Eco-Roamer - F650 based Expedition Vehicle

haven

Expedition Leader
Lynn, here's one of my favorite photos that illustrates chassis flex.

actionmobil1.jpg


This is an Action Mobil design with 3 point torque-free mount for the camper. The camper stays parallel with the rear axle, while the cab and front axle point in a very different direction. Without the torque-free mount, the camper would be badly twisted.

I understand your point about keeping the truck chassis rigid, and designing the suspension to flex as needed to keep the wheels in contact with the terrain. I'm not sure it's realistic to make the chassis rigid enough in a large vehicle. Jay's test results will help us see how rigid his chassis has become after its extensive bracing.

Chip Haven
 

CapelConcepts

Observer
Well I've lurked around this forum for quite a while now and I have to admit this is the thread that got me hooked! I can't wait to see how it turns out!
 

jayshapiro

Adventurer
Flex Test

Hi All,
Many apologies that the update on the flex test is so 'overdue' - it has been a crazy couple of months, but definitely an educational period!

Thanks to everyone who has sent words of encouragement and support for our project. I am really delighted with how it is going, and I owe so much of that to what I've learned on ExPo. "They" said it was impossible for a 'privateer' to build a competent large-scale expedition vehicle in North America, but we've had a blast doing it.

Of course there have been some hiccups along the way, but that's all a part of the 'fun'. The flex test has certainly been a part of that. And so....

In a series of posts a long, long time ago we were debating whether or not the F-650 chassis would flex at all, especially given how much we reinforced the frame.

Just as a brief reminder, or for those not following the story -- we reinforced the entire frame with very long, very heavy, Steel L-Channels:
2094914184_41b7b32a2b.jpg


Well, to those of you who 'told me so' - please feel free to post replies with "I told you so" because it certainly does flex... a lot!
2650743561_1e1dfe59e3.jpg


Pretty scary, eh!?

As you can see, with just the floor and our double puck mounts, the whole thing got twisted out of shape.

I was pretty much ready to pack it in at that point and started re-reading old ExPo posts about diamond mounts, and three-point pivots. However, Jeff our engineer said: "Give it some structure and it will all tighten up, trust me." And so we started experimenting.

First we added a 500lb steel fabricating table, lying upside down top of the floor.
2650744701_c736b2dacd.jpg



Then the guys tack welded a simple box frame on the floor to help stiffen it up.

...and then we tested again.
2650740997_4514405838.jpg


Now, the deflection between opposite corners was down to just a few inches, with the mount taking a lot of the flex.

So we tested it some more...
2650740555_b3c12e8d01.jpg


And things started looking a little better...
2747773081_6a5ddfcf47.jpg


Now, when you really twist the chassis, the mount actually does what it is designed to do and the two ends behave relatively independently:
2748607606_f929d9a940.jpg


Pretty darn cool actually. I really need to give a big thanks to all who gave me advice about this over the past few months on ExPo and in PM's. But, especially to Jeff Kuhl and the guys at Austin Engineering who have done a great job bustin' their butts to lift my truck up in the air repeatedly to see what it will do.

Based on all that, we decided to keep building, under the beliefs that:

  1. the additional structure will only stiffen it up more and let us test what is really going to happen on the trail.
  2. the 'dynamic' sub-frame mount has been designed to be easily removed. If it really doesn't work, then with a forklift and a few hours we can pick the camper up off the chassis, and replace the mount with a more traditional 3-point style mount if we have to.

And so we kept building. Here's what it looks like today:
2748608342_cdae663ae1_b.jpg


I love that shot! :jump: ...it's my new wallpaper and I get excited everytime I look at it.

We're still a long way from being done, but it's all coming together now.

We have almost ALL the parts assembled in the shop. Right down to the kitchen sink, literally.

We've changed the plan (discussed much earlier in this thread) and have been working with Geoff at AirHead to sort out a usable long-term land-use design for his composting toilet -- but more about that in a future posting.

The plan is to have the frame fully built and the alucobond skin on the camper in time for us to bring the truck to the Upper Penninsula Expo Rally at the end of the month. Then comes the hard part - putting all the little details inside: furniture, electrical, plumbing, etc...

Damn am I excited though!

Cheers,
Jay.
 

CapelConcepts

Observer
Jay, Thanks for the updated pics! This build has been great to follow!

I have a question regarding frame flex though. In the off-road/desert racing side of things we'll full cage a truck to make it more ridged, get rid of frame flex, and increase the effectiveness of the suspension. I was wondering if you had considered go this route...with the a structure solid mounted to the frame and the suspension doing the flexing. I haven't seen any large trucks doing this and I was wondering why. Is it because to get the spring rate they need, to carry the large loads, the spring they use don't really move? Or if they do move, does the truck get a ton of body roll? Thanks for any input you may have Jay. Once again this is an incredible build! Thank you for taking your time to share it with us.
 

jayshapiro

Adventurer
Cab Over

Today we got a cab-over...
2760813924_9792cc63c3.jpg


And a floor...
2759970357_6ee63314e3.jpg


Over the next couple of days the guys will be attaching the roof, and then applying the skin & adhesives.

The windows and doors from Dometic were lost for a couple of weeks. I have to commend them that they offered to air-freight them over from Germany at their cost (which would pretty much wipe out any "eco friendliness" of the project) but in the end somebody opened up one of the sea containers and found them! They are the acrylic, dual-pane, top-hinged, Seitz S4 windows. They will be installed this week as well.

Then finally, some of you may have noticed the huge gaping hole on the left side of the camper here:
2760813100_5853d62553.jpg


...it is for a bed tent door from Cascade Designs. I "stole" the concept from the back of a Lance 1131 truck camper, found the manufacturer and ordered one for our truck. It is going to make a fantastic "spare bedroom" for when the grandparents come to visit.

Looks something like this:
lance-camper-1131-truck-camper-2007.jpg


I have to give credit to Rick Klug at Cascade. It turns out that he is an ExPo member, he had been reading about the EcoRoamer, and so was incredibly supportive when we told him that we wanted to include one of their tents in our design.

More details and pics as they come available over the coming days. It's happening fast and furious now...

Cheers,
Jay.
 

02TahoeMD

Explorer
WOWEEE Jay. That is coming along nicely. I love the pop out tent design idea too. Enjoying this build a lot, even though I will never be able to have one of my own, is sure is FUN to watch. :lurk:
 

jayshapiro

Adventurer
"Solar powered RV" - errrmm... not really!?

Hi there,

Here's a story I just saw on MSNBC about a guy in Utah who has created a "solar powered RV" - well, actually more like a Lance camper with some panels on the roof, but worth watching anyhow...

nc_greenrv_080812.vsmall.jpg

click here to watch

(Sorry about the ad at the beginning, couldn't figure out how to link to just the video itself...)

Cheers,
Jay.
 

jayshapiro

Adventurer
Let's do the twist!

CapelConcepts said:
I have a question regarding frame flex though. In the off-road/desert racing side of things we'll full cage a truck to make it more ridged, get rid of frame flex, and increase the effectiveness of the suspension. I was wondering if you had considered go this route...with the a structure solid mounted to the frame and the suspension doing the flexing. I haven't seen any large trucks doing this and I was wondering why. Is it because to get the spring rate they need, to carry the large loads, the spring they use don't really move? Or if they do move, does the truck get a ton of body roll?

Hi,
thanks for the great question, it's something I was trying to figure out as well.

There's a couple of key points that I think lead to the answer:

1 - This truck has solid axles both front and rear, and leaf springs up front while the rear is exclusively airbags. So you don't get a whole lot of articulation on a truck of this size. Nothing like my Jeep. Which means when you go over something with one wheel, the entire axle is going to want to tilt.

2 - The wheel base is 250", and the basic design is still two frame rails spaced fairly narrowly apart. You would need a VERY substantial cage to try to stiffen that up to stop the twist.

3 - The big problem with using the camper box as that 'cage' is that it tranfers all the stresses of the twist into the body, which does not do well on more fragile parts like windows and furniture. That's the whole basis of the dynamic body mount, which allows the frame to do what it needs to do, while isolating the camper body.

There's been a lot of talk about this topic on the forum, with some very helpful thoughts and ideas from people like: joaquimsuave, robthebrit, chip haven and charlie aarons. Do a search around and you'll find some great info!

Cheers,
Jay.
 

jayshapiro

Adventurer
Give me some skin!

...and then there was skin!
2765525053_a928e12928.jpg

2766371466_5b08ebd373.jpg


The Alucobond is going on today. We're using some VERY strong BASF aluminum aircraft adhesive. We'll see what it's like.

The Alucobond itself is 4mm thick with an insulating type material between the two aluminum faces.
cutaway1.jpg

It uses 80% recycled materials and comes in a variety of colours. The material is pretty lightweight considering it's considerable strength. You can radius it a little, or trench out a section of the filler and one face and then radius tight corners.

We've decided to keep it all flat, and have as few seems as we thought possible. Then we're using a 90 degree rounded extruded aluminum peice to cap the edges. I'll show that in a future post when they're on.

We also got the entry stairs filled in today:
2766371114_6d708619d4.jpg


The idea is that we're going to cut big holes in the risers and put wood doors over them to make storage space for shoes/boots behind each step. The steps themselves will be covered with the same 2mmmarine floor laminate as the rest of the camper.

Stay tuned...
Jay.
 

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