For those of you that have built Torsion Boxes. Best materials for the skin and ribs? Is baltic birch required? did you dado the ribs? ACX for the ribs good enough? ACX for the ribs and the bottom Baltic Birch for the top? Opinions, Advice from those that have made them… mistakes you made… any help appreciated… I would like to have it built by the end of the weekend.
I built mine out of sanded 1/2” plywood. But if I did it again, I’d probably use MDF. I think 1/2” material ends up being plenty strong (for both skin and ribs), and I think MDF would be a little more consistent than the sanded plywood I used.
I watched as many YouTube video’s as I could find, and I think the best advice was to set your saw once and cut all the ribs at the same time. Much more consistent results this way. I did end up using dado’s for mine - worked out pretty well and I cut the dado’s just slightly deeper than needed (better a little deeper than too shallow). For glue-up - work quickly or have a helper. A lot of surface area to cover (my torsion box is 48”x48” and has 36 separate chambers if I remember correctly).
One last thing I did. I cut 1” holes in the middle of the front, back, left, right chambers - all the way through. This way, if I wanted to route cords through the table for better cable management, its a piece of cake to just fish them through.
Hope this helps…
1 Like
Thank you. I am thinking of using 1/2 " Baltic Birch throughout. I think I may notch instead of dado, that way I have continuous pieces in both directions. My 1F is already set up, I could use a 1/8 bit and cut everything on it, the T-Box is for cabinet construction.
What is your overall thickness?
Just use 1/2" MDF for the whole thing. It’s super flat and once everything is glued up will be immensely stiff. Once it’s built you can screw a piece of plywood on top, or with a little bit of planning you can glue 2x4 or 2x6 blocks inside at strategy locations underneath where the feet will be attached.
2 Likes
My ribs are 3”, so torsion box is 4” thick with skins on it. Plenty strong enough - zero flex, but still pretty light overall.
Yep, 4" is what I was thinking… what spacing on the ribs? glued? dados? slotted?
1 Like
I built mine entirely from 1/2" mdf. 4’x8’ and it’s a beast!
We may be using dado’s and slots interchangeably. Basically I used a dado blade on my table saw to cut slots through all ribs at the same time (clamped together). When I glued them all together, it was in essence a honeycomb that fit inside the lower skin and sides. I glue the ribs in and tacked it with pin nails - then glued and tacked the top on. I used every weight from my weight rack to make sure the top was as flat as possible while the glue cured. If I remember correctly, I think my spacing was about 8” on center, 36 chambers total. Something like that…
1 Like
Mine is 1 inch MDF top and Bottom. Weighs a ton and impossible to move without help.
If i made another i might do MDf top, plywood bottom.
Mine is 1/2" Birch, roughly 12" between ribs, total of 4" thick, and is VERY strong and DEAD FLAT! I use it on a tilt stand for almost a year and a half now and it works perfectly. I posted pictures if you want to see it in completed form. I might have a single picture of it before I glued the top on
1 Like
no, I know the difference between a dado and a slot, you used slots, which is the direction I am leaning. Slot at regular intervals, flip half assemble into a web… I might dado the web into the rim. since I’ll have the stack on the saw anyway
1 Like
My first CNC table was a torsion box assembly table I built many years ago that had 1/2" plywood skin with 24" rib spacing. With the CNC on it the 24" spacing caused the whole thing to resonate like an acoustic guitar body and amplified the noise of the machine. To avoid this I on my second table I went to 12" spacing and the problem went away.
1 Like
I was thinking of 8" spacing with 3" ribs. slotted so all ribs are full length. 1/2 skin top and bottom with a 1/4" melamine spoil surface on the very top. This is going to be an assembly table, I have the qcw and folding stand for my journeyman.
2 Likes
Gotcha. Pretty straight forward. Be happy to help if you have any more questions. Good luck with your build…
I’ll reach out if I do. Thanks for the help.
2 Likes
So, I found an old piece of 13 ply 3/4" birch in my trailer. It was a jobsite work table, then the floor for my sim-pit. Now it’s my new torsion box web. I remember getting this piece on sale at HD for $ 40 ! same piece is now $ 200 plus lol!
Anyway, the web is made. I have a 3/4" piece of cherry veneer core I could use for the bottom, but I’m holding off, I have to pick up some other sheet material tomorrow and I may as well get some 1/2" Baltic birch for the top and bottom. All joints are glued and toe-nailed with 18 gauge 2" pins. . . This web is rigid!
1 Like
I was going to suggest 3/4" BB over MDF. MDF is heavy and it splits easily compared to plywood and especially BB.
Looking good so far!
-Tom
1 Like
What a beast! No sagging worries on that thing - you could park your car on it! Looks great…