mhiscox
Expedition Leader
ALSO SEE THE TWO COMPANION THREADS:
CAB AND INTERIOR: http://www.expeditionportal.com/forum/showthread.php?t=20079
SYSTEMS: http://www.expeditionportal.com/forum/showthread.php?t=26415
Greetings, Happy Campers . . .
And thanks to the forum members who’d ask for me to cover the design and construction of my 2005 Sprinter expedition camper. Very gratifying to have built something people seem to like.
There’s a little problem in that I could, literally, write a book about all the research and decisionmaking that went into this truck. I roughly figure I put about half-a-person-year into the design and specification, and the construction labor was not far off of that.
The best approach I can think of is to post some of the pictures, mention some of the features the pictures show and answer any questions raised. I’ll do a few pictures every few days, starting with the exterior and the chassis, then doing the systems and the interior in later separate threads. (Though if you’re dying to know something you’re worried I might not get to for a while, feel free to ask.)
With that preface out of the way—and apologies for the three-year delay—we are off . . .
The truck is a 2005 Sprinter 2500 (single rear wheel, vs. duels on the higher-GVWR 3500) with a 140 inch wheelbase. It started life as a cargo van. It has an 8550 pound GVWR and, fully-loaded, weighs most all of that. Front GAWR is, I think 3750, with the rear being 5250 or something close to that. If you build something like this, you have to watch both the total weight and the axle weights; it'd be pretty easy to end up with too much of the weight on the rear even while still being significantly below GVWR.
The truck is 18.5 feet long, something around 78 inches wide and nearly 11 feet tall with all the stuff on the roof. Mercedes also made a 158 inch wheelbase T1N, and it was a tough call to decide which to buy. A 158 is about 21.5 feet long, and the extra three feet of interior room could have been put to good use. But the van got longer by three feet while the wheelbase only went up 18 inches, so the rear overhang was considerably longer on a 158, with the departure angle sucking proportionately. Turning radius also took a hit. All in all, I'm very glad we used the 140 and, besides, it's short enough that you drive and park it same as a car, whereas the 158 was getting up into the "small RV" area.
I designed the truck, but don't be thinking I'm any magic combination of Jesse James and Norm Abram. I can get by, but it was Owen Connaughton and his people at Creative Mobile Interiors that made the finished product so nice. CMI is quite a place, as they do a fantastic job of doing what you tell them to do. They'll give you as much help as you might want, but if you know (or THINK you know) what you're doing, they'll happily do what you tell them. It's fun to think that as designer, you get the credit for the layout, components, etc., but you also get the blame when you start to uncover all the things that weren't quite so brilliant.
On top of the Sprinter is a Kingdome satellite receiver, which connects to a DirecTV receiver.
The dome is one of the smallest available, but it looks pretty huge on a mid-length Sprinter. This antenna finds satellites automatically, but does not track them. (BTW, the dome is handy if you want people to think you're listening in on their phone conversations. I actually got accused of that once. There was also someone convinced we were geologists looking for oil with some radio wave thingie. Honest.
)
The big round lamps are Hella cornering beams. They cover shorter distances than driving beams but with a much wider beam, and longer distances than fog beams, with a higher, less diffused beam. Strikes me as the perfect lamps for slow to medium speeds off road and they are great at lighting up the campground while you set up.
The bumper is from a company called South Texas Outfitters. They make all sorts of bizarre (at least to a non-Texan) rigs to go hunting in and, against all odds, they build a heavy-duty bumper that fits a Sprinter. Can't imagine who'd takes a Sprinter hunting, but clearly if you did get a deer, you could tie it to the bumper and take it home.
But the bumper as STO sells it just attaches to the stock bumper supports, so while the bumper is very strong, if mounted in the standard manner, you couldn't winch of off it; it just would have pulled off the bumper supports. So it was necessary to to get CMI to design and build a subframe that would connect back to the "kind-of-a-frame" the Sprinter has to locate the engine and front suspension.
It's a fine piece of work (we even suspect the airbags will work correctly) but buying the bumper, shipping it around the country, painting it, and then fabbing and installing the subframe added up to a fair chunk of money. You wouldn't want to do it unless you needed to winch, since others (John Bendit at The Sprinterstore.com, for one) have less expensive alternatives if you just want to keep the critters from smashing the truck.
Once the bumper was on, though, it was easy to start hanging stuff of off it. The most important addition was the front receiver.
The winch I have is an 8500 pound Warn on a universal cradle that pins into the receiver. This approach was taken so the winch could be used at the front or at the rear, which seems handy and I'm surprised it's not done more often. There are Warn winch quick connects at the front--the red plastic thing in the right of the poorly-framed picture) and the rear, along with appropriately heavy cabling. The cabling, especially to the rear, needs to be very beefy to carry the high current the winch needs. (Bigger than you'd suspect, or will want to pay for.)
The size of the winch was chosen to be the largest that I could waddle from one end to the other. Since you want a winch with a capacity of about 1.5 to 2 times the truck weight, any recovery will mean doubling the line anyway unless I'd picked a humungous winch, so the 8500 lb. capacity is actually enough. BTW, one of the great side benefits of this approach is that you don't have to carry around 100 pounds of winch when you know you won't need it. (Incidentally, you can see a set of Hella projector fog lamps located in holes that South Texas Outfitters had already cut into the bumper for 4x6 inch fogs.)
The bumper is also a fine place to carry the 60 inch Hi-Lift jack. Bolts were welded onto the bumper verticals at the right places to hang from a pair of holes in the jacks. Wing nuts (one of them locked on) hold the jack in place. The Hi-Lift is also routinely left behind when there won't be any off-roading.
It's worth mentioning the tires. Nobody on this forum is going to get excited about my 215/85x16s, but these are the tallest tire that will fit in the Sprinter's fender wells without considerable trimming, and Bushwacker doesn't make Sprinter flares. I chose Bridgestone Dueler Revo All-Terrain tires; they're 30.6 inches tall, which is better than an inch taller over stock, and they carry 2700 pounds each, which is enough.
Don't think for a second that it wouldn't be nice to have used some of the more hardcore tires people here are used to, but they simply don't fit. I'm not, however, displeased with this option. I'm a fan of tall, narrow tires over wider stuff; in my use, it's better that the tire be able to cut through the top surface to find some better traction underneath. It's also good to have the big sidewalls if you feel the need to air down. And these will work well in snow vs. more chunky treads.
Anyway, I've got these big doughnut-looking tires, which is great, but there's a bit of a limitation because you end up running them as high as 80 psi in the rear to carry the weight. At off-road speeds, I feel OK about dropping them a whole bunch, but we're still not talking psi's in the teens like on some of my other trucks.
It's worth mentioning, too, that the tires seems to be wearing great and they probably ride as quiet and comfortably as any credible all-terrain tire around.
Enough for now. More in a few days. Post up any questions.
Mike
CAB AND INTERIOR: http://www.expeditionportal.com/forum/showthread.php?t=20079
SYSTEMS: http://www.expeditionportal.com/forum/showthread.php?t=26415
Greetings, Happy Campers . . .
And thanks to the forum members who’d ask for me to cover the design and construction of my 2005 Sprinter expedition camper. Very gratifying to have built something people seem to like.
There’s a little problem in that I could, literally, write a book about all the research and decisionmaking that went into this truck. I roughly figure I put about half-a-person-year into the design and specification, and the construction labor was not far off of that.
The best approach I can think of is to post some of the pictures, mention some of the features the pictures show and answer any questions raised. I’ll do a few pictures every few days, starting with the exterior and the chassis, then doing the systems and the interior in later separate threads. (Though if you’re dying to know something you’re worried I might not get to for a while, feel free to ask.)
With that preface out of the way—and apologies for the three-year delay—we are off . . .
The truck is a 2005 Sprinter 2500 (single rear wheel, vs. duels on the higher-GVWR 3500) with a 140 inch wheelbase. It started life as a cargo van. It has an 8550 pound GVWR and, fully-loaded, weighs most all of that. Front GAWR is, I think 3750, with the rear being 5250 or something close to that. If you build something like this, you have to watch both the total weight and the axle weights; it'd be pretty easy to end up with too much of the weight on the rear even while still being significantly below GVWR.
The truck is 18.5 feet long, something around 78 inches wide and nearly 11 feet tall with all the stuff on the roof. Mercedes also made a 158 inch wheelbase T1N, and it was a tough call to decide which to buy. A 158 is about 21.5 feet long, and the extra three feet of interior room could have been put to good use. But the van got longer by three feet while the wheelbase only went up 18 inches, so the rear overhang was considerably longer on a 158, with the departure angle sucking proportionately. Turning radius also took a hit. All in all, I'm very glad we used the 140 and, besides, it's short enough that you drive and park it same as a car, whereas the 158 was getting up into the "small RV" area.
I designed the truck, but don't be thinking I'm any magic combination of Jesse James and Norm Abram. I can get by, but it was Owen Connaughton and his people at Creative Mobile Interiors that made the finished product so nice. CMI is quite a place, as they do a fantastic job of doing what you tell them to do. They'll give you as much help as you might want, but if you know (or THINK you know) what you're doing, they'll happily do what you tell them. It's fun to think that as designer, you get the credit for the layout, components, etc., but you also get the blame when you start to uncover all the things that weren't quite so brilliant.
On top of the Sprinter is a Kingdome satellite receiver, which connects to a DirecTV receiver.
The dome is one of the smallest available, but it looks pretty huge on a mid-length Sprinter. This antenna finds satellites automatically, but does not track them. (BTW, the dome is handy if you want people to think you're listening in on their phone conversations. I actually got accused of that once. There was also someone convinced we were geologists looking for oil with some radio wave thingie. Honest.
)The big round lamps are Hella cornering beams. They cover shorter distances than driving beams but with a much wider beam, and longer distances than fog beams, with a higher, less diffused beam. Strikes me as the perfect lamps for slow to medium speeds off road and they are great at lighting up the campground while you set up.
The bumper is from a company called South Texas Outfitters. They make all sorts of bizarre (at least to a non-Texan) rigs to go hunting in and, against all odds, they build a heavy-duty bumper that fits a Sprinter. Can't imagine who'd takes a Sprinter hunting, but clearly if you did get a deer, you could tie it to the bumper and take it home.
But the bumper as STO sells it just attaches to the stock bumper supports, so while the bumper is very strong, if mounted in the standard manner, you couldn't winch of off it; it just would have pulled off the bumper supports. So it was necessary to to get CMI to design and build a subframe that would connect back to the "kind-of-a-frame" the Sprinter has to locate the engine and front suspension.
It's a fine piece of work (we even suspect the airbags will work correctly) but buying the bumper, shipping it around the country, painting it, and then fabbing and installing the subframe added up to a fair chunk of money. You wouldn't want to do it unless you needed to winch, since others (John Bendit at The Sprinterstore.com, for one) have less expensive alternatives if you just want to keep the critters from smashing the truck.
Once the bumper was on, though, it was easy to start hanging stuff of off it. The most important addition was the front receiver.
The winch I have is an 8500 pound Warn on a universal cradle that pins into the receiver. This approach was taken so the winch could be used at the front or at the rear, which seems handy and I'm surprised it's not done more often. There are Warn winch quick connects at the front--the red plastic thing in the right of the poorly-framed picture) and the rear, along with appropriately heavy cabling. The cabling, especially to the rear, needs to be very beefy to carry the high current the winch needs. (Bigger than you'd suspect, or will want to pay for.)
The size of the winch was chosen to be the largest that I could waddle from one end to the other. Since you want a winch with a capacity of about 1.5 to 2 times the truck weight, any recovery will mean doubling the line anyway unless I'd picked a humungous winch, so the 8500 lb. capacity is actually enough. BTW, one of the great side benefits of this approach is that you don't have to carry around 100 pounds of winch when you know you won't need it. (Incidentally, you can see a set of Hella projector fog lamps located in holes that South Texas Outfitters had already cut into the bumper for 4x6 inch fogs.)
The bumper is also a fine place to carry the 60 inch Hi-Lift jack. Bolts were welded onto the bumper verticals at the right places to hang from a pair of holes in the jacks. Wing nuts (one of them locked on) hold the jack in place. The Hi-Lift is also routinely left behind when there won't be any off-roading.
It's worth mentioning the tires. Nobody on this forum is going to get excited about my 215/85x16s, but these are the tallest tire that will fit in the Sprinter's fender wells without considerable trimming, and Bushwacker doesn't make Sprinter flares.
I chose Bridgestone Dueler Revo All-Terrain tires; they're 30.6 inches tall, which is better than an inch taller over stock, and they carry 2700 pounds each, which is enough.
Don't think for a second that it wouldn't be nice to have used some of the more hardcore tires people here are used to, but they simply don't fit. I'm not, however, displeased with this option. I'm a fan of tall, narrow tires over wider stuff; in my use, it's better that the tire be able to cut through the top surface to find some better traction underneath. It's also good to have the big sidewalls if you feel the need to air down. And these will work well in snow vs. more chunky treads.
Anyway, I've got these big doughnut-looking tires, which is great, but there's a bit of a limitation because you end up running them as high as 80 psi in the rear to carry the weight. At off-road speeds, I feel OK about dropping them a whole bunch, but we're still not talking psi's in the teens like on some of my other trucks.
It's worth mentioning, too, that the tires seems to be wearing great and they probably ride as quiet and comfortably as any credible all-terrain tire around.
Enough for now. More in a few days. Post up any questions.
Mike
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