Schumachers new 2WD - The checklist

[glypo]

I have been thinking about this all day. I'm sure it's no secret that a 2wd is on the drawing board and I have heard its release is pending on the success of the CAT SX. That's certainly the rumour flying around the internet anyway, so nothing secret.

I have heard other rumours about it, but don't think I should really disclose them. However, I have been thinking what I would really like to see on a new 2wd, and basically have come to a conclusion.

I would like a Schumacher Cougar 3.

Firstly, and most importantly a nice shallow chassis like the original Cougar and Cougar 2 (and Top Cat). And either made of aluminium like these originals, or how about carbon made in this style? Check this out:

http://tinyurl.com/3jk366

A great looking Top Cat - I bet that chassis would be ideal for modern 2wd, i.e. the Cougar 3. I expect tooling would be be expensive though perhaps. I am sure all will agree with me though, these earlier Schumacher 2wd's were better to drive than the later stuff like the Fireblade?

Secondly, belt transmission. I still have the original belt from '93-'94 in my Cougar 2, and it is as quiet and as effcient as ever. Not that the gearbox wasn't okay on the Fireblade, I just think the belt is better. Less maintainence, more effcient and less noise.

Thirdly, front bulkhead being non-existent. One of the major weak points on all the 2wd Schumacher I have owned are the plastic bulkheads up front. If it was an alloy chassis, I would prefer a technique like the Havoc. With the Havoc they just bent the chassis at the front to provide the kick-up - then the suspension mounted direct to chassis via pivot pins / blocks.

Finally, and probably easiest to achieve as all 2wd's are, LiPo ready.

Over to you, if Schumacher decide to release their 2wd - what would you like to see?

[jeroen206]

Nice Topcat BTW

That would be great , to have a Cougar 3
A updated Cougar 2 with with UJ's and a carbon tub.
With a moulded transmissionhousing and narrower belt (less drag)

A new version off my Cougar 2 Works Carbon


http://www.tamiyaclub.com/picturefra...6090816_10.jpg

[glypo]

Those carbon tub chassis are amazing. Very nice Cougar 2!

[minichamps11]

Firstly, and most importantly a nice shallow chassis like the original Cougar and Cougar 2 (and Top Cat).

Secondly, belt transmission. Not that the gearbox wasn't okay on the Fireblade, I just think the belt is better. Less maintainence, more effcient and less noise.

Thirdly, front bulkhead being non-existent. One of the major weak points on all the 2wd Schumacher I have owned are the plastic bulkheads up front.


Jason,

Can't think of anything worse than a shallow alloy chassis.
The Cougar 1/2 chassis used to bend easily, especially after landing from big jumps. I can live without having to worry about whether my chassis is tweaked. If you must use alloy, the RC10 showed the way to go with it's combination of deeper sides & high quality material. Apart from tweaking, alloy looks old fashioned, gets marked easily, and compared to moulded plastic, allows less integration of features like battery retention, aerial posts etc. However I can't believe Schumacher would ever create a moulded chassis due to the tooling cost.

Belt drive = bad move. One of the reasons Schumacher went away from belt drive in 2WD is because of the increased drivetrain drag on the rear wheels. This gives a "handbrake" effect, lowering cornering speeds & making the car harder to control on variable grip surfaces & inconsistent to drive.

Can't agree more with your last point though. Schumacher used the plastic bulkheads to allow adjustable kick-up angle but the B4/X6 etc seem to get along just fine with a fixed kick-up.

[glypo]

Regarding fixed kick-up, it's easy solved when stuff mounted to chassis. If the chassis is bent to the minimum kick-up anyone would want, so say 10 degrees for this example - you could use pivot pin mounting blocks angled to increase this from neutral.

I think a smaller belt as suggested above would do the trick nicely at reducing belt drag. I felt the rear belt made the car easier to drive, and more consistent- not the other way around.

As for the chassis, I can't comment on tweaking. I can only say my Cougar 2 chassis certainly looks like it has been through the wars - and it has. 14 years on original chassis - can't be all that bad?

I certainly prefer the handling of my Cougar and Cougar 2 compared to my Fireblade etc - and I think maybe the chassis has part to play in this. Either way, I certainly hope it's not some twin deck carbon fibre thing even if it's not a shallow pan.

This topic is kicking up good debate already

[Answer-RC-Pete]

Two thin HD Belts - thinner in total than the original Cougar belt and running a gap in the middle to keep load even across the diff.. Just a thought..
I remember feeling that the belt drive was smoother than a geared drive - maybe not quite as responsive though.

[Chris Doughty]

I would throw the belt idea in 2WD right out the window for a few reasons.

- it WILL be more mainteance than a sealed gear gearbox
- the motor will go in the oposite direction to the wheels, unless you add some gears in there too, and I believe the car is mid-motor so I think they would want the snap of the motor generate some weight on the rear
- the diff will have to be too big to stop the belt skipping and get the right ratio, with would mean a high diff with no way of lowering it.
- belt drag, as mentioned before, if you want a 'softer' drivetrain, thats what the slipper does, if that works well, you wont feel any harshness from the geared tranny

there is not THAT much wrong with a twin deck carbon chassis in 2WD if the bits that bolt onto it are good. don't worry about what has been available previously.

what I would like to see

- small diam diff gear and adjustable gearbox (but not motor) height
- adjustable dogbone sweep (front/back diff movement)
- big bore shocks (1 or 2 mm bigger than the Losi shock)
- standard fitment wheels (as standard as possible - AE style front wheel)
- strong steering geomerty, able to nicely hold the wheels at full lock, no flappy wheels and beyond straight links!
- verticle inner camber link balls, normal outer camber link balls.
- 'low' front and rear shock towers

[jeroen206]

Maybe they can use the complete SX rear end .
Mid motor beltdrive.
Only need a new front end and a nice Tubchassis.

[glypo]

Okay clearly mid-motor is no secret then.

And yes exactly, I was thinking use the CAT SX style transmission. Motor then rotates same direction as wheels, sorts the hassle of getting a mid-mount motor using belts on the centre-line. This also sorts the gear ratio issues.

I don't see how it can be said belt will be more maintenance though, when it has been done before and wasn't.

For sure a twin-deck carbon chassis isn't end of world, but I think it's just too much weight up front and too high up. If there was a nicer top deck, and not to many strange plastic bits bolting it all together like the Fireblade then I am sure something good could work. As you say though, looking at the past is perhaps not the best way to judge a carbon chassis.

[Chris Doughty]

I said I believe the car is mid-motor, I don't actually know either way, I hear the same rumors as everyone else

[Chrislong]

I was forever rebuild Cougar transmission until they went to geared, geared is far better.

[dancoog]

I know they invented the ball diff but what about a gear diff 2wd. If done correctly it could bring a major revolution to what we come to expect from Ep racecars.

[AmiSMB]

I remember the gear diffs in my old PB Maxima. The moldings were shocking and the screw that held the whole thing together kept undoing but I am sure that with todays technology they could do a bullet proof geared diff, just a scaled version of the 1/8th diffs would be nice so we could tune them with thick diff oil. Trouble is that the ball diffs are so light and a geared diff would increase the rotating mass considerably of the transmission.

[Kopite]

Maybe they'll use a revamped version of their old viscous drive....

but defo don't use the SACS

was it the Cat XLS or the ProCat that had the rubber band snapback front suspension arms? Maybe that could be incorporated?

[minichamps11]

Originally Posted by AmiSMB

a scaled version of the 1/8th diffs would be nice so we could tune them with thick diff oil. Trouble is that the ball diffs are so light and a geared diff would increase the rotating mass considerably of the transmission.

Why would I want to take a diff out to tune it with messy oil (I guess you have to clean it out completely when changing oils?) when I can stick an allen key in the side of a Losi and change the diff in seconds?

[AmiSMB]

Originally Posted by minichamps11

Why would I want to take a diff out to tune it with messy oil (I guess you have to clean it out completely when changing oils?) when I can stick an allen key in the side of a Losi and change the diff in seconds?

I think it has been talked elsewhere about the difference in driving a geared diff would give. And unfortunateley the only way of adjustment is with mucky oil that you have clean out completely. I know that the Team Magic M1B tried to allow you to tighten some grub screws to change the action of the diffs which was rather interesting or maybe the answer lies in 1/10th minature torsion diffs or maybe some BBF/Xray Active diffs are in order

[bondy]

I heard Phil B talking about a mid mounted motor FWD 2WD Car aka like the Kyosho MaximumFF of many a year ago ??? ----------------


or was that just me telling him he should try ???????

[Northy]

You guys are making me want to get one of my old Cougars running again!

G

[James]

Originally Posted by Kopite

Maybe they'll use a revamped version of their old viscous drive....

but defo don't use the SACS

was it the Cat XLS or the ProCat that had the rubber band snapback front suspension arms? Maybe that could be incorporated?

The vicous drive was an awesome piece of it, ive still got one in my box

An X6 stylee is the way to go methinks...

[mw02veg]

to be honest im thinking schmacher have found there own way with the sx im pretty sure well can u say it will be a far bit different from the others cars avaible on the market