Airwave

iTrader: (1)

Could somebody explains to me which are the criteria for symetric/asymetric dampering?

Does it depend on the relative grip of the track?

Thanks

OVA

iTrader: (86)

the answer is in your A700 manual

Airwave

iTrader: (1)

huh... Could you please indicate me the page, because the only information I have is page 37, where there is a short explanation about what are symmetric and asymmetric modes...

But no clue about what track conditions should help me chose between the two modes...

Sorry if this is a dumb question...

John Doucakis

iTrader: (1)

It's been a while since my last r/c related post in my blog.
I recently purchased a ball diff in order to use it as an alternative tuning option for low grip conditions following the remarks of some of the users.

Here you may get an idea of what it looks like:




a few more detials here:

JD RACING BLOG

Airwave

iTrader: (1)

Nice I'm impatient to read your test..

I'm really unable to make it work as I want. I try to mount it with silicone oil and I can't prevent the diff to loosen...

And today, I mount it with standard greases and it was a lot slippy...

I must do something wrong, but I can't find what...

John Doucakis

iTrader: (1)

I built mine with 1.000 Xray cst oil and it seems to operate correctly.
I don't fill any slip and action is silky smooth.

Have you treated the diff plates with sandpaper as per the instructions?
John

Airwave

iTrader: (1)

yep with 400 - 600 - 800 - 1000...

hana166

iTrader: (2)

TBH I spent considerable time with the ball diff including making a sanding tool on my lathe to hold the plates making sanding much easier and more precise but I found the slipping a real problem when used with 16 or 8 balls, fluid filled, unless you overtighten. Its not that obvious at first that its slipping. Don't get me wrong, car feels good, reactive, great rotation but as soon as you get to a big outdoor track there is a clear lack of forward bite in comparison to the gear diff.

Overall, I was quicker with the gear diff everywhere under all conditions, I really like the balance for my driving style with 2000 CST

hana166

iTrader: (2)

Just a note for something I found maybe it will help someone

I found my car not feeling so good for a few weeks and decided for a major rebuild. I found that after some (bigger) crashes one leaf spring bent slightly. Very difficult to notice. I think it is important to check regularly as it seems to have a big impact on the laptime, as I replaced it and went seriously quicker immediately

I notice a number of drivers using o rings on the suspension, to remove slack, I say this should be unnecessary in most cases if you set the preloads perfectly

After replacing the damaged spring I bend the end so there is a tiny, tiny gap to SPR02, so there is no pre-tension in the system when the suspension is at rest.

Then set the droop and get them identical L-R. Then wind out the preload until the slack appears. Balance the preloads by turning 1/6 at a time until both sides have the tiniest, but equal amount of slack, then add 1/6 turn, you should find the suspension return onto the downstop perfectly, but of course now the preload is the same L-R.

So when you set the ride height just turn exactly the same amount both sides so you know where you are when making adjustments

Naturally the car needs to be balanced L-R on pins etc to begin with

I found the slack appeared when the car had too little preload on opposite corners, the car settled flat so you think all is well but the digital scales showed this up

I find now the car extremely consistent from corner to corner and particularly easier to get on the power on exit as it pulls so straight. It pulled straight before, so its difficult to explain, but there is somehow more confidence to drive at the limit when the preloads are matched very precisely

OVA

iTrader: (86)

it is great to know....

erchn

iTrader: (7)

Had a fun race day today, it's great watching some of the best in the world battle it out.

My car was pretty good, I put it fourth on the grid, but had quite a few problems throughout the day. First, I ran a normal servo horn for the first time today, instead of a servo saver. This turned out to be a really bad idea. Reality is that the steering rack simply cannot be run without a servo saver. Upon nearly ANY impact, no matter how small, the servo rack can tweak and push the screw that holds the rear bearing tight pushing it away from the rack and causing the rack to be so loose that it slips out of the bearings, ending your race. In the end, I think the steering rack is in need of a design change, as a servo saver simply shouldn't be a requirement for durability. I like the concept, and it certainly looks cool, but simply isn't as durable as it needs to be.

I've once again popped apart P01/P02. I had just replaced all of them on my car, as they were starting to pop apart more easily. I believe this is yet another place that needs some design work, as I think it's certainly a weak point on the car. The need for a zip tie or shrink wrap (my method of making them more durable) is just not worthy of the quality shown by the rest of the car.

Finally, the noise out of the car, when running transverse, is really distracting. Especially when I'm practicing and there are fewer cars on the track, a plastic replacement for G01 or G02 is desperately needed.

This may sound like a gripe post, and probably is in some ways, but I'm mainly trying to bring pain points to the forefront, and give Oleg and team feedback on the car.

Finally #2, made some pretty decent sized setup changes today. Much of the changes revolved around shock dampening changes, trying to keep the same or similar spring rates but going higher dampening up front in comparison to the rear. It really helped the be more aggressive going into a corner, rotate more coming out of the corner, and teamed up with more front caster high speed steering was better. I always wanted to try more caster up front, but I couldn't justify the initial steering loss, the dampening change allowed it and it's given me more of the on power steering I was looking for.

Ethan

Oleg Babich

Ethan,

Thank you for comments.
We are going to modified P01/P02 and AM10 steering soon.

For the current parts:

1. One drop of thin CA glue in the slot between P01 and P02 after final adjustments of caster and camber will help you against popping apart during race. Further small adjustment of suspension geometry are still possible after this gluing also.

2. "Hand made" modification of current AM10 steering plate is possible.
Please see pictures attached.
This prevents the rear bearing displacement and also makes adjustment of this bearing more easy.

erchn

iTrader: (7)

Hi Oleg,

Thank you for the tips.

Funny, this was my plan for the next race.

That's a good mod, I'll put that in place, thank you.

I suspect a servo saver will still be required for durability. Reality is that the current steering rack is extremely rigid, and has no flex points other than ball cups. So, the servo saver is more of a steering system saver.

If the steering system is in for a bit of a redesign, any chance we could get more throw as well? I think it just means a longer AM09. The turning radius on the car is pretty big, and while that makes nice round corners sometimes on a tighter track, or in open (the point and shoot class), a tighter radius would be great.

Thanks again,
Ethan

Oleg Babich

Ethan,

For A700:
Max. steering angle of the inner weel is ~35 deg at standard steering system
(not IAS) and correct steering links adjustment.
This value is the same as for others current top cars.
Outer wheel's max steering angle depends on ackermann and toe out settings and is within top cars's range also.
Please try the standard steering set to get max possible steering angles.

erchn

iTrader: (7)

I will test, thanks.