Very helpful. I will be reaching out again once we have a vehicle. Our first thought of a E-450 or F-650 from a retired Uhaul is very cost effective on paper, but perhaps not the better option for a documentary film for maximum attention and functionality.
Right now, it seams the flavor of the month is F550 for cabovers, and the Isuzu platform for rectangle or departure angle habitats. I really like the International rigs... so spacious and highly capable with weight classifications. Of course the FMTV's I really like for multiple reasons.
@@RVGlobeTrekker So true. Originally I liked the cab over from the Class C camping days. But find myself being drawn to those MAN (Krug/Unicat) types of Expedition rigs. I like the MTV 6x6 Cargo military Trucks as a base and like Malkiel 👍 The prices are starting to drop. Gov planet prices have also dropped but everyone says it's still a 6 month or so wait time after for all the paperwork. Was looking at Fusos, and Isuzus but they come across as mini versions.
Not recommended. Torsional twisting, even with a stiff frame, can twist the box. A little twist does not sound like much... but do it a lot of times and soon there will be stress fractures, which lead to cracks. The reason why the Earth Roamers are painted with Raptor paint is to hide the stress cracks in their FRP two piece camper body (reported to me by a previous employee working for E.R.). We are designing a light weight subframe for the lightweight flatbed style campers that we will be releasing in the coming months.
I've been away for a while, but now, I'm back. There's a lot to unpack there, so I have watching this three times. SO is it correct to say the shelter door determines where the stairs will be and the stairs determine where the side pivots cannot be?
Yes, this video is a non-stop download of information developed from frequently asked questions and what information we need to help the clients figure out what kind of subframe and pivot placement they would need, with options. To answer your question, you are correct. The door determines the access stairs placement, which determines the area that is taken up by the stairs frame, where the side and crossmembers cannot be. Well done!
Great video...and great series. But to be fair to the SLRV you derided, the way their bodies are mounted is a recommendation by MAN trucks to have the body fixed at the rear and flex at the front. Having said that, I'm sure there is some scope to move the fixed point as MAN also approves of 4 point mounting.
The biggest problems with side mount pivots located on the rear of the truck frame is the inability to have a pass through from the camper into the cab of the truck. And the huge oscillations experienced by the camper does have a ripple effect much like a whip, whereas the strongest action is not at the base, but at the top of the camper, making it flex a lot more. This causes fatigue over time, stress fractures and leaks. Aesthetically, the looks are also not pleasing, but this is secondary (always) to functionality and long life. Thank you for your feedback... I hope this explains the intent of our video a little more clearly.
@@RVGlobeTrekker Thanks for your reply. I understand your intention (and totally agree with you!). I think the difference of opinion arises from the different ways the different vehicle manufacturers tackle the issue of wheel travel. The European truck manufacturers use chassis articulation in addition to axle articulation to maximise wheel travel, where as the American (and to a lesser extent , the Japanese), rely solely on axle articulation. I have a copy of the MAN body building manual and it specifically addresses this issue and specifies that the fixed point be at the rear axle. Mercedes Benz specifies the same. I would much prefer to limit the travel between the cabin and the camper for the very reasons you explained...but if I were to build on a MAN chassis, I would also like to keep my warranty. Again, great video and extremely helpful series and for that, you should be applauded.
@@andyg9991 I also agree that larger, more articulation frames + axles need to have the side pivots "close" to the rear axle, that is to say, in the middle of the subframe, as you will have subframe in front of the rear axle and cantilevering subframe behind the rear axle. Our solution is a 4-point subframe where the side pivots are in the middle (close to the rear axle) of the subframe, and a pivoting crossmember is in the rear. This keeps the subframe away from the rear axle as it articulates. When the tire rises due to terrain, it pushed on the truck frame where the side brackets are mounted, which in turn pushes on the subframe and habitat, which moves them both out of the way. The only way for them to contact is to hit very hard, compressing the suspension (and in the case of an F550, contacting and compressing the bump-stop 3/4"). The UNIMOG series truck (I can't remember which one) has this exact setup... crossmember pivots in the front and rear, and side pivots in the middle. Keep in mind that the further rearward the side brackets are from the rear axle, the more excessive the movement on the subframe and camper will be. In the video clip you have mentioned, It appears as though they placed the side pivots in the rear. This wildly exaggerates the subframe movement, when it could be properly effective if the side brackets were fitted near the rear axle. This is a very good discussion topic!
@@RVGlobeTrekker Interestingly, I now have a copy of the MAN body builders manual, and they recommend either a 3 OR 4 point system (or a diamond system as MAN calls it) and the location of the fixed supports can be located forward of the rear axle (which varies depending on the load and specific chassis used), which would cut down on the body movement exactly as you have described. SO while SLRV have built the sub-frame as per MAN directions, they could have also constructed the sub-frame in such a way that meets MAN's requirements as well as taking into account the ability to incorporate a cab-camper pass through.
@@andyg9991 This tech is not brand new nor anything we can patent. The outcomes are very predicable, especially since there have been so many years of study and observation of the different configurations. A pass through relies upon minimal location differences between the cab and habitat, or the "boot" (or whatever is being used as the pass through tunnel elastic connector) will pull away from the flanges or rip apart. I am glad we had this discussion, as many will read this and gain a greater understanding of the forces involved and how to mitigate them.
Are you asking as a concern for the tire to contact the subframe or habitat? If so, we do have a wheel well option available on our website if this is a concern.
We have research this vehicle, since we had a customer that wanted to do this very thing. To my knowledge, one has not been mounted on this vehicle type, yet. But nothing is stopping you from being the first. Our Zero Torsion subframe pivot system will adapt to your frame width if it is under 42". Email or call me for any more details.
If anyone else wants to see how torsion subframes work, utube unicat expedition vehicles and/or steppenwolf by hoekro then search in their videos for torsion. WAY better explanation of how and why. I've been asking these ppl to do one for over a year. They keep attempting but I'm not sure they understand it or can show it as well.
Thank you for your feedback. This video was not about how or why a torsion free subframe works... that video has already been done. This was more about helping a client figure out which one would work better for their specific situation. We don't sell our products until after we have thoroughly determined the needs of the customer and have asked them the "right" questions to find the best fit for them. What would you like to see in a future video?
@@RVGlobeTrekker a video like the 2 I mentioned but better. Preferably use a truck chassis, lift the front of one side and rear of other side to their max to show how the subframe would keep the box from torquing. Then do the same for your 4 point and your 3-4 point. I think I understand the 3 point but im not getting the 4 point. If all 4 points are bolted to the box, I don't see how that box can stay flat without some of the torquing being transferred into it. But be sure to lift opisite end tires to their max together in your video, as in crossing a ditch, river, etc on a 45. Search and watch those other 2 channels for ideas.
@@gbs7144 Oh! Well if that is what you are looking for, check out of other subframe videos. But until then, remember that the 4 point diamond shaped subframe rides on top of the frame and the front and rear crossmember pivots, pivot with frame twist while the habitat and weldment "float" above the truck frame without torsion. The side brackets, which are mounted outside of the plane of rotation, are the only items that push and pull on the subframe weldment. Because these have only one longitudinal plain they are moving in, there is no torsion that is applied to the subframe. Call me if you want to talk about this. You can find my number on our contact page on the website. 9-5 PST.
Exceedingly happy I found you guys! You guys are the foundation of a dream, literally.
Happy to help. We care most about the community we value.
Very helpful. I will be reaching out again once we have a vehicle. Our first thought of a E-450 or F-650 from a retired Uhaul is very cost effective on paper, but perhaps not the better option for a documentary film for maximum attention and functionality.
Right now, it seams the flavor of the month is F550 for cabovers, and the Isuzu platform for rectangle or departure angle habitats. I really like the International rigs... so spacious and highly capable with weight classifications. Of course the FMTV's I really like for multiple reasons.
@@RVGlobeTrekker So true. Originally I liked the cab over from the Class C camping days. But find myself being drawn to those MAN (Krug/Unicat) types of Expedition rigs.
I like the MTV 6x6 Cargo military Trucks as a base and like Malkiel 👍 The prices are starting to drop. Gov planet prices have also dropped but everyone says it's still a 6 month or so wait time after for all the paperwork.
Was looking at Fusos, and Isuzus but they come across as mini versions.
Great video and very informative! Thank you for the clarification.
Glad it was helpful! We are doing our best to help our fellow overlanders... community is import to us.
Great teachings
We hope it helps you make the best decisions you can for yourself and your family.
Is it possible to mount a small box (9 feet) on a lightweight truck 3500 kg without a subframe that moves. So a rigid box on the rigid frame?
Not recommended. Torsional twisting, even with a stiff frame, can twist the box. A little twist does not sound like much... but do it a lot of times and soon there will be stress fractures, which lead to cracks. The reason why the Earth Roamers are painted with Raptor paint is to hide the stress cracks in their FRP two piece camper body (reported to me by a previous employee working for E.R.). We are designing a light weight subframe for the lightweight flatbed style campers that we will be releasing in the coming months.
@@RVGlobeTrekker what will a subframe for a small box cost? 300 cm x 200 cm
@@guidok3762 For the lightweight overland series flatbeds, the subframes will range between $5-6K
I just love you!!!! Thanks a lot!!!
Doing our best to bring you the best. Many happy trails!
I've been away for a while, but now, I'm back. There's a lot to unpack there, so I have watching this three times. SO is it correct to say the shelter door determines where the stairs will be and the stairs determine where the side pivots cannot be?
Yes, this video is a non-stop download of information developed from frequently asked questions and what information we need to help the clients figure out what kind of subframe and pivot placement they would need, with options. To answer your question, you are correct. The door determines the access stairs placement, which determines the area that is taken up by the stairs frame, where the side and crossmembers cannot be. Well done!
Great video...and great series. But to be fair to the SLRV you derided, the way their bodies are mounted is a recommendation by MAN trucks to have the body fixed at the rear and flex at the front. Having said that, I'm sure there is some scope to move the fixed point as MAN also approves of 4 point mounting.
The biggest problems with side mount pivots located on the rear of the truck frame is the inability to have a pass through from the camper into the cab of the truck. And the huge oscillations experienced by the camper does have a ripple effect much like a whip, whereas the strongest action is not at the base, but at the top of the camper, making it flex a lot more. This causes fatigue over time, stress fractures and leaks. Aesthetically, the looks are also not pleasing, but this is secondary (always) to functionality and long life. Thank you for your feedback... I hope this explains the intent of our video a little more clearly.
@@RVGlobeTrekker Thanks for your reply. I understand your intention (and totally agree with you!). I think the difference of opinion arises from the different ways the different vehicle manufacturers tackle the issue of wheel travel. The European truck manufacturers use chassis articulation in addition to axle articulation to maximise wheel travel, where as the American (and to a lesser extent , the Japanese), rely solely on axle articulation. I have a copy of the MAN body building manual and it specifically addresses this issue and specifies that the fixed point be at the rear axle. Mercedes Benz specifies the same.
I would much prefer to limit the travel between the cabin and the camper for the very reasons you explained...but if I were to build on a MAN chassis, I would also like to keep my warranty. Again, great video and extremely helpful series and for that, you should be applauded.
@@andyg9991 I also agree that larger, more articulation frames + axles need to have the side pivots "close" to the rear axle, that is to say, in the middle of the subframe, as you will have subframe in front of the rear axle and cantilevering subframe behind the rear axle. Our solution is a 4-point subframe where the side pivots are in the middle (close to the rear axle) of the subframe, and a pivoting crossmember is in the rear. This keeps the subframe away from the rear axle as it articulates. When the tire rises due to terrain, it pushed on the truck frame where the side brackets are mounted, which in turn pushes on the subframe and habitat, which moves them both out of the way. The only way for them to contact is to hit very hard, compressing the suspension (and in the case of an F550, contacting and compressing the bump-stop 3/4"). The UNIMOG series truck (I can't remember which one) has this exact setup... crossmember pivots in the front and rear, and side pivots in the middle.
Keep in mind that the further rearward the side brackets are from the rear axle, the more excessive the movement on the subframe and camper will be. In the video clip you have mentioned, It appears as though they placed the side pivots in the rear. This wildly exaggerates the subframe movement, when it could be properly effective if the side brackets were fitted near the rear axle. This is a very good discussion topic!
@@RVGlobeTrekker Interestingly, I now have a copy of the MAN body builders manual, and they recommend either a 3 OR 4 point system (or a diamond system as MAN calls it) and the location of the fixed supports can be located forward of the rear axle (which varies depending on the load and specific chassis used), which would cut down on the body movement exactly as you have described.
SO while SLRV have built the sub-frame as per MAN directions, they could have also constructed the sub-frame in such a way that meets MAN's requirements as well as taking into account the ability to incorporate a cab-camper pass through.
@@andyg9991 This tech is not brand new nor anything we can patent. The outcomes are very predicable, especially since there have been so many years of study and observation of the different configurations. A pass through relies upon minimal location differences between the cab and habitat, or the "boot" (or whatever is being used as the pass through tunnel elastic connector) will pull away from the flanges or rip apart. I am glad we had this discussion, as many will read this and gain a greater understanding of the forces involved and how to mitigate them.
What about a split axle like the military grade trucks
Are you asking as a concern for the tire to contact the subframe or habitat? If so, we do have a wheel well option available on our website if this is a concern.
Have you installed one of your sub-frames on a M939 series 5-ton 6x6 truck? I have an M927a1 project that I am in the design phase.
We have research this vehicle, since we had a customer that wanted to do this very thing. To my knowledge, one has not been mounted on this vehicle type, yet. But nothing is stopping you from being the first. Our Zero Torsion subframe pivot system will adapt to your frame width if it is under 42". Email or call me for any more details.
If anyone else wants to see how torsion subframes work, utube unicat expedition vehicles and/or steppenwolf by hoekro then search in their videos for torsion. WAY better explanation of how and why. I've been asking these ppl to do one for over a year. They keep attempting but I'm not sure they understand it or can show it as well.
Thank you for your feedback. This video was not about how or why a torsion free subframe works... that video has already been done. This was more about helping a client figure out which one would work better for their specific situation. We don't sell our products until after we have thoroughly determined the needs of the customer and have asked them the "right" questions to find the best fit for them. What would you like to see in a future video?
@@RVGlobeTrekker a video like the 2 I mentioned but better. Preferably use a truck chassis, lift the front of one side and rear of other side to their max to show how the subframe would keep the box from torquing. Then do the same for your 4 point and your 3-4 point. I think I understand the 3 point but im not getting the 4 point. If all 4 points are bolted to the box, I don't see how that box can stay flat without some of the torquing being transferred into it. But be sure to lift opisite end tires to their max together in your video, as in crossing a ditch, river, etc on a 45. Search and watch those other 2 channels for ideas.
@@gbs7144 Oh! Well if that is what you are looking for, check out of other subframe videos. But until then, remember that the 4 point diamond shaped subframe rides on top of the frame and the front and rear crossmember pivots, pivot with frame twist while the habitat and weldment "float" above the truck frame without torsion. The side brackets, which are mounted outside of the plane of rotation, are the only items that push and pull on the subframe weldment. Because these have only one longitudinal plain they are moving in, there is no torsion that is applied to the subframe. Call me if you want to talk about this. You can find my number on our contact page on the website. 9-5 PST.