Two Design questions... (1 Viewer)

[chet]

I like the last drawing. obviously not as strong as your option#1 but almost. plus it gives a nice place to run wiring inside the tube!

 

[REZARF]

Kevin-

I am hoping to be around 800lbs dry. Add another 300 full and ready to head out... I hope.

I am leaning towards this design and keeping the ability to add a few A arms down the road if I do experience any torsional flexing of the single draw arm. Lots of trailers are built like this, just not a lot of off-road trailers.

I am not asking this trailer to follow me on a 4 or 4+ trail, but something like Elephant Hill in Canyonlands would be about max... 3 or so.

Thanks!

Drew

 

[KY854RUN]

Alright,

Here is the final decision, mostly inspired from a relook at Kurt's trailer and Wildyotes trailer...

A single 2.5" structural square tube with .25" wall. This will eliminate a bunch of fab work and geometry at the front end. It will also be the easiest to get really really square. There won't be more than 120lbs on the tongue at its HEAVIEST, so all the extra steel just isn't needed.

This also allows me to use a ball coupler on road, and then unpin and install a lunette ring for light trail work. I have a ball/pintle combo. In addition, the ability to do a 90 degree jackknife is possible with this setup.

The drawbar will be fully welded through the front and second crossmembers.

I will "gusset" the draw arm with 2" HREW tubing with .125" wall bent up on a bender, and the basket will sit on top of it. Clear is mud? The draw bar will be welded at each intersection of the crossmembers.

Any opinions? Flame away

Drew

I forgot to ask, what is the size and wall thickness of the rest of the trailer's frame going to be? And what are the frame's dimensions?

One other thought, what about running the draw bar tube all the way to the back and making a receiver on the rear of the trailer. It could come in handy every now and then.

 

[REZARF]

The rough dimensions are 4x6'

2x3" tubing with .125" wall.

I thought about running the tube down the length of the trailer but I am hiding my water tank under the box, above the axle and right where the receiver tube would run...

What do you think?

Rezarf <><

 

[brownbear]

Frazer,

Your idea with the spacing on the pintle is ok. Use the 1/4 walled tubing. Extra long bolts and your good to go.

Your towing a small trailer, it's not much load. The bolts are in the same load as if they were shorter. The bolts are in 100% tension load. Not shear. So the length is not important. It is all tight and solid it will be ok.

Use bolts designed for tension loads. Pick expensive high grade bolts. Use lock washer and same grade nuts. Do not use fiber or vinyl lock nuts, it lowers the grade to 5. Not good for tension loads(shear OK).

If you were towing a 20K trailer around on a pintle I would say use a solid spacer. But the 1/4 wall tubing spacer will offer plenty of strength. You could even cover the ends(boxed) for further strength.

 

[REZARF]

Thanks Brownbear!

Drew

 

[brownbear]

when you get the spacer drilled and are ready to select the bolts. It is important to have the bolt length just long enough that the shoulder of the bolt is exposed. Thats the non threaded part. You want that to protrude through. Then you add enough washers to ensure when the nut is tightened that the nut isn't bottoming on the shoulder. The strength is in the shoulder(or grip sometimes called). The threads are strong in tension loading, not shear. SO you always want the shoulder just out.

Then ensure the nut has a thread or two showing after you tighten it up. Ok if there is more, but if there is no threads showing the tension strength is compromised. you need all the threads to grip.

Also try not to use more than three washers. 2 plain( one under the head if possible. And one under the lock washer. Then the lock washer is up against the nut and the washer. You never want the lock washer up against the work. As the work could be softer metal and the lock tension might diminish.



Ok I spend too long learning standard practices at college.......

 

[KY854RUN]

The rough dimensions are 4x6'

2x3" tubing with .125" wall.

I thought about running the tube down the length of the trailer but I am hiding my water tank under the box, above the axle and right where the receiver tube would run...

What do you think?

Rezarf <><

Drew,

To bad about a rear receiver, but I think you'll like having the water tank better and you will use it a lot more.

I think that you are going to have a super stout frame using the materials that you listed. Here is a comparison to the 1/4 ton military trailer frames. The military drawbar arms are made from 0.125" thick metal. The military frame rails and cross members measure, 3.250" high x 1.750" wide x 12 gauge (0.988). Now IIRC, when you add the fourth side to a C-channel and make it a box tube, the strength doubles. Again IIRC, when you increase the wall thickness by 25%, the strength doubles. These 2 factors compound each other, meaning that the 2"x3"x0.125" box tubing should be 4 times stronger than the 3.250"x1.750"x12 gauge C-channel that was used in the military 1/4 ton trailers.

I have been following your other thread "Look at what the man in the brown shorts brought me!"and I'm pretty sure that that is a 3500# axle that you got for this trailer. You don't explain why the man's shorts are brown, but that is another thread all together.

Combine all of what you have and I think that your estimated empty weight of 800 Lbs is close. I feel that your load capacity of 300 Lbs is way off. Now that might be what you plan to carry in it, but I think that this trailer will be able to carry 1500 to 2,000 Lbs. I would not carry that much weight in it on a regular basis, but I do think that what you are planning would be able to handle that kind load.

 

[REZARF]

Thanks Kevin-

Yeah, the man in the brown shorts is the UPS dude

I think I am fine too. I will be only loading 300-500lbs of crap into this thing, I think the actual ability to carry a load will be a lot more.

Thanks man!

Drew

 

[Mike S]

Check out Expo...

Look in the trialer section. One of the guy sthere did a CAD section 3D drawing of the hitch I described. Shows it better than any photo could...

Mike

 

[REZARF]

Frazer,

Your idea with the spacing on the pintle is ok. Use the 1/4 walled tubing. Extra long bolts and your good to go.

Your towing a small trailer, it's not much load. The bolts are in the same load as if they were shorter. The bolts are in 100% tension load. Not shear. So the length is not important. It is all tight and solid it will be ok.

Use bolts designed for tension loads. Pick expensive high grade bolts. Use lock washer and same grade nuts. Do not use fiber or vinyl lock nuts, it lowers the grade to 5. Not good for tension loads(shear OK).

If you were towing a 20K trailer around on a pintle I would say use a solid spacer. But the 1/4 wall tubing spacer will offer plenty of strength. You could even cover the ends(boxed) for further strength.

Thanks BrownBear, I scored a 4x4" structural tube with 3/8" wall... it is beefy!

I may bolt through the crossmember and the pintle seperatly instead of one long bolt, is there anything wrong with that?

Rezarf <><

 

[KY854RUN]

Thanks BrownBear, I scored a 4x4" structural tube with 3/8" wall... it is beefy!

I may bolt through the crossmember and the pintle seperatly instead of one long bolt, is there anything wrong with that?

Rezarf <><

Hi Drew,

You should be fine using separate bolts with the 3/8 wall tubing. That is going to be strong enough without the longer bolts.

I want to see how the trailer build coming.

 

[Cat Scan]

Look in the trialer section. One of the guy sthere did a CAD section 3D drawing of the hitch I described. Shows it better than any photo could...

Mike

I thought this was the trailer section? Being in a confused state is normal for me. But do you have to help me stay in it? Seriously, is there another trailer section on IH8MUD?

 

[Mike S]

I thought this was the trailer section? Being in a confused state is normal for me. But do you have to help me stay in it? Seriously, is there another trailer section on IH8MUD?

Sorry, CS, this was in a trailer discussion on Expedition Portal, one that Drew has also been participating in...

M

 

[Cat Scan]

Sorry, CS, this was in a trailer discussion on Expedition Portal, one that Drew has also been participating in...

M

Thanks for the clarification! I need to do a little more searching around on Mud I think. Probably a lot I am missing out on.

 

[REZARF]

Thanks for the clarification! I need to do a little more searching around on Mud I think. Probably a lot I am missing out on.

www.expeditionportal.com

Have fun, nearly as addicting as this site.

Drew