torsion boxes

[chippy1970]

Im looking to build a portable work bench and thinking of going down the torsion box method. It will be made up of two 500 x 2000 boxes that will connect together to form a big flat top that will just sit on top of my existing fold up metal saw horses. The top will have a grid of holes just like the Festool MFT's. I need to know what depth I need to make the torsion boxes, I will probably make it out of 12mm ply.

This is what got me thinking about it http://www.youtube.com/watch?v=sJoGTf6KL8s but I dont want the top as deep as that as it will be too high on top of my horses.

So if there are calcs or anyone out there whos built torsion boxes please let me know.

Chris

 

[Jacob]

You could just buy a couple of doors and add a 1/2" ply top.
Can't say I've ever needed a portable bench as most site work gets done OK on 2 or 3 sawhorses plus a few G clamps and wedged door props. What about having a say 3" x 9" joist sitting on saw stools as a temp bench, japanese style?
Watched the Ron Pork video I think he's mad! Funny name funny geezer.

PS you don't need any calcs for a so-called torque box - just fix a few spars in between your boards, 2x1" or bigger.

 

[chippy1970]

Yeah I know what you mean Jacob Ive done the same thing for the last 20 odd years but thought it would be nice to get more organized and have a purpose made platform for use with my rail saw etc. The door idea wouldnt work as I need to be able to insert clamps through the hole grid to clamp things down as you do on an MFT.

 

[alex8_en]

Hi Chris, the woodwhisperer has recently done a torsion box build for his assembly table, so you can have a look at that also there is a few torsion box mft builds on talkfestool and festool owners group sites. Only thing I can say about depth is that you have enough space to use a clamp... Hope this helps and hopefully this will be a start of a good WIP

 

[sometimewoodworker]

Im looking to build a portable work bench and thinking of going down the torsion box method. It will be made up of two 500 x 2000 boxes that will connect together to form a big flat top that will just sit on top of my existing fold up metal saw horses. The top will have a grid of holes just like the Festool MFT's. I need to know what depth I need to make the torsion boxes, I will probably make it out of 12mm ply.

This is what got me thinking about it http://www.youtube.com/watch?v=sJoGTf6KL8s but I dont want the top as deep as that as it will be too high on top of my horses.

So if there are calcs or anyone out there whos built torsion boxes please let me know.

Chris

I think you mean something like this http://meekings.selfip.com/nui/Groups-of-photos/Wood_work_etc/Pages/Workbench.html if so then AFAICR my torsion boxes used either 60mm or 70mm strips. Here are a couple of other pics.
http://www.flickr.com/photos/nui-jerome/3932470377/
http://www.flickr.com/photos/nui-jerome/4173303896/

You want as few dividers as you can because they restrict the direction of your clamps.

For the top and bottom 12 mm wil be too thin.

My workbench wasn't built to be portable so I used 20mm MDF and 20mm chipboard for the top and bottom. And something like 50mm x 100mm for the sides. It is a work in progress and probably will be for some time to come.

 

[Lord Kitchener]

I dont want the top as deep as that as it will be too high on top of my horses.

There's something I'm not getting about that. If you are prepared to go to the trouble of making the bench, wouldn't it be comparatively simple to make a couple of horses to suit, so that the whole thing comes out the right height?

The deeper the top, the less thick the material will need to be to get the same stiffness.

 

[Allylearm]

You could just buy a couple of doors and add a 1/2" ply top.
Can't say I've ever needed a portable bench as most site work gets done OK on 2 or 3 sawhorses plus a few G clamps and wedged door props. What about having a say 3" x 9" joist sitting on saw stools as a temp bench, japanese style?
Watched the Ron Pork video I think he's mad! Funny name funny geezer.

PS you don't need any calcs for a so-called torque box - just fix a few spars in between your boards, 2x1" or bigger.

I also see it as a luxury having used trestles or saw horses with battens, I also was shown to use a bench made from three pieces of batten and propped of your window cill as the other leg support so making a tripod so to speak two pieces making your other leg and floor piece for fixing and top batten as bench top (with stops added). I used this when refurbish Sash and Cased and supplied planing stops for doing the staff beads etc and was moved from room to room as required.

I also do not know about other Joiners on site but I always could never get space where I needed it to setup something as big as this, due to storage for your materials in the rooms, plus if you setup in one room it would not be where you were wanting close to the job so to speak and other trades wanting it moved for access. I could see this as a bench for the workshop and seems looking at it a good sturdy method with practicality for tool storage, I have used a setup like this as a leveled platform (without tool storage) to clamp up finished cabinets and is just up from the floor and is guided by battens and sheet covering the height it is and can be 8x4 or 10x5 or extra if required, this allows for a better working height and the cabinet or work to be kept flat and level when constructing before going on site.

But if you wish to go to the expense or can justify the cost and have the space in your van (I never have), why not a good project.

 

[woodpig]

Looks like a good bench for American house builders but looks awful big to me. Scaled down it could be useful but then you'd lose the ability to handle full size sheets.

 

[chippy1970]

Looks like a few of you guys are getting the wrong end of the stick

I don't want to build a huge bench like in the video I was just saying that it had given me the idea to build a platform to go on my existing saw horses very simple and cheap. The reason for not building horses to suit is that I already have 4 metal fold up saw horses in my van don't need or want any more. As I said in my original post the platform will be 2 x 500 x 2000 sections so wont take up a lot of room in my panel van. I don't know how many of you guys use rail saws regularly but if you do i'm sure you can understand that they are easier and safer to work with on a nice flat sturdy platform/bench.

Alex yeah I had thought about the clamp clearance I will have to drill a 20mm hole in some ply and test it to see how much clearance you need. Oh and yeah i've seen the woodwhisperer video before cheers.

Jerome you're the man you see where i'm coming from.

Then while typing this I suddenly remembered this which is another great idea for a portable cutting table. sore-hoarses-mkii-now-with-added-plans-t44761.html

 

[Lord Kitchener]

The reason for not building horses to suit is that I already have 4 metal fold up saw horses in my van don't need or want any more.

In that case, simply modify the design so that the surface of the torsion box overhangs the bottom at each end by enough to hook onto your metal saw horses.

 

[chippy1970]

The reason for not building horses to suit is that I already have 4 metal fold up saw horses in my van don't need or want any more.

In that case, simply modify the design so that the surface of the torsion box overhangs the bottom at each end by enough to hook onto your metal saw horses.

Thats exactly what I thought I would do , if it comes to it. Just gotta wait until I get spare time to make them now.