Panhard Rod Suspension Modification

[MidwestCamper]

Hi Jim,

When I initially starting designing the clamp plate it was a 4 bolt and wider and a 1/4" plate welded onto the bracket. Then I was thinking that two 1/2" grade 8 fine thread bolts @ about 17K lbs. clamp force ea. would be enough, especially when Rob requested the weld-on locating plates to control the lateral forces. I don't think the clamp plates have a major effect on the lateral motion.

But, I do hear you guys on distributing the force better on the I-Beam web. I have been kind of on the edge on making them wider. This example will have 5" of clamp on each side. Using six 1/2" grade 8 fine thread bolts will give about a 100K lb. clamp force and if they were 3/8" grade 8's about 56K lbs. clamp force. This will make the web contact area 20 sq in. vs. 5.5 sq in. with the current method.

Spring hangers provide 22.5 sq. in. of I-Beam web contact per axle. The 5" clamp on would provide 40 sq in of I-Beam web contact per axle. 25 sq in bottom web to bracket plate and 15 sq in of clamp plate contact. The clamp plate method triples the thickness of the web and increases contact area with I-Beam Web.

Attachment 15477


Not really sure how to interpret this, or if I do understand it, I'm not really sure if it can be done simply. "A design that would trap the web solidly". I thought clamp plate was doing that and didn't weaken the I-Beam by drilling?

Pat

Pat,
There will be a moment on the bracket from the applied lateral forces. The abutment plates would prevent lateral motion in the x direction but as the bracket becomes longer, there will be a resultant torque on the flange. Would it be possible to extend the right side top plate up the side of the beam toward the center of web where a couple bolts could be installed? This would take the rotational forces off the clamps and provide more distribution throughout the beam and not just to the flange. This is a bit of a challenge since the flange is not square and some may not want to drill their beams. Although GDRV has self tappers all over mine.

[Cate&Rob]

Pat,
There will be a moment on the bracket from the applied lateral forces. The abutment plates would prevent lateral motion in the x direction but as the bracket becomes longer, there will be a resultant torque on the flange. Would it be possible to extend the right side top plate up the side of the beam toward the center of web where a couple bolts could be installed? This would take the rotational forces off the clamps and provide more distribution throughout the beam and not just to the flange. This is a bit of a challenge since the flange is not square and some may not want to drill their beams. Although GDRV has self tappers all over mine.

The torque on the flange should be no worse than what is currently applied by lateral axle forces, through the spring hangers. But, this idea is worth discussing further. This would essentially be similar to the reinforcements that LCI welds above the spring hanger . . . but with no welding required. If the extension came up the outside of the I beam it would be easier to work with because you would not be working inside the coroplast. Also, a hole drilled at the midpoint of an I beam web has no affect on it’s vertical load carrying capacity.

Rob

[MidwestCamper]

The torque on the flange should be no worse than what is currently applied by lateral axle forces, through the spring hangers. But, this idea is worth discussing further. This would essentially be similar to the reinforcements that LCI welds above the spring hanger . . . but with no welding required. If the extension came up the outside of the I beam it would be easier to work with because you would not be working inside the coroplast. Also, a hole drilled at the midpoint of an I beam web has no affect on it’s vertical load carrying capacity.

Robb

Rob,
If the bracket length is longer than the spring hanger there will be higher torque on the flange from the same lateral forces. Running the bracket up toward the center of the web would take care if this rotation.

[Cate&Rob]

Rob,
If the bracket length is longer than the spring hanger there will be higher torque on the flange from the same lateral forces. Running the bracket up toward the center of the web would take care if this rotation.

Jim - Agreed that the longer the bracket, the more torque it can apply to the I beam attachment. But, this bracket is also cross braced to the other frame rail. Complex load path calculations . . . even if we knew the input loads. Also, the lateral loads are currently taken by the spring hangers attachments to the frame. Almost impossible to figure out how that divides amongst the four spring attachment points. Because of the flex through the center shackle plates, I would assume that most of the lateral force is currently absorbed by the outer spring hangers on each rail (the ones that are first to break) which are about the same length as the proposed Panhard bracket.

I do agree that your idea of going up to the center of the web with a "torque reaction" brace is a good idea. Would it be better to go to the center of the web . . . or up close to the upper flange ?? Assuming that the top of the I beam is well braced crosswise by the floor cross members above it.

Rob

[MidwestCamper]

Jim - Agreed that the longer the bracket, the more torque it can apply to the I beam attachment. But, this bracket is also cross braced to the other frame rail. Complex load path calculations . . . even if we knew the input loads. Also, the lateral loads are currently taken by the spring hangers attachments to the frame. Almost impossible to figure out how that divides amongst the four spring attachment points. Because of the flex through the center shackle plates, I would assume that most of the lateral force is currently absorbed by the outer spring hangers on each rail (the ones that are first to break) which are about the same length as the proposed Panhard bracket.

I do agree that your idea of going up to the center of the web with a "torque reaction" brace is a good idea. Would it be better to go to the center of the web . . . or up close to the upper flange ?? Assuming that the top of the I beam is well braced crosswise by the floor cross members above it.

Rob

Rob,
This panhard bar design (which is really great by the way) will take up all the forces that was once applied to the spring hangers. I think we agree the bracket up the web will be a stronger solution.

[Gyro Gearloose]

Wow, now were talking, the conversation is getting good. So when you guys were talking I did some examples of the brackets for the 2x2 drop version and the clamp on for comparison.

Note that with the 2x2 drop version, frame braces could be welded on, like the ones above the spring hangers.

Thinking about braces that attach higher up on the frame, my current attachment design may lend to that because its wider than the frame and has vertical bolts to attach the brace too. The bolts could be an attachment point for the brace going up the frame. Something like angled channel.

I will give it some thought and see if it can be done easily with current brackets.

Attachment 15489

Pat

[MidwestCamper]

Wow, now were talking, the conversation is getting good. So when you guys were talking I did some examples of the brackets for the 2x2 drop version and the clamp on for comparison.

Note that with the 2x2 drop version, frame braces could be welded on, like the ones above the spring hangers.

Thinking about braces that attach higher up on the frame, my current attachment design may lend to that because its wider than the frame and has vertical bolts to attach the brace too. The bolts could be an attachment point for the brace going up the frame. Something like angled channel.

I will give it some thought and see if it can be done easily with current brackets.

Attachment 15489

Pat

Pat,
Take that center design but make the green bracket several inches taller with a spacer/mounting plate on the back side to account for the web gap, then bolt it in at the center of the beam in addition to the box channel. For the case without the box channel, the clamp could still be used but the top purple clamp plate in the right drawing still needs to extend up to the middle of the frame. This bracket would not be at a right angle where it would need to be a fabricated to account for the web angle. This entire design (which is looking awesome) should solve all the hanger issues, and it may result in a noticeable handling improvement.

[MidwestCamper]

200 posts later and not sure where we are heading(haha).
Could we be putting to much thought into this?
Are we trying to re-invent the wheel?
I believe the sideways actions of the axels are no good but they have been doing this for thousands of years.
Is the correct track add ons the reason for the failure?
Does anyone with a momentum or solitude have any issues?

Brian

Brian,
Its getting close and this design will be far better than the designs we currently have that's not much different than a roman chariot. A lot of great discussion here and its looking good. A very good statement on the Momentum and Solitudes. What's the difference in them to the reflection?
I believe the suspension add-on that Pat has come up with could possibly result in a significant improvement in trailering and not just a preventative for hanger damage. I have one or two short trips still planned and I need to get my go pro under my Imagine to see how much motion is visible on the hangers.

[Gyro Gearloose]

200 posts later and not sure where we are heading(haha).
Could we be putting to much thought into this?
Are we trying to re-invent the wheel?
I believe the sideways actions of the axels are no good but they have been doing this for thousands of years.
Is the correct track add ons the reason for the failure?
Does anyone with a momentum or solitude have any issues?

Brian

Only 200 posts.... not bad.... haha Some comments below, but not trying to hijack the thread and make it 300 .
Well I'm not into reinventing the wheel but improving it or fixing design shortfalls. Unfortunately trailer frame manufactures seem to never want to change and stay in sync with trailer designers, bigger, heavier and offset weight distribution.
I don't think we would have this hanger issues if the hangers were shorter. Not sure if Correct Trac is the issue or a design issue of either GD or LCI trying to make clearance for the tires with tall hangers.
So yes, I think its a Corrrect Trac/tall hanger is the issue, but I think its easier to install some type of solution then to replace the hangers.
So do Momentum and Solitude have short hangers?

[Gyro Gearloose]

Pat,
Take that center design but make the green bracket several inches taller with a spacer/mounting plate on the back side to account for the web gap, then bolt it in at the center of the beam in addition to the box channel.
This entire design (which is looking awesome) should solve all the hanger issues, and it may result in a noticeable handling improvement.

Jim,

(Middle Example): The outside of the green brackets are flush with the frame. 2x2 drop tube vs. 2.5 I-beam web. So a couple of straps with bends and holes for each side would accomplish what you are suggesting. Don't think they need to be over 3/16" thick. Straight strap with spacer is also an alternative as you suggested.

Attachment 15501

pat