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!

So many thoughtful replies, thank you to everyone who has taken the time to chime in. I appreciate it! It sounds like utilizing a HDT as a tow vehicle and daily driver may not be as much as an inconvenience as I had originally thought. 2gypsies- To answer your question, our four kids are 6-10 years old. If we decide to do this it'd likely be full-time so I think they'd get sick of tents. ;-) This is why we'd likely end up with a larger 5th Wheel. Sandsys- We've considered having my wife drive a second vehicle with the kids and it's still an option although if possible it'd be nice to have our family together while traveling. Although a quiet vehicle without fighting children does sound enticing. Another follow-on question. The Volvo 780 layout with the workstation looks appealing assuming we could install proper seat belts across the two benches. Is there enough room on either bench to safely put two or three kids?

Thank you both for taking the time to write such a detailed reply, I really appreciate it. This is exactly the type of feedback I was hoping to receive. If anyone else would like to chime in with their experiences, especially if it's something else not discussed above, I'd be grateful.

In an RV setting? Likely aluminum and various plastics (polycarbonate, ABS, delrin, etc.). Maybe brass, bronze, cast iron. Also, keep in mind all steels are not created equal- standard mild steels such as A36 would be no problem with a Carbon Steel tap although the tap will get dull quicker but I doubt you'd have much luck tapping other harder steels (ie truck frame rails) with the same tap. HSS taps are better suited for these applications. For even harder steels (above ~40 Rc), carbide taps are generally best but they're much more brittle (and expensive) so using them as a hand tool as opposed to using them in a machine tool can be risky.

Make sure you get HSS (High Speed Steel) taps/dies if you plan to use them with steel, especially harder alloys. I would not recommend Carbon Steel taps, they will not hold up as well. Many of the automotive tap/die sets I've come across are Carbon. Also, McMaster Carr (recommended above) sells good quality taps which will likely be much cheaper than SnapOn. From a value perspective, you'll probably get better pricing from McMaster Carr or other machine tool type shops than you would automotive shops.

Hi, I'm looking for opinions from HDT owners regarding limitations they face utilizing HDT's as tow vehicles? Increased difficulties finding a campsite or campground due to length? How often do you have to park your HDT offsite in overflow? Limitations driving over bridges or through city streets due to weight? Limitations getting into State and National Parks? Difficulties navigating city streets or campgrounds with a 13' tall HDT (low bridges, narrow streets, low hanging trees etc.)? Assuming you pull a rather long trailer, do you avoid states with conservative maximum length towing laws? While researching, I was shocked to find 15 states that prohibit vehicles with a combined length greater than 65' (source: https://www.nexttruckonline.com/). I'm assuming the majority of HDT's with a 40' 5th Wheel would exceed 65' in length. How practical is it to use your HDT as an everyday driver (sightseeing, grocery getting, etc.)? Any additional limitations I'm not considering? Due to our family size (6 currently), we'll likely settle on a 36+ foot 5th wheel so I'm considering a HDT as our Tow Vehicle. Any input you can provide regarding limitations of using a HDT as a tow vehicle and a daily driver are greatly appreciated. Thanks!

Thank you all for your input. 2gypsies- Thanks for the PPL website recommendation, I'm still in the research/gathering information phase but I've been checking their website occasionally to get a sense on options and pricing. We're currently living overseas so unfortunately we're limited to internet research for the time being which has its obvious limitations. I'm looking forward to being able to tour the different 5th Wheel and Toy Hauler options at some point so we can get a better sense of what would meet our needs best but for the time being, we'll continue to gather information online.

OK, I'll have to add Toy Haulers to the list. Any particular make/models I should look into?

Thanks Linda. My assumption is that Toy Haulers, generally speaking they aren't insulated as well or designed for full time living. Is this correct? Also, I've been researching some of the recommended models listed above and it seems like bunkhouses are not available. Can anyone tell me if any of these higher end, older models came in bunkhouse layouts?

Thank you both for your replies. I'll add your recommendations to my research list. TXiceman- You are correct, tow vehicle recommendations are next on my list of questions. Based on the research I've done so far, we'll likely fall into the MDT or HDT category unless we settle on a smaller, lightweight trailer. To complicate things a bit further, we also need something that can seat six people. I'll be starting a tow vehicle recommendations thread next but if you have any input, I'd love to hear. Thank you both for your contributions!

Hi, Our family- myself, my wife and our four daughters under 10, is considering roadschooling and I'm looking for recommendations for 5th wheels. What would you recommend in the $15,000 to $20,000 range? I realize this isn't a huge budget but I was hoping to come across something 5-7 years old or perhaps an older, higher end brand (Hitchhiker, Teton, etc) that is not longer in production. I'm fairly handy and can fix minor/moderate issues but would rather not buy a project. Also, I'm assuming a bunkhouse layout would be best for our family but am open to other suggestions. If you have a specific brand or model that you'd recommend, please let me know. Thanks so much!