06-06-2006, 06:03 PM | #1 |
Rock Stacker Join Date: Oct 2005 Location: Virginia Beach
Posts: 64
| scale long-arm upgrade
I have seen alot of builds with 4-linked axles. Every time, i see the upper and lower control arms attatched to the frame seperately. There are some 1:1 4-links out there like that, but there are also ones such as the Rubicon Express and TnT customs long-arm kits (for jeeps) where the upper arms are attatched to the lower arm. Has anyone done this on their scale rigs to give it that extra scaleness? It would also decrease binding. Since it may be hard to describe this in text, here's a picture of what i'm talking about... If i had the money and skills to build a sweet rig like some of yall's, i would deffinately do this. If anyone would like a more detailed or different angle of this picture, let me know. P.S. - I posted this in the scale section because it seems like something that would give a rig (especially a wrangler) a nice scale/realistic touch. |
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06-06-2006, 06:10 PM | #2 |
Rock Crawler Join Date: Oct 2005 Location: Clarkston, MI
Posts: 661
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That's kinda like a 3-link, except the top part isn't integrated.
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06-06-2006, 06:26 PM | #3 |
2006 2.2 National Champ Join Date: Dec 2004 Location: Big Bear Lake
Posts: 8,328
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I've tried it, but it didn't work too good. The rod ends on the lower links moved too much, which allowed the axles to move side to side. Triangulation wasn't the problem either, I had plenty built in to both the upper and lower links.
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06-06-2006, 06:31 PM | #4 |
Rock Stacker Join Date: Oct 2005 Location: Virginia Beach
Posts: 64
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most 3-links i've seen here mount the upper control arms to the frame too... maybe i did miss some.
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06-06-2006, 06:39 PM | #5 |
RCC Addict Join Date: Jan 2006 Location: The Amish Ghetto
Posts: 1,932
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most of those kits run a track bar and only have pivot balls (heims at one end) they also dont triangulate at all, the track bar keeps it all centered
Last edited by 4stAir; 06-06-2006 at 06:41 PM. |
06-06-2006, 06:44 PM | #6 |
RCC Addict Join Date: Aug 2005 Location: VARCOR
Posts: 1,826
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It is not a 4-link set up. It would have to use a trac-bar to center it. It is also a very similar set up to a front Ford radius arm set up, which many consider a 2-link (depending on whether you want to call a lateral bar a link). btw, I am in the process of designing my scale EB right now, which will use a similar set up on the front Last edited by Robb; 06-06-2006 at 06:46 PM. |
06-06-2006, 07:17 PM | #7 |
Pebble Pounder Join Date: Sep 2005 Location: Bellevue
Posts: 122
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I think it would be pretty cool for a scale rig, just integrate a panhard bar.
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06-06-2006, 07:51 PM | #8 | |
Rock Stacker Join Date: Oct 2005 Location: Virginia Beach
Posts: 64
| Quote:
read the 2nd kit down's description. 5.5" Long arm kit. Deffinately a 4-link. the control arms mount in 4 places on the axle unlike a 3-link that mounts in one spot above the axle and the 2 lower links. This kit isn't that great of a long-arm kit, but it's the design that i'm talking about. Yes it uses a trac-bar to center it mainly because it has a coil sprung suspension. | |
06-06-2006, 07:56 PM | #9 |
RCC Addict Join Date: Jan 2006 Location: The Amish Ghetto
Posts: 1,932
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yeah i understand what you are saying its not a true four link.... anyway coil springs and coilovers like we use still have to be controled with a track bar....
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06-06-2006, 08:00 PM | #10 |
I wanna be Dave Join Date: Jul 2005 Location: Cedar Rapids
Posts: 2,028
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That's a ladder bar suspension. A 4 link is suppose to keep the pinion angle right throughout the suspension cycle. The ladder bar the pinion angle is fixed and changes angle while cycling the suspension. |
06-06-2006, 08:17 PM | #11 | |
Rock Stacker Join Date: Oct 2005 Location: Virginia Beach
Posts: 64
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06-06-2006, 08:32 PM | #12 |
I wanna be Dave Join Date: Jul 2005 Location: Cedar Rapids
Posts: 2,028
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Here are some simple drawings. The first the four link. The pinion angle dose not change through out the entire suspension cycle. The second is the ladder bar. The pinion angle is fixed makeing it change as the suspension cycles. When it dropes the pinion is pointing upward. The compress the suspension past horizontal and it's pointing towards the ground. |
06-06-2006, 08:40 PM | #13 |
Quarry Creeper Join Date: Jun 2005 Location: quarryville
Posts: 299
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i dont get it ?? is it good for crawling ? |
06-06-2006, 08:42 PM | #14 |
I wanna be Dave Join Date: Jul 2005 Location: Cedar Rapids
Posts: 2,028
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Crawling it doesn't matter. You will only notice a differance at 80mph hitting bumps and jumps.
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06-06-2006, 08:44 PM | #15 |
Rock Stacker Join Date: Oct 2005 Location: Virginia Beach
Posts: 64
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Wow, when i clicked back on this thread to read your response, it clicked to me before i got down to your post. Thank you though, those pics do explain it well. Are there any real disadvantages to running this "ladder bar" suspension as opposed to a true 4-link that would make it not worth trying? I figured if it worked for jeeps in real life, it would work in R/C. Reason being it eliminates 2 links to the frame to interfere with axle twisting/ traveling. But i guess this may be one of those things that doesn't translate precisely into the r/c world from real life. :-(
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06-06-2006, 08:44 PM | #16 |
RCC Addict Join Date: Jan 2006 Location: The Amish Ghetto
Posts: 1,932
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the pinion angle doesnt change as much as the caster angle changes... there is a big change in caster angle as the long arm style kit travels... that is the important difference....
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06-06-2006, 08:55 PM | #17 | |
I wanna be Dave Join Date: Dec 2005 Location: Orlando
Posts: 7,420
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06-06-2006, 09:19 PM | #18 |
Quarry Creeper Join Date: Jun 2005 Location: quarryville
Posts: 299
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does it matter if say the right link is an iunch in from the frame rail but the left one is and inch and a half or so from the frame rail. cause on the truck im working on the mounts for shocks adn the links cant be ?symetrical?? i think is the word . because on the left side the drive shaft goes right where the right side link will be |
06-06-2006, 09:26 PM | #19 |
I wanna be Dave Join Date: Jul 2005 Location: Cedar Rapids
Posts: 2,028
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It should not make much of a differance on it. It would be best to just mount them the same though.
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06-06-2006, 09:33 PM | #20 |
RCC Addict Join Date: Jan 2006 Location: The Amish Ghetto
Posts: 1,932
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that would make a big difference... the geometry of the front end will limit travel on one side..
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