I built one but used 2x4's as the verticals  and made them one peice, dado in the bottom to fit over the T-track rather than use miter track.  Check out Tom C's link on the website, my version is a hybrid of both designs.  I have star knobs, not hex cap screws to tighten the verticals.

Not sure if I used his dimensions exactly, but also made mine so it would fit on top of my work bench and be able to be held by the bench dogs and vise dog securely.

It folds up nicely and stows between my bench and tablesaw when not in use.  

Someday I'll add folding legs underneath, but for now it goes on my bench or on a pair of saw horses when I need to use it.

I had that commercially available version with the plastic tracks.  Overall it works but if you are working alone and tipping sheets of 3/4" material onto it, you are putting a lot of torque on the extending arms.  The plastic ones ripped right through at all the screws.  Aluminum would obviously be stronger, but I predict that eventually they'd bend.  Its also rather bulky even folded down and was a storage problem in my shop--could never figure out a decent place to put it.  On mine I followed the manufacturer directions and made the table with banquet table legs which eventually bent and the table also sagged.  Adding support made the whole thing bulkier and heavier yet.  And I'm just a hobby woodworker who at that point had build cabinetry for a few bathrooms using the table by that point.  I daily use I don't expect it would hold up nearly as long.

Instead, I made a cutting grid from 3/4" plywood--2 96" long strips 3-3/4" wide and 3 48" long cross strips with notches so they slip together.  I just set it up on a set of sawhorses and when I'm not using it it stacks neatly and compactly on my lumber rack.  When it gets too cut up, I have enough strips to make 2 more from a single sheet of plywood.  No fasteners (though I do have pocket hole screws in some of the cross pieces to attach it to the horses if I want which helps keep it from sliding around) and no hardware to bend/break.

built one .do not use it very much but when i do it works very well .clamped up a door on it recently .allows room to put clamps underneath but also i could explore the underside for glue squeze out and also joint line -up . i found it made the job easier then my flat table . i used redwood .  because it is light weight and i had some from a deck i removed . plained the boards to 1 1/8" and oiled hopping glue run-out would remove easier.  I am having trouble post ing pictures but i will give another try .

I do something similar with the MFT and 8020. Basically I have several +/- 3' lengths of the 1515 (1.5") profile that I attached 2" strips of 1/2" MDF to. They can be attached/removed from the MFT with the t-bolt/knob assemblies in seconds. Then I can adjust the arms to whatever I need to support. I can securely support a full sheet of ply on the MFT.







My shop is quite small and one very useful aspect of this system is that the arms can pivot around to let me angle material to make it easier to access for a 4' cut. Shown are photos starting with 1/2 sheet I was cutting over the weekend:













The also come in handy for assembly:





That last photo shows the weekend project, quick and dirty drawers for shop cabinets, Sandy got my old ones so I am taking the opportunity to clean out the shop (amazing how much clutter 3' of water can clear out of a shop) and upgrade the layout.  This honker, with 2-pair of 100# full extension slides, now holds my hand tapper, 1-ton arbor press and bench vise, clearing the bench top until I need them.

The Festool clamps slide into the t-slots on top. These are, hands down, one of the most used fixtures in my little shop.

RMW

RMW very nice and compact . Please let us know where the "T bolt/knob assembly can be bought as well as a supplier for the 1515 rails.
Thanks
Ed Surowiec

Ed,

The t-bolts come from 80/20 (#3299) available on eBay as is the 1515 profile extrusion. 80/20 has their own eBay store, it started out with mostly overstock but they have been adding to it and seem to have nearly their entire catalog available there now.

The spacers are from www.aluminumspacers.com (.75" diameter, .75" long with 5/16" holes) and then add a 5/16" fender washer and any 5/16" knob.

Alternatively you can use a 5/16" carriage bolt but that has to slip in from the end, the nice thing about the t-bolts is they drop into the slot anywhere and turn to engage. Either one works fine.

I found a few old photos showing other uses. The maple clamping dohickies work great and only need about 1/4" of contact to provide a death-grip on the material. This came in handy when I was fairing the curve on some bubinga I had roughed out on the table saw. Almost no interference with planing or sanding. The RO90 did an awesome job on this, I love that little sander!









Spread out as shown 3 sections give plenty of support for 8' or longer stock.

Have fun!

RMW

Hi Ed,
RMW has some great ideas. (Thanks RMW).There is a good deal on the 8020 profile right now, ebay item 370737788674. I have ordered profiles and other parts to copy his design.
If you check ebay, you just might find some other of his creations.
Les

Thanks Les.

I did just recall one detail I had left out regarding the aluminum spacers. I made mine from 2 spacers (I did not have the .75" one I mentioned below on hand), I used a .75" OD .5" ID and slipped a .5" OD by .312" (5/16") spacer inside it. The problem was that the shoulder on the T-bolt hit the spacer slightly before it snugged down to the extrusion. I corrected this by grinding a 1/16" or so off the smaller spacer, you can see it in this photo:



If you already ordered the one-piece spacer you can either file/grind the whole thing down a touch or use a 3/8" or 7/16" drill bit and slightly counterbore one end of the 5/16" hole so the t-bolt shoulder has clearance to slip into it. You can also order the spacers as 2 pieces and get the smaller one in 5/8" length rather than 3/4".

Sorry I forgot to mention this earlier.

RMW

After some hassle I finally got all of the parts on order for RMW's extensions. Many thanks to RMW for his couching and recommendations. Also need to thank Alex at 8020 Inc. for his phone support. The ebay catalog for 8020 store is not user friendly and out of date.
Hopefully in a few weeks I'll have my extensions.
Ed

Do we have a part # list?  I'd like to copy this.

Thanks

Hi RMW,
   Noob question here.  How do you attach the MDF faces to the 8020 extrusions?  Thanks.

Brad

Hi RMW,
   Noob question here.  How do you attach the MDF faces to the 8020 extrusions?  Thanks.

Brad

5/16" flat head cap screws and t-nuts (parts list below), countersunk into the MDF to give me a flat surface. This way I can clamp something vertically to the side for assembly, planing etc.

RMW  

great idea rmw

Someone had a question about the spacer/t-bolt, so here is a photo of one broken down to clarify the parts. The smaller spacer is 1/8" shorter than the big one, which provides clearance for the t-bolt shoulder. Without the extra clearance the shoulder hits the spacer before the t-bolt is snug on the 80/20.



RMW

Just wondering if anyone ended up making these extension arms and what your feedback/experience is/was?

I ended up making a full cutting table from 8020 where the extension arms/rails/whatever can be screwed down in different configurations. Still tweaking it a bit but it is a handy addition to my MFT.



Anyway, just curious to see if anyone else ended up using these things.

RMW

Busy weekend in the shop & finishing one work area in my office/workshop. I had some old cabinets I built a long while back for the big shop before moving to the shore & the little shop. They got re-purposed into my office mainly because I did not have anywhere else for them. This area is dual purpose, during the day I have a place to spread out files (my work table/desk is nearby), while at night I can monkey around with my little gadgets or do leather work, tie flies, etc. The top does not need to be fancy but I wanted it to look okay, the cabinets probably need a fresh paint job. I finally got around to making the top for them this weekend and midway thru yesterday I thought it was going to be a disaster, in the end it turned out okay.

This relates somewhat to this thread because I used the the cutting extensions in a couple new ways for some awkward cuts. In this setup I needed to trim one leg of a mitered corner piece after I had glued up the miters:









These pieces were between 5-6' long so I used my 2700mm rail, the extensions also supported the end of the rail. I then had to cut them to length so I just flipped the material around and used the Woodpecker square to align the short rail:





Lastly, while the MFT is not a great platform for hand planing it works in a pinch, I have one oddball extension where I had tried gluing 1/2 by 1/2 maple strips to it before I settled on using the MDF, I use it for stuff where I need to clamp something to the side:



The net result worked out okay:









In case you didn't guess, the material is 5" Jatoba flooring I picked up on closeout. The cabinets sit 3" out from the wall so I have space to run wire/cable behind them, there are 2 sections that pop out for access.

Not bad for < $100 in material, pre-finished to boot!

RMW

Richard,
I have made up 4 42" ones and 2 34" ones but as yet have not used them.  I did get some of the bushing from the source posted (3/4 dia. x 5/8 long), they work great.  Hope to start doing some cutting on them soon.

Rusty