It's basically quite similar to a torsen diff, but it has a more consistent action as far as I'm aware of... And it's the best upgrade ever for any Ovlov(Volvo) 240 owner:)

B-fast : http://www.bfastrc.com/

Ain't got the 22 yet, It's due to be released on March 25th. But I love my CR, and I got it working extremely well, so no stress:)

Thx! I've checked it out now... but I can't really see anything new here. All they do is sand the diff rings flat for you (which we've already done ourselves for years). Good for those who wouldn't bother doing it themselves though!

I think the fact that they flattened them with machines is better than our way with sandingpaper...

We rough them, but we can't tell if they're truly flat.

That is true. B-Fast uses machine tools to resurface the rings to a flatter state before doing the two step hand finishing/flattening steps.


.

Ah, brilliant, you're here:)

I assume this flattening process is done to both sides of the ring, of course?

Agreed, I forgot to type that. I'll give them a try of course! :thumbsup:

Yes, both sides of the diff rings are processed.

http://www.fioroni.com/inglese/prodo...ngua=ita&pag=2

Looks like those "tractive" diffs are used front, center and rear for 1:8...

Considering how much weight we re-add to our cars with LiPo, fitting diffs like this wouldn't be a problem weight wise at least...

Oh! And I remember reading about THE car and some very small diffs... are they std. diffs?

I didn't know proper clutch type LSD's were made.

C'mon Schumacher, Durango, whoever.. make some of these for 10th

Going back to the Eaton Truetrac diff...

It's not for us. This is from their instruction manual "Note: TrueTrac differentials require a certain amount of resistance at the ground in order to start the power transfer. A TrueTrac differential may not transfer power if the spinning wheel is off the
ground. If spinning occurs, often a light application of the brakes, while carefully applying power, will slow the spinning wheel enough to allow the TrueTrac differential to transfer torque to the other wheel."

Although it's open until one wheel spins, if that wheel lifts or spins too much, it goes open again.

Torsen diffs are a better option, but the amount of work needed to tune the helical angles of the gears to get the performance we need is probably a cost beyond the reach of most manufacturers. Love it or hate it, a friction or fluid clutch is probably the best-cost option to see if an LSD is a performance enhancer or not compared to the beloved ball diff.

http://www.ymr.no/bilder/Lars&SHY/1N.../BRUK/diff.jpg

...my lazyness + rain races...

-I guess one of the advantages of an oil filled gear diff is no rust! :lol:

I dont wheter to laugh at this!!!

I have used ball diffs and geared etc etc.
the simple rule is a good quality car should have good diffs. ball or otherwise. You need to know how to first build and run in and maintain.
If you ask about benifits of different diff type i think its purely to fit in the car design to get best weight and power transfer.
But an oil filled diff will have problems if you get water into the gearbox and bearings just like your picture.



BTW I thought Cecil Schu was the first to transfer bevel diff into model cars??

Nono! He invented the ball diff!

http://www.racing-cars.com/images/sc...ogo_cougar.jpg

The top left Schuey logo depicts the principle of the ball diff I've heard.

I hope you understand that the last post was a joke :D

Cecil did indeed invent the ball diff, and that was the first product of Schumacher Racing. They were made during the week in the evenings, bagged and shipped off the kitchen table at weekends!

I did an article about Cecil for Model Cars many years ago, and spent a wonderful afternoon at his house hearing about his life and times. He is a remarkable man, and one of the great pioneers of RC. If we ever got to have an RC Hall of Fame, he would be in my top three nominations as an inaugural member.

Maybe if Cecil could be persuaded out of retirement, this problem would get solved a bit quicker!

Could you please scan and email me that article? I'd love to put it into my Model Car History web page! www.ymr.no/historie.htm

that diff looks like a quaife automatic torque biasing diff (the one found on the focus RS)

Fioroni made a 1/8 buggy version of the quaife ATB diff called the Storm traction diff. A series of worm gears that mounted together inline with the drive/outputs

Before the Storm traction fioroni had the Hyper traction torsen style diff and the original (older) Japan traction torsen diff

main difference between Hyper and Japan was the Hyper had 3 pairs of worm gears perpendicular to the inner gears and the Japan had only 2 pairs.

The Storm diff was available with different worm gear sets which had more or less angle on them to change the aggressiveness of the action.

Shy, sorry but I don't have anything to scan with, and I don't hold the copyright. I suggest that you write to Alan Harman at RC Car Racer magazine and see if he knows who holds the copyright. HTH :)

i think we get most of the diffs mentioned here for our 1/5th scale cars, from self locking to manual blocking using plates etc

we also get this: http://www.rctek.com/phpBB/viewtopic.php?t=5614

http://www.rctek.com/technical/oddie...ferential.html


magnetic diff thats self ajusting to always give the best drive and traction in any condition, from people that have them they say its a huge improvment over the stock alloy gear diffs

http://www.rctek.com/technical/image...g_diff_126.jpg

Magnetic!!! Funky shit!!! And it works?!!!

How cool is that! :thumbsup:

Looks hardcore Mad Scientist!!! :D

Now this is interesting:thumbsup::thumbsup:

yup they work, cost a fair bit though, i think a HARM mag diff new from HARM is £200+ odd then ian oddie mods them at extra cost (adds the internal wires and does some other stuff to them)

then again a stock alloy diff is £180 odd new for most cars lol.

not sure if they would work as well being scaled down for 1/10th as your diffs are about 5 times smaller than the 1/5th units we use (my stock diff was not much under the weight of my x10 without wheels and radio and running gear lol) not sure if the magnetic feild it generates would have the same effect (might do as the cars are smaller/lighter and the diffs do rotate alot faster than our 1/5th things)

i wonder if mr oddie has made one for that psychotic reliant kitten yet (if he still has it!) he's worse than me, he will modify anything!!

I volunteer to test a prototype from Mr. Oddie! :thumbsup::woot:

send him an email then:

http://www.oddified.com/index.php

im sure he has all the gear to make them as he makes his own parts for 1/5th cars etc (also the lovely 1/5th ecu's)

Sent! :thumbsup:

gear diff v's ball diff in durango
 

following this very interesting thread, after some posts of gear diff inconsistency/difficultness in handling/performance, I decided to install a ball diff into my durango to see for myself if a ball diff will make this car handle better.

testing to follow in the next couple of weeks.

will keep you posted! :thumbsup:

Is that a Kyosho ring gear? They are bullet proof when properly meshed with the Kyosho pinion gear but I am not sure (because I don't know anybody who has tried it) how well it will last with such a small meshed area with the Durango pinion. Might be worth trying to get the mating Kyosho part in there if at all possible.

It's right at the outside though so it'll stand the best chance it could of surviving! It might be an idea to fill in the inner half of the teeth on the diff gear with epoxy to give the outer part of the the teeth that's being used a bit more support.

I bet the car has loads more grip with ball diffs ;)

ASAIK the D diff is a direct fit in the K, so should be the same vice versa

correct, its a ball diff straight off a zx5sp. All it needed was a 1mm thinner bearing. Mating with the original durango drive gear was the easiest option, if it fails I'll try mating with kyosho to kyosho.
good idea!

I'm betting that too.

on the FS at least.

I'm not going to bother getting an FS and putting a gear diff in, as I feel ball diffs in offroad will be superior, IMO.

I understand that fully :lol: Just thought it might be a good idea to use also the plastic planetary gear (small one) from the Kyosho, as that one is also plastic. Looks like you've kept the Durango steel gear as for now.

Remember the ball diff I was telling you about, that was still good as new after a few thousand laps on carpet?

I've been running a month or so now, I would guess about 5000 laps or so, still good as new...... :P

The new 22 uses two more diff balls, which means 14% more surface area, that should mean a lot more solid, and a lot less wear and maintenance!

will see how it goes as the durango gear was the easiest option. I cannot see the kyosho drive gear fitting at all to be honest the way the durangos front shaft is arranged.

You're starting to sound like Cramer now, in that episode where he wanted to see how far he could get before filling up the gas tank... :D

Have you run the car yet with K diffs?

Did you have to modify the Kyosho out drives for the durango shafts to fit in?? The pin is thicker then the kyosho ones so you will need to open up the outdrivs, slots to fit..i wonder about the ball with pin through it as well.. this is bigger and maybe to tight in the outdrive..

Ive tried Durango diffs in the FS2... good but too brutal..pretty straight forward to fit, just make sure all meshing is spot on.
:thumbsup:

I only have a K diff in the front.

had a run yesterday, failed within 5 minutes. I couldn't tell you how it handled any differently as the track was blown out from all the rain we have had. Metal bevel gear ate up the kyosho diff gear fairly quick. I dont know if I can fit a kyosho bevel in, as durango setup has a cvd 2cm coming out of gearbox. It sure would be nice to know someone handy with a lathe at this time lol

I used kyosho sp drive shafts, along with kyosho hex.

gear diff in fs2 no good? if you could explain how it handled.....thanks. That just makes me want to make this durango ball diffed even more.