Plasma cutter.

This topic contains 32 replies, has 17 voices, and was last updated by Profile photo of Kris Kris 3 months, 3 weeks ago.

Viewing 30 posts - 1 through 30 (of 33 total)
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  • #7925
    Profile photo of Marc A
    Marc A
    Participant

    Hi,

    Today the first test run

    First pieces jpeg.
    Start went well, then the x axis broke down, restart arduino, then the y axis broke down.
    1 of 2 attempts no problem
    Laptop and arduino stood three meters away from the plasma cutter.
    Anyone have an idea what I can do about this?
    Arduino in an iron box?
    Shielded cables for motors? (Now used ordinary UTP cable)
    Kind regards Marc A

    #7928
    Profile photo of Marc A
    Marc A
    Participant
    #7935
    Profile photo of Ryan
    Ryan
    Keymaster

    You are my hero!!!!!

    Are you sure the issue is the plasma? Just to be sure can you run a long file without the plasma on then it only messes up with the plasma on? Using an LCD controller or a laptop?

    A few other things it could be but never know.

    Someone else just grounded all his metal tubes in the forums, this might help. The wires are shielded, the connections on the solder less mount’s aren’t ideal in this case, maybe solder them up, a metal box for the arduino couldn’t hurt.

    #7937
    Profile photo of Leo69
    Leo69
    Participant

    Wow! Speechless….

    #7955
    Profile photo of Marc A
    Marc A
    Participant

    Hi!

    We use a laptop, no lcd at the moment.
    We will ground the tubes, put the arduino in a metal box and get some shielded cables for the motors.
    We have drawn your logo four times with a pencil connected to the cnc without any problems.
    We have run each cut without the plasma cutter turned on and we never had any problems.
    When we ran the cuts with the plasma cutter on however sometimes one of the axis stopped working, exept for the Z-axis, this one never failed.
    Apparently, only the activated axis fails when the plasma ignites.
    As soon as we rebooted the arduino everything worked again.

    Before I forget, thanks for sharing your project!

    #7958
    Profile photo of karltinsly
    karltinsly
    Participant

    That’s so cool! Wish I had a big fireproof place to build one of these. Not going to happen, but very neat to see it can be done!

    #7983
    Profile photo of nerdyrcdriver
    nerdyrcdriver
    Participant

    Figuring out the grounding and shielded cables would be the best place to start if it works w/o the plasma cutter turned on.

    Aside from that issue, your cuts look pretty good for initial testing. What are you using to trigger the torch on and off?

    #7993
    Profile photo of Dave Gun
    Dave Gun
    Participant

    Very cool!!

    I have some picture of how I grounded mine in this post. I did this more for static electricity.

    Dave's 24" x 24" Build

    The white cables are shielded and you would need to bond the shielding to the ground. Also for your setup, connect it to a electrical system ground, like through grounded power supply.

    Dave

    #8013
    Profile photo of Ryan
    Ryan
    Keymaster

    The wires I include are shielded you just need to ground them.

    Looks like this thread is going to get very popular!

    #8035
    Profile photo of Marc A
    Marc A
    Participant

    ESTL CAM

    Setup > Laser etc >

    Cut Start
    M106 Close relais on D9 (can be switched with D10 on the firmware)
    g4 s0.7 Wait 1 sec before moving

    Cut Stop
    M107 Open relais on D9 (can be switched with D10 on the firmware)

    Use a 12V dc relais on D9 on the MEGA. to switch torch.

    Kind regards.

    #8045
    Profile photo of nerdyrcdriver
    nerdyrcdriver
    Participant

    Cool, definitely makes me want estlcam more now that I know it is easy to control the torch with a relay.

    #8192
    Profile photo of MrMeatGrinder
    MrMeatGrinder
    Participant

    You win! Congrats are in order, you beat me to it.

    #8511
    Profile photo of mage2
    mage2
    Participant

    I think you have all covered the possible noise generated by the plasma.
    Plasma tends to draw a goodly amount of current, could it be causing some sort of brownout situation?

    #8516
    Profile photo of John Wells
    John Wells
    Participant

    Cool. How do you ensure the D9 output isn’t PWMing? Is M106 enough, or do you need to specify “M106 S255”?

    For the flaky electronics, you could try adding filters to your power supply — ideally monitor the 12V line with a scope and then select capacitors to filter out the frequencies you are seeing. Or just take a guess; put at least one nice big electrolytic cap across your 12V/ground rails in case you are getting brownouts.

    #8882
    Profile photo of Steve Devers
    Steve Devers
    Participant

    What brand of plasma cutter are you using. I just finished building a cnc plasma table. I tried using a older Esab but the HF start jammed up my electronics. I know allot of the
    Chinese plasmas put out some nasty frequency’s as well.

    #8886
    Profile photo of Marc A
    Marc A
    Participant

    Photo in Attach

    Attachments:
    #11490
    Profile photo of mark leino
    mark leino
    Participant

    Do you have any more details on how to hook up the relay, and the wiring for swapping out the torch? I’m brand new to plasma torches, and haven’t really used relays very much.

    #11540
    Profile photo of Marc A
    Marc A
    Participant

    Hi,

    Start here,

    https://nl.wikipedia.org/wiki/Relais

    I used A solid state relais.

    http://www.futurlec.com/Relays/SSR70A.shtml

    Kind regards Marc

    #11643
    Profile photo of mark leino
    mark leino
    Participant

    So for you plasma guys out there… what would be the “ideal” plasma cutter for using for cnc? I cancelled my order on my unit I ordered since it was High Frequency start, and I’m trying to find a unit that is a pilot arc start, to be easier on the electrical trouble shooting. The problem I’m having now, is finding something affordable, that is pilot arc. The more and more I thought about it, the chinese plasma cutters scare me.

    So really what I’m asking, is which torches has anyone found that is pilot arc? All the product descriptions around the internet are pretty vague on details….. I’m trying to keep this *semi affordable*

    Awesome video of the cutting by the way

    #11717
    Profile photo of Jonas
    Jonas
    Participant

    Want one! I thought the pantographic plasma cutter setups were awesome, but CNC plasma cutting is a goal worth working for.

    #11718
    Profile photo of Ryan
    Ryan
    Keymaster

    Amazon has a 3 in one right now, pilot arc plasma, stick and tig. I understand that this sort of tig welding isn’t ideal but I think I might give it a try with this machine. It is inexpensive and for the amount of times I will use it in any given year I am sure it will be good enough. The only “bad” thing I can find is its consumables are kind of proprietary and it goes through them quickly, but if I switch out the “gun” for a pen style plasma torch I hope that will help both of those. Add a foot pedal and maybe have a decent functional scrape start tig welder?

    http://amzn.to/1NjWzAf

    #11752
    Profile photo of nerdyrcdriver
    nerdyrcdriver
    Participant

    I’ve had my eye on that unit after seeing it in another thread. If only I wasn’t a college student. The plasma cutter I use at school is the biggest Lincoln Electric model you can get before making a huge step up to industrial stuff (well, as of a few years ago). It is total overkill though. The only real benefit is that it can cut 3/4″ steel and the duty cycle is pretty long. The only cut that I’ve done that exceeded the duty cycle was a sign that was nearly a half hour of straight cutting. Getting that unit and switching to a different torch, even a cheap Chinese one with more common consumables, isn’t a bad idea. One thing to keep in mind is that the Hypertherm units have drag cutting so the tip can directly touch the material and not be a dead short.

    No idea on what to say about the welding functionality since I have no experience in welding. I’ve tried to learn a lot online so that I might have better luck when the time comes to try it out. We just got a Square Wave TIG 200 and it is supposed to be an absolute dream to work with but the guys on the baja team stick to their trusty old Miller.

    #11802
    Profile photo of MrMeatGrinder
    MrMeatGrinder
    Participant

    That Lotos is a decent machine as far as the China made ones go. The torch model is a PCON40 EDIT: SG-55 (just some conflicting reports) and the consumables are sold in sets of 40 for around $100 EDIT: 80 pcs for ~$50. They are nickel or nickel plated, so they should last quite a bit longer. LOTOS is the brand that all of the other copycat Chinese machines are based off of, so they are at least leader of the pack. The only thing I remember hearing about them is that they are MOSFET driven and not IGBT, which isn’t optimal, but if you aren’t running it for 6+ hours every day, it shouldn’t matter… unless it puts out the blue smoke on the first few uses lol

    I got a chuckle out of the “scrape start” though, never heard it called that. 🙂 The accepted industry term is scratch start. If you aren’t using a pedal, you’re doing scratch start (you strike the tungsten tip like a match to start the arc, or just like you were starting an arc for a stick welder) TIG welding, if you do have a pedal, it’s lift start (tungsten tip to the work piece with no juice and as you depress the pedal, you lift the electrode to create an arc). I believe that unit does have a connection for a foot pedal but doesn’t come with one. I’d suggest making a foot pedal so that you can do lift start if you want to learn to TIG without HF. This welding discussion is probably better served in a different topic on the forum though because there is a ton of stuff you can do with these cheap welders. I added an adjustable frequency PWM flip-flop circuit to mine almost immediately after I got it so that I could weld copper.

    #11807
    Profile photo of MrMeatGrinder
    MrMeatGrinder
    Participant

    Hypertherm is a great company and they have excellent support. The trade off is that you pay for it. We use ESAB at work, and they are also top notch.

    Square wave A/C is the real deal. Also not available on most budget machines like what we usually discuss here 🙂

    #14907
    Profile photo of Michael Jones
    Michael Jones
    Participant

    Will you guys have a look at my post here and let me know your thoughts on shielding? (Cables/Arduino/ramps/laptop)

    Thanks so much! I sure do appreciate any help!

    #15542
    Profile photo of mark leino
    mark leino
    Participant

    I’m about to to start assembling my mpcnc plasma, and I think I have most everything worked out except a cam program to post process the files, which it seems like sheet cam is the best option. Maybe some of you guys who have completed a set up or are more used to using a plasma can help me out. I’m using a lotos ltp5000d plasma, with pilot arc.

    1. Triggering the torch with ramps. I have a solid state relay that I am going to wire into the torch trigger to the ramps board. How do I set up pins to turn on at start of cut, and off at end of cut?

    2. How is a pierce delay figured into the program? Will I have manually go enter in a time delay for each start?

    3. The relay I have is 3v dc low voltage, 50 amp 120-240v ac. Is this even the correct relay, or does it need to be dc to dc?

    4. Is there a program that’s open-source that can do plasma tool paths?

    Unfortunately I can barely muddle my way through programming the ramps board, so this is all a learning experience.

    Thanks.

    #15545
    Profile photo of Marc A
    Marc A
    Participant

    Try ESTL CAM

    Go To Setup > Laser etc >

    Cut Start
    M106 Close relais on D9 (can be switched with D10 on the firmware)
    g4 s0.7 Wait 1 sec before moving

    Cut Stop
    M107 Open relais on D9 (can be switched with D10 on the firmware)

    Use a 12V dc relais on D9 on the MEGA. to switch torch.

    Kind regards.

    #30253

    I know this is an old thread, but since I have a similar proble, maybe the OP has some feedback now.

    I tried to plasma cut with the MPCNC yesterday for the first time: the arduino blew up right after firing the torch for the first cut.

    Any thought?

    @Marc A : did you finally manage to find a working solution? How did you do?

    #30351
    Profile photo of Dave Gun
    Dave Gun
    Participant

    A plasma cutter puts out some strong electro magnetic (EM) noise. You may need to shield your electronics from the EM. You should put your RAMPS in a metal case and ground it. I also suggest some shielded wires to your steppers and bond the shielding to the grounded case. It would hurt to run all the wires from the outside your enclosure through a ferrite core to take care of any voltage spikes coming down the wires.

    Dave

    #30352
    Profile photo of Vincent
    Vincent
    Participant

    Just ran the first plasma cut test on my machine using a Hypertherm Powermax 1650 and haven’t had any electrical issues so far. I assume this is because it’s not a high frequency plasma?

    BTW just want to thank Mark A for your reply about controlling the start/stop, we were a bit lost on how to do that before!

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