7'*18' V-Nose Cargo Trailer Toy Hauler Conversion

[McDave]

The thing is you would be giving up the diaphragm and shear effect of the panel with all of its mounting points.

It is always difficult to re-engineer a thing when you don't understand the criteria on which it was designed in the first place. What were the loads and directions of the loads that were considered in the original design? How have those loads changed based on the changes in configuration that have been made and the intended usage?

A thin metal strap will buckle much more readily than a 3/8 thk plywood panel. The strap will only be good in tension, whereas the ply is good in tension, compression, torsion, bending, shear and diaphragm effect.

I love that kinda talk. However I'm not totally convinced the manufacture intentionally engineered and designed the original panels with that much foresight and attention to stress forces, based on the final product and workmanship and materials used, in my trailer anyways. I'm thinking material and labor costs were the dominant drivers, any real benefit in terms of strength was more of a lucky byproduct, but I could be wrong. It's possible the intent was pure, but the execution just sucks. Spent all the money in design engineering and had to use the guy who sweeps up and cleans bathrooms for Quality Control. It's more likely that the inner panels are just a feeble attempt at keeping rouge objects from puncturing or damaging the outer skin from the inside. When the panels were removed and inventoried, it seemed clear that using scrap and "generous" i.e. copious amounts of staples would hide a multitude of sins for most consumers. These are cargo trailers and were not expected to be dissected, inspected and critiqued. So, we probably got what we paid for basically.

McDave

[flboy]

I agree in terms of the design criteria and not being the result of rigid engineering discipline. These are built by good old boys using carport engineering methods. It is not rocket science and it works.

Almost all the quality issues were hidden, but should have been obvious to any builder or inspector at each phase of build. In most cases, nobody would be the wiser; however, I am building and investing in a trailer I plan to keep long term. My goal is just to make it as best as possible. The plywood issue was just a question to reduce weight and increase strength or at least not decrease it. That simple.



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[lrrowe]

Don, too bad we were not neighbors and could build our CT's side by side since we seem to share the same general construction philosophies. I do believe that there are many very good trailer manufacturers that apply sound engineering approaches and then there are some (will not gamble on the qty estimate nor mention manufacturers who are suspect to me) who do what they can to get by.
Before I purchased mine, I did call one or two builders and asked specific questions about aerodynamic testing and was told that they were not aware of anyone in the industry doing it. Whether true or not, I am not sure. But I had no reason to doubt them.

[KCStudly]

...I'm not totally convinced the manufacture intentionally engineered and designed the original panels with that much foresight and attention to stress forces, based on the final product and workmanship and materials used, in my trailer anyways. I'm thinking material and labor costs were the dominant drivers, any real benefit in terms of strength was more of a lucky byproduct <snip> It's more likely that the inner panels are just a feeble attempt at keeping rouge objects from puncturing or damaging the outer skin from the inside...

Yes this, I emphatically agree. I wasn't actually implying that they had designed for anything else (though I suppose the inner side panels also add some buttressing for the nose and wind loads coming off of that), more I was just trying to allow a pause to consider what loads might not be accounted for if the ply were to be eliminated. Puncture resistance, or even just denting the outer skin when that big CI dutchie tries to roll out the back of a cabinet comes to mind.

As always, the builder has the last say and is in the best position to determine adequacy. Judging by your work so far, Flyboy, I am sure you won't go far wrong.

[flboy]

Thanks all for the input. I really do appreciate the comments, thoughts, ideas and encouragement.

I have a few more weeks before I am at the point of closing the walls back up. I know I can't go wrong putting the plywood back up. I am also looking at a way to cover the plywood with the type of Vinyl wall covering material you see in RV's. If I do that, I 'll need to use fillers over screw heads and other imperfections. Decisions... decisions.

[lrrowe]

I did try and order my CT without the plywood installd and the manufacturer would not do it.

[flboy]

I did try and order my CT without the plywood installd and the manufacturer would not do it.

I asked the builder of my trailer to cut the plywood and leave it inside not installed (and with a bag of screws). I got the same response. They did say it is part of the "structure". At the time I figured that would save me some time since i needed to just turn around and take it back off.

[Mark519]

Hi, flboy, nice build! I have a couple of comments especially about the Lark trailers which I have also. I did not weigh mine until recently and it was a lot heavier than I thought. The sticker says the payload is 5010lbs which implies it weighed only 1990 lbs. My recent weight was 5753 lbs. So I don't know if the sticker was wrong as I suspect, or I really added all that weight. I would be interested in knowing what other trailers weighed as originally built.

I would reinstall the wood on the inside and add screws where necessary. I think without it your outer skin will buckle. Driving over rough roads has buckled my skin some even though I have the plywood installed.

I had a problem with water leaking in the ramp door mainly in really heavy rains. I moved the drip rail down and that seems to have solved it. For some reason Lark (and maybe others) put the drip rail several inches above the ramp door top.

[flboy]

Mark519, thanks for the feedback. I think I will add it back on just to be safe. My ramp door has not leaked, but I have several other leaks I noticed since the plywood is off and we are having heavy rain. They did not seal well along the roof where it meets the sides. Very thin layer of sealer which cracked. I added a heavy layer of Dicor and fixed that. I also have a few small drips due to screws along the roof line where water runs over. I'll fix that with some silicone. What really is irritating is that I ordered mine 7.5ft tall inside and had the diamond plating added all around. The aluminum wasn't run all the way down and they added more underneath the diamond plate in a way water is getting underneath. They caulked along the trim and did a poor job there too. I'll need to seal all along the diamond plate trim on both sides. I am very disappointed. This would have never been discovered if I had not removed the sides to insulate and it rained while the plywood was off.

I was going to seal along the inside bottom, but I am not going to now in case leaks develop. The water will need to get out somewhere. Did you have any of those issues with Lark?

Btw.. I don't believe my weight either. I am going to weigh it when I am done building. I think the 2000 lb threshold means something in DOT terms if they cross that line, so they don't. I know it makes a difference in registering costs.

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[Mark519]

I did not notice water inside the walls but it was dry then. My top is well sealed but I guess some could get in somewhere so its time to reseal. I wonder if would be a good idea to drill weep holes up into the wall space.

Another problem with the ramp door is the D-seal has a certain range and if it gets crushed it will not rebound. That takes time to occur. I replaced mine with a thinner D-seal.

[flboy]

I ordered one of these from Amazon today. I am hoping this will boost the start torque on the 6000BTU AC so it will start on the Honda Eco setting. My understanding is that this should boost the torque allowing for a quicker start an less current in rush. I'll give you the first hand review if it does work. I do know the Honda won't kick the air conditioner over when in ECO mode and I really want to use Eco mode so it will idle when the AC shuts down and only idle up as loads demand.

[Mark519]

I have a solution that should work if you are comfortable with electrical wiring. Someone has probably done this but I have never seen it written up. Basically, wire your AC unit to control your generator automatically.

Find the wire that goes to the AC compressor motor (hot side) and wire a delay timer to the compressor motor. 5-10 seconds should be plenty. Also wire it to a 110VAC relay. Leave the relay inside the AC unit case. You will need a control cable with connectors on both ends. I would use use an outdoor extension cord for durability (don't need the ground wire) and some type of unique low voltage connector. There are so many to choose from.

I believe the ECO mode is off when the switch is open so this description is based on that being the case. Depending on whether you want the ECO switch to function normally for other uses you can leave it in series or disconnect it completely. Either install a connector in series with the switch or in place of the switch. When the compressor is off the contacts close and the generator goes into ECO mode. If the cable is unplugged it stays in full power mode. You would either use the control cable or need a jumper connector to use ECO mode.

Here is a 110VAC "delay-on-make" timer http://www.amazon.com/dp/B00SXB66IS

[flboy]

I have a solution that should work if you are comfortable with electrical wiring. Someone has probably done this but I have never seen it written up. Basically, wire your AC unit to control your generator automatically.

Find the wire that goes to the AC compressor motor (hot side) and wire a delay timer to the compressor motor. 5-10 seconds should be plenty. Also wire it to a 110VAC relay. Leave the relay inside the AC unit case. You will need a control cable with connectors on both ends. I would use use an outdoor extension cord for durability (don't need the ground wire) and some type of unique low voltage connector. There are so many to choose from.

I believe the ECO mode is off when the switch is open so this description is based on that being the case. Depending on whether you want the ECO switch to function normally for other uses you can leave it in series or disconnect it completely. Either install a connector in series with the switch or in place of the switch. When the compressor is off the contacts close and the generator goes into ECO mode. If the cable is unplugged it stays in full power mode. You would either use the control cable or need a jumper connector to use ECO mode.

Here is a 110VAC "delay-on-make" timer http://www.amazon.com/dp/B00SXB66IS

Being an electrical engineer I am comfortable with the wiring aspect and I can see how that would work. I'll do that as a plan B if the $10 capacitor doesn't work. Thanks for sharing.

The AC is not a big load for the generator I have but it just can't spool up fast enough from ECO mode and the AC low volts sensor shuts the compressor down. It don't need much help I think, and the hard start capacitor and relay may do it. By starting the compressor faster, the inductive reacance of the motor windings increases faster and the in rush current is decreased. Sounds good in theory... we'll give it a go.

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[Mark519]

Well you said you were were a Ham operator but now I may be asking you some questions!

[lrrowe]

I ordered one of these from Amazon today. I am hoping this will boost the start torque on the 6000BTU AC so it will start on the Honda Eco setting. My understanding is that this should boost the torque allowing for a quicker start an less current in rush. I'll give you the first hand review if it does work. I do know the Honda won't kick the air conditioner over when in ECO mode and I really want to use Eco mode so it will idle when the AC shuts down and only idle up as loads demand.

I will be watching for your results with this one.