oOple.com Forums - Enough Rear and Mid motored buggies!

oOple.com Forums (http://www.oople.com/forums/index.php)

- I Made This ! (http://www.oople.com/forums/forumdisplay.php?f=25)

- - Enough Rear and Mid motored buggies! (http://www.oople.com/forums/showthread.php?t=44869)

Enough Rear and Mid motored buggies!

I've wanted to build something like this for a while now... Rear-motor cars are awesome, but mid-motor cars (till late) are pretty unique, but for something really rare, how about a FWD off-road buggy!

Inspiration...
The project was inspired by buggies like these...

http://i137.photobucket.com/albums/q...oto/ryuz_2.jpg
http://i137.photobucket.com/albums/q...photo/FF-2.jpg
http://i137.photobucket.com/albums/q...photo/FF-3.jpg
http://www93.sakura.ne.jp/~time-tunn...8-4-27/013.jpg

Always thought they looked extremely unusual in a cool way and according to what little information there is on the internet they didn't run too badly either. FWD supposedly offered advantages on loose tracks as they didn't spin out. Kyosho produced the Maxxum FF buggy and while I never drove one of those many didn't consider that a "race-inspired" design like some of these purpose built buggies.

Unlikely to ever get a chance to buy one of these so I decided to try my hand at building my own.

The plan...

When designing the car I wanted to do a few things differently though...

CG : Most of these cars I researched mounted the battery on a lower deck and all the electronics went on an upper deck. Possibly electronics were bigger back then... but with today's smaller electronics (and availability of saddle pack batteries) I wanted to try to position the electronics all on one deck for a lower center of gravity.

Steering : Many of the buggies also used direct steering setups like on cars like the Frog / M03. I suspect probably this was also because of space constraints. With about half length of the car being the rear wishbones, everything else needs to fit in the remaining space... we're talking gearbox, steering assembly, servo, esc, rx and battery! However, such steering setups typically result in a lot of bump steer, so I wanted to try to use a more established bellcrank type steering in this buggy.

Donor parts : I like the RB5/RT5 transmission so I knew that'd be my gearbox of choice. For the front suspension I decided to try to adopt something from a current 4WD buggy. The Tamiya DB01/501 suspension was chosen as I had significant spares for that and it was also metric. These arms have also earned a reputation of being strong so it seemed like a good choice. All the parts to mate the two together and the rest of the car would have to be scratchbuilt.

The Result

The whole buggy took about 2 weeks to design and build... and after all that it's still just a prototype. G10 was used for the main chassis to try ideas as I could always redesign and reproduce them in CF later. Some parts that needed more rigidity were cut from CF straight away while shocktowers, rear wishbones and other little odds and ends were made with Delrin.

I tried to incorporate as many tuning options as possible in my design as I really have NO IDEA what would work and what wouldn't - so for example the rear wheels alone have full camber and toe adjustment available, there are a variety of shock mounting positions, even the transmission height is adjustable...

Enough text though... here are some pics.

Oh... the shell is a donor too until I can decide on something nicer to use... but I don't think it looks half bad. :lol:

http://www.cool.per.sg/external_link...project_03.jpg

http://www.cool.per.sg/external_link...project_04.jpg

http://www.cool.per.sg/external_link...project_05.jpg

http://www.cool.per.sg/external_link...project_06.jpg

http://www.cool.per.sg/external_link...project_07.jpg

Now I need a name for the car... any suggestions? :)

Let me know what you think of this project.

Thanks!

WOW, you have made a good job of making it, but im not so sure how it will handle on the track.

Let us know how it goes and maybe post a youtube clip too.

As for name, how about "crabull", for the front of a bull and rear of a crab.lol

Jamie.....

I want one :D

I always fancied a go on one of those FF buggies, having driven an old yokomo(?) FF touring car a couple of times I always fancied a go at a FF buggy.

I also used to run my old TA-03F a few times without the rear belt/transmission and it was great fun outdoors.

looking good. The only thing with front wheel drive buggies, is with ROAR rules they count as 4wd, 2wd means only the rear wheels powered, so fwd counts as 4wd. Then again, I think you guys use a differant organisation, so your rules may be differant.

t'Is all good to run this car within the BRCA rules.

Quote:

23. CONSTRUCTION RULES - GENERAL
23.1 Two wheel drive cars (2WD) are those having only one pair of driven wheels on the same axle. Either
the front or rear axle may be driven. Four wheel drive (4WD) cars are those having all four wheels driven.

Carl

very nice handiwork :thumbsup:

Quote:

Originally Posted by BloodClod (Post 369984)

http://www.cool.per.sg/external_link...project_07.jpg

like it a lot. good work.
how about calling it the bulldog
cos all its powers up front and it kinda reminds me of one

that is really nice and unique. i used to have a maxxum and it was actually quite good fun to drive, worked well on high grip and you could throw it around without any chance of spinning, but on low grip the traction and on power steering were awful, it just span and pushed strait on, just wish i had kept the damn thing....

I tried Bloodclod's special home brew and all i can say it handles great! :thumbsup:

Awesome :thumbsup:

My Dad was thinking of making a car just like that too

Wow Bloodclod, our friend is getting really good with his camera... :woot:

I got a name for it, but not a very good commerical name, just based on it's looks which wood be The WAF - Weird As F**k.

Looks like it handles well though. With the heavy stuff being at the front, does it make it easier to handle jumps? I often forget to reduce the power to make the nose point down for landing you see.

Performance Report

The car was tested and it really ran better than anyone expected. The other drivers today generally rated the track as "inconsistent" but towards the "loose" end of the spectrum.

Car on the track and off we go!

This buggy doesn't drive anything like a mid or rear motor car (expected of course...). It can be driven with the throttle on throughout the entire track - in fact, it performs best when driven that way. Going into the turn the rear end comes round nice and crisp and once the car is past the apex, throttle up again and it's off we go without a fuss.

While the other rear driven buggies had to contend with the rear ends losing traction and spinning out if the throttle was applied too quickly, this never happened with the FF. On the other hand, what the FF had to contend with was wheel spin. Punch the throttle too hard and the front wheels would spin and hunt for forward traction - but without losing it's heading or composure. This meant that on the straight and out of turns it takes a tad more time to get up to speed.

However, any time lost there is gained back by the speed it carries into the turn. With the throttle on throughout the turn and no fear of the rear end kicking loose, the car handles the technical sections of the track with ease. In fact, one "stick" only racer took my wheel radio and drove the car round amazingly well. His comment "I only need to think in the steering channel". :)

Now I was worried about the jump handling of the buggy given it's front weight bias, but it appears my fears were unfounded. The car was driven by at least 4 different drivers at today's run and within a lap or two everyone was tackling the jumps with relative ease. The suspension soaks up the landings well and with a tad more throttle the car flies level without the much feared nose-down attitude. On the downside, our track has a triple jump coming of a 180 turn that some 2WD buggies clear at a go. The FF didn't do this comfortably today not because of jumping attitudes, but more because the earlier wheelspin characteristic meant the buggy couldn't pick up enough speed to clear it. It *almost* did, but didn't actually do so. perhaps on a better day with better traction or perhaps with some setup to increase the front traction a tad this buggy will do the triples.

Everyone who drove the buggy had a big smile on their face... it was just unlike driving any rear-driven buggy and the experience was truly unique. :)

This is definitely the coolest project I've seen in a very long time!:thumbsup:

Cheers,
Ty

i love it.
very very cool buggy.
grtz jeffrey

I have to make me one of these... Very good craftsmanship..:woot:

Would love to se a action video :thumbsup:

Making some drawings of my own as we speak...

Bloodclod's home built buggies never fail to amaze me. First was his mid motor RB5x and now this and the best thing is that all his buggies work and handles really well. Lastly, he's a great driver too. BC you're my hero!! :lol::thumbsup:

Looks really cool :thumbsup: and refreshing to see something a bit different.

We started to design a modern replacement for the FF a couple of years ago but never got it finished. But you did so congratulations! Looks great!:thumbsup:

Looks excellent...but is it brca legal?

Thanks everyone for the very kind comments.

I'll post some more detailed pictures of the various parts of the project, the steering in particular is one of the more unusual setups, designed to fit a bellcrank system into a chassis where space is a premium. :lol:

I've also got a V2 chassis drawn up to give the front arms more "kick-up". It would have been cut from carbon fiber today too if not for a loose nut on my mill... messed up my tolerances and wasted good portion of costly CF plate. Oh well... there are days one should just know when to take a break. :)

Will try to get some videos taken at the next run...

BRCA legal? As I'm not from your neck of the woods I'm not so sure about BRCA rules - but as far as dimensions go I designed the car to be very very close to the RB5.

According to the brca rules it would be legal :)

23.1 Two wheel drive cars (2WD) are those having only one pair of driven wheels on the same axle. Either the front or rear axle may be driven.

It would fail the BRCA control tyre rules for the rear axle.

nice project, any video in action?

But the national entry from only advise minispikes and no part number, so you could use a slim 2wd front minispike maybe ?.

The exact wording of the rules is slightly ambiguous, but.................................

The entry form refers to rear tyres, and schumacher tyres are labelled as front or rear on the packaging.

It would certainly be an interesting conversation with the scrutineer.

Lets see a Atomic Carbon CR2 FWD??!! :woot:

Very interesting and different, good work on making this car up! Id race one of these in the winter if produced! :thumbsup:

Hey I might just ask one of my friends to race this at the next race here, I think it would do very well!

Here are some pictures of the steering on my FF buggy...

Instead of the pivot point being in the middle of a bellcrank, I moved the pivot point right up front and this allows it to actually sit on the sides of the front gearbox, close to the outdrives. To achieve this, the bellcranks actually mount to the upper deck instead of the lower one. The bellcranks now pivot forward instead of backwards in a typical setup.

This took a long time to figure out how to get everything working freely but it's working!

Bellcranks mounted on bottom side of upper deck
http://www.cool.per.sg/external_link...project_17.jpg

That's all the space there is between the servo and the front gearbox.
http://www.cool.per.sg/external_link...project_18.jpg

Today I cut new chassis plates out of carbon fiber and while I was at it I decided to make some small changes. I changed the shape of the upper deck slightly to add strength to some areas (although I didn't really have any problems with breakage yet) and removed some area for aesthetics.

Biggest change to the bottom chassis is that I've modified it to give more front kickup. The hingepin mounting block used to be mounted on top of the lower deck but now it is sitting flush with the bottom of the upper deck. This is done via spacers which will also allow me to add or remove "kick-up" if I need it.

In case you're wondering, the hingepin blocks come from a DB-01. :)

Hingepin blocks now sit flush with chassis bottom to give more "kick up"
http://www.cool.per.sg/external_link...project_15.jpg

Pic of everything mounted up in front.
http://www.cool.per.sg/external_link...project_16.jpg

Doesn't everything look better when it's in carbon fiber? lol!

http://www.cool.per.sg/external_link...project_14.jpg

Very impressive build!
You might get copied...;)
Had also the same thoughts of a reversed rb5 about a year ago but the efforts were spent om my rb5 mid at that moment. Have you narrowed the DB-01 front? I still can not figure out how to get tha lazer-sp/fs front narrow enough to get within 250mm with wide rims mounted.

/Johannes

everything looks better with some cf and new tires, looks amazing

Amazing job you've done there :thumbsup: looks the nuts ...

I'd be interested to see some more detail shots of the front and rear suspension hub bits .....

I started on a B4 mock up earlier this year but didn't see it through .... still got the bits tho ...

Quote:

Originally Posted by BloodClod (Post 371601)

Doesn't everything look better when it's in carbon fiber? lol!

http://www.cool.per.sg/external_link...project_14.jpg

:woot::woot:

Even better now. Great work!!

I'd like to make something similar once i finish my 1/8th electric project :yawn:

Quote:

Originally Posted by Mr. Pink (Post 371611)

lol! It would be interesting to see more FF buggies around - do build and share!

Yes, I have narrowed the DB-01 front end. It's done at the suspension blocks. Currently the front of the car car is running a Kyosho RB5 narrow hingepin block in front and DB01 blocks in the rear. The DB01 blocks as pictured are separate pieces so they are easily positioned.

In the end the car comes to a hair under 255mm wide in front from edge of tire to tire.

Not sure of your local rules but i thought the ifmar standard was maximum 250mm wide?

Regardless, the project looks fantastic and once you have it all completely finished perhaps you might be able to sell a conversion kit?

I have an RB5 and the Durga parts are easy enough to get so I'd love to drive one :thumbsup: