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Post by darrenoakley on Apr 4, 2011 22:02:24 GMT
Just wondered if anyone that has this function on the transmitter uses it. From what I have gathered it adjusted the sensitivity around natural or the end of travel.
In my manual it says mostly positive is used if anything but really wanted to get the opinion of anyone that uses it.
If I turn from 0% up this would be positive right ? and will it make it easier to track straight but not compromise turn in.
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Post by Reality Racer on Apr 5, 2011 8:59:19 GMT
I have this function on my KO and have used it in the past, but no longer use it.
Positive will show a +% on the screen. Never use negative expo on steering.
It can be useful to make the initial steering more controllable but don’t use to much as it can make the car a bit snatchy nearing full lock.
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Post by martinchallis on Apr 5, 2011 9:41:37 GMT
les set mine up for me, I remember him saying that spectrum are quite funny with what their values mean. Essentially they do the opposite of everyone else.
I will tell you my expo settings when i get home. I cant drive without it now...
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Post by darrenoakley on Apr 5, 2011 10:38:52 GMT
Cheers guys I will give some a try in a practise. Yours would be good Martin as I remember our cars and transmitters feeling very similar last time I had a go on yours.
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Post by Reuben on Apr 5, 2011 12:06:28 GMT
I tried it, didnt like it.
I felt I lost control and predictability of the car as the curve increased. But again I like a very linear steering.
Like Terry I found it snatchy towards the end.
im sure if you set it and try it, you can get use to it and might find it suits you. But I tried it and never liked it because I was always having to correct it because I wasnt use to it.
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Post by yellowshark on Apr 5, 2011 17:00:17 GMT
Darren, if you are having trouble tracking straight then ,assuming nothing is wrong mechanically or tweaked then other alternatives are, bodyshell eg if using a Mazda spread 6 then try a standard 6 or an Alfa; or a longer wheelbase but if you are using XRAY kit settings on wheelbase I doubt you would want to lengthen it at Bashley.
You could also play on the transmitter with some negative curve or slowing the response down.
Failing that an unsurpassed remedy is to fit some smaller thumbs ;D
HTH
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Post by yellowshark on Apr 5, 2011 17:01:55 GMT
That should of course be a Mazda speed 6!
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Post by darrenoakley on Apr 5, 2011 18:10:09 GMT
Na wasn't having problems just wanted to see what it was like using the expo on the transmitter mate. I also use a spread 6 bodyshell.
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Post by martinchallis on Apr 5, 2011 19:00:40 GMT
on my ds3s i have it set to -30%
that makes it less twitchy in the middle and as it gets to the end of the steering throw it will chuck the lock on faster...
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Post by martinchallis on Apr 5, 2011 19:10:28 GMT
soz dx3s
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Post by Martin Young on Apr 6, 2011 15:16:50 GMT
on my ds3s i have it set to -30% that makes it less twitchy in the middle and as it gets to the end of the steering throw it will chuck the lock on faster... Martin Negative values on the DX3S & R Handsets make it more sensitive around the centre point. Quote from the DX3S Manual. " Positive and negative Expo values are
available. A positive Expo value results in the
center being less sensitive (desirable most of
the time) while a negative value increases the
sensitivity around center (normally not used)" Hope that helps, |
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Post by martinchallis on Apr 6, 2011 18:50:26 GMT
oh dear - back to 0 for me... Thats why im so slow!!!!!!!  |
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Post by lesbaldry on Apr 20, 2011 7:37:52 GMT
Steering Expo is not only personal feel but can be car specific! Various cars have different steering systems,rack or post type and even then they both have adjustable set ups with Ackerman.Its basically used to make the steering have a linear feel (Ackerman angle depending) I normally set mine up "on the track" but a quick bench check should give you an idea of whats happening. Looked from above the car I move the steering very slowly from lock to lock to make sure the wheels follow the movement ot the stick proportionally.IE no quick or slow movement of the cars wheels compared to the stick movement at either end of the wheels travel from center. The non adjustable early post type steering systems suffer more than rack types.this type the wheels tend to accelerate toward full lock on the last third of the travel for the same servo speed so some times Expo is needed to make this more linear. Example: If you like running with little Ackerman "very little toe out in turns" (agressive steering feel) it can pay to play with minus Expo as this will calm the initial steering into corners some,making the car easier to drive....I know one top driver who even reduces his servo speed by 50% via the trany to reduce tyre scrub  ...hmmm even more stuff to confuse our minds with the black art of set up  lol Most drivers tend to use -20% these days....Have a play with it,its easy to change on the rostrum ,you may well find it calms the steering down some,especially on those "grippy" days or high speed tracks Hope this helps ....Les |
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Post by darrenoakley on Apr 20, 2011 8:13:25 GMT
Cheers for that mate. Was feeling a little jiggy at points on the track so was trying things out to calm it. I have also got ride of the servo saver to see if this changes anything for the next meeting. It's not a big deal but just something I wanted to experiment with.
Glad your on the mend mate.
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Post by lesbaldry on Apr 20, 2011 19:20:13 GMT
Cheers for that mate. Was feeling a little jiggy at points on the track so was trying things out to calm it. I have also got ride of the servo saver to see if this changes anything for the next meeting. It's not a big deal but just something I wanted to experiment with. Glad your on the mend mate. Just be warned that with some tranys Pos and neg Expo can be a different affect.....The main idea is to "soften" the steering at neutral stick,so give your steering max expo in either Pos or neg and operate it just to make sure what part of the steering throw you are affecting Example Martin Youngs post states that pos expo softens the center point of the steering(DX3S)...My trany (KO) neg does this!.....Many don't realize this and wonder why the car feels odd even though they have thought "from well meaning given advise" the steering center has been softened by giving it +20%...20% is barely noticeable "by eye" but will feel very "twitchy" on the track if its set at the wrong end of steering travel |
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Post by justchris on Apr 29, 2011 15:44:39 GMT
Whats the differance between expo and steering rate ?
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Post by Dave Chamberlain on Apr 29, 2011 17:34:11 GMT
Hi Chris, Steering rate is a constant sensitivity adjustment, higher rate more steering.. Expo allows you to make the steering either more or less sensitive around the center point, normally you use expo to make the steering less sensitive around the center point so when at high speed slight steering inputs do not make big movements at the wheels.. Makes the car easier to handle and less "skitish" Expo does not increase or decrease the amount of steering, thats steering rate and end point adjustment.. Hope this helps  |
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Post by yellowshark on Apr 29, 2011 17:59:50 GMT
BTW, I could be wrong on this because too lazy to get the manual but I am sure you will find that KO Esprit transmitters do not refer to this as exponential, they call it Steering Curve. So -ve 20% curve is less sensitive, ie much flatter, and +ve 20% is more sensitive, much steeper. I have a suspicion too that on the Esprit 3 you can adjust the shape of the curve but I have never played with that, so I might be pushing my luck there - but if it is of concern to you then you probably have the manual ;D
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Post by yellowshark on Apr 29, 2011 18:15:36 GMT
Hmn, interesting Dave. KOs do not have anything called steering rate. They have steering speed, which either speeds up or slows down the actuation of the servo (linearly from neutral to full steering)- clearly the same settings may work differently with different servos. Importantly though this does not change the amount of steering, just the speed with which it is delivered. So for a newbie it is beneficial to slow the speed down.
On the KO you can set the speed independently for speed from neutral and return to neutral. You can also break each of those legs into two segments and have a different speed setting for the segment (that overrides the statement above about it being linear, but it will be linear within each of the two segments); not that we have ever played with that.
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Post by lesbaldry on May 2, 2011 5:27:02 GMT
Hmn, interesting Dave. KOs do not have anything called steering rate. They have steering speed, KO's Terminology& my interpretation Steering travel = total servo throw/travel overall (steering rate) Steering Balance= individual travel/rate adjustment for left and right lock(end point adjustments) Steering speed= allows the speed of the servos travel from center to full lock to be slowed and also the return to center if required ( can be handy for those with heavy thumbs when used on the throttle ;D) Steering curve=Exponential (as Dave explained) Steering punch= the complicated parts of Petes posts  lol..........As far as im awear its never used in 10th TC,just some KO gimmick and something for Pete to worry about Chris mainly the only two adjustments that can help a driver and his car set up are individual end point adjustments and Exponential, to understand Exponential its best observed with the car on a stand with some one showing you its effects to the steering operation...Basically Expo is a "helpfull driving aid" and is not an absolute necessity,especially at our short little track in the slower stock classes. Ok Ill try and simplify matters,Our cars need lots of steering lock to navigate hair pin bends,but having lots of lock will make the car feel very twitchy on the steering the faster we go especially on a very long fast strait due to the limited and short trany stick or wheel throw (unlike a full size cars steering wheel travel from lock to lock )... So Expo "sort of" gives the trany some "free play" at the center to stop the car reacting to the slightest input,making small high speed direction changes easier,smoother and less violent. |
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Post by justchris on May 2, 2011 7:09:23 GMT
Thanks lads !!!!!!!
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Post by yellowshark on May 2, 2011 12:20:21 GMT
Hi Les, on board with just about everything you said there, good overall description too; just a couple of comments. Interpretation of KO commands mine too Steering punch - we have never used it either  I would say 1. Steering speed is helpful too. IE slowing down the entire steering reaction speed can be beneficial for newbies. We used it for Craig in the early days and it did help. Obviously the heavier the thumbs the more beneficial it is ;D and the setup of the car, responsive or not, will have an impact I use 60% when I am driving the buggies ;D ;D ;D 2 FWIW I set up steering travel/EPA as follows. Assuming Craig wants 25 degrees. I set steering travel to 100% and EPAs to 27 degrees (say). I then set steering travel to 90% which gives 25 degrees. This means that on the rostrum Craig can easily change +/- from 25 degrees Note on the KO you cannot set steering travel >100% |
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Post by yellowshark on May 2, 2011 12:26:25 GMT
Hmn, thinking about, which course one never does before one posts. I guess you could argue that if you use negative curve you do not need to worrry about reducing speed. I will admit that when we first used steering speed I did not know anything about steering exponential control
The feel must be different though I guess because speed is linear whereas curve is not. But of course as a non driver I wouldn't be able to comment on that even though that 2.1 in Mathematics tells me so.
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Post by lesbaldry on May 2, 2011 14:00:24 GMT
1. Steering speed is helpful too. IE slowing down the entire steering reaction speed can be beneficial for newbies Note on the KO you cannot set steering travel >100% Steering speed(servo slow) I found was helpful in very high grip and on carpet.It allowed the tyres to bite with out initial scrub,steering felt "less snatchy"....As I posted earlier I know of one very fast guy who uses 50% all the time when using super fast servos,and one other who has found it usefull on the throttle especially in low grip.....the theory been  ,the rubber cant grip the surface as fast as the rapid input of some servos.therefor the rubber will initially "scrub" during input for a fraction of a second then bite as it acquires grip,possibly feeling snatchy or slightly "delayed"  I'm not with you on the KO 100% steering travel bit?....My KO Esprit 3 allows me to raise from 100% to 150% of std travel,so did my old Sanwa. Steering curve (expo) V steering speed ....As you say Pete Expo is not Linear,if you soften (effectively slow) the start of steering throw using Expo it will have the opposite effect by speeding up the same entered percentage towards the end of the travel.....some tranys have a graph that demonstrate this well. This effect can be detrimental to some Post steering systems that arnt too mechanicaly linear by exaggerating the increase in steering throw speed towards the end of travel making the car suddenly "hook" ( loose its rear) .....Basically for any new racer don't use stupid amounts of Expo on the steering,15 to 25% is about right. |
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Post by yellowshark on May 2, 2011 16:59:42 GMT
Sorry Les I was referring to the ET-3 dial which lets you directly modify the steering travel (from 100% down to 40%) that you have set via the steering travel command structure, . Yes you are right, going through the menu system you can use steering travel command to set 150% of dialled in EPA.
Having dialled in steering travel/EPA via the menu structure (takes time) to give us 27 degrees, I then reduce it to 90% with ET-3, takes .5 second, to set 25 degrees. Of course these numbers are just ours, you could say set steering travel so that 80% on ET-3 was 25 degrees and give yourself a greater range of +ve adjustment via ET-3.
As always, multiple ways of achieving the same end but I do think ET-3 is advantageous as it gives you the ability to very quickly tune the steering angle. Certainly something that Craig uses
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Post by lesbaldry on May 3, 2011 5:53:33 GMT
Bloody hell thats a bit complicated Pete!......I just set the hubs to max lock with end point adjustment,make sure I have equal L&R turning circles then reduce/increase ET3 (duel rate) by feel for "on the day" conditions.....I don't worry about angles or percentages as they along with EPA will change dramatically if you happen to play with Ackerman,toe,camber or bump steer adjustments during the day. |
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Post by yellowshark on May 3, 2011 10:03:24 GMT
Nah, in essence we are doing the same thing Les; if there is any difference in reality, it's the difference between a driver and a chief mechanic I think (don't forget a chief mechanic has time and loves the preciseness of the science). My job is to try to give Craig a car that is spot on from the start - which for us is as per the setup sheet for the time of year, with maybe one of two potential changes for Q1 depending on how practice looks.
Everybody's brain works differently; I prefer to talk to myself and do diagnostics in degrees rather than EPA %s and put the milk in after the tea. ;D
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Post by lesbaldry on May 3, 2011 12:17:16 GMT
Everybody's brain works differently; I prefer to talk to myself and do diagnostics in degrees rather than EPA %s and put the milk in after the tea. ;D ......... |
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...hmmm even more stuff to confuse our minds with the black art of set up 
lol 
lol..........As far as im awear its never used in 10th TC,just some KO gimmick and something for Pete to worry about 
,the rubber cant grip the surface as fast as the rapid input of some servos.therefor the rubber will initially "scrub" during input for a fraction of a second then bite as it acquires grip,possibly feeling snatchy or slightly "delayed" 