poor cut quality

[retiredcpo]

ok heres more from a FNG
Not real happy with the results we are getting.
I am running a hypertherm 260HD and most of the time I run things through the MTC pronest software
I tried cutting the "queen of everything file from this site and lost the center of the "o" and "g"
also ran the deer clock and lost several of the numbers. Lots of dross on the botom side.
I tried using the 50 and 80 amp heads cutting 14 guage sheetand several places where not smooth(look at the"e's"

[I Lean]

I'm not at all familiar with your machine, but are there consumables available designed to run at lower (much lower) amperage? To cut 14ga "correctly" with 50 and 80 amps would require your machine to cut at insanely fast feedrates. See if you can get down to more like 30 amps, and whatever speeds will match that amperage. (maybe 150IPM, as a random guess off the top of my head?)

[retiredcpo]

yep I can go down to 30 amp torch but I was advised by tech supports from hypertherm to stay away from the 30 amp torch I called them with the same issues using the 30 amp head. I dont rember what the ipm is but I do rember the kerf is smaller with the 80 amp torch.
I only use the settings that are factory, either through the hypertherm software or the MTC pro nest
I dont know enough to inout my own settings.
Retiredcpo

[retiredcpo]

I just looked at the queen of everything file again
the "y" in the picture should have a tail in it and it has been clearly cut away

[jimcolt]

I am not sure why anyone would have told you not to use the 30 amp process on your HPR......they work great and will slow the process down adequately so you will get much better quality. Use the 30 amp process, set all your specs exactly as the book (operators manual suggests), make sure the height control function (set ohmic contact during cut) is shut off.....this will provide for more stable height control (absolutely critical) with the close cutt height of the 30 amp parts.

You can see the heat shadows on the details.....and clearly see that the 50 and 80 amp processes are inputing far too much heat into the plate....this is because the machine motion cannot maintain the speeds required at those amperages. There are thousands of users that use the 30 amp process...it was designed specifically for fine detail on thin materials....go ahead and use it!


Jim Colt Hypertherm

yep I can go down to 30 amp torch but I was advised by tech supports from hypertherm to stay away from the 30 amp torch I called them with the same issues using the 30 amp head. I dont rember what the ipm is but I do rember the kerf is smaller with the 80 amp torch.
I only use the settings that are factory, either through the hypertherm software or the MTC pro nest
I dont know enough to inout my own settings.
Retiredcpo

[retiredcpo]

Jim
I tried the 30 amp head and had better results but it is still not what I think we should be getting. I am still cutting things off or running in to other cuts.
as you can see I am still getting a blue heat mark
One thing
I keep getting a message saying the kerf is to large the lines have dissapeared.
Can I reduce the size of the kerf.
I have not changed anything it the machine its set to factory settings
Do you like the MTC pro nest software may be affecting the quality?
Thanks
Retiredcpo

[Loyd]

What speed are you running?
Loyd

[retiredcpo]

Loyd
Honestly I could not tell you for sure If I rember right it was around 60IPM
Im sure it is a setting that can be adjusted but we simply set the Size of the torch and the thikness of the metal and let the software set everything else. I think this machine has potential for do real nice work but so far we are not seeing it. And we certenly not getting what the sales guy said we would. we where told it would be plug and play which we are finding out it may not be

Retiredcpo

[muzza]

G'day Retired, I can understand your frustrations having only just got own my table up and running so I am far from an expert but can I offer my 2c worth.
After using a couple of other tables and having spent a heap of time reading here on Plasmaspider I spent a heap of time getting to know my table. I purchased somebody else's problems and basically modified and rebuilt it to suit my requirements which probably compounded issues a bit but before I even tried to cut my first notable item I burned up half a sheet just cutting lines, then rectangles and circles to check squareness, accuracy and speeds etc. writing down heaps of notes and what difference changing what did but more importantly getting an understanding of what happened each time I changed something. Again following advice here, changing one thing at a time and observing what it did. As Jim Colt constantly points out here, they have spent thousands of hours and dollars to give us the best possible starting point. Mine uses CandCNC controls so I also spent a lot of time conversing with Tom. The mechanics of the table I have also tweaked along the way and probably will continue to as time rolls on.
It's only a few weeks and most of my cuts are now turning out how I anticipate, I still keep tweaking a bit here and a bit there and to date have not cut thicker than 3mm (1/8") and am getting some real neat cuts with minimal dross but that first day or two where I was getting sick of cutting lines, squares and circles I now know was cheap learning. Even though I had done a fair bit of previous cutting I still would have stuffed half a dozen sheets if I jumped straight into cutting artwork.

Walk the road a step at a time and before you know it you'll reach your destination.

Murray

[jimcolt]

You cannot reduce the kerf.....you have to design your parts with the kerf that plasma produces in mind. If your kerf is .040".....then your cut parts need to be drawn to accomodate that. Lasers and waterjests have a narrower kerf....but cost 4 to 10X what the plasma costs to operate.

The blue indicates to me that the plasma torch is not moving at the required speed. Often, cnc machines have their drive parameters set at a rather sluggish rate....and when cutting small features...the machine can not accelerate to the speeds required to get the best cut quality. I would look at your acceleration rates (maybe consult with the machine builder) and see if you can incrementally increase them to get better quality on small parts.

If you want...I can cut one of your part programs on the same plasma on a machine at Hypertherm that has high accleration to show the difference.


Jim Colt

Jim
I tried the 30 amp head and had better results but it is still not what I think we should be getting. I am still cutting things off or running in to other cuts.
as you can see I am still getting a blue heat mark
One thing
I keep getting a message saying the kerf is to large the lines have dissapeared.
Can I reduce the size of the kerf.
I have not changed anything it the machine its set to factory settings
Do you like the MTC pro nest software may be affecting the quality?
Thanks
Retiredcpo

[RobertM]

retiredcpo.....I can tell you that plug and play is just a phrase. It implies simplicity. It's never that easy. I bought a plasmacam and a hypertherm 1000 and I thought that I'd be cutting parts in minutes. The video that plasmacam gave me made everything look easy. Well, the bottom line is that anything that could go wrong, did go wrong. I fried tips, I fried parts, I got frustrated trying to cut everything. If I finally got something cutting good I didn't want to switch material thickness for fear that I would never get it back. I couldn't make heads or tails until I started learning how troubleshoot. Once you understand why it's doing something you don't like, you just fix it. When I looked at your pictures I recognized the heat problem. It reminded me of my own hell when learning. I thought I'd never learn the process. One day everything clicked and I just started making parts. I bought mine to do hobby work. I built some offroad parts and a Sandrail for myself. I have had many people come to me asking for parts. I would turn them down because I thought the job would not go smoothly and I would cut into the profits of my machine shop. Since I have been coming to this site almost every day for the last few years, I thought, why am I not using my plasma to make money. Last month I decided to put my plasmacam to work. Almost as if someone heard my thoughts a large company across the street from my shop came to me and asked me to do a bracket job for them. I would normally do it as a machined parts job. I only had a night to get the job done so I put a big premium on the job. I bought material put it on the table, made some preliminary settings, ran a couple of test cuts, made adjustments, then slam dunked a $2500.00 job in 9 hours. They were so happy that they asked if I could cut Stainless Steel diamond plate. I thought about it for a second (I have never cut sst or diamond plate) and I said sure let me see what you have. That job will keep my plasma running for about three months. I asked for a sample of the material and had it cutting in no time flat. Suddenly, I feel like a pro. The bottom line is this. I can hear the frustration in your post. Keep in mind that you are going to look back in a short while and say, what was my problem. Good luck and pay attention to the people on this site. Jim and the people on this site are a goldmine of information.

[retiredcpo]

Thanks for All the help guys
I must clear up on thign first of all, I have made some great parts with this machine. I have done several things nobody ever thought we could do.
This is not MY machinemy boss convinced his boss(ect)the major selling points where plug and play and great quality.
I was told while I was building the water table we would not need Autocad or any other software "just click the screen and run your parts" well theyhas found out its not that easy
We do real goood on the thicker stuff, The only thing we dont like there is the holes are so hard you cant use a counter sink in them.
Its the thinner material and the detail that is giving us trouble.
There are so many differant setting I and wary of changing things since I not sure what to change.
Right now my plan is on monday check the machine to see if I can change the setting jim reccomnded and
Im going to talk to the boss about runnigna bunch of test making slight changes
I thinking is we keep track of what we do once we get things for a certern thinkness we should be able to go right back if we change.
I was thinking of drawing up something with a 2-3 line, a letter(like a A or G something) and a 1/4x1/2 in slot
retiredcpo