using trailer balance worksheet question, HHRv build project

[working on it]

As I have previously posted before in my infrequent progress reports (due to infrequent progress), I have overbuilt the frame; it weighed 400 lbs. exactly, with floor and fenders and lights, no upper structure. Y'all warned me about overbuilding, but I wanted a sturdy structure. Now, just about to button up the exterior shell (no cutouts for windows yet), with inner galley wall but nothing else inside, I'm about ready to weigh it again. I'm almost afraid to do so. I was aiming for 1000 lbs overall/100 lbs tongue weights, to be towed by HHR or Cobalt, but based on my projections using Angib's trailer balance worksheet (as altered by me), I am looking about 20% over weight overall, tongue weight variable. I've been moving locations and weights around on paper in lieu of the real thing. I may be over-estimating some items. but the spreadsheet looks pretty accurate. My question is this: how close did any of you come to the spreadsheet projections, based on estimates only, or did any use accurate weights and measurements to finalize their plans? I'd like to post a copy of my spreadsheet for your perusal, but can't seem to get it to work. note : Just added a JPEG of my latest spreadsheet to my album; can't send it any other way, so if anyone can view it...comments please!

[S. Heisley]

If your balance sheet is part of your thread, people might be quicker to comment(we hope); so, here ya go:

[working on it]

Thanks for bringing that sheet forward. I tried several ways, all afternoon, and the best I could manage was the Excel to PDF to JPEG conversion. You oughta see the mess I made trying to post pictures. At one point, it was like in the movie "The Prestige" where Tesla didn't think his device worked...I had hundreds of copies of pics in other places unknown to me! Now maybe someone can see the mess I've made of my "lightweight" TTT.

[working on it]

Since no one has commented on my use or misuse of Andrews spreadsheet, I'll ask outright. Am I using it correctly, or have I misunderstood what figures to plug in or have I mangled the formulas somehow? Heres the background: 1) the trailer as weighed with only the wood floor and rolling stock (including coupler,chains, jack, wheels,tires,running lights,license plate) was exactly 400 lbs. 2) by measuring actual wood used (in square inches), multiplied by a measured sample weight of .0148 lbs/sq inch, and guesstimating oak reinforcement wood and glue-screws-nuts-bolts-connectors-hinges and miscellaneous hardware weights at about 75 lbs altogether, I arrive at 360 lbs for the superstructure above the 400 lb base. 760 lbs at this time. Where should these weights be plugged into the spreadsheet? The weights for the tongue and suspension are, by my reckoning: 61 lbs for a 6 ft. length of tubing, of which 44 " are actually unreinforced "tongue" with 15 lbs coupler and 12 lb jack = 79 lbs tongue.And 20 lb axle/stubs + 15 lbs hubs/bearings + 10 lbs spacer/adapters/lugs&nuts + 70 lbs wheel and tire assemblies = 115 lbs unsprung weight + 30 lbs actual springs/shackles/hanger weights = 145 lbs suspension Are these to be used as the weights of the "basic weight" section? If so, by my latest calculations, the measured tongue weight at present, no gear or frills added yet, should be 88 lbs. Yet, using two different methods, both found within this forum, I had a 41 lb observed tongue weight. Obviously, I'm doing something wrong. The spreadsheet above was just posted to try to get experienced TnTTT builders to share the way their planning stages compared with the actual results of their builds, and help the befuddled first time builder make sense of his build plans.

[working on it]

Seriously trying to get this right; now I've got 2 more spreadsheets that are more precise than earlier. If I could spend more time in building, instead of theorizing, I would already be finished...lack of time spent with the build (100 mile trip on weekends only) and lacking the ready funds to move forward....This is how I have to spend my time, overthinking instead of building and enjoying. Supposed to be spreadsheets pictured,not X's. Oh well.Thanks Mike

Here's the two pics...

I am leaving your old links in there until I figure out why they didn't work...

Mike...

[angib]

Sorry - been away. As I wrote the spreadsheet, it seemed obvious to me how it worked and so I never explained it too well (or at all?).

The 'basic weight' section covers all the normal weight of the whole trailer - so, frame, body, suspension, wheels, etc. You enter a total for this and then you can divide off two parts of that (tongue and suspension/wheels) because those may be enough to affect to overall result.

Then, if you want to, you can add 'extra weights' - these are only intended to be for major, heavy items that could affect the balance significantly. With your trailer having a basic weight of 700 lbs, I don't think items weighing less than 50 lbs need to be added as 'extra weights', but your generator and battery are prefect examples of what the 'extra weight' category is there for.

I wouldn't expect your inner wall/cabinet weight to be an 'extra weight' but if you want to make it a separate entry, it makes the result more accurate. But don't start trying to calculate the tongue weight to any precision - this is an estimating exercise and as long as the result is in the right ballpark, that's good enough.

[working on it]

Thanks for your reply,and your design work, Andrew. Your spreadsheet, especially, has given me HOURS of entertainment, and kept the build going, as a mental exercise at least, while the actual build stagnated. i'm trying to be as accurate as I can, because the intended TV's are so light and manufacturers recommended max weights are 100lbs. tongue/1000 lbs. total trailer. A few lbs. here and there can make a lot of difference. As I see it, designing by using your tool now will save me from drastic changes later, from trial and error. If I am truly going to end up 20-30% overweight, then I'll be prepared to make mods to the TV or trailer to accommodate such an event, though I don't see the factory figures as gospel. I am more concerned with tongue weight percentage, and why I'm having such a large discrepency between observed and calculated figures. Admittedly, my scales and setup may have been off, but both methods used gave the same results. The final verdict will be shown whenever I get to actually re-weigh the trailer as it stands now, my materials' weight estimates could be wrong, I will report that back to you.

[working on it]

Here's my latest version of Andrew's spreadsheet, please feel free to play around with it and point out any glaring errors or make suggestions please!

[working on it]

Life,emergencies, general b.s., and other things are slowing me down as usual...started the generator installation and put first poly on hatch 2 weeks ago, but nothing since. I had to rebuild the front end brakes and bushings on my daily driver, spent time and money in the ER after trying to "kill" my wife (her words) with the pushmower (flying metal), I caught the hinduflu (a co-worker brought it back from India), then my friend went out of town (no access to his shop where the TTT is). Chomping at the bit. So, with too much time on my hands, I revised my version of Andrew's balance spreadsheet once again. Here it is, if anyone is interested. Boy, do I ever want to finish this stage of the build; once the exterior is poly'd and painted, then I'll take it home (it's safe at his shop, but needs to be sealed up before it comes to my dusty garage on a sandhill).

balance revised 5-12-12,ver.9.xls

[RandyG]

When you get it all done, let me know how it pulls. I am also looking to pull with my HHR. 1000 lbs sounds a little low for these cars so I may push it to 1200 loaded with all camping gear and food.