Newbie Has anyone had success with DIY HF-pilot start?


Results 1 to 7 of 7

Thread: Has anyone had success with DIY HF-pilot start?

  1. #1
    Registered
    Join Date
    Feb 2017
    Posts
    2
    Downloads
    0
    Uploads
    0

    Default Has anyone had success with DIY HF-pilot start?

    Hello!

    I've been viewing these boards for a while and have built a couple of CNC machines. Next I'm intending to build a CNC table for my R-Tech P50HF plasma cutter. Every thread I've seen is a response to interference issues, with suggestions that they need better grounding.

    Unfortunately I've not seen any of these threads with a definite positive outcome!

    Most threads I've read end with no response, or the OP replaces the HF with a Hypertherm. I've searched, but I cant find a thread where someone suggests "you need to add a ground rod" and the response is "I've now done that, it fixed everything. Solved".

    I appreciate there are many commercial systems that use HF, but they were designed by teams experts... not me


    So, has anyone heard of any success stories?!

    Thanks

    Similar Threads:


  2. #2
    Member
    Join Date
    May 2009
    Location
    usa
    Posts
    226
    Downloads
    0
    Uploads
    0

    Default Re: Has anyone had success with DIY HF-pilot start?

    I originally built my table with a Cut40, HF contact start torch (chinese made cutter). It caused a lot of problems and took a little planning to eliminate them. Make sure ALL of your electronic components are electrically grounded (power ground).Then I used shielded, twisted pair wiring with a drain wire wherever I could (all switches, etc.). Make sure that ONLY one end of the drain wire is grounded to the table. Then I sunk a ground rod for the table and connected it with 6 GA wire (ground wire to table frame). This should take care of most of the HF noise.

    Even after all of this, the PC still occasionally went nuts or locked up. I finally had to move it about 20' away from the table. Once I did all of this, the table ran fine with no problems. I've since upgraded to a Hypertherm Pmax65 and could finally move the PC back near the table. You can make it work and it's probably good to use all of the extra grounding even if you don't use a HF start torch. I know that I won't have ant problems now.

    You can look at my build "A Different Machine - Downdraft/water table". Might give you a few ideas.

    Good luck with your build.

    Willy

    P.S. I also grounded the cutter case to the table. Don't know if that helped any but it didn't hurt.



  3. #3
    Member coherent's Avatar
    Join Date
    Apr 2003
    Location
    Arizona, USA
    Posts
    540
    Downloads
    2
    Uploads
    0

    Default Re: Has anyone had success with DIY HF-pilot start?

    Most of the issues I've seen were folks using a G540 which seems to be very prone to interference issues from the import HF start plasma cutters. None were able to completely eliminate issues with the G540. Some switched to KL drivers and a C10 breakout board and that resolved the problem. I think its a matter of which cutter, what driver/bob and your general grounding. I've also seen folks run a ground to the plasma torch tip to ground (using a simple band type hose clamp and length of wire). If you do some tests and make any progress, I'm sure others would be interested in your results. It's a subject I've also researched and a number of folks have voiced similar questions/interest.



  4. #4
    Member
    Join Date
    May 2009
    Location
    usa
    Posts
    226
    Downloads
    0
    Uploads
    0

    Default Re: Has anyone had success with DIY HF-pilot start?

    I am currently using the G540 and have not had a problem with it when I was using the HF start cutter. I don't believe the 540 is the problem. I think the problem is not using shielded, twisted pair wiring for the motor cables. The unshielded motor cables will act like an antenna and pick up the HF noise. Use the shielded, twisted pair with the drain wire and the 540 will work fine.

    One other thing I forgot to mention in the previous post was that I also ran a ground wire from the PC case to the table and this helped to reduce the errors I got initially when the PC was next to the table.

    Good luck.

    Willy



  5. #5
    Member coherent's Avatar
    Join Date
    Apr 2003
    Location
    Arizona, USA
    Posts
    540
    Downloads
    2
    Uploads
    0

    Default Re: Has anyone had success with DIY HF-pilot start?

    Quote Originally Posted by flyinwilly View Post
    I am currently using the G540 and have not had a problem with it when I was using the HF start cutter. I don't believe the 540 is the problem. I think the problem is not using shielded, twisted pair wiring for the motor cables. The unshielded motor cables will act like an antenna and pick up the HF noise. Use the shielded, twisted pair with the drain wire and the 540 will work fine.
    Willy
    I'm glad to see someone is using a G540 with an HF plasma and has it working. There are couple of threads here where folks tried everything (including shielded cable, grounding etc) and never could get it operational without interference issues. I have a G540 on my mill and have never had issues. I think it also depends on the specific brand and model of cutter used.



  6. #6

    Default Re: Has anyone had success with DIY HF-pilot start?

    I've been CNC cutting with a Hypertherm as well as a nasty Chinese cutter and most recently an R-Tech 50A Plasma, all of which have been HF start.

    If you believe what you read on most threads / forums, this is bad / impossible because of the HF spark interfering with the NC controller.

    The problem isn't the HF start, its poor electrical build practice (sorry!). If your setup is affected by the HF start, it will likely be interfered with by welding, radio transmitters and anything else producing RF. Changing to a non HF plasma isn't really fixing the problem, just sticking a band-aid over it.

    Good practice would be to put all the electronics in an earthed, metal box and to use screened cables with the screen earthed at one end only. However, this may not be what you've got - and you're not prepared to change it.

    However, it's still possible to retro-fit a good solution.
    Buy a load of snap-on RF Chokes. Put at least one on every wire which goes in or out of your control box and one on every wire that connects to your PC. The chokes filter out high frequency spikes.

    £20 worth of chokes and the problems vanish!

    Step 16: https://www.instructables.com/id/CNC-Plasma-Table/

    Si



  7. #7
    Registered
    Join Date
    Jul 2011
    Location
    Venezuela
    Posts
    1
    Downloads
    0
    Uploads
    0

    Default Re: Has anyone had success with DIY HF-pilot start?

    Quote Originally Posted by NoSpark View Post


    So, has anyone heard of any success stories?!

    Thanks
    Hi,
    I commented that I have already had great results, I am from Venezuela and I had to figure out 1001 ways to be able to walk these cheap Chinese cut40, I hope soon to be able to finish my invention "no more interference" Regards ...
    Has anyone had success with DIY HF-pilot start?-cut40-improvement-jpg
    Has anyone had success with DIY HF-pilot start?-cut40-improvement2-jpg



Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Has anyone had success with DIY HF-pilot start?

Has anyone had success with DIY HF-pilot start?