Basic Questions

[madjack]

Ed, I almost always encourage folks to "roll their own"...you get a custom frame designed specifically to your camper and the satisfaction to boot...although it has been a couple of years, my last frame, built with 1x2x3/16 channel and a 1500# Dexter torsion axle ran less than 500 bucks with tires/wheels/fenders included...I did have a 5' piece of 2x1/4 sq tube for the tongue on hand..........
madjack

[John T. Hodgen]

Hey all,
When I first started out welding, my teacher called them Gorilla Welds--UGLY but DANG Strong!!!!
Til later by the fire--John T.

[Ed K.]

[quote="kennyrayandersen"]What I meant was if you build the frame yourself you can save some cash and get you a good welder like a Lincoln, Hobart or Miller. I've generally paid for all of my tools over the years but DIYing it. I'm not sure it's THAT much cheaper in the end, but you get to collect and use a bunch of tools. The loads an a teardrop trailer frame are minuscule and I'm SURE you could weld it good enough to hold even if you never welded before. (since the trailer frame is pretty much redundent anyway if you build the body robustly./quote]

Ken,

Thanks for clarifying that. I have a Millermatic 180 MIG welder already that I haven't even used yet. I got it in the dead of winter so I haven't had the chance to use it since my garage is not heated and I don't have an outlet wired for it yet. I've never welded before so it will be a learning experience.

Ed

[Ed K.]

Ed, I almost always encourage folks to "roll their own"...you get a custom frame designed specifically to your camper and the satisfaction to boot...although it has been a couple of years, my last frame, built with 1x2x3/16 channel and a 1500# Dexter torsion axle ran less than 500 bucks with tires/wheels/fenders included...I did have a 5' piece of 2x1/4 sq tube for the tongue on hand..........
madjack

madjack,

I just checked the rough price of making it with 2x2x 1/8" tubing and 2x2x 3/16" tubing. The 1/8" tubing would cost about $250 and the 3/16" would run me about $335.n That's considering two 10ft sides and four 5ft cross memebers and a couple more for bracing the tongue tube. What thickness of tubing would be adequate for building a 5x10 Ken-Skill?

Ed

[Esteban]

I hired a local welding shop to make my 5'x10' frame. The outside of the frame was made from 2"x2"x1/8" tube. The A-frame tongue was made from 2"x3"x1/8" rectangular tube. The 4 cross supports were made from 2"x2"x1/8" "L" angle. The L cross supports are lighter than tubing and easy to drill holes through for bolting the floor to the frame.

On my "next" frame I'm considering making the outside of the frame from "C" channel to make it easier to attach the outside walls to it, which I prefer to cover the trailer frame. With "C" channel it'd be easy to bolt or screw the sides and floor to the frame. (I don't want to drill holes into tubing). I think it'd make wiring easier too because you can run the wire through the open "C" where it'd be supported. I might make it easier to wire to the side running lights too because it's be easy to drill through the side of the "C". It might help you to balance the trailer because you could drill into the "C" to attach the axle wherever it balances best.

I'd also be very tempted to attach one or two battery trays to the frame like halfdome Danny does. (edit) This is a picture of Danny's trailer frame, not of mine. His frame design seems very well thought out.

[madjack]

Ed, I use channel for the frame and tube for the tongue...tube is more expensive...I believe others have used tube as thin as 16ga successfully........
madjack

[kennyrayandersen]

I hired a local welding shop to make my 5'x10' frame. The outside of the frame was made from 2"x2"x1/8" tube. The A-frame tongue was made from 2"x3"x1/8" rectangular tube. The 4 cross supports were made from 2"x2"x1/8" "L" angle. The L cross supports are lighter than tubing and easy to drill holes through for bolting the floor to the frame.

On my "next" frame I'm considering making the outside of the frame from "C" channel to make it easier to attach the outside walls to it, which I prefer to cover the trailer frame. With "C" channel it'd be easy to bolt or screw the sides and floor to the frame. (I don't want to drill holes into tubing). I think it'd make wiring easier too because you can run the wire through the open "C" where it'd be supported. I might make it easier to wire to the side running lights too because it's be easy to drill through the side of the "C". It might help you to balance the trailer because you could drill into the "C" to attach the axle wherever it balances best.

I'd also be very tempted to attach one or two battery trays to the frame like halfdome Danny does.

Nice trailer!
Is that a Dexter 8 or 9? Does anyone know what the amount of pre-curvature is that comes in their full axles? Is that something that is determined by the trailer seller? Or do they just come from the factory like that with the bow in it and the seller (trailer manufacturer) just orders them to width?

Those battery trays are a nice touch.

For the frame – I can’t imagine that the 16 gage wouldn’t be alright. One thing to keep the cost down is to keep the weight down. If you use a frame, it really can [usually] be quite light-weight since the overall stiffness and strength actually come from the trailer walls. As long as you meet the tongue requirements that Andrew posted in the design library, you’d be OK for that and if you keep the rest of the frame fairly light then both the weight and cost can be reduced (since you are basically buying the steel by the pound). Think of the body as something that strengthens (unless it’s not well built) the chassis rather than something that supports it. The frame could actually be a bit flimsy in fact. Once the body had been bolted to it, the flimsiness will disappear. ‘C’ sections should be fine and if your body is well built (not necessarily heavy) then 16 gage stock would probably be plenty; the same goes for the x-members.

I’m always amazed at those thin self-assemble metal shelves. The individual parts are so wimpy out of the box, but once you have them assembled they’re pretty strong – quite a transformation.

[Ed K.]

I've decided to go with 11 gauge 2x2 tubing for the outside frame and 14 gauge 2x2 tubing for the cross members. Going with all 14 gauge would have saved me only $36 and I don't like the thought of using anything thinner even though others have done it successfully. I'm thinking of 3/16" thick 2x3 for the tongue tube.

Ed

[kennyrayandersen]

We have a joke in the aerospace bidness that we use when something is particularly robust (heavy). After the blast (atomic bomb), the plane will disintegrate, and this part will fall out of the sky.

There is no doubt why many of these little teardrop trailers are are pushing 1000-1200 Lb [or more]. Weight costs, as you've noticed, a bit up front (you could save even more that the $36 if everything were'right-sized'), it also costs over the life of the product as you haul it. Now it may not be a crazy amount or anything, but it is really significant on something like a truck trailer or airplane or something that is used or driven often. Funny thing is, as Andrew pointed out on a trailer that just had a relatively small angle around the perimeter -- even that would be strong enough. Anyway, it will be REALLY robust with those gages.

BTW -- what is your projected weight, and what is the distance from the ball to where the teardrop vertical wall is? The design library has tables for determining what dimensions your tongue should be. Unless it going to be reall heavy and you tongue really long, you may not need so much -- if you need help interpreting the data, I'd be happy to look at the sizing according to the tables if you can provide some weights and dimensions.

[Ed K.]

:shock:

Anyway, it will be REALLY robust with those gages.

BTW -- what is your projected weight, and what is the distance from the ball to where the teardrop vertical wall is? The design library has tables for determining what dimensions your tongue should be. Unless it going to be reall heavy and you tongue really long, you may not need so much -- if you need help interpreting the data, I'd be happy to look at the sizing according to the tables if you can provide some weights and dimensions.

Kenny,

I want it to be robust but at this point nothing has been cast in stone. My projected time to start the build won't be until sometime next fall so I'm in the information gathering and planning stages. I'm not even sure yet if I want to build a Benroy or a Ken-Skill, although I'm leaning towards a Ken-Skill based on looks. But I might end up going with the Benroy based on less curves being easier to build for a first time TD builder. I do know what dimensions I want it to be though and that would be 5ft wide by 9.5ft long by 4ft tall. I have no idea what the weight will end up being.
I would love to take you up on your offer of helping figure out some of this stuff. I work in engineering but it's electronics not mechanical so I can use all the help I can get. The woodworking part is no problem since I've been a hobbyist woodworker for decades and have all the tools at my disposal.
Just sitting here typing this I'm thinking some more and wondering if I should go with a generic Benroy as a first TD build? Then if I want I could always build a Ken-Skill later on and sell the Benroy once the Ken-Skill is complete. OK, I've convinced myself to scale back and go with a generic Benroy at 5ft wide by 8ft long by 4ft tall. I have no idea what the weight will be so I can certainly use some help interpreting the data.

Happy Easter!

Ed

[kennyrayandersen]

OK I'll tell you what you can help me when I get to the wiring. Who knows what might happen and you'd only be able to build one. I say build the one you want. If you've been wood working for a long time then you won't have any trouble modifying the plans a little if you need to and so I don't think either of those will be beyond your capability.

The link to the tongue strength is:

http://www.angib.pwp.blueyonder.co.uk/t ... tear84.htm

If you were 30 inches from the body to the ball and the trailer weighed 750 Lb you moment would be .5*30*750=11,250 Ft-Lb

Look on the chart and 2x2x14gage is sufficient

mind you that's a single 2x2

piece O cake

[madjack]

...let me interject 2cents wortha my thoughts on tongue construction..mind you, I am not a trained engineer but rather have many years of experience with many different types of trailers...a single tube tongue can work just fine BUT it is more prone to difficulties with both shimmy and eventual fatigue...at the very least, I prefer an "A" frame tongue or my actual preference, a "Y" frame...of course length of tongue has a lot to do with it and considerations for what you might wish to mount on the tongue...my present tear has a 5' long tongue, with a 1' deep front box(actually, integral to the cabin), a petcool and 20# propane tank mounted on it...a lotta stuff I know, so I built it out of a piece of 2X1/4" tube with 1X2X3/16 "C" channel side braces...works out very well for me.........
madjack

[Ed K.]

Who knows what might happen and you'd only be able to build one. I say build the one you want. If you've been wood working for a long time then you won't have any trouble modifying the plans a little if you need to and so I don't think either of those will be beyond your capability.

Kenny,

That's kind of what I was thinking when I was trying to decide between a Benroy and a Ken-Skill. I'd rather build just one so I might as well go with the Ken-Skill since I like the looks of it better. OK, back to the Ken-Skill at 5ft wide by 9.5ft long by 4ft high. Now, how does that affect the tongue length and steel gauge?
I would like to use aluminum for the skin but I don't know how that effects the construction so I'll have to research that.

Thanks for the help, I do appreciate it.

Time to get my taxes done before I head to my sister's for Easter dinner.

Ed

[Ed K.]

...let me interject 2cents wortha my thoughts on tongue construction..mind you, I am not a trained engineer but rather have many years of experience with many different types of trailers...a single tube tongue can work just fine BUT it is more prone to difficulties with both shimmy and eventual fatigue...at the very least, I prefer an "A" frame tongue or my actual preference, a "Y" frame...of course length of tongue has a lot to do with it and considerations for what you might wish to mount on the tongue...my present tear has a 5' long tongue, with a 1' deep front box(actually, integral to the cabin), a petcool and 20# propane tank mounted on it...a lotta stuff I know, so I built it out of a piece of 2X1/4" tube with 1X2X3/16 "C" channel side braces...works out very well for me.........
madjack

madjack,

I had planned on making my tongue tube long enough to reach the first cross member. So it will be welded to the end cross member and the next one in as well as having two angle braces from the tongue tube to the end cross member. I want to be able to mount stuff to the frame like you did so I want it strong.

Ed

[kennyrayandersen]

More important is how the weight is distributed on the trailer. If you have a heavy tongue box AND a fair amount of weight in the back you increase the mass moment of inertia. If all of your weight stays near the CG, you shouldn't have lateral shimmy problems. Andrew had a great link -- I'll see if I can find it later. It's a site that explains about the situation and also lets you play a game where you change the trailer (caravan -- actually a British site) weight and loading distribution and it check for stability -- fun AND informative.