Free 173 Best Homemade Tools eBook:  
Results 1 to 8 of 8

Thread: Universal Low Cost Electronic Edge Finder for use in a Machine Shop

  1. #1
    Supporting Member rgsparber's Avatar
    Join Date
    Nov 2012
    Location
    Phoenix, AZ
    Posts
    651
    Thanks
    223
    Thanked 1,224 Times in 361 Posts

    rgsparber's Tools

    Universal Low Cost Electronic Edge Finder for use in a Machine Shop

    I have been trying to design the ultimate Electronic Edge Finder (EEF) for over 4 years. It had to be low cost, work over a wide range of spindle bearing electrical resistances, and be 100% reliable. Well, maybe this time I have it.

    This EEF is built on a Harbor Freight Multimeter which commonly goes for $6 if it is not being given away for free. The added circuit should cost under $5. It can detect changes in resistance as low as 0.1 milliohms but typically only needs to detect changes of tens of milliohms. The user is warned if the spindle resistance is too low to detect touchdown. A twist of the spindle brings it back into range. Low battery indicators and a bad connection indicator are also included.

    If you are interested, please see

    http://rick.sparber.org/MCEEF.pdf


    Your comments are welcome. All of us are smarter than any one of us.



    Thanks,

    Rick
    Rick

  2. The Following 5 Users Say Thank You to rgsparber For This Useful Post:

    Jon (06-02-2016), Paul Jones (06-11-2016), PJs (06-02-2016), threesixesinarow (09-09-2018), Toolmaker51 (06-07-2016)

  3. #2
    Frank S's Avatar
    Join Date
    Aug 2015
    Location
    Peacock TX
    Posts
    4,600
    Thanks
    699
    Thanked 3,698 Times in 1,857 Posts

    Frank S's Tools
    Thanks Rick.
    For the most part I claim to be electronically illiterate, but your PDF explains it well enough that I think that I might be able to construct one should the need arise.
    Never try to tell me it can't be done
    When I have to paint I use http://kbs.justoldtrucks.com/

  4. #3
    mklotz
    Supporting Member
    mklotz's Avatar
    Join Date
    Aug 2015
    Location
    LA, CA, USA
    Posts
    1,953
    Thanks
    159
    Thanked 3,785 Times in 1,285 Posts

    mklotz's Tools
    Well done, indeed. The circuit explanation makes me think you might be an EE? I have some LM324s left over from my days of electrical experimentation and may give it a try. Thanks for posting this.
    ---
    Regards, Marv


    Home Shop Freeware
    http://www.myvirtualnetwork.com/mklotz

  5. #4
    Supporting Member rgsparber's Avatar
    Join Date
    Nov 2012
    Location
    Phoenix, AZ
    Posts
    651
    Thanks
    223
    Thanked 1,224 Times in 361 Posts

    rgsparber's Tools
    Frank,

    Do let me know if you build the circuit. I can always use what you learn to improve the article.

    Rick
    Rick

  6. #5
    Content Editor DIYer's Avatar
    Join Date
    Aug 2013
    Posts
    3,091
    Thanks
    458
    Thanked 979 Times in 902 Posts
    Thanks Rick! We've added your Electronic Edge Finder to our Measuring and Marking category, as well as to your builder page: Rick Sparber's Homemade Tools. Your receipt:


  7. #6
    Supporting Member Paul Jones's Avatar
    Join Date
    May 2014
    Location
    Del Mar, California
    Posts
    1,179
    Thanks
    5,327
    Thanked 1,295 Times in 622 Posts

    Paul Jones's Tools
    Rick,
    I second Marv, and thank you for the excellent video and PDF explaining the circuits. Also, your general information about using op amps will be useful for electronics experimenters. You got to love the concise packaging of the LM324 from the early 70's and so many useful applications taught and used in EE classes. Thank you for the explanations and posting (and yet another clever use of the HF multimeter).
    Regards, Paul

  8. #7
    Supporting Member rgsparber's Avatar
    Join Date
    Nov 2012
    Location
    Phoenix, AZ
    Posts
    651
    Thanks
    223
    Thanked 1,224 Times in 361 Posts

    rgsparber's Tools
    I have improved the circuit plus doubled the size of the article. Same URL.

    The device now has automatic power control yet costs about $5 less.

    Rick
    Rick

  9. The Following User Says Thank You to rgsparber For This Useful Post:

    Paul Jones (06-15-2016)

  10. #8
    Jon
    Jon is offline Jon has agreed the Seller's Terms of Service
    Administrator
    Supporting Member
    Jon's Avatar
    Join Date
    Jan 2012
    Location
    Colorado, USA
    Posts
    16,780
    Thanks
    4,003
    Thanked 17,013 Times in 5,009 Posts
    Congratulations rgsparber, your Electronic Edge Finder is our Best Documented Build winner for June 2016!


    More importantly, this is your third Best Documented Build win, which makes you our FIRST 3-Time Best Documented Build winner, and the first recipient of our bronze wrench-on-scroll award graphic, now visible in the awards showcase in your postbit beneath your avatar.





    Here are all of your Best Documented Build winning tools:





    Please confirm your email address via PM to me, and I'll get your $35 award sent out, via your choice of PayPal, Amazon, GiftRocket, or bitcoin.

    Congrats again and nice work!


    Post your reply!
    Join 41,949 of us and get our 173 Must Read Homemade Tools eBook free.



    173 Must Read Homemade Tools
    Homemade Tools Supporters Forum
    Tool plans, build guides, ebooks, and more.

    Click here to become a supporter

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Bookmarks

Posting Permissions

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