CNC Plasma Table Build

found some 12g mild steel I had,

tool settings I used
.052 Kerf
.015 pierce height
.07 pierce delay
91 ipm
40 amps






I noticed I am getting a bit of a noticeable bevel, wider on bottom of cut, I noticed the torch was throwing sparks forward of its travel direction. So I am guessing I need to slow down?

 

Before I get into dialing speed, amps, etc I like to take care of the few things that will affect all cuts.

Is your torch completely square?

Is your cut height correct?

I know you have an air drier now, but are you sure you're not still seeing moisture? Pull your consumables and check.

On 12 gauge it's looking way better, but not sure what's going on at the right edge of your opener.

 

looks like I never squared the new torch when it came in, It was slightly off.






That was an improvement in getting rid of the bevel. However, it was still noticeable.

I then pulled the nozzle an electrode. I don't have a lot of time with a plasma cutter, but the nozzle looks worn out, compared to a new one. Electrode, looks like may have some life left?

I recently picked up some Hypertherm consumable for the torch, so I replace both the nozzle, and electrode.




I used the same setting as before except I slow the cut speed a bit
.052 Kerf
.015 pierce height
.06 cut height
.07 pierce delay
85 ipm
40 amps

I also played around with the lead in distance and that cleaned up the pierce marks



nearly dross free, just a bit at the pierce points

 

Where I lack experience in DIY table building, I made up for in dialing in my cuts

Dude, you are there!

Looks fucking awesome now.

 

Also just noticed, if ya wanna get rid of that little nub on the outside perimeter (where your lead in was), you can add FINISHING OVERLAP and it'll burn it right off.

For 1/8" you can do as little as .06" to .10" of finishing overlap and it should remove it.

 

The pierce point should be on the drops or outside the outer cut.

Can you make your lead in longer?

But, yeah, the consumable looks like it's at EOL.

 

Back when you was going into super detail with your test cuts, I knew that experience would be useful when it came time for me to dial in my settings. it gave you the experience to see what was going on an the most likely adjustment needed. every single tip and comment you gave while getting this figured out was dead on.

It is a such a great feeling seeing the table cut so well. taken nearly 4 years to get to this point, I started buying parts back in Dec of 2020.

Still not done, I need to figure out if I want to take on building the water table, or have it done. I do not have a really good way to make a 50" bend. I know I can figure out a solution though if I go that route.

 

I cheated.

I used 4 pieces of angle welded to the sheet metal. No needs to have the sides bent up. Instant water table pan.

Seriously, the water just absorbs all the smoke. It is a must if you are gonna cut regular.

 

It only helps that I have ADHD and allows me to be methodical as hell

Really though, seeing your table not only complete but cutting really well (with the size it is) is fucking awesome.

I can say many people even on turnkey systems like mine, have gone out to get a one piece done locally.

If you make it deep enough, there's nothing wrong with going mild steel and coating it all around with flex seal or a similar paint. It'll be way cheaper than going all stainless.

It's how STV supplies their water tables. They're all mild steel otherwise, like the CEO said, if they were stainless they would be charging another $1-2k per table.

My friend cuts extensively on his with a Hypertherm 65 SYNC all without issue.

 

That is an option I am considering. did you have any issue with the bottom sheet warping?

There is no way I could do much cutting with out a way to control dust and smoke, it super messy with out. and the smoke detectors freak out if I open the inside door before the garage fan has pulled the smoke out

Stainless is not even an option for me, to costly, and I have never welded stainless, and right now I am not in a rush to learn that skill just yet.

I am looking at using 14g mild steel, I would prefer it to be at least 3"

 

I used 16 g mild steel then coated it with truck bed liner paint.

It warped in the corners, but not enough to cause issues.

It's been 3 years, the coating is still fine.

I did weld in a black iron nipple so I could easily drain it.

 

Decided I was going to go this route...

Picked up the metal today, and the water table dry is going to be beefy. but it will add some weight to the table and help with rigidity. I estimate 50 to 60 gallons to fill.

The water pan will be 4" deep, and I am planning on the slats being 3" this will give room to make cuts underwater IF I ever decide to try stainless. the bad thing is that the 4" angle, came in at 1/4" for the thinnest available from my local supplier. 14g mild steel for the bottom. and the whole water pan will rest on 2x2x3/16" angle.

I will need to cut some lifting tabs to weld to the 4" angle. an I still need to order the metal to make the actual slats. but the water table is officially in progress.




I knew the 55"x55" sheet would be pushing the limits of what I could carry.

 

Dang, that's gonna be a beefy water table.

 

I remember how amazed I was on how much the extra weight of the pan smoothed out the shock of direction change.

My table is on rollers. I have anchors that I can extend, but I don't bother anymore. The water weight keeps things right where they supposed to be.

 

started on the water pan support for the table today.

I am building the support for the water tray out 2"x2" 3/16" angle that is getting welded to the 2"x2" frame.


There will be a couple of inches from the top of the water table to the top rails, hopefully this will keep splashing contained



About as Level As I can get it.



First support partially welded in



Before I cut the 4" angle I will need to re-square the band saw, the new blade is not cutting straight enough for a good fitup

 

I was able to get the 4" angle that rough cut.



I will notch the angle tomorrow, I will break out the hand torch and slice off what I need to get everything fitting well.

I also picked up a second little fixture table from harbor freight with the two it should make life easier welding the 55" x 55" frame up. I also picked up a 2 ton cherry picker, once this water table is done it is going to be heavy an I was not looking forward into moving it into place by hand.

 

One of the angle pieces notched and fitted. It has hit a heat index of 104f an I am done for the day. time to cool off while I can. Looking like we will be seeing a heat index around 105 to 110f all week.



Still needs a bit of cleanup.

 

It's early though!

Finish her up!

 

ok.. slave driver

Finished up, the last piece. now its ready for be squared up and welded. used the porta band this time, much faster, but the cuts did wander a bit. Guess who gets to practice filling large gaps....