MFT Plywood Panel Cutting Jig (aka more fun with 80/20)

[rmwarren]

I have been fiddling with different setups to come up with a way to easily and simply cut full sheets of plywood on an MFT. Yesterday I tested a setup on some ¼” ply panels.

The setup uses 80/20 extrusions and the guide rail clips developed for the Rip Dogs experiment.  ½” pins mounted to the extrusion are used instead of the Rip Dogs to align the guide rail. The extrusions mount to the MFT from underneath with carriage bolts, spacers and knobs. The pins are attached to 2 short arms at 90 degrees to the main extrusion and the saw blade runs in the t-slot channel. There are a bunch of extrusions that can be moved or swiveled to support both sides to the panels being cut. It all breaks down in a few minutes; the longest piece is 52”. Here is the setup for ripping 8’ material:

[attachthumb=#]

[attachthumb=#]

[attachthumb=#]

[attachthumb=#]

[attachthumb=#]

The basic setup uses a two-piece extrusion for ripping 96” and 1-piece for 48”, although I can cross-cut 48” using the 96” setup. By removing one half of the 2-piece main rail I can still cut 48” material. Cutting stock less than the rail width is easy and I can also set stops for repetitive cuts:

[attachthumb=#]

[attachthumb=#]

[attachthumb=#]

[attachthumb=#]

[attachthumb=#]

[attachthumb=#]

In this last configuration I plan add ruler scales to the support extrusions for the stops, then butt them to the main extrusion to get a repeatable setup that will even work with narrow stock.

Overall it worked great with the ¼” ply, although I think the weight of the ply overhanging the MFT may be an issue if it were ½” or ¾”. Needs more testing, might need support legs for thicker ply.

RMW

 

[Alan m]

there is a lot of potential in that system.
i am not sure about it on 1 mft. it would work a lot better on two or even on its own bench.

 

[Stone Message]

Hi RMW

Why not make life easy and not try to use the MFT 3 but build yourself a simple pair of folding trestles that allow you to handle 8x4 sheets and still have the MFT 3 free for other tasks?

Just and idea.

Peter

 

[RONWEN]

Nice.

What's cook'in on the Big Green Egg today?  [wink]

 

[Stone Message]

The trestles are made from beech but anything stable will do. They each have a channel in which you can see a sacrificial piece of wood. When cutting down the length of an 8x4 that is all you need. If you want to cut across the width of a sheet then I put the sacrificial cross members on the top (as in the photo). I also use them, often with some MDF on top, as an additional working platform.

Peter

 

[rmwarren]

Nice.

What's cook'in on the Big Green Egg today?   [wink]

Chinese take-out...  [big grin]

Building up the gumption to smoke a couple briskets soon though.

RMW

 

[rmwarren]

Hi RMW

Why not make life easy and not try to use the MFT 3 but build yourself a simple pair of folding trestles that allow you to handle 8x4 sheets and still have the MFT 3 free for other tasks?

Just and idea.

Peter

Peter,

Mostly I am just playing with ideas in this case, I often use the 2 big saw horses you can see in the background for plywood cutting but that day I needed them to hold other stuff and pressed the MFT into service.

What I am aiming for is a self supporting frame that will replace the MFT for cutting plywood, until I get the kinks ironed out bolting the pieces to the MFT lets me experiment. Ultimately I want a configuration that breaks down for storage, assembles in a few minutes and that will handle full sheets of plywood. Once that is ironed out it will probably just sit on the sawhorses when in use.

I will say that it is very flexible to be able to swivel those supports around depending on which way I was cutting. If I can ultimately come up with a one-size-fits-all design I would also like to be able to use pieces of it on the MFT if for less than full sheets (as in the second series of photos), so flexibility is key.

Thanks for the input.

RMW

 

[Stone Message]

I have never seen one in the flesh (as it were) but take a look at the Walko Workbench. The video that I saw seems to go a long way to fitting your requirement.

Peter

 

[ScotF]

I have never seen one in the flesh (as it were) but take a look at the Walko Workbench. The video that I saw seems to go a long way to fitting your requirement.

Peter

It's just too bad that they are no longer available over on our side of the pond...they were for a short while at a couple of places, but I think that the price was high and not a great seller.

Scot

 

[rmwarren]

I have never seen one in the flesh (as it were) but take a look at the Walko Workbench. The video that I saw seems to go a long way to fitting your requirement.

Peter

It's just too bad that they are no longer available over on our side of the pond...they were for a short while at a couple of places, but I think that the price was high and not a great seller.

Scot

I am very interested in a Walko 4. They are available on eBay, shipped from a UK dealer who is a member of this board, for just under $1,000 including shipping for the 4.

I looked into the costs of importing them in quantity and when freight, tariffs and other import costs are factored in they are not much cheaper.

I may end up buying one on eBay when/if the urge overcomes me, in the meantime I will keep fiddling with the 80/20.

RMW

RMW

 

[Stone Message]

Hi RMW

If your dealer is Intelligent Workshop then you will find him to be very good. He and I are coresponding over my design of a new type of bench dog for both the MFT and Walko.

I hope you have success.

Peter

 

[Alan m]

Hi RMW

If your dealer is Intelligent Workshop then you will find him to be very good. He and I are coresponding over my design of a new type of bench dog for both the MFT and Walko.

I hope you have success.

Peter

come on peter stop teasing us.

rmw. buy the walko . it is a great piece of kit. one of the best purchases ever made

 

[Stone Message]

Alan

As dear Father Reilley always told me '...patience my son, patience'.

Peter

 

[rustym]

RMW,
What fastener are you using to connect the pin holding piece of 8020 to the long beam of 8020?

Rusty

 

[sancho57]

For a cutting bench breaking down sheet goods , have you looked at these?

http://www.benchmarktable.com/

Since I have a small shop Im looking for ways of doing things that I can use, fold up and put away.

Kreg McMahon did a Utube video using this bench to cut up a 4x8 sheet of ply.

Looking at the height Im sure I could adj this to the height on my MFT and cut and slide to the MFT for cross cutting.

I must say it did seem pretty slick.

 

[rmwarren]

RMW,
What fastener are you using to connect the pin holding piece of 8020 to the long beam of 8020?

Rusty

The pin is a 1.5" by 1/2" aluminum spacer with 5/16" thru hole, I ran a 8mm machine screw thru it into a t-nut. You can get the spacers at: http://aluminumspacers.com/, look for #AS50-16-96.

Cleaned up the overall setup this weekend to convert it to a frame that rests on any flat surface, the MFT, sawhorses, etc. What I am ultimately aiming for is a simple, knock-down frame that supports the plywood AND has built-in scales for setting repeatable cuts. Basically it will do the job of the parallel guides.

RMW

 

[rustym]

Sorry, guess I didn't make myself clear, I meant the 2 pieces of 8020 that are at a 90 deg to each other (the one that has the pin and the long one), how did you fasten them together?

Thanks
Rusty

 

[rmwarren]

Sorry, guess I didn't make myself clear, I meant the 2 pieces of 8020 that are at a 90 deg to each other (the one that has the pin and the long one), how did you fasten them together?

Thanks
Rusty

Sorry Rusty, I misunderstood. I use this fastener, you need to drill an access hole thru the long extrusion for the Allen wrench to tighten it.

[attachthumb=#]

PS - package arrived today, thank you.

RMW

 

[Julian Tracy]

I've had and used the Smart Table plastic extrusions for close to 5-6 years and it's got to be the easiest, lightest and best system for sheet goods.

http://www.thesmallbusinesscoach.com/ezguide/eztable1.htm

Just did a large cabinetry project and used at least 15-18 sheets of 3/4 Melamine board.

Using the Smart table components mounted to a single pc of 2'x3' 3/4 Baltic Birch plywood.  Set that on a pair of plastic sawhorses and can cut down fully supported full 4x8 sheets.  As you cut and your sheet gets smaller, they can be folded in to make the surface as small as the 2x3' board they're mounted to.

I've got 1x3 pine sacrificial boards in the Smart table extrusions, have just flipped them over after 5 years of using the original sides.

Lightweight, cheap, fully supported, fold up, no aligning for blade protection and simple.

I've got a bunch of 80/20 stock from a CL purchase, but wouldn't care to use it for a cutting table - too much added weight as well as a lot of time & work attaching it to the MFT to install and remove.  Darn MFT is too heavy as it is for lugging to jobsites, though the MFT3 is better than the older 1080 was...

JT

 

[rustym]

Thanks for clearing that up.  That is exactly what I was looking for. 
Glad you got the package, hope it was in good shape.
Also did you get the email about the pics?

Rusty