Ikea style folding CNC table?

Duncan (rtfm) ran across a pretty neat 4x8 CNC machine with 3D printed tricky bits. The really cool part is it's all open source. Even if you buy the parts from the designer it's about a $500 machine.

We want to put one together for the EAA chapter but real estate is an issue. So I'm working on a way we can tuck it away when it's not being used.

Idea #1 is the cheapest and easiest and stows with the smallest foot print:



Idea #2 is more work and cost but it's cooler and it'd be a one man operation to fold it (not really an issue with people hanging around the hangar all the time). It also has a larger foot print.



There'd be a little bolt on fixture to lock down the Y axis carriage when it's folded.

Rack on the back to store extra plywood would be nice. ...but it's 36" wide ;/

 

That's a really fine looking table! I'd quite like one for my kitchen! Are you going to get the machine, set it up, cut the table, put it on the table?

 

A few more parts. Cut the legs off on the red lines and build another pivot along the blue. To reduce the footprint pivot the legs about 70 degrees, or just enough that the table can still be carefully pushed into it's storage on the castors.

 

Cut along the red lines, add a pivot on the blue. For storage pivot the legs about 70 degrees, or just enough that it can be carefully pushed into the storage location on the castors.

 

which comes first? the cnc machine or the table for the cnc machine that will cut out the table?

 

It all started here about 40 years ago...........

 

DIY CNC table kit

 

Do you have a wall you could hinge it off of? That would keep it locked in one part of the shop but also probably be the easiest way to get it out of the way.

 

Tiger Tim beat me to it... a wall mounted Murphy bed.

Another idea is to suspend it from above if your roof beams are strong enough, lowering it down using four cheap HF winches when it is needed. If you're building it out of wood instead of behemoth welded steel frames, then the weight will be manageable.

And in the finest cheapskate model airplane and homebuilder tradition... what's wrong with a couple or three salvaged or surplus hollow core doors for the table, instead of spending the chapter's money on new plywood?

 

Hinging it off a wall would work but the table is about 5' wide so reaching across to do all the stuff you need to do would be a challenge. ...but the hinge could leave a gap (2 feet?) big enough to get to the back side of the table.

Re: "chicken or the egg"
It's only a problem if you try real hard to make it a problem. You could run the machine on a sheet of ply and a couple of 2x4's set on sawhorses. You'd lose some cutting area until you got a proper table cut out but it'd work fine.

My machine (CNRP4896) not only cut out it's own table, it machined it's own 80/20 rails for the table bolts ...while the rails were installed.

EDIT: this table might look like a complicated mess but it would literally only take an afternoon to cut out and put together.

 

This router at 75 to 85 deg angle fix on the rollers, this is it what I need.

The drawback of the gantry weight, is acceptable for me as long as the footprint of the router is as small as possible when operating.

 

I smell already the Rangerparts!

 

He smells Ranger parts like Yogi Bear smells picnic baskets !

 

that machine does not look very robust.....maybe I am wrong but will it even cut 1/2 ply......now aircraft ply is thinner but bulkheads could be pretty thick....truss ribs only cutting is the gussets,....great machine but not sure how many aircraft parts it would cut. Thin aluminum sheet possible after you screw or glue down, but would it cut 1/8 alum?

Table is really beautiful....I see model kits in your future

 

I think there's a misconception here. Just about *any machine will cut just about any material that we use in homebuilt airplanes.

The question isn't weather or not a certain machine can cut a certain material, it's weather or not it's rigid enough to cut the material fast enough and accurately enough for what you want to do. ...you could cut a battleship in half with a Dremel tool but it'd take a while.

Just looking at the LR2 I'm sure it'll cut 1/8" aircraft ply in a single pass at a reasonable speed with reasonable accuracy. 3/4" ply would take several passes but it'll still be much faster and much more accurate than cutting it by hand, especially complex cuts.

Same for aluminum or steel. If it'll cut .020 aluminum, it'll cut 2" aluminum. You just have to set your depth of cut and your "feeds and speeds" for the job. And with something like 4130 you may only be able to take a few thousandths on a pass. It might take 30 minutes to cut out a strut fitting but that's still faster and more accurate than using a hacksaw, grinder and files.

*The Maslow is an exception. It could possibly work with a laser but as long as it has inertia and relies on cables to resist bending (torque) it won't work for detailed "tab and slot" airplane parts.

 

Wow. Turn my back, take the dog for a walk, and the forum goes off!

Love the table, Fritz. I've been thinking hard about how to build mine. Space, for me, isn't an issue. I already have a full sheet of MDF against one wall acting as a storage place for small bits/odds and ends/junk. I'd simply tidy it up, pack stuff away, and put my table there. But I love the idea of building a temporary table (as you say, on a piece of MDF placed on trestle tables), and cutting your table with it.

Will you post the DXF files? I think this is a REALLY great design, and certainly better than anything I've seen on the Lowrider site.

Again, congratulations are in order.

Duncan

 

A quick question: What material would you cut the bench from? 12mm MDF ok? Or is that overkill for the "ribs"?

And another: Would this table enable you to cut a full sheet of MDF/ply?

Duncan
PS I'm off to clear the shop, set up my trestle tables and get ready for the 1st job - that of cutting a decent table.

 

I think it would still be more accurate than a hand cut part even if it takes the same amount of time doing the multiple passes needed. The parts can also be made much more complex (tab and slot) with little time penalty in the cutting.

My CNC is really only good for cutting wood plastics and aluminium commercially, but I have cut some steel parts very slowly on the CNC and they are far better than I can make by hand. I now wish I had cut all the 4130 parts for the CriCri on the CNC.

 

The "ribs" and the bottom skin are 1/4" (6.35mm) ply, the top and the rails along the sides are 1/2" MDF. The tilt legs are 2x4's and 1/4" ply, the "cheap/easy" legs (top pictures) are 1/2" ply. If your ply isn't pretty close to that we'll have to change the tabs and slots to fit. Your welcome to the DXF files.

The table is ~5' wide to allow the Y carriage to roll back and forth and give the router room enough to cut all the way to the edge of a 4' sheet. In typical LR2 style the table is 8' long but the "wings" allow the carriage to cut all the way to the edge of an 8' sheet.

P.S. When you print the X mounts you might want to turn "support material" off. I printed one with it turned on the keep the bolt holes nice and round but I don't think it was necessary and it was a PITA to dig it out of the holes. I'll print another one without supports and see how the bolts fit.

 

I've only cut a few little test pieces out of 4130. I don't remember my feeds and speeds but my depth of cut was real shallow because I was worried about tool deflection on cheap ebay mills. ...I didn't want to experiment with good bits.

I chased the bit around with a little WD-40 to blow the chips out (not ideal but handy) and it worked fine.