nizee

Ahhh...ic...i learn something today..... i knew my teacher was wrong....

PUNISHER

iTrader: (2)

Nizze,
For some odd reason you do see more wear in the aluminum pinions then the steal ones. I guess it’s the heat of the friction of the gear mesh soften up the aluminum.

fmolzer

Wow, talk about a long and active debate started by a 14 tooth pinion gear.... I guess it goues to show that we are all looking for snappier acceleration. How about that german site that did 14 tooth gears, any chance we can get a link? And no, my buddy Salven never said anything about the price of gears, just wanted to mess things up a little... Know your comment about dutch/german numbers translation though, they say eight and twenty instead of twentyeight. weird. On the other hand, the US still thinks that inches and feet is a good system to measure distance.....

nizee

Now i know my teacher is wrong....... i know i can break and bend plastic parts, this time i'm going to try alu and steel block!!!

Pit-racer

iTrader: (4)

And don't forget the titanium hinge pins!

markp27

Major crash both wheels on the righthand side of the car broke! My local dealer doesn't have any wheels Can't drive anymore

I've also got two broken shock absobers.

It came about due to my car spinning when I hit the breaks hard. Even though I tweaked my car and did the setup correctly, the car's rear end still breaks away under heavy breaking.
I spoke about this with my dealer and he reckoned that one can't break too heavily due to the front one way diff - therefore one should set the breaking to be relatively light.

Is this true - can you guys not really hit the breaks to slow the car down quickly?

After I'd adjusted my breaks, I went a little too quick into a hairpin, couldn't slow down quick enough, car got sideways and hit a high curb just off the circuit and then it was wheels-flying-off-rolling-yellow 705. The rear wheel is totally destoryed and the front wheel's spokes are broken. Also rear shock absorber came apart, destroying the screw threads on the absorber body.

Now I've found that in two of the shock absobers, the rubber seals (that fits on the top of the absober body) have holes in them!!! This has let air into the oil. I think this may have been so before the accident, as I noticed the other day that there were air bubbles in the shock absorber's oil.
This may also have been the cause of my car loosing control under breaking - what do you think??

Nothing else seems to be broken on the car (I hope!), so I'm pretty impressed how strong it is!!!

Just to add something to the dicussion about the Dutch/German number system: I've been living in Germany now for several years and although I'm now fluent in German, I still have some problems with the ordering of the numbers, i.e. eight and twenty (28).
Then suddenly I realised that in english we also use this kind of system in the "teen" numbers, i.e. seventeen - the least significant number is mentioned fist, in principle we say "seven and ten". So maybe German is logical in continuing with the system through the rest of the numbers


Cheers, Mark.

modellor

Hi Mark,

Dont know how much your hobby shop owner knows but it sure doesnt seem like he knows to much about one-way diff set ups.

You should be able to break straight at full lock up regardless. If the rear end is breaking loose then something is not right on the geometry.

The main cause with the Serpent would be the shocks not being equal, or the pivot balls not all the same length or a tweak in the chassis.

But once you get both sides of the car equal it will brake straight.

markp27

Hi Modellor,

Thanks for the answer! He had me almost conviced.

I think at the moment, I'll have to lay the blame on the shock absorbers. I set the car up last night and spent about 3 hours trying to get everything right with the toe-in, camber, track, etc.
I used the tweak method in the manual, and although it was very labour intesive, I both the front and rear wheels to lift at the same time. So when my car still broke loose when I very surprised.

I'll have to get a couple of new shocks built up and then wait for some wheels to turn up.

One more question: what does Shore mean, in context of tyres? Is it hardness?

Cheers, Mark.

modellor

Yeah,

The shore rating is the tires hardness.

The softer the tire the smaller the number the shore rating will be.

At our track we were very amazed to see that 35 shore front and rear worked very well giving the car a nice balance. With my Yokomo I am having to run 42/45 in the front with 37/40 in the rear to get the same handling.

The 705 seems to be an awesome car. Cant wait to get mine on the track

fmolzer

Careful now, don't jump to conclusions here. I am not sure of where some of the info on this forum comes from, but I have been driving nitro cars with front one-ways for quite a while, even at national competition level, at tracks with so much traction that your car will traction roll in the corners if you are not careful, but still, if you lock up the brakes on a car with a front one way, it will almost certainly spin out. Think about it, when you brake, the weight transfer to the front of the car, leaving you with very little pressure on the rear tires, now, if those tires are locked up, what will happen? Mark found out for himself... The way to set up the brakes on a car with a one-way is to dial it in so that the car has just enough brakes when under full brake power to where the tires do not lock up. A locked up tire will also always slow down the car less efficiently than a tire that still is rolling but offers resistance to the surface. Mark, once you have your car back in shape, dial in the brakes so that they do not lock up, but slows the car down. The fastest way around the track is to dial in drag brake, meaning, at idle, the servo acctually holds the brakes at a semi-soft setting. This allows you to slow the car down before turns by simply letting of the gas. Since the drag brake is consistent (same point at the radio all the time), it is easier to control than slamming on the brakes every time and trying to hit the same braking force. The set-up requires an analog throttle servo though as a digital one will burn up very fast. This is what all pro drives are using to get around the track fast. As for shore, it is a hardness rating on the tires. The higher the number, the harder the tire. front/rear foams are different, so a 40 shore rear tires is still softer than a 40 shore front tire. usually, you will want to use a rear tire in the 37-40 region and a front tire in the 40-42 region. try to avoid more than a 2-3 points difference in shore hardness. If you need to have a large spread in the shore between front and rear, it normally indicates that the setup is less than perfect. play with springs/dampening/angles instead.

Now, go put the snake back together. Crashing is part of the
game, the only way to avid it is to put the car on a shelf... and how much fun would that be?

markp27

I certainly don't have your experience, but I'm very pleased with the way my 705 handles - and as it seems I still haven't got everything running optimally, then I can't wait to see what it's like when I get it really dialled in!!!!

I've got a little lost off with all the gear ratio talk, but certainly on the track where I'm driving the gearing is too long. I'm just getting into second gear at about the point where I have to slow down.
Do I simply change the gears on the clutch bell to get the desired ratio?

Just getting my new order for rccarinternational ready now that I need some new wheels

modellor

Yeah, I agree with you that under full lock up the car will still snap but that is to do with left/right balance of the car.

I too have been racing nitro for 16yrs at National/International level (mainly 1:8th on-road) and I never had a car that couldnt brake straight with a one-way in it.

Setting up shocks, pivot balls and tweak is only half the battle. You have to consider uneven tire wear, a slight difference in shores in any pair of tires and the overall weight distribution of the car.

Maybe more mathematical thought before slamming someones credentials

And please dont take this post the wrong way. Not attacking you, just stating my opinion.

markp27

Hi fmolzer,

Thanks also for your reply.

That's kind of what my dealer was saying too, which seemed to make sense. However, I don't think I'm getting to the point where the breaks actually lock.

It seems that I can't apply the breaks too heavily, i.e. the breaking effect is very weak and limits me to non agressive driving.
It also seems that at first (when the car is travelling quite fast) the car breaks in a straight line, but then as it slows it suddenly spins out.

I can't wait to get the car back together. I had about 3 hours at the track today - and had it all to myself

fmolzer

modellor, I did not at all mean to miscredit your statement. I think I might have misunderstood you a bit, you talk about braking straight, and yes, of course you can brake straight, you just can't lock up the rear wheels on a NTC and excpect the car to continue to go straight. It would be like going down the highway in your full size car and pulling the emergency brake.... In 1/8:th scale, you have so much more rubber on the ground than with a TC that you can get closer to getting away with locked up rear tires, (especially if you set the droop to prevent weight transfer and run on a high bite surface), but even with a perfectly set-up car, I think that it is not advisable to try to produce fast and consistent laptimes while braking beyond the lock-up point. ...

just my 2 cents...

fmolzer

modellor, I just noticed your number of posts you sure live an active life here on the forums....