CNC Plasma Table Build

I appreciate it. I jumped into a half built setup without knowing anything. I haven’t even tested the water table yet to check for leaks. I will get some pics and better detail later. I have completed install and adjustments to calibrate the motors but need to finish the hard limit switches (which I may just delete now). My real challenge was torch height control and touch off. I got lost in the various versions of g-code translations of different CAD files then decided to take a break for awhile. More to follow when I get back to it after Thanksgiving, thank you all.

 

Picked up a couple new tools to help with this project.



A metric drill and tap index



Metric counterbore set



Pair of 3 way clamps, just because I saw them and decided they may come in handy.

 

The Counterbore bits worked very well in my drill press.





This will be needed for several holes on the Z axis.





This 3d printed block is the same hole pattern as the carriages for the rails. I ended up drilling out one hole to create a tap guide, and it worked great. the Metric taps set is super sharp and it cut through the aluminum plate like it was butter



I started on the Z axis today, I was able to get both rails mounted and fairly true to each other. For basic tools I am pretty pleased with this.




I ended up needing to order some hardware, and I also pick up a few more sizes of transfer screws to help with this project as well. they along with the transfer punches have been very useful so far.

 

The Z axis is getting Closer..



I need to make the mounting bracket for the stepper motor, brackets for limit switches, drill the mounting holes for everything, and trim the bolts or order shorter ones. but the almost Z axis is moving pretty smoothly


The extrusions showed up, so it will be working on the gantry shortly and the base table.

 

Countersunk all the holes on the face of the Z axis and replaces all bolts with shorter ones.

Ordered a stepper motor mount with a built in BK12 bearing block.

 

Looks beefy!

As close as you can get before having something like that CNC milled.

 

Stepper motor mount arrived, bolted right up in place of the old bearing block. However, one little problem, I now need a longer coupler to connect the motor to the ball screw.

uxcell Shaft Coupling 10mm to 10mm Bore L35xD25 Flexible Coupler Joint for Servo Stepped Motor

https://www.amazon.com/gp/product/B07G6QHP26?ie=UTF8


An in case anyone is curious, this is the mount

$43 CNCTOPBAOS Nema23 Stepper Motor Steel Mounting Bracket and BK12 Bearing End,Integrated Motor Mounts Fixed Seat with End Support for 16mm Ballscrew SFU1605 SFU1610 SFU1604 SFU1616 SFU1620

https://www.amazon.com/dp/B09LV6FGCR?ref=ppx_yo2ov_dt_b_product_details&th=1

 

I started on the main base frame today, have most all of it tacked up.

Ignore the messy garage



The welding squares from @koditten where invaluable in getting this all tacked up





The front an rear bottom braces need to be cut yet,



I was curious what it would look like with the extrusion on the frame.

 

Looks good!

 

The Z axis is moving under the control of Mach4.

 

This table is going to take some room in the garage at 60x60.





Was curious to see how it will look. Looming forward to that first test cut

 

Spent a good portion of tbe day getting the main table base mostly done. Will need some grinding to blend in the welda on some of the joints.


Bit of vertical down



Been awhile since I did any overhead welding



But overall, the table seems to be within acceptable limits for squarness and level.



Typical front front/back rails to side rails.


And typical of the single rails

The base is pretty rigid an stable, and that will only improve once I add the water table supports.

 

Made up the brackets to mount the 3030 Extrusions that will become the Y axis to the main table base.







Still undecided if I want to weld these to the frame, or drill and tap them.

After confirming the layout was right and it fit, it was time to make 13 more.

 

I decided to weld the mounting tabs for the extrusion.



I also have the Y axis rails in place, they still need to be trued to the frame rails

 

Spent the weekend working on the X axis.





Since the holes in the bearing blocks for the ball screw, do not match up to the slots in the extrusion, i made some adaptor plates to go inbetween.



The mounting plate for the Z axis. This will have 6 M8 holes the Z axis will gwt counterbores so nothing interferes.

The longer rails where much harder to get aligned. I endes up using the mointing plate assemby as a guide, moving it back an forth an adjusting the rails as needed. I am goingnto repeat this once the Z axis mounted an the gantry bolted up in its final posistion. Hopefully this will account for the additonal stress from gravity an any deflection from the M8 hardware being torgued down

 

Made a bit of progress today.



The Carriage brackets for mount the X axis to the Y Axis, now that I know they fit and move smooth, I can put a radius on the sharp corners, Yes I thought of after the fact, and yes I caught the edge of it.

I also need to order 2 more corner bracket kits for the front side, At first I was not sure if they would interfere or not so I only ordered the ones for the back, But it appears they will not be in in the way after all.






The Z axis motor Needs to be rotated 180 Degrees, this will keep the wiring coming out to the right side.

 

Made some more progress, over the the weekend.

I got the X gantry square to the Y axis, Needed a bit of shimming on since it had a slight tilt forward.





ended using folded aluminum foil as the shim stack.





ball screws are mounted an I seemed to have done my measurements correctly when I did some quick and dirty calculations when I ordered the extrusions. there was not much room for error left in the final assembly.



Some 1/4 aluminum flat bar I had laying around from an old project, became the anchor point for A axis and the Z axis plate,



I used the same stepper motor and bearing block combo I used on the Z axis. this one however gave me a bit of hassle as you see later.

Some quick an dirty stepper motor cables for testing.



I took the short test cables I had made up previously cut them in half and extended them. I will be ordering more GX16 connectors to remake them properly.



This thing has some power, and will happily Tear itself apart. turns out there was some binding in that motor mount caused by the lock nut having TWO set screws instead of one like every other mount on the machine. and it caught and locked the One side up while the slave axis kept on trying to move the gantry, once it was racked way out of square, it tore it self apart.

Good thing is other then a bit of hassle in having to take the gantry back off, to get the screws and tnuts back into the upright, there was no serious damage. Nothing a ratchet strap could not take care off along to pull everything back into place.

I really should have wired up the Estops, would have been faster than the computer screen button. it might have prevent the problem...

One thing that I need to do is slide all the rails and balls screw back. this will gain me some cutting area. right now sitting at 50x46" , Hoping to get 50x48 at least.

 

Don't beat yourself up. You will have crashes. They suck, but we learn from them.

The steppers don't care. I've stalled mine lots of times.

 

Readjusted the rails and ball screws an got a bit more cutting area.

I will lose a bit on the torch and the floating head mount is attached.

I need to check an see if I am running out of travel on the rails or the ball screws. If its the last i can male longer mounts for the motor bracket, of its tbe rails kinda out of luck unless i go to a single.carriage. either way seems like a lot of work for limited gain, right now i will have a useable cutting area of 50"x46" rough guess on the 46"

Need to tune the motors an get the steps right an see how fast i drive the ball screws before they start whipping..

For now i am going to use an open table until i figure put the watertable issue. Limited ability to haul sheet metal big enough to make it at the moment.

 

Any way you can extend the cut area to something like 50" x 50"? This way you don't have to rezero and you have the extra space for when you need to edge start a cut.