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Post by mattsedgley on Jun 1, 2009 19:40:35 GMT
Can anyone explain what makes the 416 steering setup so good? not just cause it's tamiya, but a range of people have mentioned that it's really good... I'm confused with what makes a good steering setup against what is a bad steering assembly??
Many thanks!
Matt
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Post by lesbaldry on Jun 1, 2009 22:51:46 GMT
Can anyone explain what makes the 416 steering setup so good? not just cause it's tamiya, but a range of people have mentioned that it's really good... I'm confused with what makes a good steering setup against what is a bad steering assembly?? Many thanks! Matt You have got to be kidding  .....It even confuses the experts expert ;D |
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Post by Simon Crabb on Jun 1, 2009 22:57:22 GMT
Rumour has it that some 'people' were measuring the 416 steering to see if it fits the xray!
I guess it's to do with it having two pivot points, rather than just the one? So the geometry changes will be different as it goes from lock to lock? The inner to outer wheel angles will be different.
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Post by lesbaldry on Jun 1, 2009 23:18:54 GMT
Rumour has it that some 'people' were measuring the 416 steering to see if it fits the xray! I guess it's to do with it having two pivot points, rather than just the one? So the geometry changes will be different as it goes from lock to lock? The inner to outer wheel angles will be different. I was only informed tonight as it so happens from someone in "the know" that the 416 maintains steering/front grip slightly better than other makes with worn tyres....An advantage to us club drivers in the slower stock classes...dunno??  I must admit that when a single post steering is turned to full lock the gradual "toe out in turn " angle's are not very progressive (the inner wheel greater angle comes in with a bang close to full lock)This is more noticeable when running so called "more Akerman"...I would emagin the twin post method smooths the angle change between wheels more like the direct steering rack and pinion method on a full size car . It will be interesting to see if current makes and recently released makes come out with a modification...or Mk 2 versions ..Apparently HB/HPI have been testing a new Cyclone with similar steering and a modded top deck. |
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Post by TryHard on Jun 2, 2009 7:58:15 GMT
I think les has it spot on, with a single bell crank, the more ackerman spacers being run, the less progressive the link change will be. Wth a rack style system, your keeping it the angle change smoother.. it's bloody difficult to explain, all to do with the rate the wheels steer etc. Beyond my capability to do so! And HB have been testing a similar system, actually correct that, the SAME system... it's a 416 assembly on the front of the car. There's pics of Moore's proto on redrc.net, from the ETS meeting. Difficult to see the steering system as it's coloured black (to hide the blue), but I know from personally having seen the car and spoken to Andy, that it is from the 416 Moore Cyclone 1Moore Cyclone 2On another slightly different point... interesting to see Marc Fischer's Phi2 running all Tamiya suspension as well... guess the blue boys are doing something right! Fischer Phi2 1Fischer Phi2 2Ed |
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Post by lesbaldry on Jun 2, 2009 8:55:38 GMT
Hey Ed whats that Fischer car all about,Ive never heard of it?...Tell us more chap.
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Post by Simon Crabb on Jun 2, 2009 9:36:03 GMT
Fischer's car is a heavily modified Corally Phi? You must have heard of it Les!
I'm not sure where the fashion for a single steering pivot came from, I'm sure touring cars from the beginning of time have always had twin pivots, it's hardly anything new!
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Post by lesbaldry on Jun 2, 2009 9:55:13 GMT
Fischer's car is a heavily modified Corally Phi? You must have heard of it Les! I'm not sure where the fashion for a single steering pivot came from, I'm sure touring cars from the beginning of time have always had twin pivots, it's hardly anything new! I must of missed it Simon The Old pro 4 did Simon,as did the MSX but that under steered like a pig....also a lot of cars in the early days were shaft drive? Perhaps makers found the single post easier to manufacture plus it might take up less space??....one things for sure though the less links/posts the less wear/slop in the long run. |
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Post by TryHard on Jun 2, 2009 9:58:34 GMT
Yup, it's a Corally Phi 2... easily spoted by the way the arm mounts bolt to the chassis. Now the prodction Phi 2 is ment to have the swept back arms like normal Corallys, but looks like Marc has gone full blown Tam setup on his (including shocks)... says alot about the Corally if you ask me.....
The thing with the old racks is that the pick up points for the link were quite wide apart.
In some respect, these new style racks, with the balls in the middle, behave simialrly to the centre points to start with, as the joints are very close together in the middle of the car. However, at the full travel, funky things can start to happen with the angles, as mentioned before. The flat rack kinda avoids that, as the balls follow a more linear change.
I've just drawn out a diagram in fornt of me, and it basically shows the rack system to have produce less overall steering lock for the same steering input (30deg on my diagram). Interesting, set the outside wheel lock to the same amount for the two systems, and you get more inner wheel lock on the rack system....
So basically, it's a more of a progressive system than the centre point, but at the same time, producing more inner wheel steering... at least, thats my theory!!
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Post by lesbaldry on Jun 2, 2009 11:02:16 GMT
 ...that figures Ed!
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Post by mattsedgley on Jun 2, 2009 11:26:45 GMT
Ed load up the Diagrams! let's have a look see what's going on with both systems!
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Post by Simon Crabb on Jun 2, 2009 11:41:59 GMT
Ahh yes, the older 'rack' TCs had the ball joints far far apart, at the end of the rack. The recent Tamiya system has the balls very close together.
As Les says, it goes back a few years to the 415, but perhaps no-one really noticed it, until the 416 started winning everything?
So a tighter inner wheel at full lock means better rotation, speed carried better, I think? As there's less scrubbing going on?
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Post by TryHard on Jun 2, 2009 11:46:38 GMT
Gonna need a pdf viewer for it... but here you go www.thard.co.uk/download/file.php?id=139Blue is the inital positions, Black with the same steering input (30deg on the servo), whilst the light blue has the inner wheel angles matched. The inner ball joints, you'll note, are in the same position, so the steering links etc are all the same length. I also drew it to keep the distance between the steering post and inner joints similar. It's a bit difficult to tell, thanks to the scan and hand drawing, but for the centre point to match the rack in terms of inner wheel lock, it needs a bit of extra outer wheel lock. Also note how more evenly spaced apart at the outer joint the rack system is, suggesting that the steering lock is much more progressive whilst it turns. Also interesting to note is how much less the inner joints have to rotate, there's some funky angles going on with the centre point. Ed |
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Post by mattsedgley on Jun 2, 2009 11:59:47 GMT
Hmm that really is interesting... something i doubt many racers would be even bothered about... however it's still interesting to see the differences.
I'll try and draw up a wider verision and a narrower version and also one showing 4mm of "Akerman" and 0mm of "Akerman"
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Post by yellowshark on Jun 2, 2009 12:06:29 GMT
Ahh yes, the older 'rack' TCs had the ball joints far far apart, at the end of the rack. The recent Tamiya system has the balls very close together. As Les says, it goes back a few years to the 415, but perhaps no-one really noticed it, until the 416 started winning everything? So a tighter inner wheel at full lock means better rotation, speed carried better, I think? As there's less scrubbing going on? Nope! A tighter inner wheel can mean a too tight an inner wheel with plenty of scrubbing going on. And it is not as easy as that. You have to factor in Ackermann angles/effect too. IE as you adjust your inner wheel you need to look at your Ackermann - ie it is too easy to say as you adjust your inner wheel you need to adjust your Ackermann, it all depends on your starting point in terms of the angle you are carving in relation to speed vs scrubbing and the consistency of your turning circle. In very broad terms I use Ackermann to maintain consistency and the inner wheel angle to balance speed against scrub and if you are reasonably setup in steering terms, then if you adjust one you probably need to adjust the other. |
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Post by yellowshark on Jun 2, 2009 12:09:10 GMT
Out of interest Simon what inner wheel angle do you run at?
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Post by yellowshark on Jun 2, 2009 12:12:24 GMT
Out of interest Simon what inner wheel angle do you run at? Oh Simon this will help. Set you inner wheel angle to 0. You will get zero scrubbing but you won't go round corners very well! Now set it to 90 ;D |
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Post by lesbaldry on Jun 2, 2009 12:15:50 GMT
Just out of interest quite a few years ago there was a KEPT quiet Manufactures recall on a certain make of car  for "scrub steering fault(premature wear to front tyres)....new front struts were fitted with a different arm angle to alter Akerman (our pivot hubs) Tamiya seemed to of worked hard on this overlooked problem maybe? Mind you most of the front tyre wear issues with our cars is probably spool related..no diff action!!....how would a manufacture compensate for this with geometry   ...Tamiya must have. |
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Post by Simon Crabb on Jun 2, 2009 12:28:39 GMT
Out of interest Simon what inner wheel angle do you run at? The honest answer is I have no idea! I sold my setup guages that used to tell me, they seemed overkill: I set camber up with a camber guage I set front toe-out with the lines on a hudy board I set rear toe-in with the suspension blocks etc For steering angles, all I do is set my end points at 100% to be the maximum steering the car will physically allow before anything rubs on anything else, and make the wheel to shock (say) gap equal either side. Then I turn D/R down to 80 or 85% and set the car up around that. Then I can dial in or out a bit of steering as needed. Though, I note, on the 415 I've been running almost maximum steering of late. I just trust the designers and don't fiddle with the ackerman etc, leave it all as stock setup. I don't really understand it, or how I should tune it. |
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Post by Simon Crabb on Jun 2, 2009 12:30:54 GMT
Nope! A tighter inner wheel can mean a too tight an inner wheel with plenty of scrubbing going on. I guess it's relative, I was really meaning tighter inner wheel on a rack system, as opposed to a single pivot system, ie slightly tighter, but not so tight it scrubs? |
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Post by lesbaldry on Jun 2, 2009 12:38:24 GMT
Dont forget chaps there is no diff action to consider too,this throws the wheel distance traveled on lock angle theory right out of the window...one tyre will allways scrub.
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Post by Simon Crabb on Jun 2, 2009 13:15:19 GMT
Oh yes! We're dealing with spools which don't help the understanding!
Just stick it on the track and race it I say ;-)
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Post by lesbaldry on Jun 2, 2009 13:26:44 GMT
Oh yes! We're dealing with spools which don't help the understanding! Just stick it on the track and race it I say ;-) Me too Simon,let the Experts worry about it......As someone said to me last night "dont get to deep into the car and its problems" concentrate on the basics and your driving  |
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Post by yellowshark on Jun 2, 2009 17:25:18 GMT
Out of interest Simon what inner wheel angle do you run at? The honest answer is I have no idea! I sold my setup guages that used to tell me, they seemed overkill: I set camber up with a camber guage I set front toe-out with the lines on a hudy board I set rear toe-in with the suspension blocks etc For steering angles, all I do is set my end points at 100% to be the maximum steering the car will physically allow before anything rubs on anything else, and make the wheel to shock (say) gap equal either side. Then I turn D/R down to 80 or 85% and set the car up around that. Then I can dial in or out a bit of steering as needed. Though, I note, on the 415 I've been running almost maximum steering of late. I just trust the designers and don't fiddle with the ackerman etc, leave it all as stock setup. I don't really understand it, or how I should tune it. Pop over to Team Campell pit tomorrow Simon and I will check it for you |
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Post by yellowshark on Jun 2, 2009 17:27:57 GMT
Just out of interest quite a few years ago there was a KEPT quiet Manufactures recall on a certain make of car for "scrub steering fault(premature wear to front tyres)....new front struts were fitted with a different arm angle to alter Akerman (our pivot hubs) Tamiya seemed to of worked hard on this overlooked problem maybe? Mind you most of the front tyre wear issues with our cars is probably spool related..no diff action!!....how would a manufacture compensate for this with geometry ...Tamiya must have. Interesting Les, I wonder if that though would be a forward motion scrub rather than a sideways motion scrub - who cares ;D Remind me, why are we all racing spools these days? |
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Post by TryHard on Jun 2, 2009 20:37:04 GMT
Interestingly, I was chatting to Chris Grainger about the steering setups tonight (he was returning my 416 following a measuring session), and he mentioned that they were also of the opinion that in terms of lock angles, the rack works best, simply as you can have more outer wheel steering for the same inner wheel lock, or more inner wheel lock for the same outer wheel lock... basically like the diagrams above. He also mentioned that on the Mi4, they tried a large number of different systems, and the best they could achieve was 26° inner, with 20° outer. He measured up my 416, and for 26° inner, it gives 23° outer... and also doesn't overrotate ball cups etc, or do funky things with the link at big angles. Conclusions... erm, does ti really matter for the clubbies? probably not, mainly as most of us would never notice the difference  However, wouldn't be suprised to see the Mi4.5 go with a rack... |
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Post by lesbaldry on Jun 3, 2009 6:59:08 GMT
Conclusions... erm, does ti really matter for the clubbies? probably not, mainly as most of us would never notice the difference Probably not Ed...not with our stock classes anyway.....I would imagine that the Tamiya (in mod at top level) is proving to be better on the second or third run with the same tyres giving the car an advantage if the two tyre set rule is used??.....Mr Westwood did piont out the the MI4 was only good (in mod) on new rubber! |
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Post by yellowshark on Jun 3, 2009 12:06:29 GMT
He also mentioned that on the Mi4, they tried a large number of different systems, and the best they could achieve was 26° inner, with 20° outer. He measured up my 416, and for 26° inner, it gives 23° outer... and also doesn't overrotate ball cups etc, or do funky things with the link at big angles. quote] Interesting Ed. I was taught not to exceed 20 degrees and indeed with 27T we found that between 17.5 and 18.5 gave us best speed at Bashley. No doubt the same rules do not apply to 10.5 but we are not exceeding 20 (out of habit); 18.5 to 19 at them moment I think. Should we be trying higher? |
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Post by TryHard on Jun 3, 2009 13:35:51 GMT
Just cause he's measuring a max value, doesn't necessarily mean it's being run on track. Gives a good indication of the differences between the systems though.
Personally, I'm rarely above 17-18deg on lock, but it's good to know that more is there if needed.
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.....It even confuses the experts expert ;D
...that figures Ed!
for "scrub steering fault(premature wear to front tyres)....new front struts were fitted with a different arm angle to alter Akerman (our pivot hubs) Tamiya seemed to of worked hard on this overlooked problem maybe?
...Tamiya must have.
