RoamingRanger

Phoenix- Very interesting data from the strain gauge!

I agree largely with the sentiment regarding using Nitrogen as opposed to air but something else to consider is that Nitrogen from a tank will be "dry" compared to air from a compressor without a properly functioning dryer which would be filling your tires with moist air. I've never really given it much thought but perhaps this is the main benefit of N2.

Great job Bob, coming along nicely!

Gotcha, that makes sense.

Just curious- do all of these shops make their own frame extensions or are they purchased? You'd need a pretty good sized press brake to bend steel that thick. Also, the radius always seems to match pretty well which leads me to believe they're purchased.

I don't want to interject myself into the debate but perhaps a thin strip of an engineered plastic such as acetal/delrin would be a good compromise. It would prevent corrosion between the two metal layers, minimize squeaking and should not break down or change shape over time.

You're awesome Slixter, I really appreciate it!

Nice work Henry! Did you model the bed in Solidworks?

Beemergary- A very creative solution, I like it! Question- How did you minimize the gap between where the two planks butted up to one another at the angled portion of the bed (plank two and three counting from the rear of the bed)? Did you have to miter them? Also, what size did you use? 12" x 2"?

I'm not sure if this is helpful for selecting your bed frame tubing size or not but if you want to compare the different tubing sizes from an engineering perspective, I ran a few quick calculations. The first column is the weight per foot of different square tubing options. I know many aren't concerned with weight since it's a HDT but I've come from a racing background so I couldn't help myself. The second column is the "Section Modulus" which determines the strength of the member relative to a bending load. For both calculations I've used 2" x .120" wall square tubing as a baseline so you can compare both the weight and strength of other sizes to a 2" x .120" wall square tubing baseline. As an example- 2" x .25" is 71% stronger compared to 2" x .120" but weighs nearly twice as much per foot whereas 2.5" x .120" is only 27% heavier per foot compared to 2" x .120" but is still 62% stronger. I think the big takeaway is that if you're interested in increasing strength, you're always better off increasing the height of the member (or outer diameter for tubing) than you are increasing the wall thickness.

I'm currently out of the country and was wondering if it would be possible to get the following measurements from someone who has access to a 780: Length across the bottom bed (so I can determine how wide of a bench seat or jackknife sofa I could squeeze in) Width of bed Headroom height (measured from bench without cushions to the bottom of the top bunk). I have a lead on a 4 wide bench seat but I'd like to ensure it fits before purchasing. The attached picture may help detail the dimensions. Thanks so much!

Seems like it might be a good solution for his family. What does something like that cost at auction? How/where would you mount the hitch?

Trimster- What ended up being the full story on the truck?

Seems like quite the discount. They're listing it on their website for $39,977. You must be quite the negotiator. Any idea why they're willing to let it go for so cheap?

Thank you all for your input. It looks like I may have to reconsider seating arrangements in the sleeping quarters. If it's not too much of an inconvenience to someone with a 730 or 780 accessible, would it be possible to get the following measurements? Length across the bottom bed (so I can determine how wide of a bench seat or jackknife sofa I could squeeze in) Width of bed Headroom height (measured from bench without cushions to the bottom of the top bunk). Also, anyone know how much this measurement varies from the 730 compared to the 780? I'm trying to determine if a four wide bench seat arrangement or 2x2 arrangement would be better. The attached picture may help detail the dimensions. Thanks so much!