I gotta ask... about plasma cutter tables...

[e9999]

been wondering about this for too long...

(yea yea, not that there aren't other pressing matters in the world today, but eh, a man's gotta have his priorities straight...)

So, you know how those fancy plasma cutters that are all the rage with fabbers can cut through an inch of steel with no sweat?

Well, how come those grate-top cutting tables don't get seriously damaged when you cut stuff on them? They are grounded too usually, I guess, if that even matters, and if you cut thin sheet, there should be plenty of "plasma" reaching underneath I guess. So how come those grates don't get all cut up? Or do they?

I know, I could google this, but MUD knows best!

 

[sleeoffroad]

The slats that the metal sits up is considered consumable and they are cut and would need to be replaced when needed.

 

[e9999]

OK, I can see that. I'm surprised that they don't get cut up dramatically very fast. How much below a thinnish piece can the jet still cut things up? Or can one dial the cutter so it barely cuts the piece in question and not much more?

 

[firestopper]

It depends on the amperage setting. You generally don't run max amps on thinner material. Like in welding, you set up your machine according to material thickness. Plasma cutter set up= enough amperage to quality cut material resulting in slight damage to the replaceable support slats.
That simple.

 

[Weber Sarge]

That is correct - most of those table designs use flat stock that is basically a drop-in consumable piece . When they are done , just insert a new chunk of flat stock cut to size . Homemade versions are pretty easy - just use heavy wall 2x2 or 2x3 tubing and cut out slots for the cross bars to sit inside of .
Sarge

 

[Jetboy]

I think it's been covered pretty well. The only thing I'd add is that when plasma and gas torches hit the end of a thin pieces of steel the cutting deflects and only cuts slightly into the top of the flat bar. Even in the case of cutting say 3" plate with a big gas torch, it won't cut very badly into the slats due to deflection around the slat.

 

[hairy_apple]

Speed too.... cutting thin stuff I am running the torch pretty fast... its doesn't have enough time touching to cut it too deep. That being said... they do get chewed up pretty bad. Doesn't really hurt anything. When they are too far gone I will flip them over for a few more years of use. The are just loose in the table.

 

[iou180]

I also have a plasma cutting table and agree with the previous replies, the slats are indeed considered sacrificial. As mentioned earlier they can be flipped over, but also can be repositioned to another less used area of the table. Even with a lot of cutting the slats can last a long time.

My slats are 3 years old and haven't been flipped yet. They typically only get nicked up to about a 1/2".

Draining the table and cleaning out the sludge...well that's a different story.

 

[firestopper]

My 60"x 110" CNC plasma table is 10 years old and I have only replaced 1/2 the slats, so they do last if your running the cut correctly.