This is my setup

[minnfatz]

I am running a Precision Plasma CNC table, controls from CandCNC, and a plasma cutter/welder from Longevity. I really like my setup and it seems to be working pretty well. I made the water pan for the table. I have a bunch of pictures of the whole building/assembly process, but I am going to start off by just posting a couple from when I first got everything together. Thanks to everyone on this site and those from the companies listed above that helped me get up and running.

[jimcolt]

How about some cut quality pictures with feedback on cut speeds, consumable life, cut edge angularity, dross, etc?

Jim

[minnfatz]

I posted a couple of pictures on the projects page. It will be a while before I have a ton of feedback. I have only cut a few things so far, but I am happy with the cut quality and the dross isn't too bad. I am still trying to dial things in properly and there are a lot of thicknesses that I have not cut yet. The thickest I have cut on my table so far is 3/8". I am as happy with the cut quality with the Longevity as with the Hypertherms that I have used, except maybe when it comes to arcs and circles. The Hypertherms I have used tend to cut cut holes and arcs better and my speeds with the Longevity are slower as well, although the Hypertherms were much more powerful machines. Time will tell if I continue to be happy, but so far I am a happy camper.

[Dennis]

How about some cut quality pictures with feedback on cut speeds, consumable life, cut edge angularity, dross, etc?

Jim

Bad boy Jim I know what your thinking

[minnfatz]

LOL! I was thinking the same as you Dennis. I have mostly done thin stuff so far and the cut quality with the Longevity is excellent. I don't know how it will do with thick stuff, but it cut 1/4" really well and has done well on 3/8" also.

I like big name welding and plasma cutting units, but with Longevity I got a plasma cutter, tig welder and stick welder for the same or less than I could have bought a Hypertherm or Hobart or Miller or Lincoln, etc. I don't know how well the Longevity will hold up over time, but I have been very pleased with their customer service.

[Dennis]

Does your system have THC... Looks alot like a Plasmacam.

[BrianMick]

Does your system have THC... Looks alot like a Plasmacam.

I was thinking the same thing the frame and setup looks alot like a plasmacam except for the rails and gantry...
Brian

[jimcolt]

Actually I am rather curious as to the mechanized cut quality from the Longevity system with the Trafimet style torch you are using. There probably are a lot of good low cost applications for this set up.....regardless of how it compares with Hypertherm systems. Here is what the Hypertherm 45 amp system does on my cnc.....The first two pics are of 1/4", the third is 1/2", the last one is 3/8"....all as cut with virtually no dross. This is only 45 Amps, and the system is less than $1500, made in the USA.

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[Dennis]

Jim do you cut your holes CCW, and what percent do you drop your speed...

Looks like there is very little taper... Also do you use a lead in and a lead out on your holes..

Thanks Again
Dennis

[minnfatz]

I need to work on slowing the hole speeds down some to reduce taper. I am still teaching myself Sheetcam and Mach 3, so I will get things down eventually. My unit does have THC and I can't imagine cutting without it.

I have used a Plasmacam system, it was the first CNC plasma cutter I ever used and it was pretty decent, but I prefer the Precision Plasma system. I believe it is better engineered than a Plasmacam and I wasn't a big fan of the Plasmacam software. It doesn't hurt that the Precision Plasma with the CandCNC controls, Sheetcam, and Mach 3 is about half the price of a Plasmacam. I have met the guy that makes and sells Precision Plasma, he lives about 20 minutes away from me, and he is passionate about making CNC plasma systems that poor folk like me can afford. I searched for many months trying to find an affordable CNC plasma cutter and decided on the Precision Plasma. If any of you are wondering, I don't work for or have any interest in any of the companies I have mentioned, I am just a satisfied customer.

I will post more pictures and background information as soon as I get some stuff cut.

[Dennis]

Its nice when you only have to go down the street for tech support.

[Dennis]

I need to work on slowing the hole speeds down some to reduce taper. I am still teaching myself Sheetcam and Mach 3, so I will get things down eventually. My unit does have THC and I can't imagine cutting without it.

I have used a Plasmacam system, it was the first CNC plasma cutter I ever used and it was pretty decent, but I prefer the Precision Plasma system. I believe it is better engineered than a Plasmacam and I wasn't a big fan of the Plasmacam software. It doesn't hurt that the Precision Plasma with the CandCNC controls, Sheetcam, and Mach 3 is about half the price of a Plasmacam. I have met the guy that makes and sells Precision Plasma, he lives about 20 minutes away from me, and he is passionate about making CNC plasma systems that poor folk like me can afford. I searched for many months trying to find an affordable CNC plasma cutter and decided on the Precision Plasma. If any of you are wondering, I don't work for or have any interest in any of the companies I have mentioned, I am just a satisfied customer.

I will post more pictures and background information as soon as I get some stuff cut.

You can set hole cut speed in Sheetcam , just create a different layer for yor holes and adjust the speed as required..

[minnfatz]

Dennis wrote:
Its nice when you only have to go down the street for tech support.

LOL! It is nice that he is close by, but I only had to call him once and e-mail him a few times.

Thanks for the info on the holes Dennis, I will mess around with layers. Can I change layers in Sheetcam or should I do it in my CAD or Corel draw program?

[Dennis]

You can do it in sheetcam.

[minnfatz]

Ok, thanks!

[jimcolt]

On the holes in the pictures that I did:

-There is a straight lead in on each hole, no lead out.
- The holes are cut at approximately 60% of the Hypertherm recommended cut speed for this material, thickness, amperage
- The height control pierces at pierce height, indexes down to cut height while still on the lead in, then freezes height (no arc voltage feedback control) for all holes under 1" diameter.

All of these functions are automated in the PlasmaCam software. Very easy to cut nice holes with these systems.

Jim Colt

[BrianMick]

Is there an advantage to a lead out or why are they sometimes used and does plasmacam software have it? if so ive never seen it
Brian

[Dennis]

On the holes in the pictures that I did:

-There is a straight lead in on each hole, no lead out.
- The holes are cut at approximately 60% of the Hypertherm recommended cut speed for this material, thickness, amperage
- The height control pierces at pierce height, indexes down to cut height while still on the lead in, then freezes height (no arc voltage feedback control) for all holes under 1" diameter.

All of these functions are automated in the PlasmaCam software. Very easy to cut nice holes with these systems.

Jim Colt

Thanks again Jim for the info!


Dennis

[jimcolt]

Lead outs....which lead back into the scrap (center) of a hole are not a good process for plasma cutting. The best air plasma systems built today (notice I said best, not all!) utilize a calculated current ramp down at the end of each cut cycle that is designed to resolidify the hafnium emitter on the electrode. This ramp down is rather quick, but if you have a lead out that leads into air (the center of the hole usually drops into the cutting table) the arc loses its electrical connection, the plasma snaps off (no ramp down), and the electrode spits out a little bit of hafnium oxide....the result, shorter consumable life.

A properly programmed hole for plasma either shuts the plasma off at 360 degrees....or even better, shuts the plasma off at 360 degrees but keeps the motion going past the lead in kerf crossing, staying on the hole radius until the arc is extinguished. High end industrial systems from Hypertherm have the ability to do this automatically (the CAM software reconizes holes and automatically applies the best lead in, lead out to support consumable life and cut quality).

The PlasmaCam software has a few choices for lead ins and lead outs....the best for a Hypertherm air plasma is with no lead out, and a lead in that is sufficiently long so the the torch moves from pierce height tocut height while still on the lead in.

Jim

[BrianMick]

thanks for the info Jim
Brian

[cypher]

What post processor are you using? did you modify one of the ones in sheetcam for mach 3?

[minnfatz]

I'm not at my plasma cutter computer right now, but I think I am using the MP3000-THC-HighRef.post.