Some legal stuff: I make no claim whatsoever to the safety of this loft bed, or its ability to support children of any age or weight. It's enough to hold me and my son for bedtime story time and that's good enough for me. If you have concerns about structural stability, I encourage you to consult with an engineer and/or add supporting members as you see fit. *whew* glad that's over with :)
Step 1: Parts List
(4) sheets 3/4" plywood - finish grade
(4) 4"x4"x8' fir posts
(3) 2"x4"x8" fir
(1) quart of shellac or other non-toxic finish - optional
(2) boxes of #8 x 1.5" screws
(1) box of #8 x3" screws
(1) 1/4" x 4" standard hex bolt with 2 nuts and 5 washers
light colored wood filler putty
composite nails (available at techshop)
180 & 120 grit sanding pads
1/4" end mill router bit (for CNC router)
1/8" end mill router bit (for CNC router)
3/8" roundover router bit (for hand router)
3/4" bullnose router bit (for hand router) - optional
screw driver bit and 1/4" drill bit (for drill)
Tools (all available at Techshop):
hand-held power sander (recommend black&decker mouse)
CNC router table (recommend Shopbot PRC Alpha)
battery powered drill / screw gun
plug-in drill / screw gun - optional
two adustable crescent wrenches
Step 2: CNC Cut the Plywood Pieces
Use the brad nailer to secure your wood to the CNC's cut bed. The plastic nails (available from the front desk at Techshop) won't hurt your end mills . It's pretty important to put one brad in each corner plus a few in the field. Some of our pieces take up most of a sheet and it's tragic when your sheet stays on the machine but your piece flies off and on to the floor. Plastic nails sand down flush with the surface and become almost invisible in the finished material.
Cut the holes with the 1/8" bit and cut the rest with the 1/4" bit. The CNC mills at Techshop don't have tool changers so you'll have to do it manually (ugh). This means, for each sheet, running 1 job with the 'holes', then changing the bit, re-zeroing the Z axis, and then running another job with all the other toolpaths. It will probably take you at least (2) 4-hour sessions on the ShopBot.
ALTERNATIVELY - and I didn't do this but it would have been smarter - you could run the 'holes' layer first with the 1/8" bit , and then run the whole job again (including the 'holes' layer) with the 1/4" bit. HOWEVER on the second run, set the cut depth to only 1/4" for the holes. That gives you nice countersunk holes with no icky error-prone manual drilling. I'd do it that way if I had it to do over again.
Step 3: Route the Edges
I used a 3/8" round-over bit to give a nice radius to all the edges that little hands and feet would be touching. This means (yes) running the router over everything on one side, flipping the piece over, and (yes) doing it again. One thing I did not try, that I've found out about only recently is a 3/4" bullnose router bit . I probably would have at least tried that one if I had know about it. HOWEVER I would still need the roundover bit for the side edges of the top and bottom front pieces (where the panels meet in the corners). those only get routed on one side; Make sure you keep track of which side is which! It's also important to remember that the side panels don't get any routing at all on their sides. Also the top and bottom pieces don't get any routing where they meet in that long horizontal seam.
IMPORTANT: If you clamp your pieces down to the work table, don't forget to put a little spacer underneath. I used some 1/4" thick masonite that was in the scrap bin. This is both to protect your wood from the scarred and bumpy work table, and also to make clearance for the little ball-bearing on the bottom of the router bit - Another reason to take the class and use the table router.
Step 4: Sand, Sand, Sand
Mid-way through I took everything home (Techshop is great but it's tough to leave work there overnight) and bought a black&decker 'mouse' sander to finish the job. This little sander was genius at getting into all the tight places (ladder rungs etc...) I highly recommend.
Step 5: First Assembly
Attach the posts to the bottom side panels (the ones that look like they have headlights and tail-lights). Make the edge of the plywood flush with the face of the 4x4. Screw them together with the 3" #8 screws. You might need a plug-in drill; My batteries ran out 3 times while doing it. Add the top side panels too, making the gap between top and bottom as tight as possible.
Once the side panels and 4x4s are together, stand one of them up (they should stand on their own) and stand up the front-panel next to it. Screw them together at right angles. The rounded edge of the front panel should be flush with the side panel's face. Do the same with the front top panel. Check that the ladder on the bottom front lines up with the opening in the top front.
Once all the plywood panels are attached to the 4x4s, it's time to add the 2x4s. Measure and cut the 2x4s to length so that they fit between the 4x4s. Screw through the plywood panels from the front, holding the 2x4s in place from behind. Use the 1-1/2" #8 screws. It might be nice to have 2 people here to make sure the 2x4s are level. Start at one side and work your way around, checking level across at the corners. The 2x4s should be centered on the gap between top and bottom plywood panels. The rear 2x4 doesn't have a plywood panel to screw into so just toe-screw it into the 4x4s on either side using 3" screws.
Once all the 2x4s are in, place the bed panel on top. It should fit just right with the corner notches fitting around the 4x4s. Screw down from the top, through the pre-drilled holes using 1-1/2" screws.
Step 6: Finishing
Give exposed sides and edges of all the 2x4s and 4x4s a quick sand too. They are liable to have some imperfections and we can't have any splinters!
For a sealant, I used Shellac, famous for being non-toxic and natural (its actually excreted by bugs - really!) but was disappointed in how long it took for odor to dissipate. It's been almost 2 months now and it still smells faintly! It could be the brand or the expiration date (shellac has a shelf life of only 6 months). Aside from odor, the shellac worked very well - dried quickly with a very faint yellowish color, almost totally clear.
Step 7: Steering Wheel(s)
Step 8: Move In!
First, take the screws out of the bed panel and out of the 2x4 that spans across the back. If you didn't putty the screw holes in the front (except the horizontals), you can take out those screws easily too. Your firetruck should easily break down into four pieces (front, sides, bed) for moving. Put it all back together and throw a mattress on top, you're ready to go!