals unchanged (other than flipping the diff around) and adds an external idler gear to give the correct rotation, not just overall but in our opinion of the spur / slipper assembly for superior control in the air ... basically you get for free similar to what you would if you fitted the brass flywheel to an X6 transmission.

Are you sure Rodger? The Slipper assemblies are rotating in different directions.....

G

[RogerM]

I am sure G'.

Without pictures harder to visualise but I'll try;

External idler box

Rotor + pinion = anticlockwise
external idler = clockwise
Top shaft + slipper = anticlockwise
internal idler = clockwise
Diff + wheels = anticlockwise

Internal idler box

Rotor + pinion = anticlockwise
Topshaft + slipper = clockwise
1st idler =anticlockwise
2nd idler =clockwise
Diff + wheels = anticlockwise

I hope that comes across ok ... a picture would have been a load better.

[Northy]

Well I'm still not convinced! They rotate the opposite ways!

G

[RogerM]

Ok mate, when I get a moment I will draw a picture .... till then trust me ... I'm a doctor

[carlin]

Originally Posted by RogerM

Ok mate, when I get a moment I will draw a picture .... till then trust me ... I'm a doctor

Lol love the punch line.

Roger looking very good & all the hard work is paying off.

Just like to get my hands on one have good gander it wont be long if he lets me have ago lol

[RogerM]

Originally Posted by carlin

Lol love the punch line.

Roger looking very good & all the hard work is paying off.

Just like to get my hands on one have good gander it wont be long if he lets me have ago lol

Actually I am .... doctor of engineering ... I don't put all the letters on my e-mail sigs as I think it makes you look a bit "try to hard".

As for the Scorpion, well there should be a couple in your part of the world very soon. If nobody else will let you have a go pop over to Ardent when i am next there and run mine. I use Spektrum and sticks but changing a reciever isn't hard if you needed to use something else!

[RogerM]

Ok gents, sorry for the silence ... life has been super manic lately but I've kept moving on with Scorpion and true to my word I am starting to take orders mid November as promised.

For those guys who have already been in touch I will be mailing you in the next day or two to confirm a price and ask you to confirm your still wanting the pack reserved for you.
As soon as that is done I will post the ordering details here, I think it's only fair to reward the guys who have shown long term interest to let them have first call on the first batch.

Just so you know I have all the parts for the basic kits sitting in front of me other than the build instructions, they are being produced this weekend ... there is a shiny new RB5SP2 waiting to be stung

There are quite a few things in the pipeline for both Scorpion, RB5 and also ZX5-FS, along with a couple of suprises ... stay tuned

[Chris Doughty]

I'm with G here,

X-factor's flywheel thing is used to lessen the effect of the motor, because its rotates in the oppo direction to the motor.

so where I do agree that your method does give more control in the air with the motor and slipper assembly spinning in the same direction, I disagree with it doing the 'same' as x-factors brass flywheel, I was of the impression that the xfactor brass flywheel was to lessen this effect

EDIT - add an idler between spur and pinion AND a brass flywheel, wow, now there is some serious airtime stunts to be had