Trailer design review please

[Diemjoe]

I just drew out my trailer frame to get the weight estimates. I have attached it here. It is based on the trailer for Angib's 10ft cub design. I added some additional steel hoping to make it even more solid. I upgraded to tube steel for for easier welding effort. Am probably going to go with a torsion axle.

The measurements and cross member positioning are rough-ish. Any comments or concerns?

Don

[tony.latham]

It's my belief that you're over building a bit. (Yeah, I know, too heavy is better than too weak.)

Your internal cross members don't need to be made out of tubing, 2", 1/8" angle is just fine. (I did that on my first build too.) Keep in mind that a torsion axle adds strength to the chassis and so does a properly built teardrop. Your corner angles are a good idea, but it may work better –and possibly easier to cut– if they are 1' pieces of 2" angle iron welded at 45º. That'll give you some good bolt-down points for your floor that aren't going to interfere with your walls.

T

[Diemjoe]

Thanks, you reminded me that I will be using the 1x's in the corner for the levelers. I will think about the cross beams.

As a hiker, I am well aware that an ounce here and there seem trivial but soon add up to a struggle. I only have a v6 Ford Escape with 100k miles that I don't want to stress out. It has been very good to me.

Don

[bobhenry]

Your internal cross members don't need to be made out of tubing, 2",

Can I respectfully disagree ! I have seen two of these cross members on two different trailers and both
were bent downward due to the upward impact at the hitch. (Both were 2x2 angle stock)

[Diemjoe]

Just so we are all looking at the same part of the picture. You're referring to the stress on cross members attached to the tongue? How about the front and middle and back being 2X2 tube and the cm between the front and middle being 2x2 angle?

[tony.latham]

Can I respectfully disagree !

Bob: Permission granted!

I look at the way Grant Whipp builds the tongue on his frames: https://www.facebook.com/teardrops.net/ ... =3&theater

As I said it many times, Grant has built more 'drops than I'll ever see. He uses a piece of rectangular tubing and welds it up as a box joint, butted it into another piece of rectangular steel. Obviously, it wouldn't be as stout if he were butting into angle. Soooo... I think Bob is right about the angle vs.the tubing. But there's lots of ways to skin a cat.

Tony

[Diemjoe]

Thanks for the respectful disagreements. I'll dig deeper.

[KCStudly]

I think the difference is those issues Bob saw were on lightly built trailers with single member tongues that had the 2nd xmbr too close to the front. So with full tube 'A' members well connected and overlapping , if it wasn't for the center tongue member sticking so far out from the tip of the 'A', I would agree with Tony. On the other hand, connecting the center tube to the angle xmbr's where they cross would require some more details.

One more little thing, that is kind of moot now anyway, on the gussets it is better to nip the sharp ends of the triangles off about 1/2 to 3/4 inch (usually I will make the gussets in pairs from a slightly rectangular piece, cut it in half on a 45 and just have to nip one corner from each piece). This way when you go to weld it you don't have to worry about melting out the little tip and it is much cleaner and easier to wrap your weld around the end of the gusset. Works well for wood gussets, too, less splitting and easier to make accurate joints.

[Diemjoe]

Thanks KC. What additional Details would you like to know regarding the cross member? The one closest to the Axle would be 1/8th 2x2 tube. The tongue would be welded to the bottom. I am currently planning for a 2x3 1/8th tongue. 3 on the up/down. I am a little concerned that the tongue would only contact the one angle CM for 2 x 1/8 Inches. I am sitting here thinking about welding a plate on the down side of the angle and length on the tongue. The worst roads I plan to take the TD on are The back roads that get to the National forest campgrounds. As the season goes o , the get pretty washboardy so vibration will probably be my greatest enemy.

Tongue Attachment.gif (16.1 KiB) Viewed 1035 times

[KCStudly]

When working with square or rectangular tube I like to work back to the sides of the tube rather than the face, and at times such as this it can make it easier to weld, too. So where you show the L crossing the tube the contact point not only ties in to the face of the tube it also bridges across the vertical walls (so that's good). The gusset, on the other hand, only contacts the face of the tube in the middle. So not only could that be hard to get in there and weld, in theory, with heavy loading (perhaps more than it will ever rightfully see) it could have a can opener effect or deforming effect tending to crease the top of the tube along its length and pull the vertical sides in.

I would be more likely to turn the gusset 90 deg (turning that little section into more like a channel with the legs down) and weld it along the toe of the L and across the tube. Another option that I would favor is having two gussets like you show, one on either side of the tube except make them a little longer so they straddle the tube. That way you can weld them to the L first, they will register on the tube during assembly helping with alignment, and you have easy access to weld (with the frame upside down).

In reality, we are probably over engineering, and if you just weld the bottom toe of the L to the top of the tube it would be just fine.

Remember, where the tongue members cross the front xmbr you only want to weld with the long axis of the trailer, not across it (do as I say, not as I did).

Also, think of it this way (if not already stated above or elsewhere): the trailer holds up the front wall and bulkhead; the front wall and bulkhead hold up the walls; the walls hold up and stiffen the edges of the floor and the trailer frame. So build a tight box with glued and screwed joints, and fasten the floor to the trailer using several smaller fasteners distributed along the length, rather than just a few at the corners. Unify the structure and you can build light and strong.

[Diemjoe]

Thanks for that very considered response. I appreciate the time. Don't even have the steel yet so there is plenty of time for this kind of thought process.

[ctstaas]

Hi Don Here's what worked for me. I don't know who drew my plans but a friend gave them to me. My tongue and tube for the axle are 3"x 3" x 3/16" I carried it to the rear to accomadate a receiver. The perimeter of the frame is 1 1/2"x 0.065" square. The axles are bolted to 1/4" plate welded to the axle tube. The floor of the cabin (3/4") is bolted to the perimeter. No diagonals to the tongue. Battery/ propane holder welded to the underside of the front frame. The spare tire holder and jack are welded to the tongue. Hatch frame is 1"x 0,065" square rolled and fit. Have your axles before you locate your axle tube. My light brackets are 1/4" plate.
Bullet proof and fairly light. My frame turned out square but the plywood from the factory was 1/16" out. It made things interesting but turned out fine. Anything you do will be superior to a HF trailer. Pics of my build are on page 25 of the "Cs" in the members gallery.
Enjoy, Chris

[Dale M.]

Maybe I missed it in discussion, but on my corners I use a section 1/4 inch plate about 9 inches square welded to my tube (flush with bottom) to act as gussets and accommodate stabilizers....

Dale

[Diemjoe]

Hi Dale,
There was discussion about the corner gussetts. I originally was just going to use 3 or 4 inch triangles but was reminded that I would need to attach the stabilizers. So I have to decide to use the plates or the diagonal 1X1's

Thanks for responding to my inquiry.

Don