Ohmic Sensor

Discussion in 'Tech Support - SignTorch' started by Rockyhud, 5/9/17.

  1. Rockyhud

    Rockyhud registered

    Roles:
    • Plasma CuttingPlasma Cutting, CNC RouterCNC Router, Hobby / PersonalHobby / Personal, Just Getting StartedJust Getting Started
    Location:
    Falcon, CO
    Hi Gary,
    I'm new to the website and forum. I found your site while researching "CNC plasma torch initial height sensors" and discovered your post with the ohmic sensor circuit that you came up with and a while later showing the prototype encased in plastic. My question is whether this sensor is available from you or is the info provided only so others can make one themselves? I looked around the site and haven't found a "store" link for buying this item, but then again, I'm new to the site and forum and could have easily missed it. Thanks in advance for your help and response.
    Steve
     
  2. SignTorch

    SignTorch Artist

    Roles:
    • Vinyl CuttingVinyl Cutting, CNC RouterCNC Router, Designer / ArtistDesigner / Artist, Hobby / PersonalHobby / Personal
    Brands:
    • Corel DrawCorel Draw, Adobe PhotoshopAdobe Photoshop, V-Carve ProV-Carve Pro
    Location:
    Vidor, TX
    I was going to make a batch - but then my mom got sick - and everything is right where I left it - rusty and dusty - so it's officially a make-it-yourself project now
     
  3. Rockyhud

    Rockyhud registered

    Roles:
    • Plasma CuttingPlasma Cutting, CNC RouterCNC Router, Hobby / PersonalHobby / Personal, Just Getting StartedJust Getting Started
    Location:
    Falcon, CO
    Thanks for the update. I truly understand taking care of your mother. I was in that position several years ago when my mom started her slow decline with dementia/Alzheimer's disease. Hopefully your situation isn't/wasn't as dire. Anyway, based on the schematic you posted I should be able to make one of these. On the same topic, do you know if the WaterSwitch that user East German said he used works as well as your ohmic sensor? From the videos and comments it appears to work, just not sure how well.
     
  4. SignTorch

    SignTorch Artist

    Roles:
    • Vinyl CuttingVinyl Cutting, CNC RouterCNC Router, Designer / ArtistDesigner / Artist, Hobby / PersonalHobby / Personal
    Brands:
    • Corel DrawCorel Draw, Adobe PhotoshopAdobe Photoshop, V-Carve ProV-Carve Pro
    Location:
    Vidor, TX
    thanks - my situation isn't dire per se - I'm just out of my element -

    that's all I know to - it appears to work - ironically, that's about all I know about mine to - mine's strength is high sensitivity and fast response time so it can be used for micro end mills without banging the bit and on very flexible material - I suspect the water sensor might be slower and less sensitive, but for plasma on typical steel sheet that is fairly clean then the water sensor might be the way to go - since I'm not an electrical engineer, mine was developed with trial and error, and could have bugs that I'm not aware of, I haven't used it enough to have 1000% confidence - if the water sensor survives being connected to an operating plasma torch with no isolation relay like mine has then that'd be impressive to me -
     
  5. SignTorch

    SignTorch Artist

    Roles:
    • Vinyl CuttingVinyl Cutting, CNC RouterCNC Router, Designer / ArtistDesigner / Artist, Hobby / PersonalHobby / Personal
    Brands:
    • Corel DrawCorel Draw, Adobe PhotoshopAdobe Photoshop, V-Carve ProV-Carve Pro
    Location:
    Vidor, TX
  6. East German

    East German member

    Roles:
    • Plasma CuttingPlasma Cutting, Hobby / PersonalHobby / Personal
    Brands:
    • Mach3Mach3, V-Carve ProV-Carve Pro
    Hello,

    the power supply fore the Sensor not from the CNC! Use another litle power supply!

    This is my circuit runs since years.

    Regards Peter
    Kemo switch.
     
    Rockyhud and SignTorch like this.
  7. SignTorch

    SignTorch Artist

    Roles:
    • Vinyl CuttingVinyl Cutting, CNC RouterCNC Router, Designer / ArtistDesigner / Artist, Hobby / PersonalHobby / Personal
    Brands:
    • Corel DrawCorel Draw, Adobe PhotoshopAdobe Photoshop, V-Carve ProV-Carve Pro
    Location:
    Vidor, TX
    thanks for the diagram - it looks like the probe input is mislabled - it should be the other 2 wires that run through those 2 relay contacts (to disconnect both probe leads from both the table/material and from the torch when the torch/spindle is on) - then what is labeled as probe inputs would be the relay terminals on the water switch which would go to the bob inputs to signal when contact is made
     
  8. Rockyhud

    Rockyhud registered

    Roles:
    • Plasma CuttingPlasma Cutting, CNC RouterCNC Router, Hobby / PersonalHobby / Personal, Just Getting StartedJust Getting Started
    Location:
    Falcon, CO
    Many thanks to both of you. After I look this schematic over some more I'll likely have a few questions for Peter, to better understand how he's using the water switch. Initially though I agree that it seems the probe input wiring should connect to the sensor wires and the table/material and plasma torch wiring to the relay wiring. And thank you Gary for the link to a US source for the water switch.

    Steve
     
  9. East German

    East German member

    Roles:
    • Plasma CuttingPlasma Cutting, Hobby / PersonalHobby / Personal
    Brands:
    • Mach3Mach3, V-Carve ProV-Carve Pro
    Hello
    this works as indicated on the plan.
    The relay has two NO contact and 1 closer.

    Peter
     

Share This Page