The subframe is my project - The camper normally sits on a flatbed
Isuzu npr 4wd
- Thread starter gator70
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The subframe is my project - The camper normally sits on a flatbed
mog
Kodiak Buckaroo
Even using the progressive spring style of mounting your sub-frame, one end of the sub-frame can/should(??) be fixed. Just make the front the fixed end.
Opposite of these photos I took these at the Abenteuer Allrad show in Bad Kissingen, ( builder - 4wheel24)
SkiFreak
Crazy Person
Just for comparison... my kinematic subframe is not hard mounted at any point, but in order for that to work safely the spring mounts have to provide fore, aft and lateral support.
I have seen lots of subframe designs over the years and there have been many differences between them. Ten years ago kinematic mounts were not really that common (or understood), but thankfully that has changed a bit of late.
I have seen lots of subframe designs over the years and there have been many differences between them. Ten years ago kinematic mounts were not really that common (or understood), but thankfully that has changed a bit of late.
Ferjablito
Member
Ultimark
Active member
Our subframe, to which the tray is mounted, is fully floating; that is, it isn't fixed.
This is our tray part way through construction, it is welded to the subframe rails. If you look carefully, you can see the two rails which will sit atop the chassis rails that are welded to the tray frame.
These are our chassis rails with two of the spring mount holders bolted to the passenger side chassis rail with four bolts for each mount, you can see the opposite tops of the spring mount holders on the drivers side chassis rail. Note that they are proud of the chassis rail. The space is taken up with a soft almost non compressing material, so you don't get a metal on metal chafing arrangement. Note the ATW parabolic springs, super single wheels and tyres were fitted later.
This is one of the spring mounts, the bolt is 140mm long, to give you an idea.
Assembly of the tray onto the chassis rails.
This is our under the tray water tank, custom made plastic tank enveloped inside a stainless steel outer to protect it from rocks, and what have you. Holds 140 litres, gravity fed and gravity drained, no pumps or whatever to break down. This tank is well clear of the chassis rails and the fore and aft crossover sections of the chassis, thereby allowing the chassis to twist to it's hearts content.
You can also see the gaps in between the parabolic springs in the background, parabolic springs are able to work independently without friction from other leaf springs, supposedly giving a better ride.
Whatever people think about parabolic springs compared to standard leaf spring arrangements, every single person driving a standard leaf spring arrangement on their NPS truck when they are in our truck, are very impressed with our suspension comfort factor, compared to theirs.
Mick.
This is our tray part way through construction, it is welded to the subframe rails. If you look carefully, you can see the two rails which will sit atop the chassis rails that are welded to the tray frame.
These are our chassis rails with two of the spring mount holders bolted to the passenger side chassis rail with four bolts for each mount, you can see the opposite tops of the spring mount holders on the drivers side chassis rail. Note that they are proud of the chassis rail. The space is taken up with a soft almost non compressing material, so you don't get a metal on metal chafing arrangement. Note the ATW parabolic springs, super single wheels and tyres were fitted later.
This is one of the spring mounts, the bolt is 140mm long, to give you an idea.
Assembly of the tray onto the chassis rails.
This is our under the tray water tank, custom made plastic tank enveloped inside a stainless steel outer to protect it from rocks, and what have you. Holds 140 litres, gravity fed and gravity drained, no pumps or whatever to break down. This tank is well clear of the chassis rails and the fore and aft crossover sections of the chassis, thereby allowing the chassis to twist to it's hearts content.
You can also see the gaps in between the parabolic springs in the background, parabolic springs are able to work independently without friction from other leaf springs, supposedly giving a better ride.
Whatever people think about parabolic springs compared to standard leaf spring arrangements, every single person driving a standard leaf spring arrangement on their NPS truck when they are in our truck, are very impressed with our suspension comfort factor, compared to theirs.
Mick.
Ferjablito
Member
I understand that the most appropriate thing would be for the water tank to be anchored to the subframe that you are manufacturing for the box.
You should find the Load & Inflation Tables for that particular tire, but here are some general guidelines, from my notes:
A 10 ply MPT in 275/80R20 can carry #3300 per tire @ 35 psi on grassland, at speeds up to 30 MPH. It can carry #3300 per tire @ 22 psi in mud/sand, at speeds up to 12 MPH. A 12 ply 335/80R20 carries #3600 at 30 psi and 30 mph on grassland, #3600 at 16 psi at 12 MPH in mud or sand. An MPT80 clears mud well, but an MPT81 is probably better everywhere else. (37.4” diameter) These tires are heavy in 14 – 16 ply.
335 MPT 81 is only available in 22 ply, a 68 MPH speed rating and #6700 load rating. A 335 MPT 80 is said to be quieter on road, but not as good off road, except for mud. A 10PR military version is available, rated at #3960 and 62 MPH.
An XZL MPT in 335 will carry #4400 per axle at 18 PSI at speeds up to 45 MPH on hard surfaces. For short sand/mud stages, 10 PSI can be used at a #5500 axle weight at a maximum speed of 10 MPH. For dirt road stages, at speeds of 35 mph or less, with a #4400 axle weight, 16 PSI should be used.
EDIT: The numbers below provide what the tire is rated to hold at a given pressure. This is likely under ideal conditions and should be taken with a pinch of salt.
Toyo Mud Terrain in 37x12.50R20E: #1930 (25 psi), #2225 (30 psi), #2470 (35 psi), #2705 (40 psi), #2925 (45 psi), #3085 (50 psi), #3335 (55 psi), #3525 (60 psi), #3750 (65 psi)
Toyo Mud Terrain in 37X12.50R18E: #2095 (25 psi), #2395 (30 psi), #2680 (35 psi), #2915 (40 psi), #3150 (45 psi), #3415 (50 psi), #3590 (55 psi), #3795 (60 psi), #3970 (65 psi)
Toyo Mud Terrain in 40X13.50R20LT: #2470 (25), #2815 (30), #3085 (35), #3425 (40), #3705 (45), #3970 (50 psi in D load range), #3970 at 55 psi – 65 psi for E load range.
A 10 ply MPT in 275/80R20 can carry #3300 per tire @ 35 psi on grassland, at speeds up to 30 MPH. It can carry #3300 per tire @ 22 psi in mud/sand, at speeds up to 12 MPH. A 12 ply 335/80R20 carries #3600 at 30 psi and 30 mph on grassland, #3600 at 16 psi at 12 MPH in mud or sand. An MPT80 clears mud well, but an MPT81 is probably better everywhere else. (37.4” diameter) These tires are heavy in 14 – 16 ply.
335 MPT 81 is only available in 22 ply, a 68 MPH speed rating and #6700 load rating. A 335 MPT 80 is said to be quieter on road, but not as good off road, except for mud. A 10PR military version is available, rated at #3960 and 62 MPH.
An XZL MPT in 335 will carry #4400 per axle at 18 PSI at speeds up to 45 MPH on hard surfaces. For short sand/mud stages, 10 PSI can be used at a #5500 axle weight at a maximum speed of 10 MPH. For dirt road stages, at speeds of 35 mph or less, with a #4400 axle weight, 16 PSI should be used.
EDIT: The numbers below provide what the tire is rated to hold at a given pressure. This is likely under ideal conditions and should be taken with a pinch of salt.
Toyo Mud Terrain in 37x12.50R20E: #1930 (25 psi), #2225 (30 psi), #2470 (35 psi), #2705 (40 psi), #2925 (45 psi), #3085 (50 psi), #3335 (55 psi), #3525 (60 psi), #3750 (65 psi)
Toyo Mud Terrain in 37X12.50R18E: #2095 (25 psi), #2395 (30 psi), #2680 (35 psi), #2915 (40 psi), #3150 (45 psi), #3415 (50 psi), #3590 (55 psi), #3795 (60 psi), #3970 (65 psi)
Toyo Mud Terrain in 40X13.50R20LT: #2470 (25), #2815 (30), #3085 (35), #3425 (40), #3705 (45), #3970 (50 psi in D load range), #3970 at 55 psi – 65 psi for E load range.
For now, and since I plan on towing a TOAD (Suzuki Samerai - Tintop), I will carry a water tank in the back as a backup fresh water supply. This is the simplest and easiest solution to enhance my fresh water supply.
While on camping trips with a habitat, what are the storage challenges for tools, equipment, clothes, personal items, sport equipment, cooking equipment, electronics, fire place, outdoor furniture, outdoor lights, recover gear, ect?
My habitat is fully equipped, yet short on internal storage.
My habitat is fully equipped, yet short on internal storage.
Attachments
Mastercraft Safety, Triple X (Phoenix) or another high-quality suspension seat, as used in desert racing applications. (Baja 1000 type stuff) There, the driver takes a beating for hours over very rough terrain.
Custom seats with 'poured' foam are also an option, but are quite expensive.
Years ago, I saw a sprung, suspension seat with the springs on the side of the seat, not underneath it. In a COE, you are still limited by sitting atop the wheel well, and thus, do not have the range of motion that you would have in a bonneted medium-duty or heavy-duty truck.
Make the frame, chassis and body as stiff as you can make them and let the suspension do the work. Think of how much better a modern half-ton truck rides that one does from 30 years ago. Yes, frames have gotten better, but the majority of the improvements have come by way of marked progress in suspension design.
Custom seats with 'poured' foam are also an option, but are quite expensive.
Years ago, I saw a sprung, suspension seat with the springs on the side of the seat, not underneath it. In a COE, you are still limited by sitting atop the wheel well, and thus, do not have the range of motion that you would have in a bonneted medium-duty or heavy-duty truck.
Make the frame, chassis and body as stiff as you can make them and let the suspension do the work. Think of how much better a modern half-ton truck rides that one does from 30 years ago. Yes, frames have gotten better, but the majority of the improvements have come by way of marked progress in suspension design.
