Plasma Table Build - Plasma Bot 4.0

[sportbike]

Yeah, I've been resisting the urge to make some cuts since I got off the phone with Probotix on Friday. I gave myself 15 minutes since I've been sick all week. It will probably sit for 2-3 days before I get another chance to make some cuts. I'm getting close!

Well....it's been more than 2-3 days....

[SeanMurphy265]

Well....it's been more than 2-3 days....

Well, My wife had surgery last week and I have done some playing, but nothing worth showing. I followed hypertherm's cutting speeds and that was too fast; so I have a melted outline of what I was trying to cut!

I'm having some trouble getting my Z axis configured correctly. Either the torch goes down too far or not far enough.

I'm not getting my THC set properly. I'm not sure how to how many volts on the thc for the amps on the plasma cutter.

I'm going to back up a little and just get it cutting properly without the Z axis or THC.
I spent some time today getting the gantry 100% level. It was close, but not close enough without THC (working properly). I bolted plates to the end of my tubing rails and they are bolted to the corner post. I think one of the screws was causing it to be off a little.

Tomorrow I'm going to cut with the torch in a fixed position without any safe Z settings. I'm going to slow it down considerably 20-30 ipm and then work my way back up on some scrap pieces of 3/16"

I also made me some slats form 3"x1/4" flat yesterday right now I have 4 total and have another 20' to cut and then I will have the bed made. I used 1/4" because that was all I could get locally, and I did not have time for the 30 minute drive to the closest steel supply.

[Rambozo]

I followed hypertherm's cutting speeds and that was too fast; so I have a melted outline of what I was trying to cut!

Are you using the same voltage, amperage, and the same tip size? I would think as long as those are the same, the speeds should be too. The rest is just a power supply.
It's always good to break a problem down into smaller ones. Running with a fixed Z will let you try a lot of things without the THC fighting you for control. Can you have the THC show you the voltage even if it is not doing the control? That way as you change heights and speeds, you will be able to see what voltage gives you the best cuts. Then you will know what to program the THC for, on the same material. I'm sure over time you will come up with a chart of voltage, amps, pierce heights and feedrates for most of the common stuff you cut. Also with a fixed Z SheetCAM can do a pre pierce run where you set the torch at pierce height and it goes along and does all the piercings, then reset the torch to cut height and it will do all the cuts. That's a lot easier on your torch and consumables.

[SeanMurphy265]

Are you using the same voltage, amperage, and the same tip size? I would think as long as those are the same, the speeds should be too. The rest is just a power supply.
It's always good to break a problem down into smaller ones. Running with a fixed Z will let you try a lot of things without the THC fighting you for control. Can you have the THC show you the voltage even if it is not doing the control? That way as you change heights and speeds, you will be able to see what voltage gives you the best cuts. Then you will know what to program the THC for, on the same material. I'm sure over time you will come up with a chart of voltage, amps, pierce heights and feedrates for most of the common stuff you cut. Also with a fixed Z SheetCAM can do a pre pierce run where you set the torch at pierce height and it goes along and does all the piercings, then reset the torch to cut height and it will do all the cuts. That's a lot easier on your torch and consumables.

Some of this was caused by the pierce delay setting; I think I had .5 sec of delay, and I think I need at least 1 second of delay (maybe more). Right now I'm guessing on the voltage setting and amp settings; meaning I do not know how many volts I need to set my THC for 40, 50, or 60 amps. I know that I need to figure that out, but for now I want to get my pierce delay and IPM's figured out. If I get it cutting properly then I will add the safe Z setup back and then try it again. After that I will add the THC back.

I'm also wondering if I need to add limit and home switches at some point.

Where can I get consumables for the pp60c machine torch, they are not listed on Everlast website?

[Rambozo]

The nice thing about home switches, is that if anything goes wrong and you lose your position in the middle of a big job, (power loss, motor stall, dropped pulses, jam or crash, sometimes even hitting the E-stop will cause you to lose position, etc.) you can do a rehome and pickup where you left off. Limit switches will protect your machine from bad gcode. Having your gantry slam into the stops at full speed is not a good thing, and all it takes is a missing minus sign or a misplaced decimal to make that happen. There are programs that can attempt to prove your code before you run it, but some things can sneak by, or you might accidentally make a change when you do your setup.

[acourtjester]

HI Sean
Reading your post it sounds like you are having problems with the “Z” movement.
Have you checked the consistency of “Z” movement like finding 0 then back up to .100 then down to .060 back to .100 down to .060 about 5 times checking each movements distance.
Then try some pierces alone with plasma move “X” .100 and pierce again. I think a pierce of 1 second is way too long I was using .2 or .3 second on 3/16” fine. I used .070 pierce height and .060 cut height. Go to a location drop G1 z0.070, m3, G4p0.30 G1 z.060, m5 G1 z0.70 that should blow a hole in the metal move and do it again. Rambo has it right do small checks with the least thing involved then move to doing more.

[SeanMurphy265]

HI Sean
Reading your post it sounds like you are having problems with the “Z” movement.
Have you checked the consistency of “Z” movement like finding 0 then back up to .100 then down to .060 back to .100 down to .060 about 5 times checking each movements distance.
Then try some pierces alone with plasma move “X” .100 and pierce again. I think a pierce of 1 second is way too long I was using .2 or .3 second on 3/16” fine. I used .070 pierce height and .060 cut height. Go to a location drop G1 z0.070, m3, G4p0.30 G1 z.060, m5 G1 z0.70 that should blow a hole in the metal move and do it again. Rambo has it right do small checks with the least thing involved then move to doing more.

I think some of it was due to the gantry being a little out of level (slightly). But I need to re-check my Z axis. Do I just type in G1 z0.070, m3, G4p0.30 G1 z.060, m5 G1 z0.70?

[SeanMurphy265]

Ok, I did some playing this today, and I kinda know where I am at. The plate that I was cutting has been cut on several times and was warped. I was cutting at .5 without THC. Some place it was cutting excellent, and where the plate was warped the torch drug the plate. I have a video that I am uploading. At the end of the video my compressor shut off and was only using the air left in the tank. Also in the video the plasma cutter is sputtering I think that is because of the slag in the plate.

[SeanMurphy265]

Here it is, I'm getting closer!

[Rambozo]

Take it easy on that poor torch.
Looks like you just need to find the sweet spot of amps, feedrate and torch height, to get the cleanest cuts possible. It looks a little slow compared to other videos. Maybe crank up the amps and the speed a little. Is the dross the low speed kind or the high? Yeah, warped material is where the THC will be your best friend.

[SeanMurphy265]

Take it easy on that poor torch.
Looks like you just need to find the sweet spot of amps, feedrate and torch height, to get the cleanest cuts possible. It looks a little slow compared to other videos. Maybe crank up the amps and the speed a little. Is the dross the low speed kind or the high? Yeah, warped material is where the THC will be your best friend.

The speed rate was 25ipm, which is way too low, but I needed to get a base line and now I will speed it up. The dross is a combo of low speed, and then I cut across some places where I had it cutting way too high and it did not pierce.

[acourtjester]

HI Sean
What size tip are you using the kurf width look big I think the smallest tip for that torch is a 1.0 for 60 amps.
Here is a cut I made with pierces for drilling holes latter and then cutting the part out the kurf looks smaller then yours.

[sportbike]

Perhaps it woudl be beneficial for those that have plasma tables if we started a sticky with settings used for different materials, consumables, etc. Might help in the future for build start-ups as well as help those that already have tables when they come across a different material, etc.

[EmptyNester]

Perhaps it woudl be beneficial for those that have plasma tables if we started a sticky with settings used for different materials, consumables, etc. Might help in the future for build start-ups as well as help those that already have tables when they come across a different material, etc.

I'll second that!

[SeanMurphy265]

HI Sean
What size tip are you using the kurf width look big I think the smallest tip for that torch is a 1.0 for 60 amps.
Here is a cut I made with pierces for drilling holes latter and then cutting the part out the kurf looks smaller then yours.

I honestly do not know! I'm using the consumables that came in the pp60c box!

[SeanMurphy265]

Well I finally had a day to work on my plasma cutter! I have some video I will post later. I spent a little time working on my THC. I know it works, because I found the test mode! Some how either I have a loose wire or my THC is not reading the voltage. When the torch fires the voltage appears and then goes away. I'm not sure if I have a loose wire, or if the THC is not getting a good arc voltage reading. Still have lots of learning, but I'm close.

[SeanMurphy265]

Here are some pics of some hinges I tried cutting yesterday. I'm not sure what happened if the plate moved, but the holes were suppose to be on the hinges. I'll work out that problem later! I hope to get some time tomorrow and see whats going on with the THC not reading the arc voltage.

[SeanMurphy265]

[Rambozo]

Are you running that off a generator?

It doesn't look like the torch is doing a touch off, to set the start height at each cut. I can't see if it's even doing the piercing at the larger height. I think it crashed into the metal and lost position at about 0:52. Unless your metal is perfectly aligned to your axis, you are gonna need that THC to make it work right.

[SeanMurphy265]

I may not have it set right, but it starts off sitting on top of the material. When it starts it does not touch the metal after it moves from 0,0. I am not running any limit switches.