Anvil*
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« Reply #15 on: January 23, 2010, 03:46:27 PM » |
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Center hub pivots on a short spindle inside the hub. Much like an I-beam axle only centered relative to the tire with a zero scrub radius. Caster remains the angle of the pivot with the vertical. If mounted in a single swingarm, caster angle changes as the suspension moves. The focus-link arrangement is using two 4-bar linkage systems. One set controling pivoting in the vertical and one set for the horizontal. A four bar can approximate a pivot but on this, trail moves a bit with suspension travel and trail and camber have a unique pattern of movement with steering angle. Thanks Blue. I'm still trying to convince Solidworks to generate the ports in a head I want to test, so a long way from having motive power. If I get the power, you'll see a two wheeled streamliner with focus-link designed. It's fun here, learn things.  |
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Blue
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Don't guess, TEST!
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« Reply #16 on: January 28, 2010, 01:28:36 AM » |
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Thank you to everyone who posted on center hubs. Very interesting.
The focusing link has no bump steer at zero steering angle, and can have neutral, proverse, or adverse bump steering at high steering angles depending on the vertical and longitudinal spacing of the arm pivots on the swing arm. Bump-roll can also be changed the same way; it gets pretty complex. Locating everything at the back and minimizing the vertical and longitudinal distances between the pivots yields the most neutral setup.
Although it would be interesting to play with all of the permutations of bump-steer/bump-roll, experience with my hands on the bars/wheel tells me that it's best to go neutral.
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"Doing the same thing as everyone else insures the same result", Shawn Fischer
"Extraordinary ideas do not come from ordinary thinking", Dan Bond
"Don't compromise, optimize", Eric Ahlstrom
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mike mendoza
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« Reply #17 on: January 29, 2010, 04:08:51 PM » |
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I have the plans and drawings i made my centersteering with. Go them from "Pappy" John Stege Mec. Engineer with the Gov. up in Portorchard Wa. can build or share the plans.
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Rex Schimmer
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Only time and money prevent completion!
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« Reply #18 on: May 26, 2010, 12:55:40 AM » |
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If you are at "high steering angles" on a Bonneville car you are getting ready to do backwards!
Or you are in the pits.
Rex
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Rex
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Glen
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SCTA/BNI timer 1983 to 2004,Semi Retired,.
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« Reply #19 on: May 26, 2010, 10:34:02 AM » |
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One big disadvantage/advantage of the focusing link is that high steering angles compress the suspension.
Vick If you go to the tab and introduce yourself it would be helpful to all of us. Who are you, what is your background, are you a racer, what area do you live in. |
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Glen  South West, Utah |
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Peter Jack
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« Reply #20 on: May 26, 2010, 11:48:08 AM » |
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Vick's a spambot Glen.
Pete
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My avatar shows Tok, a 100# Alaskan Malamute.
He's the one who runs everything around here.
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Seldom Seen Slim
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Nancy -- 201.913 mph record on a production ZX15!
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« Reply #21 on: May 26, 2010, 12:52:24 PM » |
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And "Vick" is gone. I banned the spambot this morning -- but I guess I missed a post or two. Sorry for the inconvenience, and thanks to the bunch of you that keep your eyes open and let me know when these Acuraholes get into the Forum.
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Jon E. Wennerberg
a/k/a Seldom Seen Slim
Skandia, Michigan
(that's way up north)
2 Club member x2
Owner of landracing.com
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High Gear
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« Reply #22 on: May 26, 2010, 12:58:04 PM » |
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This is one way to avoid bump steer.
[/url]http://www.arrowracing.org/photogallery/photo12540/Center%20Hub%20Steering.JPG[url]
Gary
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Fix What You Know is Wrong First
Spirits Of The Lakes E/FMS Berkeley #569
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sheribuchta
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« Reply #23 on: May 26, 2010, 01:59:46 PM » |
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woops that didnt work willie
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« Last Edit: May 26, 2010, 02:05:02 PM by sheribuchta »
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John Noonan
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245 200+ mph time slips. 252 mph on a dirtbike
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« Reply #24 on: May 26, 2010, 02:09:50 PM » |
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This is one way to avoid bump steer.
[/url]http://www.arrowracing.org/photogallery/photo12540/Center%20Hub%20Steering.JPG[url]
Gary
http://www.arrowracing.org/photogallery/photo12540/Center%20Hub%20Steering.JPGNeed a larger image.. |
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On 9-27-08 we lost a great friend and fellow racer, he was the BEST, he helped anyone with anything at anytime. His name is Dave Owen and he will be missed by all that knew him and I am glad to have met him.
Seeing him at Bonneville during 2008 Speedweek was the tops, Dave was in awe of the salt and as usual was there helping out anyone who asked..simply put we lost a great man who will be missed by all.
J
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4-barrel Mike
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Any fool can drive a V8
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« Reply #25 on: May 26, 2010, 02:32:22 PM » |
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Mike Kelly - PROUD owner of the V4F that powered the #1931 VGC to a 82.803 mph record in 2008!
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John Noonan
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Location: 6 X 200 club member: El Mirage 2 Club, Bonneville 2 Club, Australia 2 Club, Maxton, 2 Club, Mojave 2 Club, Bubs 201 Club
Posts: 3306
245 200+ mph time slips. 252 mph on a dirtbike
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« Reply #26 on: May 26, 2010, 03:23:50 PM » |
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On 9-27-08 we lost a great friend and fellow racer, he was the BEST, he helped anyone with anything at anytime. His name is Dave Owen and he will be missed by all that knew him and I am glad to have met him.
Seeing him at Bonneville during 2008 Speedweek was the tops, Dave was in awe of the salt and as usual was there helping out anyone who asked..simply put we lost a great man who will be missed by all.
J
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Darxus
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« Reply #27 on: March 14, 2011, 02:39:33 PM » |
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Does anybody have a photo of an actual focusing link steering setup? Or a more complete diagram? I'm kind of excited about the concept, but related information seems to be very rare on the internet, and the image on http://www.rotaryeng.net/roadable.html doesn't seem to provide a way to prevent the wheel from flipping upward. I imagine you'd add something like an additional link on each side, attached at the yoke above and horizontally in line with the side links, to vertically brace the side links. I realize this post is ancient, but this subject really doesn't seem to be discussed anywhere else. |
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Anvil*
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« Reply #29 on: March 16, 2011, 11:51:48 PM » |
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The roadable plane diagram does not show the springs and shocks that would prevent the U-shaped piece from flipping up, only the linkage. The buddfab also uses a 4-bar linkage to allow steering but is holding a leading-link fork. The arrangement of two 4-bar sets in two planes would be lighter, so a bit more suitable for flight. Both work, as does center-hub steering. The nice bit is seeing the various solutions to a problem and being able to match how it couples the loads into the frame with the structure one selects (or already has). You also get to spend more time on other problems in the overall design because people shared. |
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