DIY CNC table (paging HOOD)

[Hood]

With Alu you should get very little dross except where is passes over a bar but the cut edge is always a kind of rough edge, 2 seconds running the flap disc over it cleans it fine for welding but it is not smooth like steel is when direct off the table.

 

[Hood]

You’d like the results off the ESAB SGX tables running mixed gas. Super clean aluminium cuts.

Aye, maybe, wouldn't like the price or running costs though

Don't get me wrong, the cuts are nice just a kind of furry edge to them but they clean up quickly with just a single pass of the flap disc.
Think I may have a vid I took to show someone, will see if I can find it.

 

[thinfourth]

Just a table from xtreme wouldn’t be too much. Looking at threads on here by the time you factor in all the research, time gathering the consumables and then building it you’re not gonna be far off a machine ready built.

saying that you probably get a higher spec table for the time and money spent.

Yes

BUT

What i am making is mostly a rather robust cutting table which is going to have a somewhat shonky CNC plasma bolted to it

This lets me learn what i do or don't want from a CNC and even if it is of any use

Also i already have a plasma cutter which if will press into CNC service with 3D printed bits and duct tape so thats another saving

there is another advantage of if i have made it then when it goes wrong i can fix it

and finally

Its a project to keep me vaguely sane and my labour costs are sod all as i've already been given the boot from work due to the oil price

So mornings will be job hunting and being a house husband

Afternoons will be making blue smoke come out of cheap chinesium CNC parts

 

[thinfourth]

Welcome any time.

The one I have at the moment is not the best as it had been designed for a limited space workshop so it was to tilt out of the way when not in use. As I just started to progress with the build I got gifted a shipping container so that was now the home for the plasma but I had to continue with the original design (minus the swivel) due to it being already started and also I didn't have time to alter as the table was needed for a few jobs I had lined up.

Electronically/electrically it is good, no changes needed there, so that part will remain the same on the table I am currently constructing.

that is most appreciated

Once grand leader lets us out of our allocated boxes i shall come down bearing the gift of some free range eggs

 

[Hood]

that is most appreciated

Once grand leader lets us out of our allocated boxes i shall come down bearing the gift of some free range eggs

Please do but please leave the eggs
I get as much as I can handle already

 

[Hood]

The ones I get the eggs from even do a bit of welding

 

[julianf]

I would also be tempted to see if I could look at making it suited to adding a router for cutting wood or engraving metal etc. Not sure if its desirable to make a multi purpose machine but I always fancied something that could be used for more than just plasma cutting.
Would be handy to have some sort of feedback recorder on the electronics to trace items placed on the bed, like a 2d version of a cmm machine

It's kind of not worth trying to make a jack of all trades. The "spindle" mass of a plasma torch is nothing, and you have no resistance, so the gantry can be built accordingly.

Stick a big motor on there and start pushing it through material and you need a heavier gantry. Which then has more mass, more inertia, slower tracking moves, etc.

I mean it all seems possible, but physics gets in the way, and you end up with a master of none.

 

[Hood]

It's kind of not worth trying to make a jack of all trades. The "spindle" mass of a plasma torch is nothing, and you have no resistance, so the gantry can be built accordingly.

Stick a big motor on there and start pushing it through material and you need a heavier gantry. Which then has more mass, more inertia, slower tracking moves, etc.

I mean it all seems possible, but physics gets in the way, and you end up with a master of none.

Servos can help in that respect but they are not the route most take due to the price.

 

[mtt.tr]

The ones I get the eggs from even do a bit of welding

View attachment 228320

ND peck test, used all the time in industry

 

[thinfourth]

The ones I get the eggs from even do a bit of welding

View attachment 228320

ah you have feathery helpers also

I have had to help a chicken pass a lump of o-ring rubber it had mistaken for a large long black worm

or

in other words

Spoiler

i've pulled a piece o-ring out of a chickens ****

 

[hotponyshoes]

My idea (if I ever get around it...)
Would be to have one heavy duty long axis, a foot longer than I needed to provide a 'parking' space at one end. 2 short axis gantrays, one light weight and a heavy one. Either engage/disengage the drives as needed or maybe even mount the heavy side drive into the axis.
It would also be nice to mount a 3d printer head (or several combined) to print really big stuff (or at least print colour infill into engraved alloy parts etc.
I would also like a pecking drill (or even just a center punch) that could put accurate holes in full size sheets of alloy.
I dont have the computer skills for this though!

If somebody was any good with computer programming would it not be simple enough for them to create something that checked the planned cut path against the layout of the supports on the table and flash up a warning if a cut was running along a bar? Maybe combined with a laser pointer or something for sheet positioning?

Some other software I would like is something that records the cuts you make on a sheet and remembers what's left of that sheet and could nest further parts into the remainder of it at a later date. I presume the commercial operators must have something like this already?

If making your own table you could have an area in a corner or something with a much smaller gap between the bars (or a 1mm lower section that you could drop a sacrificial sheet/bit of weld mesh in) for cutting small parts over.

 

[Hood]

Anything is possible if you are good with software but afraid I am not, I muddle through with macros but that is my limit.

 

[Hood]

Something I would of liked for ours is either plasma marking with Argon or Pneumatic engraving.

the next machine up had the engraving feature as an extra and the pro machine could do marking.

Just a diamond stone dresser on a spring loaded arm deployed with an air cylinder would likely do for marking. Maybe even just using the plasma cutter at a fast rate of knots and low power would do, never tried though.

 

[Fraserb]

That was the downside I was thinking of.
What spacing do you have on the bars?

The upside is there are only small contact points for the arc to cut through so the majority of the time they will be missed. When cutting Aluminium, assuming you have everything correct, then the only time you get slag is when the arc crosses or runs along a bar.

Pretty wide spacing which can be an issue cutting small parts, did see someone had made a frame with fine mesh to slide under when cutting small stuff.

 

[Hood]

Pretty wide spacing which can be an issue cutting small parts, did see someone had made a frame with fine mesh to slide under when cutting small stuff.

Is yours one that has the square pattern slats? I have seen them, maybe Xtreme tables, and they seem to have a large space between the squares.

 

[Fraserb]

Is yours one that has the square pattern slats? I have seen them, maybe Xtreme tables, and they seem to have a large space between the squares.

Yeah mine is an xtreme table.

 

[Bladevane]

Mine’s an Xtreme with the pointy slats and they are easy to repair. I cut 1.5 mm replacement tips, made a jig and tack welded the inserts into place. Quick, cheap, effective and saves chucking out the slat, which is mostly untouched.