index index

Most of this information is for my own use, but others find it interesting too.
HitchVanTT.jpg, 46kB

TrailerWeight.jpg, 73kB Some preliminary information...

Hitch-TotalHitch-400.jpg, 20kB
EAZ-Lift Elite 14000lbs
with Round Bars

The hitch itself is great, but I do not need this much of it. I did not buy this thing knowingly: a dealership "sold" it to me, for about $300.
The dealership was Cusin Garys in Redding California. It is about a quadrillian times the weight rating of what I needed, and it was about the maximum amount of money that they could get from me. Evidently, they saw me coming, and were laughing at me when I was leaving...
If you have NOT done your homework - like me - do NOT go there!
Hitch-Label14000-6000-400.JPG, 23kB

Class 4 Heavy Duty

Weight-Distribution (with the torsion bars):

BBALLBLU.GIF, 139B (MGTWR) Maximum Gross Trailer Weight Rating is 14000lbs
My trailer weighs 3875 lbs - and that is a LONG way from 14000 lbs!
BBALLBLU.GIF, 139B (MVHC) Maximum Vertical Hitch Capacity is 1400 lbs.
My trailers tongue weight is 230 lbs - and that is a LONG way from 1400 lbs!

Weight-Carring (without bars):

BBALLBLU.GIF, 139B (MGTWR) Maximum Gross Trailer Weight Rating is 6000 lbs
BBALLBLU.GIF, 139B (MVHC) Maximum Vertical Hitch Capacity is 600 lbs.
I can even THROW AWAY the bars, and it is still overkill.

Parasitic weight:
Basic hitch unit is 40 lbs, actually 40.6 lbs.
4 inch rise, 2inReceiver, 1.25 ball shank hole, 2 5/16 ball
Bars are 29 lbs.
BBALLBLU.GIF, 139B Total is 70 lbs dead weight.
I need this extra 70 lbs weight like I need a hole in the head!

179RD-Spec3875.jpg, 16kB
Travel Trailer 2009 West 179RD
TT Dry Weight 3875 lbs
TT Cargo 2110 lbs
TT Hitch capacity 485 lbs
TT Tires ST205/75D-14C, RIM 15x5
TT Tires B:1,430 lbs at 35 psi, C:1,760 lbs at 50 psi

TT Length overall (brochure): 20ft 10in
TT Width (brochure): 8ft 0in
TT Width Outside (measured): 8ft 1 inch

Tongue: 3 foot 6 inches
Box: 17 feet 6 inches
Rear bumper and Spare Tire: 16 inches
TT Length overall (Measured): 22.5 feet

BBALLBLU.GIF, 139B TT Fresh 60 gal
insulated working Heat Reservor.

BBALLBLU.GIF, 139B TT Grey 30 gal

BBALLBLU.GIF, 139B TT Black 30 gal

BBALLBLU.GIF, 139B WC714-TW259.jpg, 9.4kB TT LPG Canisters

TW 24.9lb steel/ea, 18 pounds Al/ea, Empty weight, Tare
T 11.3 Kg
TC Canada ok, 16 bars canister working pressure, = 232 psi
(Propane LPG is 177 psi at 100F degrees)
08A08 2008.Aug Manufacture Date

Holds aprox 30 lb propane/ea (7.25gal of propane/ea, 4.11 pounds per gallon)
14.5 gal Propane Total in two bottles
WC 7 1/4, WC 32.4 liters
BTU 649,980/ea canister
Aprox 55lb total/ea, (Propane + Canister)/ea
Aprox 110 lb tongue weight Both canisters

BBALLBLU.GIF, 139B TT WaterHeater 6 gal

Hitch-4inchLeft-400.JPG, 33kB
I adjusted for a static four inch rise with the hitch, and this gives a perfect level of the van and a perfect level of the TT, with 15lbs in AirBags.

Originally the dealership placed the ball height at second to maximum.
Needless to say, I drove around with the front of the trailer looking up to the sky, and the trailer weight shifted off the front axle to the back axle. I took the TT back to CusinGary and insisted they "make it level". The guys told me not to worry; the thing would be level as soon as I packed it up with stuff. I had to buy a crescent wrench that was big enough, and lower it myself. I have found four inches is perfect. Also, anything over 15 or 20 lbs of air will rise an inch or two too much, and air makes a big difference on rise and ride.

If you have a forty one foot, fully loaded, with three slides, 150 gallons, two boats on top, and a harley on back bumper, travel trailer, it would not be hard for you to talk me OUT of this bhitch, because this is the perfect hitch for you. Somewhere out there, there could be a nitch in the market for this behemoth.

Hitch-Ball-2516-400.JPG, 35kB
Standard 2+5/16 ball
Keystone travel trailer manufactures got that one RIGHT, for once.
BANASTAR.gif, 1.5kB The whole crowd of disciples began joyfully to praise God in loud voices for all the miracles they had seen:
Luke 19:37


The only thing that loads down my van is the trailer hitch itself. The hitch is very heavy. However, my van can handle the trailer just fine.

VanInsideBack.jpg, 14kB Van, 1997, 2500 RamVan, 3/4 ton, Light Duty Truck
modified Custom from Coachmen, extended Sport Roof
Van, trailer-tow pack, 3.50 axle ratio, oil cooler, 46RE Tran, 4sp Ovr
Power: 5.2L, 318cc, 220HP, 300 ftlb
Gas capacity: 133L, 35gal Tank
Drag Coefficient 0.48, Frontal area is 36.27 sq ft
Alternator: 117 Amps.

I measure these gas milages:
19.6 miles/gal straight roads, (optimum driving, less than 55 mph)
19 miles/gal freeway speeds
10 to 16 miles/gal town
10 to 12 miles/gal towing

BBALLBLU.GIF, 139B Van GVWR Gross Vehicular Rating (Vehicle and contents): 6800 lbs.
BBALLBLU.GIF, 139B Van Curb Weight: aprox 4200 lb
BBALLBLU.GIF, 139B Van Cargo Capacity while with seven 150lb passangers: 407 lbs.
BBALLBLU.GIF, 139B Van GCWR Gross Combined Weight Rating (Tandem, GVWR+Trailer): 12,500 lbs
BBALLBLU.GIF, 139B Van Pulling Weight Rating: 8,900 lbs towing.
BBALLBLU.GIF, 139B Van supportable Tongue Weight: 800 lbs vertical. (Measures 330 lb)

Van GAWR, Gross Axle Weight Rating:
BBALLBLU.GIF, 139B Van Front 3300lbs with tires 35 lbs,
BBALLBLU.GIF, 139B Van Rear 3850 lbs with tires 41 lbs
Van tires: P235/75R15XL

RULERMAR.GIF, 1.6kB Here is another exercise, concerning the hitch...
The objective is to not ever have to remove the spare tire before a trip. This is only an experiment, as all efforts actually failed.
DistCrankHandle.jpg, 44kB
Crank handle will touch. Crank has to go! There remains the possibility that an electric replacement will work. But it looks to close to call.

CrankHasToGo.jpg, 47kB
I always carry my hydraulic jack, that can replace the crank. The hydraulic jack is shown under the tongue. Later, I found that the two stabilizer sizers jacks in the front each individually have plenty of power to lift the tongue. So there are four alternatives:
1) Replace the crank after every move. (Three bolts.)
2) Use a portable jack.
3) Use the onboard stabilizer jacks.
4) Upgrade to motorized crank.

HardRightBack.jpg, 36kB
So, to begin: I begin by slowly placing the Van in a hard right hand turn. Steering wheel is turned as sharp as it can be. Continually stoping and jumping out of the van to take measurements. Finely, the trailer is tracking around with no further change in the distances, with a radius of 15.25 feet. This is as close as it is going to get.
...Unless, I am going backwards.

HardRightParWheelCovTop.jpg, 38kB
A view from top, parallel with spare tire wheel cover. OK, I removed one propane tank. It was going to hit for sure.

HardRightParWheelCoverSide.jpg, 40kB
Side view, parallel with spare tire wheel cover. Again, the propane tank will hit for sure. And the crank will probably hit, even if converted to electric. It is just way too close to call.
Woofie.jpg, 57kB
Woofie is intently watching all the measurements...

HardRight45degree.jpg, 42kB
A 45 degree view, parallel with spare tire wheel cover. The cable is coiled around what used to be the crank. I would be nervous about replacing it. Before I would do that, I would redesign the spare tire carrier. Two inches can be hack sawed out of the three brackets (not shown) and rewelded. The spare tire would be mounted two inches closer to the door.
HardRightNearest45.jpg, 34kB
About 4.5 inches from the nearest object, which is the hold down bracket. The piece of wood is just temporary. The piece of wood serves as an "artificial" tank. Obviously, the second tank has to go, because the sides of the tank are much bigger than the base. The closest thing that remains is this backet, at about 4.5 inches from the spare tire cover.
HitchTank04.jpg, 29kB
Here is how to reduce a two-tank holder to a single tank...
And without buying a a new single tank holder.
And you can change your mind - at any time - and add the second tank again.

Replace the wood with something more durable.
I choose a 24 inch section of black ABS Two-inch schedule 40, for under two dollars.

I painted the ABS a white to match everything else on the tongue. A second reason is that ABS can not withstand loads above 140F degrees. And will deform at even lower temperatures. If you get some white PVC schedule 40, you will still have to paint it, otherwise PVC will photo degrade and become brittle. I would rather have a slow failure than a catastrophic one.

Actually, I should have gotten CMT electrical conduit. It is light enough, and will last forever.

Cut the ABS to the height of the missing propane tank: 21 inches.
Cut two notches so that the height would be approximately 20.5 inches.

HitchTank08.jpg, 25kB
Use an end plug or end cap, put a screw into base to secure to propane platform. Place ABS tube over plug. Now the bottom of the tube can not move.
HitchTank10.jpg, 35kB
Tighten down the top over both the phantom tank and the one remaining real tank. Now this two-tank propane holder can be used for a single propane tank. ... and I never have to remove the spare tire on the van anymore!

Actually, it will not work. I do not want to give up one propane tank, nor will I give up the crank.

RULERMAR.GIF, 1.6kB Calculating Tongue weight by placing different weights on back bumper.
(with 5 lbs air)
12.75+1/16 inch  empty                            =   0 lbs  10.25 at running board 6 ft from bolt
12.75            hitch 40 lb                      =  40 lbs
12.75-1/16 inch  hitch 40 lb +bars 30 lb          =  70 lbs
12.50            me, 168 lbs                      = 168 lbs
12.25            168 lbs + 40 lb hitch            = 208 lbs
12.0             trailer  (calculated aprox)      = 230 lbs to 300 lbs
Should be linear. It is not. Air bags and Leaf Springs must not be coming into play at the same time.
Starts out hard (1000 lb/inch), then changes to soft (233 lb/inch).
Ridicules! This method will not work at all.

Another place...
13+1/4           Hitch                            =  40 lbs    
12+1/4           Trailer + Hitch                  = 370 lbs     One inch for trailer

---              trailer  (Measured)              = 330 lbs     Tongue weight

13+1/8           Hitch  8 lbs air                 =  40 lbs    
13+1/2           Hitch 15 lbs air                 =  40 lbs      half inch / 10 lbs air  
So, I borrow the bathroom scales and measure 330 lbs tongue weight. No guessing anymore! Quite definitive! Also measure the trailer drop: one inch, plus or minus 1/4 inch. It changes each time it is measured, and does not move smoothly as weight is added or subtracted. The suspension is kinda "grippy". You could put oil on the leaf springs to help the leaves slide over each other, but you would still have to contend with such a short travel for the measurement.

Also, I measured the Air Bags lift as a half inch for every 10 lbs air.

The tongue weight is with an empty fresh water tank, which is aft of the center of the two axles. With a half load of fresh water, which is 30 gallons or 240 lbs in the back of the TT, then the front could get real light. I could loose control with yaw oscillations, as well as a lot of bobbing, as well as loss of front wheel steering. With a full fresh tank the tongue weight could go to zero - or even a minus. Can not risk the handling instability!

BANASTAR.gif, 1.5kB For my thoughts are not your thoughts, neither are your ways my ways, declares the LORD.
Isaiah 55:8
Now, I should keep that heavy torsion hitch!
...thought I was rid of it. Can never do what I want to do.
RULERMAR.GIF, 1.6kB Update:
Had to put back the second propane tank; My wife and I and Woofie were using too much propane along the coast. Put back the hand crank too. All the above work was for nothing.
I wish that I could have warned you not to read through all this futility...

RULERMAR.GIF, 1.6kB Putting the failure behind me. Moving on...
Knowing the amount of propane left in a bottle has become more important.
LoadSens-Bath.jpg, 37kB
I tore apart the bath room scales and retrieved these four load sensors. Two have not had their plastic feet removed. I measured the resistance with a meter, and they do work; decreasing resistance with pressure from my fist. Do to their thickness, they will just barely fit under a propane tank around the edge if the plastic is removed. Three or more sensors under a tank will yeld a stable platform with no rocking.
LoadSens-Pen.jpg, 23kB
But unfortunately I did not do it that way. I purchased an individual load cell: a 10245.

The dimple on the load cell is a real problem, and way too dangerous to mess with. If a bottle is ruptured, it could become either a missile or a bomb. In fact, I am afraid of this whole project. I just want to see if it will work, and if it is viable and possible.
Penny.jpg, 27kB
I am not happy with it, but one solution is this penny. Drilled, or counter sank, the penny to accommodate the dimple. At least it will suffice for a while.
Schem-LoadSensor.gif, 17kB

Load Cell in purple
I reached in my parts trays for one of my favorite op amps: an MCP602 rail-to-rail op amp. Working without a schematic, I picked up my soldering station and soldered up this schematic, created from just the "pin out" of the MCP602. After I had seen that my circuit was working, I then drew the schematic of my work. Normally, people build circuits in the reverse manner: they sketch out a schematic on a piece of paper, then build the circuit. But mine worked fine from my head the first time. I have been an electrical engineer for over 35 years. So I am qualified to do things backwards.

However, the 1 k ohm resisters were very sensitive to temperature utilised in this form of a wheatstone bridge. I could touch one and the reading would go up, I could touch the other and the reading would go down. To solve the problem, I cut several strands of copper wire and layed them all over the two resistors, and encased the resistors and copper in hot glue. Thermally they are more "one unit" now. That worked good.

To calibrate the circuit, I placed a nearly empty bottle on the sensor and adjusted the offset resistor for zero. Then I placed a full bottle on the sensor and adjusted the gain for one volt which represented 100%. Then I repeated the process several times until 20 pounds was zero and 55 pounds was 1 volt.

Propane82.jpg, 15kB This digital meter reads percent propane.
The one volt signal was wired inside to my digital meter on the wall. It was already calibrated to read "100.0" on the display. A switch applied 5 volt power only when a reading was desired, as the circuit is a high consumer of power.

There are still problems:
There is no problem with sensitivity. I can see the resulting loss of weight, about a tenth of a pound, of three burners burning on the stove, which is after only 5 minutes. But the consistency is real bad. Each day a full tank can measure 92.3% or maybe 82.3%. I have been coming out here to the TT almost every day, only to find no consistencies. I am lucky to get withen 10% repeatability, depending on how the tank is resting in the cradle.

Which brings me to yet another problem:
Before moving down the road to the next park, the tanks have to be screwed down tight. I can not leave the tanks loose. They could be bounced out. Now that means that I can not measure contents while I am in route. By clamping down on the tanks, I can see on the inside meter the reading can exceed 200%. That represents over 100 pounds. The sensor is rated for not over 150 pounds. I am going to guess, that if I hit some pot holes in the road the shock impact could go to 150 pounds.

And there could be real liability issues with loose tanks. I think I will walk away from this.

In conclusion, my invention of measuring the active weight of an installed propane bottle is riddled with problems. No dought, the problems can be solved with enough time and thought, perhaps an inflatable carriage for the tank to set on...
Yet again, all my work is for not...

RULERMAR.GIF, 1.6kB So much on this page has been a disappointment... Everything on this page was a mistake, a stupid idea, or was not ment to be.

Propane-GaugeBox.jpg, 23kB For $15 I got this better way to do it. Just lightly unscrew the hold down, and weigh the tanks by hank! Same strain gauge technology that I was designing. But this works much better. This is a suit case scale. There is a manufacturer that makes one for a propane tank, but not for the 7 gallon RV tank. But, strangely, that turns out to be a good thing. Because you do not want an "RV one" if it is not graduated. You do not want to see vague green or red bands. You want to see portions of a pound in fine detail. Do not buy an "RV" scale; buy a travelers scale! And they are cheaper at half the price, and vastly more accurate.
PropaneGauge33.jpg, 29kB My Left tank is 33.2 lbs. This particular model has a selection for readings in kg too.
My Right tank is 41.8 lbs.

Empty weight is aprox 25 lbs.
Gas capacity is aprox 29 lbs propane, (at usable safety capacity: 80%).
Total Full bottle is aprox 54 lbs.

With this scale:
I weighed my empty 7 gal canister: 24.2 lbs.
I weighed my full 7 gal canister: 53.8 lbs.
Measured gas contents at fill station: 7.05 gals.
Calculated my gas weight: 29.6 lbs , theory 4.24lb/gal: 29.68 lbs
So, everything is about right.

One more final thing for this to work: I need to make up a label for each tank.
It reads:
Full tank: 54 lbs
Empty tank: 24 lbs
So the reading will always be in between these values...
But stupid Dymo Labels keep popping off in the sun.

I recently used 33% of 7 gal propane during 4 nights at aprox 35 degrees outside. That is 0.57gal/day. If near freezing outside, I can go 12 days on one bottle.
So, everything on this page is a failure, except this neet little scale. I will keep that...