This inspiration for this project came from this instructable <https://www.instructables.com/id/Freestanding-Indoor-Rock-Climbing-Wall-For-150/> And if you don't need the lofted bed and are looking for a less expensive project check that one out, it's great!
This bouldering wall was designed to go into my dorm room at college and thus needed to maximise space and be able to be transported the three hours to school. The general design is comprised of three sections that make up the main frame. Each frame is a 4x8 shape which is the general size of the bed of most pickup trucks and (for me!) mini vans. The three sections are held together by two eight foot 2x10's and an eight foot 2x4" which also supports the bed. Plywood climbing sections are then bolted onto the frame and all are small enough to fit into the specified transportation. As far as the design goes, the bed is located behind the top section and storage can be added behind the angled climbing section. It was a super fun (if at times a little frustrating haha) build, and the climb is surprisingly challenging and robust for the 8x4x8' foot print of the structure.
Step 1: Materials
This project was not as inexpensive as I was originally hoping, but I think the end result was definitely worth it. I tried to use stock sizes as often as possible as I hate wasting materials as scraps. But with that in mind, bring a tape measurer when you go to buy the wood because a few of our boards came up a couple inches short or long and there is nothing more frustrating than figuring that out AFTER you've finished shopping. ** NOTE the picture is not all of the materials, many subsequent trips to the local hardware store were made
* 132 ft of 2x4" boards. (I recommend buying in 8ft lengths to minimize cutting, and if you do you'll need 19 boards.)
* 16 ft of 2x10" boards. (At 8ft lengths you'll need 2 boards.)
* 96 sqft of cabinet grade 3/4" thick plywood (This comes in 8x4 sheets, you'll need three)
I know I know, this is quite a chunk of plywood. But it makes for a very stable wall, I promise! Also I strongly strongly recommend not being stingy on the ply wood! The cabinet grade is much sturdier and is key for stabilizing this design. Also it looks nice and will keep a lot of splinters out of your hands and feet when climbing.
* large box of 2" wood screws (~150)
* medium box of 1.25" wood screw (~50)
* small box of 3" wood screws (~20)
*  right angle brackets for 2x4's
*  3/8"-16 x 5-1/2" carriage bolts (3/8in thickness, 5.5in length)
*  3/8" x 3" carriage bolts
*  3/8" washers
*  3/8" hex nuts
Be sure to check the picture of the right angle bracket. I hope I counted this all right haha... buy a little extra and don't be mad if I didn't!
* [~50] climbing holds with bolts and T nuts
I used the link from the other freestanding climbing wall's instructable. <http://rockymountainclimbinggear.com/id71.html> I also highly recommend these holds. The shipping was fast the holds are great and were the lowest price I could find. Also peep some other instructables on how to make your own if you've got the chutzpah for that too. If you have some that are better/cheaper/magical post a link in the comments for me!
In the end the holds I first went with proved to be some very difficult climbing for some of my less experienced friends (and myself!) so I went a ahead and got one of the megapacks by Metolius. I got the 50 hold pack and it's a great amount of holds for this wall and is by far the best value of the mega pack sizes (most jugs/macros and least footholds for your $). These holds made it fun for everyone to jump on the wall and climb which definitely made it worth the extra money, also the colors really helped to brighten up my room! Here's a link if you have a little extra cash and want to go that route! <http://www.metoliusclimbing.com/mega_packs.html>
In my shopping around I also found some other good companies, including a personal favorite The Detroit Rock Climbing Company. I have yet to get my hands on their holds but it looks like they have some really good quality stuff along with a variety pack similar to the metolius one above. I'll update this instructable once I can get some for my wall, but I'm from Detroit and love to support that city so if you like this instructable, go with DRCC! <http://www.thedrcc.com/catalog/>
The tools are pretty generic. A good drill with lots of extra batteries is a must. A circular saw is great, you'd fry your arms trying to hand saw all this stuff. A good t-square and straight edge are key and you will use them a ton! Socket wrench with a tall 3/8" socket. 3/8" drill bits and whatever you need to pilot them. A crowbar and hammer will be your best friend when you get some bolts jammed too.
Step 2: Connecting the 2x4's
If you can find untreated 4x4's get the correct amount of those and skip this step! My guess is that you'll have a tough time, its not a common piece of lumber. The goal here is to have thicker and more stable legs at each corner than just a 2x4. So lay one 2x4 ontop of the other and pilot some holes at either end and put the screws in once you're lined up. After that put out about 8 screws into one side of the board altering the edge to put them closest to as you move down the board. Flip it over, put your screws in at the ends and put 8 more in the opposite edges so your screw tips aren't running into each other. If you want to throw down a layer of liquid nails, do it! Just get these 2x4's put together straight and strong. You'll need 5 of these modified "4x4's", the measurement is NOT exactly 4x4 so keep that in mind as we go further.
Also in this step we're going to attach our right angle brackets to the our 5 "4x4's". The bottom corner of your top right angle bracket should be 24" from the top of the plank and the bottom corner of your bottom right angle bracket should be a half inch or so from the bottom of your plank just to avoid having the metal bottom scratch any floors. Screw these into the flat face of your plank using some 2 inch wood screws.
Step 3: Making the Side Frames
If you want the frames to sit perfectly flat in the bed of your car, you should use crossing planks that are 3.5 feet. If you want to maximize climbing space (recommended) and conserve wood just cut two of your 8 foot 2x4's in half and use the 4 foot lengths. Once you have them cut, slide the crossing planks into the right angle bracket, pilot some holes and screw them down with some 1.25" screws. You should have two nice looking rectangles when you're done (NOT 3! we'll do the middle frame next).
To put in the diagonal bar measure 1.5' from the bottom of the back plank. This is where the bottom of diagonal should be touching. The top of the diagonal should be flush into the corner of that crossing bar. You're going to want to attach the bars with some of your longer bolts. Counter sink some holes in the boards for a flush fit with the washers and a flush fit against the wall. Drilling at an angle through the 2x4's is tricky, just make sure you mark where you want the bolt to go in AND come out on the other side, line the two as close as you can with your first pilot hole and work it close to perfect with each successive pilot hole.
Keep all your edges clean and flat! If you're not precise somewhere go back and redo it, don't let it slide!
Step 4: Making the Middle Frame
For this step you'll need your last "4x4" and a couple more of your 2x4 planks. Cut two 2.5" lengths of 2x4 and attach them in the same manner you did the 8 foot sections. Put in your right angle bracket two feet down on that 2.5" length and attach it to your last "4x4" with a 4 foot cross beam. Attach another diagonal in the exact same way you did on the last step. This middle section should look exactly like your end pieces except without the bottom left corner section. It is critical that all your edges are flat and precise on this step!
Step 5: Assembling the Frame
Stand your two end frames and run your 8 foot 2x6 planks across the top. Screw them down in the at the back and front edges of the frame. Run a 2x4 down the middle and screw that down. Measure EXACTLY half way (4ft) down each of those planks that you just laid across the top. Line up the middle frame section so it is at that EXACT 4ft mark. This structure will feel very wobbly and you'll probably start to question this whole project... as long as you've been precise with your measuring and building this thing will end up being bomb proof. Keep up the confidence!
**Notes on the picture: The 2x4 in the bottom of the diagonals is not screwed in. I considered putting it there, but you do not need it in the long run. If you want to add a little more stability while you're putting on the plywood feel free... but it won't need to stay long term. Also in the picture I have all 2x4's across the top. I switched the end ones out for the 2x6's. You'll need the 2x6's to support a bed.
Step 6: Cutting the Plywood
Let me emphasize again now that you've seen how wobbly the frame can be; you NEED the cabinet grade plywood! If you tried to cut a cost corner there, I strongly suggest you go and return your stuff and get the good stuff. My plywood pieces came in 4x8' measurements which was great. All the pieces you need will be 4 feet long. The top pieces need to be two feet tall, the middle section six feet tall and the bottom section one and a half feet tall. You should be able to cut get the top and middle sections out of two plywood sections with one cut in each, great! The last one you'll have to cut two 1.5ft lengths out of the plywood and you'll have a little plywood left over, save it for something cool later.
Step 7: Plywood: Top Section
This is where the project starts to get pretty tough. Put a line directly in the middle of the top section of your middle frame. Your goal is to get the plywood to create a perfectly flush seam along this line. I did it by putting screw in the frame front where I wanted my ply wood to come down to. I got the seam flush then piloted everything and put the bolts in. It's not this easy and you'll have to mess with it for a bit to get it just right. Another tricky part is getting four bolts into the middle 2x4, make sure you measure well! Have friends help you hold the stuff in place, you'll need them for the rest of the project. Use the longer bolts and washer your stuff up. Good luck!
Step 8: Plywood: Bottom Section
Do the bottom section next, you'll need the practice for the middle section. These pieces require a small notch in the bottom corner to get over the bracket so measure it out and cut it. Again you're going to want a tight seam so measure your line on the center frame and line it up. You'll need to use your long bolts again and be sure to counter sink the back so the structure can sit flush against a wall. If your seams have been tight on the last section and on this one you should notice the project start to gain some serious stability, if not tighten those seams up!
Step 9: Plywood: Middle Section
The middle section is tough, but it's really rewarding to see it completed. You'll need some more notches in each of the top corners so measure out what you need and cut it. You'll need another straight middle line so draw it out. A key to keeping these held up is resting them on the lip of the bottom boards, it also creates a nice seam there so utilize it. Hold them up one at a time and match it up to your center line. Pilot and drill a hole in two corners while its being held up and feed a bolt through to get it held up in place. Now pilot the rest and pop some bolts in, you can use your shorter bolts for this section. Repeat with the other side. As long as you kept true to that center line you should have a real solid structure at this point, relax for a second and enjoy the beauty of it!
Step 10: Putting on the Handholds
This step requires a lot of drilling so get your batteries ready! Mark out the size of grids you want on your wall. I did ten across and four tall on the top section, ten across and six tall in the middle, and ten across and three tall on the bottom. Don't drill too close to any edge of your plywood, and pilot a lot to minimize splitting. Give your boards a good sanding if you had any splinter come up around the holes. Hammer your T- nuts into the back of the board (it's nice to have one for every hole so you can switch handholds easily), and bolt your hand holds to the front.
Step 11: Customization
Your wall is pretty much done from here! Enjoy the climbing! You should be left with a bit of scrap wood and there's some cool stuff you can do with it all. A small step ladder up to the bed is a nice feature, putting in shelving behind the angled section works well too. If you wanted to use the left over plywood and add more holds onto the corner that would be cool! The bolts on each end are also good for hanging a hammock. I had some left over hooks at my house and I put them into the frame to hold gear and what not. You could make some holds out of the scrap wood or other things and bolt it on. The wall is pretty much your oyster!
** Small disclaimer: Climbing and building are both inherently dangerous. I'm sharing my design with you but I can't guarantee it won't fail. Use common sense, if your seams aren't tight or you think you need some more stability then add it! Double and triple check all your bolts and screws. Have fun, but be smart!
Here are some links to articles about the wall!