Plasma table + 4th axis

Here is a teaser of the design so far. Im sure a fair amount will still change.

-5x5 table
-4th axis on the side big enough for 6x6 square tube (so far)
-I havent drawn this but I plan on indexing a full size tube for cutting every 5 feet so I can process a whole tube in one setup. 
-scribe, sharpie, crosshair green laser, and hyperthem mini torch on the z axis (I plan to add a bolt on 20w diode laser someday... maybe)
-4 to 6 inches of z travel (going back and forth... probably 6)
-hypertherm 45xp with finecut consumables and shop air
-rotating ball nuts on x and y
-carbon fiber tubes for linear bearing on the z axis (provided I can get the od more precise using an od grinder... total experiment)
-chicago scribe and retractable sharpie deployed by steppers (as opposed to stuffmadehere's pneumatic example)
-torch collision detection
-designed for 2g acceleration (this is arbitrarily high and I am pretty loosely estimating things other than mass - like friction)
-mesa 7i96, thcad torch height control, thcad ohmic sensing, stmbl drives, 60ST-M01930 servo motors
-QTPlasmaC, touch screen monitor, sheetcam
-$6k budget

This machine will help me take on job shop work as well as prototype designs for a business I am building to manufacture motion simulators. 



 

Thanks for the tip tommy.



I made an attempt at making commodity carbon tubes into linear rails lasts night. In the end, it was more trouble than its worth.

The tubes i bought were 1.5mm wall 25mm od tubes off amazon. My hope was to bairly scratch the surface to true in any change in diameter so I could slide an igus bearing on it smoothly. I already purchased 25mm igus bearings and they slid with slight changes in friction along the length.
 

I figured since they are made on a mandrel the id would be concentric but it was pretty out - like .4mm. This meant that I would have to drop the tube down to the next igus bearing size of 24mm. Of course that meant I could grind off a good amount of carbon. The grinder handled this really well. With coolant the wheel didnt load up at all. 

 


Unfortunately the layers under the top are all pulltruded layers rather than a weave. I should have guessed this would be the case. Since there was only pulltruded fibers they were fraying in places rendering this tube useless.

 


The way to do this right is lay up your own tube with plenty of carbon past where you will grind it back to - all with a weave fabric. This doesn't sound appealing to me so Im changing the z bearings to linear rails. 



 

This is going to be fun to watch. You seem capable of doing some really high quality work.

I do, but not always. When using the machine every day i fill the table above the material about 1-3 cm, it is a nice showcase, less metal dust and less ultraviolet radiation. Does not last long though as it evaporates quickly if used all day in about two days it gets under the material level.

Tommy,

Do you have any issues with excessive dross, since the sheets are underwater?

I watched a video with Jim Colt who said cut quality can be better if the water level is slightly below the bottom of sheet.



I was also wondering if the water level affects the THC readings in your experience?

Thanks!

This is exactly what I want to build. I was looking at just buying a 3 axis table, but then I saw a laser machine that had the 4th axis on the side like this. I've got a healthy budget as this isn't for hobby use, but I'm not sure I have the time. I know whatever time I think it's going to take, I might as well multiply by 10.

So, ever make it anywhere past design stage?