Nailhead
Well-known member
Thanks, man!
I guess I gotta write one then...
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Alaskan on a 97 F250 4x4 Diesel
- Thread starter Motafinga
- Start date
Thanks, man!
I guess I gotta write one then...
Sent from my iPad using Tapatalk
YnotDIY
New member
@Motafinga could you post the part numbers from mcmaster carr of the springs you got for the subframe? Interested in seeing what max load you went with considering they change as diameter of spring increases or decreases. Looks like maybe 1" diameter springs on your setup? Difficult to tell from the image. Thanks in advance. We are starting on the F-350 build in the coming weeks and of course following your thread pretty closely thus far. Appreciate your time!
Motafinga
Adventurer
Here's a link to the page with the "gold" springs I'm currently using. They are color coded and go from Blue being lighter, Red being Medium and Gold being the stiffest. I've tried the lighter springs also and while they did work they kind of let the camper flop side to side just a bit to much in rougher terrain, the stiffer springs seem to control the flop while still allowing things to flex.. still testing different combos though and might try a combo of gold in the rear and Red in the front which I haven't done yet.
The length I use is 3.5 and 1 1/4 hole diameter
McMaster-Carr
McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
YnotDIY
New member
Awesome, thanks for clarifying! Looks as though those springs are rated for 686lbs at max load. I'm familiar with the idea behind the torsion free frame and am curious what forces are actually being applied to those springs as the frame and camper articulate. Wish we could test this to get an appropriate spring load. Certainly the forces are more than 686lbs, but that might give just the right amount of "wiggle room" to dampen camper movement.
Also curious how much force it might take to snap a bolt or rip off one of those spring buckets that hold the spring apparatus. All questions I'll probably not get answers to unless anyone knows an engineer and can run tests.....
Looks like they also make green (extra heavy load) which come in at 759lbs max load rating at the specs you're running. Would be interesting to see those in action as well.
Just running through my mind at this point so I'll stop, but thanks so much for sharing! Good to know you've moved onto the Gold springs over the Blue / Red combo you started with.
Also curious how much force it might take to snap a bolt or rip off one of those spring buckets that hold the spring apparatus. All questions I'll probably not get answers to unless anyone knows an engineer and can run tests.....
Looks like they also make green (extra heavy load) which come in at 759lbs max load rating at the specs you're running. Would be interesting to see those in action as well.
Just running through my mind at this point so I'll stop, but thanks so much for sharing! Good to know you've moved onto the Gold springs over the Blue / Red combo you started with.
Motafinga
Adventurer
Not sure how you even begin to calculate all that but you need to remember the weight of the camper and bed are resting on the chassis and the springs are just keeping it clamped down until they have a torsional twist causing them to compress and lift away from the truck. Also there are 4 of the springs and the buckets are bolted to the frame with 1/2 inch grade 8 bolts with a couple stitch welds to mitigate any movement as well. If you think about the "happy jack" turnbuckles that keep a slide in camper mounted to a truck bed, this is a far more robust system than that and the happy jacks seem to do the job fine.
YnotDIY
New member
Absolutely and I know your system has worked very well for you, my questions are more out curiosity because sometimes I just nerd out on all that stuff. Definitely not necessary to actually know those factors and you're absolutely right your system is much more rigid than the turnbuckles.
I should be getting started on the subframe very soon. Bed came off the truck today, going to clean it up before I get started with the SF, but I'm going the same route you did. Would it be okay to direct message you with questions or would you like them posted here?
Cheers and thanks!
TJ
YnotDIY
New member
Was there a specific strength advantage you were going for using 1/8" square tube w/ 3x3 in the back and front or was that choice for the specific design of the underside of your Utility bed. Just thinking maybe you could have gotten away with 1/16" 2x2 or 3x3 instead and saved a bit of weight? 1/16" square tube has a PSI of like 42,000 right?
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BajaSurfRig
Well-known member
@YnotDIY if it is OK with @Motafinga it would be great if you could post questions here as I plan on copying what he has made to some extent and will probably have some similar questions.
Motafinga
Adventurer
Yes posting all related questions here is fine by me, I went with 1/8th partly because I had a buddy with several pieces of square tubing in that spec that I could incorporate into the frame and to save $$ but also because I could put a lot of heat into it with a mig welder without much worry of burning through it. And also it's quite strong and I don't need to sweat it being being under built and flimsy... when you see the forces at work on the whole assembly when you go off-road / rough road, you feel good knowing it's overbuilt. The weight isn't as much as you might think I didn't weigh it, but my girlfriend and I could lift it on and off the truck without much trouble.
YnotDIY
New member
Always good to use available resources for the build! That's awesome! A scrap metal yard near me has lengths of 3/16" - 1 1/2" x 2 1/2 square tube that I'm picking up today. $30 for 12ft, so that's what I'll use to build. From my calculations it's around a 50lb difference in using 1/8 to 3/16.
3/16" steel = around 150lbs (didn't include 1/4" steel to fix back of SF to chassis)
1/8" steel = around 101 (same with this one)
So I'd guess yours is around 132lbs including those 1/4" rear plates. Does that seem right?
EDIT* Just saw you used 3/8" plate for the rear frame attachments not 1/4"
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YnotDIY
New member
@Motafinga It's difficult to tell if there's a metal spacer under the fixed portion of the frame. I know you shimmed the front with HDPE, is this also the case in the back? It looks like metal on metal contact to me.
Motafinga
Adventurer
Yes that’s 1/2 inch Solid steel spacer Block that I used to make the SF sit at the proper and level height. It is welded to the SF. Good eye!
Motafinga
Adventurer
For example, here's a typical trash truck in my neighborhood, note the lateral mounted heim joint for the spring... pretty cool, 2nd pic shows the chassis mount side plates that are forward of the spring
ExpoMike
Well-known member
@Motafinga Just read through you full build. Nice setup and nice work on the SF and box/camper setup.
Curious, have you ever weighed the full rig (loaded up and ready to go)? I have a 2000 Ram 2500 and without the bed, I got it weighed and it came in at 6000 lbs. GVWR is 8800 lbs. I saw your camper weight earlier so I am curious how much the service bed and SF setup added to the overall weight. Trying to get an idea for mine and what direction I am heading. Thanks!
Curious, have you ever weighed the full rig (loaded up and ready to go)? I have a 2000 Ram 2500 and without the bed, I got it weighed and it came in at 6000 lbs. GVWR is 8800 lbs. I saw your camper weight earlier so I am curious how much the service bed and SF setup added to the overall weight. Trying to get an idea for mine and what direction I am heading. Thanks!