RCCrawler Forums

Rikpal · 10-10-2006, 04:10 AM

DISCLAIMER: I didn't build a single piece here.
I just assembled using parts I had laying aroud to see if my idea works ;)
So there's a million things to correct. I'm obviously open to critics and suggestions.

Hi guys.
I was playing around with the forced artic idea.
Well this is what I have thus far:

I started from the connecting cantis idea, but I decided to connect them
in diagonal, so the front left is connected to the rear right with a pivoting
leverage in between. When the the front left raise, the rear right also raise.
In the pics there's a single connection, but the final layout will have two
diagonal connection cause a single one let the not connected wheels to raise under the shocks compression.
The leverage keep the frame stabilized. It can't slant.

Mandatory artic shot.

This is what happens during artic. You can see that the two shocks aren't compressed.
They works as rods since they are pulled at maximum extension and not compressed by the artic movement.
So all the wheels are connected togheter during articulation.

Check the vid.

So what do the shocks do? Well since the 2 wheels of a single side
are not connected they can both raise compressing the shock to get axle vertical movement.

Check the vid. In the second half I did a drop and if you pay attention you can see the center leverage moving while landing.

The only problem is that the vertical movement is work on flat. I mean all the tires must raise togheter. It can't dampen only the front or the rear.
This make me think cause since we are talking about a crawler I could need some suspension action falling down from a step.

Replacing the shocks with rods will result in forced artic with no vertical travel.

Opinions? ;)

Creep · 10-10-2006, 08:54 AM

Nice! When I was messing around with forced artic I came close to what you have now at one time. But instead of having the two shocks mounted to the cantis and the two links mounted to the swivel.... Think about replacing the two links with 4 touring car shocks to act as links between the swivel and cantis and then eliminate the two big shocks altogether. Each wheel will have it's own shock to compress on those hard landings. The resistance to sidehillling is lessened but can be overcome with a front-to-rear sway bar mounted on a pivot on each side which would also act as pseudo overload springs while landing a jump or fall. If that makes any sense!?

BENDER · 10-10-2006, 09:12 AM

I tried a version of this with TLT axles, TXT canti's and savage shocks. The problem I ran into was the chassis rocked back and forth. The bracket connecting the two shock assemblies seems like it would remedy that.

Rikpal · 10-10-2006, 09:19 AM

Creep - that one option I'm figuring.

Bender - Yes the center linkage completely eliminate the rocking fore and aft issue.

Thorsteenster · 10-10-2006, 09:29 AM

hmmm, deja vu. i could swear ive seen this post before.......

i was thinking some way for forced artic on a gimmick crawler i want to try but was thinking fluid equalization instead of mechanical linkages. the vid looks like your making real progress in getting a trail ready system

Etype R · 10-10-2006, 10:07 AM

Crazy Italians! It might work just fine without any actual suspension. Though it would be a lot of work to keep the suspension moving with the truck.

EeePee · 10-10-2006, 02:32 PM

Looks good so far.

And now I want to get mine back together. The forced articulation trucks are a different animal, and very enjoyable to drive.

I'll be curiuos to read about any quirks your design might have.

Cool!

Rikpal · 10-11-2006, 05:10 AM

Thanks guys.
Thor - I can't understand your deja-vu

Etype - Quoting a bud sig "What's the fun in making something simple?"

EeePee - It's your fault (well at least your fault even)

I played a bit this morning. I found a different setup that seems to work even if there are things to check.
I'm far from the final set-up.
First the Z- linkage became a X-linkage. This eliminate the direct connection between cantis. They are all (4) connected via the pivoting center system.
Then I tried the small shocks at the end of the cantis, but I don't like the behavior.
So I tried to move the shocks attaching point. I ended with the shocks placed at the same point the x- linkage attach to the cantis.
So technically the cantis aren't cantis now I mean they are only pivoting bar.

I hope the dramatically edited attached pic could help understanding.

In this way I have the 90% of the flex given by the linkage and the remaining 10% given by the shocks. I have a bit of axle vertical movement given by the TC shocks as in every other rig.

Hope to get pic ASAP.

What do you think?
;)

Soya · 10-11-2006, 05:39 AM

I don't really think you need suspension for that application, stick clods seem to get away fine without any.

Creep · 10-11-2006, 07:42 AM

Quote:

Originally Posted by Soya

I don't really think you need suspension for that application, stick clods seem to get away fine without any.

People don't need many of the crazy contraptions they come up with, it's just fun to come up with. Let the man PLAY!

Rikpal · 10-11-2006, 07:54 AM

Technically I don't need any of my rigs even

Rikpal · 10-12-2006, 04:12 AM

That's what we have now:

Close-up of the shocks attaching point. The cantis will be replaced if I'll follow this direction. I tried to place the shocks at the end of the cantis (replacing the rods) but the system seems to work better this way.

That's the X-linkage. We should probably call it H-linkage though

It's absolutely improvable. The width of the alloy part stops the canti's movement in droop. If you look at these 2 pics you can see that the drooping cantis stops before hitting the frame while the raising canti hit the frame at maximum artic.

That's the articulation with the shocks completely extended:

That's what happen compressing the shocks

So I have to increase the forced artic movement and to reduce the shocks travel.
One interesting thing is that I can easily change the ride height moving the shocks upper attaching point.

That's the vid

rockmike · 10-12-2006, 04:29 PM

ive messed with this also i just mounted a servoe on the back of chassis,ran a wire down to the axle on each side,you could stuff one side at a time,much simpler setup ,lighter,i realise youre not able to force a tire down,this would be the only downfall to what i did.Never really had much use for it,ended up useing that extra channel for afrnt dig,i use that alot.Thats a cool setup thoe nice work bud.

xjman · 10-12-2006, 04:45 PM

Wow, that works better than I expected. As others have stated I would look into killing the shocks. The crawlerstore stick doesnt use them and its a proven winner.

I am now dead set on having forced articulation on my rig now.

10-10-2006, 04:10 AM	#1
Rikpal Quarry Creeper Join Date: Jan 2005 Location: Milan, Italy Posts: 323	Forced Artic DISCLAIMER: I didn't build a single piece here. I just assembled using parts I had laying aroud to see if my idea works ;) So there's a million things to correct. I'm obviously open to critics and suggestions. Hi guys. I was playing around with the forced artic idea. Well this is what I have thus far: I started from the connecting cantis idea, but I decided to connect them in diagonal, so the front left is connected to the rear right with a pivoting leverage in between. When the the front left raise, the rear right also raise. In the pics there's a single connection, but the final layout will have two diagonal connection cause a single one let the not connected wheels to raise under the shocks compression. The leverage keep the frame stabilized. It can't slant. Mandatory artic shot. This is what happens during artic. You can see that the two shocks aren't compressed. They works as rods since they are pulled at maximum extension and not compressed by the artic movement. So all the wheels are connected togheter during articulation. Check the vid. So what do the shocks do? Well since the 2 wheels of a single side are not connected they can both raise compressing the shock to get axle vertical movement. Check the vid. In the second half I did a drop and if you pay attention you can see the center leverage moving while landing. The only problem is that the vertical movement is work on flat. I mean all the tires must raise togheter. It can't dampen only the front or the rear. This make me think cause since we are talking about a crawler I could need some suspension action falling down from a step. Replacing the shocks with rods will result in forced artic with no vertical travel. Opinions? ;)

10-10-2006, 09:29 AM	#5
Thorsteenster I wanna be Dave Join Date: May 2006 Location: Arlington, VA Posts: 3,377	hmmm, deja vu. i could swear ive seen this post before....... i was thinking some way for forced artic on a gimmick crawler i want to try but was thinking fluid equalization instead of mechanical linkages. the vid looks like your making real progress in getting a trail ready system Last edited by Thorsteenster; 10-10-2006 at 09:41 AM.

10-10-2006, 08:54 AM	#2
Creep Quarry Creeper Join Date: Feb 2006 Location: Glenrock Posts: 277	Nice! When I was messing around with forced artic I came close to what you have now at one time. But instead of having the two shocks mounted to the cantis and the two links mounted to the swivel.... Think about replacing the two links with 4 touring car shocks to act as links between the swivel and cantis and then eliminate the two big shocks altogether. Each wheel will have it's own shock to compress on those hard landings. The resistance to sidehillling is lessened but can be overcome with a front-to-rear sway bar mounted on a pivot on each side which would also act as pseudo overload springs while landing a jump or fall. If that makes any sense!?

10-10-2006, 09:12 AM	#3
BENDER 2006 2.2 National Champ Join Date: Dec 2004 Location: Big Bear Lake Posts: 8,328	I tried a version of this with TLT axles, TXT canti's and savage shocks. The problem I ran into was the chassis rocked back and forth. The bracket connecting the two shock assemblies seems like it would remedy that.

10-10-2006, 09:19 AM	#4
Rikpal Quarry Creeper Join Date: Jan 2005 Location: Milan, Italy Posts: 323	Creep - that one option I'm figuring. Bender - Yes the center linkage completely eliminate the rocking fore and aft issue.

10-10-2006, 10:07 AM	#6
Etype R Web Wheeling Join Date: Jan 2005 Location: Twin Cities Posts: 3,004	Crazy Italians! It might work just fine without any actual suspension. Though it would be a lot of work to keep the suspension moving with the truck.

10-10-2006, 02:32 PM	#7
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	Looks good so far. And now I want to get mine back together. The forced articulation trucks are a different animal, and very enjoyable to drive. I'll be curiuos to read about any quirks your design might have. Cool!

10-11-2006, 05:10 AM	#8
Rikpal Quarry Creeper Join Date: Jan 2005 Location: Milan, Italy Posts: 323	Thanks guys. Thor - I can't understand your deja-vu Etype - Quoting a bud sig "What's the fun in making something simple?" EeePee - It's your fault (well at least your fault even) I played a bit this morning. I found a different setup that seems to work even if there are things to check. I'm far from the final set-up. First the Z- linkage became a X-linkage. This eliminate the direct connection between cantis. They are all (4) connected via the pivoting center system. Then I tried the small shocks at the end of the cantis, but I don't like the behavior. So I tried to move the shocks attaching point. I ended with the shocks placed at the same point the x- linkage attach to the cantis. So technically the cantis aren't cantis now I mean they are only pivoting bar. I hope the dramatically edited attached pic could help understanding. In this way I have the 90% of the flex given by the linkage and the remaining 10% given by the shocks. I have a bit of axle vertical movement given by the TC shocks as in every other rig. Hope to get pic ASAP. What do you think? ;)

10-11-2006, 05:39 AM	#9
Soya Quarry Creeper Join Date: Oct 2004 Location: illinois Posts: 433	I don't really think you need suspension for that application, stick clods seem to get away fine without any.

10-11-2006, 07:54 AM	#11
Rikpal Quarry Creeper Join Date: Jan 2005 Location: Milan, Italy Posts: 323	Technically I don't need any of my rigs even

10-12-2006, 04:12 AM	#12
Rikpal Quarry Creeper Join Date: Jan 2005 Location: Milan, Italy Posts: 323	That's what we have now: Close-up of the shocks attaching point. The cantis will be replaced if I'll follow this direction. I tried to place the shocks at the end of the cantis (replacing the rods) but the system seems to work better this way. That's the X-linkage. We should probably call it H-linkage though It's absolutely improvable. The width of the alloy part stops the canti's movement in droop. If you look at these 2 pics you can see that the drooping cantis stops before hitting the frame while the raising canti hit the frame at maximum artic. That's the articulation with the shocks completely extended: That's what happen compressing the shocks So I have to increase the forced artic movement and to reduce the shocks travel. One interesting thing is that I can easily change the ride height moving the shocks upper attaching point. That's the vid

10-12-2006, 04:29 PM	#13
rockmike Rock Crawler Join Date: Apr 2006 Location: pasco,Wa Posts: 639	ive messed with this also i just mounted a servoe on the back of chassis,ran a wire down to the axle on each side,you could stuff one side at a time,much simpler setup ,lighter,i realise youre not able to force a tire down,this would be the only downfall to what i did.Never really had much use for it,ended up useing that extra channel for afrnt dig,i use that alot.Thats a cool setup thoe nice work bud.

Sponsored Links

10-12-2006, 04:45 PM	#14
xjman Rock Crawler Join Date: Jan 2006 Location: In the basement Posts: 929	Wow, that works better than I expected. As others have stated I would look into killing the shocks. The crawlerstore stick doesnt use them and its a proven winner. I am now dead set on having forced articulation on my rig now.

RCCrawler Forums

Thread: Forced Artic