PINS Base Camp (Build Plan)

[PINSTER]

About a year ago, while considering the idea of buying a trailer to carry my kayaks down the beach, I stumbled across ExPo... The rest is history, after several long nights of "catching up" on all the build threads, there was no way I wasn't going to build a custom trailer. With no clue, I immediately started putting down sketches of ideas, these ideas compounded with the build threads fresh in my mind quickly got out of hand. You can see my initial post here to see where I was last year.
http://www.expeditionportal.com/forum/threads/122859-Introduction-and-initial-build-concept

Now, I haven't given up, just had life slow the roll a bit, which I think was a good thing. I joined ExPo in January '14, posted in February, bought a welder, and then found out we were having a baby, our first! Needless to say, trailer funding was immediately redirected to scrambling/bracing for the costs of the new guy
. WELL, October came and I have an awesome little baby fishing partner. Now that the dust has settled on the homefront, the project can continue...slowly.

The main objective: To build a kayak hauling beach trailer.
Ive had a lot of time in the last year to think about what I needed in the trailer and what was more wishful thinking. The primary need is to get two 16ft kayaks along with sailing, camping, fishing gear down a 60mile undeveloped beach, Padre Island National Seashore (PINS). The sailing gear includes two carbon masts 15' long that will ride in pvc pipes inside the body so a long length is necessary. The terrain ranges between hard packed washboard to deep soft rutted sand.


The build plan:

Frame/Body
18' main frame of 2x4/2x3 with 2x2 crossmembers
body frame is 1x1
kayak rack is 1.5x1.5
Tongue is 2.5x2.5
Cargo body 1/4 ply (CPES internally and glassed on top)

Suspension
3500lb straight axle w/ elect brakes and 6 on 5.5 pattern
33" Nitto Terra Grapplers
16" FJ SE wheels
Jeep YJ Springs
Gas shocks

Accessories
Deep Cycle Battery
Morningstar Charge Controller
Solar Panel
Flojet Pump
21G Water tank
LED cargo lights
LED spotlight
Built in icebox/livewell

Here is where I am at in Sketchup, still learning the program...


and a sketch.

The front third of the trailer will be insulated with 4" foam walls that i have left over from a warehouse cooler construction, it will be glassed within to make a super yeti that should hold ice for extended stays during the summer. If I wanted, I could use it as a livewell for bait while down island but wouldn't travel with it filled with water. Im hoping the water tank placed behind the axle will help to keep tongue weight in check.


Any feedback on the frame design is appreciated!

 

[PINSTER]

Frame Question

So I have a question for you engineers/welders/experienced fabricators. If you look at this frame, you'll see how I cut into the main 2x4s with the crossmember 2x2s, essentially rabbiting the joint, which in the wood world would add strength. Im new to metal work so Im guessing at what works and what doesn't. Is the design of the rabbited crossmember reducing the overall strength of the main 2x4s? Or does it net out to be the same since I am cutting out 2" and filling it with 2"? Assuming that the welds have proper penetration.

Here is a close up of what Im talking about.



Any suggestions? Since the trailer is long, I don't want to jeopardize the strength along the length of the 2x4s. My thought process was to tie together as much as I could with as few triangles as possible, all to help distribute load when the trailer rolls over bumps.

Here is a view from below

 

[drgrenthum]

I see you talking about tubing size but i dont see what gauge you are talking about using. A 2x4, even at 16ga, is probably going to be way over kill for the weight you are talking about carrying. On this site we tend to go with overkill but this may be detrimental in the case of soft sand, i am assuming you will be using it on. You can find weight of tubing per foot on a site like onlinemetals.com. May want to see how much weight your design is going to be. You could half your tubing sizes (depending on ga.) on all except the body frame, and still have more than enough strength for your build saving weight and money.

You also have alot of bracing. I can't put my head around it, but your design reminds me more of a full cage buggy then a trailer. Nice, robust, strong, protect everything in a roll over at 80mph but probably unecessary.

 

[PINSTER]

Sorry, I did forget to mention gauge. I had made the plans considering .120 wall for everything except the center receiver tube. My weight calculation on the bare frame came out to under 600lbs, so trimmed out with suspension/wheels/accessories Im guessing around 1000lbs dry.

So I say 2x4, but really it's just the center portion over the axle/springs that's 2x4. The front 5' is 2x3 and the back 4' is also 2x3. I guess its hard to tell from the picture. Also some of the bracing that shows on the "bottom view" is actually the upper body frame/kayak rack.

 

[axehead]

I would simplify the whole frame. Looks like it wants to be a space frame but none of the diagonal members meet at the nodes.

You have multiple member sizes, all kinds of angles going on. After you start cutting all those sections you might wish for more 90 degree cuts.

I wouldn't notch (rabbit) the main members. Cut the secondary members around the main members.

I would double check your axle location too. What would your hitch weight be on the way home from a trip when your water tank is empty? Looks front heavy to me.

 

[PINSTER]

axehead, drgrenthum,

Thanks for the feedback. Yeah, I can admit to over doing it...and I definitely don't want to over build it to the point where its too heavy to pull around. I didn't intend to make a space frame (didn't know what that was, till i looked it up), but I read about triangulation so thats where my conceptualization went. The good thing is its still just a concept, and sketchup is easy enough to make changes in. About the tube sizing, I have two 7' pieces of 2x4 120wall, so thats where I started the design. But, I don't have to use them, was just being cheap, I could actually use one piece for the bumper.

Here is the model scrapping the 2x4 sections and making it a uniform 2x3 frame. Also cleaned up the receiver tube triangulation.



You're right axehead, it would be quite the pain cutting each of the angles and notches. And about the axle placement, the sketch is old, the sketchup model has the axle one foot forward of where it is in the sketch. It will be tricky though, with a depleted water tank and a full cooler up front. If all goes to plan then I'm coming home with the forward coolers full of fish. I plan to place a group 24 battery (50lbs) and a spare tire on the back end, but will have to get further along to really see how it all works out.

Thanks guys for helping me keep things in check before I start buying materials.

 

[jdillard]

I'd advise you not to attach rabbits to your trailer as they tend to attract coyotes. Rabbets, on the other hand...

(though what you're talking about I think is called a dado, as rabbets are grooves made along the edge of a material)

Apologies for the interruption. Please continue. :sombrero:

 

[PINSTER]

Man... There are lots of coyotes where I'm going. Probably the best advice yet.

 

[PINSTER]

v7.4

Here is another revision to the frame, this version is a 2"x3" main frame with simplified 2"x2" triangulation. Also adjusted the placement of the kayak racks towards the aft to distribute the load a bit. Also, moved the axle placement forward, now its at a true 60/40 assuming the front angled box is included as part of the "body" and not the tongue.





and a skinned mock up


Not set on the fenders, just added these to see what it looked like. A step will help to get up and strap the yaks, so there'll definitely be something.

Im getting faster working in sketchup now that I'm used to using keyboard shortcuts, still have some things to learn for sure.

 

[PINSTER]

v7.4

 

[UB70]

Check this one out

Here is one set up to haul 2 AI's. Not mine, just thought it might give you some ideas.

http://texaskayakfisherman.com/forum/viewtopic.php?f=3&t=223734

I have been compiling ideas and sketches for a few months now for the exact same purpose.

Good luck and keep us posted.

 

[PINSTER]

Lol, thanks UB70.

"redeemed" is a friend, and yes, his trailer is very nice. That's actually what led me on this trailer adventure!

 

[UB70]

I figured with where you were and what you were doing you had probably seen it, but you never know. If it was not so specific for masts and other little things I would have just bought that one and been done with it. But what fun is there in that!