Custom 7 Trailer

[WestTexasS2K]

Here are some pics of the trailer that I am currently building for someone on this site. I will leave it up to him to claim it if he wants. But it is a 7x12x4 with a tilting top to allow easy access in and out of the car and 4ft ramp door with sloped rear floor. The idea is to have a low overall height for easier towing and better gas mileage. It has a 3500lb braking axle and will be covered in white .040 aluminum panels 3/4 plywood floor. It should be a reallty sweet trailer when all finished. I would consider building others if anyone is interested.

http://www.usa7s.com/aspnetforum/upload/918984742_DSC01568.JPGhttp://www.usa7s.com/aspnetforum/upload/30630948_DSC01569.JPGhttp://www.usa7s.com/aspnetforum/upload/603770155_DSC01570.JPG

[WestTexasS2K]

i can not get the photos to upload what gives? I hit the upload image and put the file in there and hit upload and nothing. What am I missing here?

[slngsht]

Problem solved... the account used for saving images on the server had reached its maximum quota. Opened up another 100 meg :cheers:

[stevet]

Slightly off topic, but what is the material lining the walls of your garage (I'd like to insulate my garage, but don't want the hassle/expense of dry-waling)? Thanks.

[lowflyer]

Very nice trailer.

 

I have a similar design, which was originally designed for a Formula Ford I raced. It had a hinged top which tapered to the center, but relied on lots of "ooomph" to raise. When making it fit my Stalker I had to do away with the aluminum top since it wouldn't work with the Slaker's roll bar and windshild. What are the hydraulic lifts you are using from? They must be rather stout to handle all that steel and aluminum.

 

One thought... on mine the front is tapered back for the first two feet, which offers a small aerodynamic advantage. Mine is 14' down the centerline, but only 12' at the wheels.

 

I rebuilt mine a couple of years ago, removed the floor which had some dry rot in it, replaced the wood sides with aluminum diamond plate and rewired it.

 

Out of curiosity, what is the cost of something like your building?

 

http://www.usa7s.com/aspnetforum/upload/621215725_trailer2.jpghttp://www.usa7s.com/aspnetforum/upload/2140257367_trailer18.jpghttp://www.usa7s.com/aspnetforum/upload/1525661002_trailer1.jpg

[WestTexasS2K]

Steve that is fiber backed insulation that is used on metal buildings it come in rolls 6x150' works really well on a metal buiding at least I can work in my shop year round in relative comfort. Just open the doors the let breeze thru in the summer. I do have a big shop fan for days with no breeze. It doesnt get real cold here often but I have worked out there for days in 19 degree weather and a small kerosene shop heater to knock the chill off.

[WestTexasS2K]

lowflyer I thought about the tapered front but with my top hinging there it makes it a little more difficult to do. And sing the customer is pulling it with an SUV the truck will block most of the wind and makes it less of an issue than if it were pulled with a pickup. I had even thought about tapering it into a wedge at the front but then that really limits some storage space in the front and may also limit the resale of the trailer. So I decided to just keep it a little more universal approach with a slant to 7 use. Having not completely finished this trailer yet I am not sure of how I am going to come out on price. I have a good Idea. I am building this one for 3600.00 with aluminum skin but if I were to do it again I would most likely have to go to 3900.00 or so I had a few expenses that I missed on my bid for this one.

 

P.S. the gas struts were sorced from http://www.mcmastercarr.com they have struts of all different lenghts and lift capacity. I will have to get some softer ones these are way to stiff. They are 150lb lift each I have to hang on the back to lower it. But I will wait till I have the skin on and then weight the top and see what is needed I am thinking about 75lbs each.

[locost7018]

westtexas, If it is 1" square 16ga tube it is .827#/ft and .032 ali is .452#/sf so your ali will be slightly higher. I know this because I am building a similar trailer for my 7. Only the top will slope down at a 30deg angle. Russ

[stevet]

Thanks for that :thumbs:

 

Steve

[Keith]

You might get better aero if you tapered the height of the trailer down towards the back instead of concentrating on the "bow". Tapered fronts do improve the jackknifing angle, that's handy.

 

I like the looks of your trailer, I've been kicking around the idea of rebuilding my open one with a box. Thanks for sharing! What's the estimated total weight of the trailer?

 

Hmm, would the sides be stiffer if they were triangulated instead of vertical studs?

[WestTexasS2K]

Thanks Locost. Its 16g 1x1 and 2x1 16g around the perimeter. The steel place is right around the corner from my house I will get the weight of the 2x1. i assume i would have to use some percentage of the total weight since it is hinged in the front and it will not be picking up the whole top. What are your thoughts?

[locost7018]

There are ways to determine that but it would take a mechanical or structural engineer to figure it. I think if you figured 1/2 or 3/4 of the total you would be safe. I used gas struts on anothere trailer I modified and just took an educated guess and it worked out great. It is better to have too much than not enough. Think about wind, rain, snow loads also. I would also add 5% for welds, fasteners, caulk, etc . 1x2 .072 is 1.83#/ft 14ga is 1.6#/ft. .040 ali is .564/sf. Russ

[locost7018]

LOwflyer, that is an interesting trailer. How did that top work?????? What guage ali diamond plate did you use? How did you fasten it? Russ

[WestTexasS2K]

Keith I thougt about adding some triangular supports but that just adds more weight and it is pretty stiff as is. Besides it will have .040 aluminum skin with screws every six inches that should lock it all together. All the enclosed trialiers that I have ever seen have had just the vertical struts and they are usually made of even lighter material than what I made this out of. As far a jack knife angle the 4" longer than the width of the tow vehicle so it should have a really good turning angle.

[Keith]

I was thinking of triangulated members instead of the vertical ones. Right now it looks like the walls of a house, could it be lighter and stronger if it looked more like, oh, a Se7en? They still make hot rods on ladder frames but that doesn't mean it's right...

 

Just thinking. I'll probably go with diagonals on mine when the time comes.

[powderbrake]

Loren:

The trailer looks great. I understand your construction, and the fact the sheet metal will act as a stressed member when you screw it on to the sides.

 

Triangulating the sides will only add strength in vertical bending of the sides, and they have no load in that direction. It will not help the side to side bending, which is mostly generated by wind forces. Multiple latches ( like our adjustable hood latches) between the sides and the top will help to rigidize the whole box, as well as pins or other method to tie the top to the sides and not allow the top to move from side to side relative to the sides.

 

I wish I had a low trailer like that, I have a 7X16 Utility trailer, and being much higher, it creates more drag.

 

 

[WestTexasS2K]

Thanks Jerry. I had planned on installing a 1x1 angle on the top rail of the trailer to provide a 1" overlap to help keep the weather out while going down the road. I think this will help lock the top to the side. But a locator pin on the rear wouldn't be a bad idea. I hadn't thought of that myself. I had also thought of putting an outside support bar that would go up and tie into the side. Not sure if I want to do that. Those support tubes outside the trailer tend to snag on things when tuning if you are not careful. I attach a drawing to show what I mean. What are your thoughts. [/img]

[Keith]

I was worried about parallelogramming, allowing the whole box to flex (or collapse) sideways under a wind load. The skin will certainly help here of course.

 

I know, this is how all other trailers are built. But I can't help myself

[WestTexasS2K]

Keith are you from Grand Junction CO.? I was pretty sure you were from Colorado. We went thru Grand Junction on the way to Pueblo this year on the 1 Lap. We came in on 70 and had a broken brake line when we hit the brakes. Luckily there was an Auto Zone on the left. We coasted into there at 9.02pm they had just closed but we banged on the door and the guy was nice enough to sell us a hard line that we replaced in the parking lot.

 

Then we almost got kill going thru the mountain pass. It was about 1 am we were doing about 70 going down a winding hill and we make a right hand turn going onto a bridge with cement walls on both sides. about 150ft down the road some DA was parked sideways across both lanes with his lights off. Luckily he was in a white car and we saw him a little soonier that we probably would have other wise. We hit the brakes hard. Still had mostly front brakes because we didn't have a hose to bleed the rears and didnt want to ruin the newly powder coated wheels. We almost ended up ruining the whole car. With our trailer on behind us there was no way we were going to be able to stop. about 50ft before we hit him he turned right and pulled over a bit and we able to just squeeze between him and the wall with inches to spare. It is a good thing Kevin left his gun in his truck because he would have stop and shot that DA he was so mad. Luckily it kept us up for the next 10 min. That was an eventful night. The elk on the road about 50 miles later was another good adraline pumper.

[Keith]

Yup, I'm in Grand Junction. Isn't night travel through the mountains fun? I'm betting you came over Monarch Pass on highway 50 - that's a risky one with a lot of weather. Shortly after is a real black spot for deer on the road. But you probably remember this.

 

If you run the One Lap again (you're nuts), I'll give you my contact info in case you are in need again. I have a collection of brake lines and tools in my garage along with a pile of other bits. I even know a couple of S2000 owners who could act as "parts cars" as long as we don't ask first.