RCCrawler Forums

Jamus · 04-13-2007, 12:55 PM

WARNING: This is only a pieced together hack of a mock-up and in no way represents how I build things for actual use. But at least there's no duct tape on it.

After seeing Double J's Shaft built, it helped me understand the suspension design behind the Crawler Store's stick. Basically to me, it's a wishbone 3 link where the wishbone can't move up and down. So that brought me back to the forced articulation setup, which I had tried before but was troublesome. I thought the stationary wishbone, would solve the problems with the forced articulation. So I pieced this pile of poo together to test it. Have not ran it yet and it need much fine tuning. Just cycling the suspension it seems to have solved the "floppy" nature of forced articulation unless extra links would have been. I also wire clamped an old chassis I;d made back in my nylint days on top. If it turns out to work well I have a pile of 3/16" solid stainless rod that I will transfer the mounts onto a tuber. Anyway, here's the pics.

havik · 04-14-2007, 02:23 AM

nice rig
those tires look awsome. how tall are they?
more info on this truck please

clodstall · 04-14-2007, 05:36 AM

how does the suspension work for ya? looks good so far and interesting.ive thought about doing something kinda like that same idea.cant wait to see it finished.

Jamus · 04-14-2007, 11:52 AM

Tires are LSTs cut down and narrowed, 5.5" tall and I think around 2.75" wide with stock stanpede sidewalls. They're kind of stiff for 2.2 tire standards but are fairly good. I don't have it running yet and there are a few bugs to work out. Everything is off, like bolt holes and things because I just threw it together quick to see how it would work. I like the forced articulation idea because it does away with torque twist and no need to mess around with spring rates. The stock TLT cantilevers aren't great. 90* would be better than the roughly 120* that they are. With the higher angle of seperation, they can invert at full flex. Also a different cantilever arm ratio would probably work better. The TLT cantis have both arms the same length, it would work better if the arm that was linked to the axle was longer that the arm connected to the other canti. I also had another thought to expand on this suspension design. A coupler nut and bolt to replace all the links. It's been done on nylints, I made one on my old 1:18 nylint.

klrp · 04-14-2007, 12:11 PM

Omg, definetly more pics and info! Looks great.

Jamus · 04-14-2007, 12:55 PM

Something similar to this is what I was talking about with the bolt and nut. It would replace the lower links, which just like in DoubleJ's build, need to be angled with the chassis mounts closer together to keep axle steer down.
http://i2.tinypic.com/sl1h7c.jpg

EeePee · 04-14-2007, 01:11 PM

I'm not sure if you've ever seen my old TXT forced articulation truck. I had pretty good results when all was said and done with it. The biggest problem I had was on very vertical climbs. If the truck is near rolling over backwards and the right front tire became unloaded, there was nothing to push it back down. You can see it in a video I made, found in my thread:

No shocks or springs, forced articulation shafty

I really want to piece it all back together, I enjoyed driving it a lot.

Keep tweaking, and good luck with that thing.

Jamus · 04-14-2007, 05:37 PM

Yup, your build was the inspiration for when I attempted forced articulation the first time. On your rig you needed solid links on one side and cantilevers on the other side. With the stick/shaft design that isn't needed. I like trying out the non-ordinary suspensions. This rig was a torsion stick. Rebuilding it as a forced articulation tuber probably will make it perform worse, but I think I;d rather have a beater than a comp rig anyway.

Jamus · 04-30-2007, 07:59 PM

My builds go slow anyway, but I've been working on my Chevy so it seems the crawler is going slower than usual. Gotta have it done by memorial day weekend though so I can take it to an offroad event I'll be attending. If ya can't drive your trail rig atleast you can crawl on the rocks with an RC when everyone stops to help someone change an axleshaft or something. Anyway, got a very small amount done today. Also sporting my pizza box mockup of the tubing, atleast the important tubing. The front and rear tubing I haven't decided on yet.

Bknight · 04-30-2007, 10:27 PM

I worked on a forced artic set up that didn't pan out as nicely, with mine each side was tied into one shock, and the idea is that when one tire on a side goes up, it forces the upward preasure to the other wheel on the same side, giving you more traction. i forgot about my cantilevers, that might be the missing link

Jamus · 05-01-2007, 12:10 PM

I got some revo cantilevers, should work better than the TLT canti's. I was looking through EeePee's TXT build and watching his videos. I think I can live with some of the quirks like getting the tire stuck in a hole. Not like this will be for a comp, so I'll just back up. I'm off to cut more rivets out of my Chevy, hopefully I'll get back to the crawler sometime.

EeePee · 05-01-2007, 01:04 PM

The biggest quirk I had issues with was after 1:33 in this video: http://www.rcpics.net/view_single.php?medid=71115

There's a way to alleviate this problem, and I think a spring mounted somewhere to straighten the suspension back out would be the ticket.

In my thread SlinkySam made me aware that such a problem was going to happen. There's nothing to counter the twist motion, and because all the tires aren't loaded, it just stays in that position.

The spring might slow the flopping over problem also.

Jamus · 05-19-2007, 04:05 PM

Got the tube work finished more or less. I may add more when I get back from my trip next weekend, but for now this will do. I also made a thick aluminum tierod for the front. 1/4" aluminum that I got out of a scrapped car amplifier. I'll get some skins on it and a skid for the bottom sometime. I also switched back to the larger homemade tires with wideners due to clearance problems, plus they look meaner.

too much · 05-19-2007, 05:37 PM

How long will the TLT axles live with that tire ?
I would like to do the same thing but I'm concerned about massive breakage with that size of tire.
Your build looks awesome, I love the look of the claws on your truck!

STEEL_CITY_CRAWLER · 05-19-2007, 05:59 PM

Quote:

Originally Posted by too much

How long will the TLT axles live with that tire ?
I would like to do the same thing but I'm concerned about massive breakage with that size of tire.
Your build looks awesome, I love the look of the claws on your truck!

read post #4......

Quote:

Originally Posted by Jamus

Tires are LSTs cut down and narrowed, 5.5" tall and I think around 2.75" wide with stock stanpede sidewalls. They're kind of stiff for 2.2 tire standards but are fairly good. I don't have it running yet and there are a few bugs to work out. Everything is off, like bolt holes and things because I just threw it together quick to see how it would work. I like the forced articulation idea because it does away with torque twist and no need to mess around with spring rates. The stock TLT cantilevers aren't great. 90* would be better than the roughly 120* that they are. With the higher angle of seperation, they can invert at full flex. Also a different cantilever arm ratio would probably work better. The TLT cantis have both arms the same length, it would work better if the arm that was linked to the axle was longer that the arm connected to the other canti. I also had another thought to expand on this suspension design. A coupler nut and bolt to replace all the links. It's been done on nylints, I made one on my old 1:18 nylint.

Jamus · 05-19-2007, 06:21 PM

Yeah, they're about the same as All-Ts or Redrocks, plus they're stiff. So I'd say the axles will last. Now if they were soft tires like proline rubber, then maybe they'd get enough bite to break something. Not that it can't be done, but with conservative driving it should be fine. There's always CVDs, haha.

jatoisthematto · 05-19-2007, 11:22 PM

i love that tuber in the first pics

Jamus · 05-20-2007, 11:22 AM

Quote:

Originally Posted by jatoisthematto

i love that tuber in the first pics

Thanks, I still kinda like the formula chassis but that one is all kinds of bent.

So I pieced this thing together and drove it through the house. Not too bad, but I screwed myself on the battery and electronics placement. Originally I intended to put a rhombus(sp?) pack on the other side and that's why the pede tranny is upright. Well, the connecting link for the cantilevers is running there now. So my idea is to put the battery in the "trunk" area. So the weight is getting higher and rearward. I still think it will work ok, not intended to be a comp rig anyway. I guess with that setup I'll just run weight in the front tires and none in the rear. I'm leaning towards fullsize diamond plate panels, because I have it and it'll add some flash.

Jamus · 05-21-2007, 03:47 PM

Took it for a shakedown run, and shook the wheels off, haha. I got video that I posted in the video section. Forgot to bring my wheel nut tool and they loosened so it was a short day. All the pics are posed because I lost 2 wheels in making the video. It did good, more permanent mounting of the batt and electronics would help. Well, here they are.

Jamus · 06-07-2007, 02:44 PM

Well, I suck at taking action shots, probably because I'm driving. Here's some poser shots with the skins on though.

04-13-2007, 12:55 PM	#1
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Stick/Shaft with forced articulation. WARNING: This is only a pieced together hack of a mock-up and in no way represents how I build things for actual use. But at least there's no duct tape on it. After seeing Double J's Shaft built, it helped me understand the suspension design behind the Crawler Store's stick. Basically to me, it's a wishbone 3 link where the wishbone can't move up and down. So that brought me back to the forced articulation setup, which I had tried before but was troublesome. I thought the stationary wishbone, would solve the problems with the forced articulation. So I pieced this pile of poo together to test it. Have not ran it yet and it need much fine tuning. Just cycling the suspension it seems to have solved the "floppy" nature of forced articulation unless extra links would have been. I also wire clamped an old chassis I;d made back in my nylint days on top. If it turns out to work well I have a pile of 3/16" solid stainless rod that I will transfer the mounts onto a tuber. Anyway, here's the pics.

04-14-2007, 02:23 AM	#2
havik Pebble Pounder Join Date: Jul 2005 Location: vandenberg afb Posts: 104	nice rig those tires look awsome. how tall are they? more info on this truck please

04-14-2007, 05:36 AM	#3
clodstall I lost my vendor privileges Join Date: May 2006 Location: TOP OF THE HILL Posts: 3,014	how does the suspension work for ya? looks good so far and interesting.ive thought about doing something kinda like that same idea.cant wait to see it finished.

04-14-2007, 11:52 AM	#4
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Tires are LSTs cut down and narrowed, 5.5" tall and I think around 2.75" wide with stock stanpede sidewalls. They're kind of stiff for 2.2 tire standards but are fairly good. I don't have it running yet and there are a few bugs to work out. Everything is off, like bolt holes and things because I just threw it together quick to see how it would work. I like the forced articulation idea because it does away with torque twist and no need to mess around with spring rates. The stock TLT cantilevers aren't great. 90* would be better than the roughly 120* that they are. With the higher angle of seperation, they can invert at full flex. Also a different cantilever arm ratio would probably work better. The TLT cantis have both arms the same length, it would work better if the arm that was linked to the axle was longer that the arm connected to the other canti. I also had another thought to expand on this suspension design. A coupler nut and bolt to replace all the links. It's been done on nylints, I made one on my old 1:18 nylint.

04-14-2007, 12:11 PM	#5
klrp Quarry Creeper Join Date: Dec 2006 Location: Finland Posts: 208	Omg, definetly more pics and info! Looks great.

04-14-2007, 12:55 PM	#6
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Something similar to this is what I was talking about with the bolt and nut. It would replace the lower links, which just like in DoubleJ's build, need to be angled with the chassis mounts closer together to keep axle steer down. http://i2.tinypic.com/sl1h7c.jpg

04-14-2007, 01:11 PM	#7
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	I'm not sure if you've ever seen my old TXT forced articulation truck. I had pretty good results when all was said and done with it. The biggest problem I had was on very vertical climbs. If the truck is near rolling over backwards and the right front tire became unloaded, there was nothing to push it back down. You can see it in a video I made, found in my thread: No shocks or springs, forced articulation shafty I really want to piece it all back together, I enjoyed driving it a lot. Keep tweaking, and good luck with that thing.

04-14-2007, 05:37 PM	#8
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Yup, your build was the inspiration for when I attempted forced articulation the first time. On your rig you needed solid links on one side and cantilevers on the other side. With the stick/shaft design that isn't needed. I like trying out the non-ordinary suspensions. This rig was a torsion stick. Rebuilding it as a forced articulation tuber probably will make it perform worse, but I think I;d rather have a beater than a comp rig anyway.

04-30-2007, 07:59 PM	#9
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	My builds go slow anyway, but I've been working on my Chevy so it seems the crawler is going slower than usual. Gotta have it done by memorial day weekend though so I can take it to an offroad event I'll be attending. If ya can't drive your trail rig atleast you can crawl on the rocks with an RC when everyone stops to help someone change an axleshaft or something. Anyway, got a very small amount done today. Also sporting my pizza box mockup of the tubing, atleast the important tubing. The front and rear tubing I haven't decided on yet.

04-30-2007, 10:27 PM	#10
Bknight Quarry Creeper Join Date: Jan 2006 Location: Reno Posts: 448	I worked on a forced artic set up that didn't pan out as nicely, with mine each side was tied into one shock, and the idea is that when one tire on a side goes up, it forces the upward preasure to the other wheel on the same side, giving you more traction. i forgot about my cantilevers, that might be the missing link

05-01-2007, 12:10 PM	#11
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	I got some revo cantilevers, should work better than the TLT canti's. I was looking through EeePee's TXT build and watching his videos. I think I can live with some of the quirks like getting the tire stuck in a hole. Not like this will be for a comp, so I'll just back up. I'm off to cut more rivets out of my Chevy, hopefully I'll get back to the crawler sometime.

Sponsored Links

05-01-2007, 01:04 PM	#12
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	The biggest quirk I had issues with was after 1:33 in this video: http://www.rcpics.net/view_single.php?medid=71115 There's a way to alleviate this problem, and I think a spring mounted somewhere to straighten the suspension back out would be the ticket. In my thread SlinkySam made me aware that such a problem was going to happen. There's nothing to counter the twist motion, and because all the tires aren't loaded, it just stays in that position. The spring might slow the flopping over problem also.

05-19-2007, 04:05 PM	#13
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Got the tube work finished more or less. I may add more when I get back from my trip next weekend, but for now this will do. I also made a thick aluminum tierod for the front. 1/4" aluminum that I got out of a scrapped car amplifier. I'll get some skins on it and a skid for the bottom sometime. I also switched back to the larger homemade tires with wideners due to clearance problems, plus they look meaner.

05-19-2007, 05:37 PM	#14
too much Newbie Join Date: Jan 2006 Location: spruce grove Posts: 35	How long will the TLT axles live with that tire ? I would like to do the same thing but I'm concerned about massive breakage with that size of tire. Your build looks awesome, I love the look of the claws on your truck!

05-19-2007, 06:21 PM	#16
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Yeah, they're about the same as All-Ts or Redrocks, plus they're stiff. So I'd say the axles will last. Now if they were soft tires like proline rubber, then maybe they'd get enough bite to break something. Not that it can't be done, but with conservative driving it should be fine. There's always CVDs, haha.

05-19-2007, 11:22 PM	#17
jatoisthematto Rock Stacker Join Date: May 2007 Location: illinois Posts: 82	i love that tuber in the first pics

05-21-2007, 03:47 PM	#19
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Took it for a shakedown run, and shook the wheels off, haha. I got video that I posted in the video section. Forgot to bring my wheel nut tool and they loosened so it was a short day. All the pics are posed because I lost 2 wheels in making the video. It did good, more permanent mounting of the batt and electronics would help. Well, here they are.

06-07-2007, 02:44 PM	#20
Jamus RCC Addict Join Date: Aug 2005 Location: Naoma, WV Posts: 1,479	Well, I suck at taking action shots, probably because I'm driving. Here's some poser shots with the skins on though.

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Thread: Stick/Shaft with forced articulation.