• Ken Lau
    4
    Hi all
    just wondering if any of you use a disc grinder to flatten a blade? I have seen videos of Nick Wheeler doing it and I notice that he's using one with a VFD and speed control. I bought myself a 2nd hand one by Draper that has a 12" disc on it but no speed control. Its fantastic for flattening handle scales but I dare not use it on a blade. Any advice? Or should I not use it as it's only running on super fast speed!!!
  • Jeff Kushen
    31
    Ken, is this a 120v or 240v grinder? If it is 240v you can get a cheap VFD on Ebay/Amazon for $100 and give yourself a speed adjustment.

    If it is 120, you COULD disconnect the plate from the motor, mount it on a shaft, and use pulleys to adjust speed. Just a thought.

    OR you could get a 240v motor and a VFD and use the Draper plate and make your own. I just found a Baldor 1.5HP 240v for $80! Shipping included!
  • Ken Lau
    4
    Hey Jeff, it's 240V. Didn't think that I could easily hook up a VFD to do the job. Thanks for that. I'll have to look into it. Cheers.
  • Jeff Kushen
    31
    If its 24v, then speed control is super easy! You just have to make sure to get the right VFD.

    If for instance it is a single-phase motor, then you need a single phase vfd. If it is a 3-phase motor, then you need a single-phase to 3-phase vfd. Either way, less than 2hp vfd should cost less than $140 shipped. The ones I bought were 1-phase to 3-phase and cost me $95.99 shipped.. Still the same price on Amazon! https://www.amazon.com/gp/product/B01DKJWM62/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

    If you want to locate the keypad closer to you and hte vfd mounted elsewhere, get this. For my setup it was perfect. and you can trim it to length, it's a simple ribbon cable.

    https://www.amazon.com/LAPOND-keyboard-keypad-extension-Meters/dp/B01MY12HSW/ref=pd_bxgy_328_2/146-2912344-9193710?_encoding=UTF8&pd_rd_i=B01MY12HSW&pd_rd_r=59cd40a6-92aa-11e9-b2b9-957ca6e38bcc&pd_rd_w=rZYjx&pd_rd_wg=Iovpa&pf_rd_p=a2006322-0bc0-4db9-a08e-d168c18ce6f0&pf_rd_r=VV88AFC5TXAAY0806726&psc=1&refRID=VV88AFC5TXAAY0806726
  • Ken Lau
    4
    Hey Jeff. Thanks for the info. I bought a new single phase motor for my poorly pillar drill and I asked them about a VFD for a single phase motor on my disc grinder. I spoke to a techy guy at motor direct and he told me that you can control the speed of 3 phase motors but not single phase. I personally have that set up at home. I have a 3 phase motor and a VFD that does single phase in and 3 phase out. You had any experience with single phase speed control?
  • Jeff Kushen
    31
    Ken, If you need one, there is a 1.5HP Baldor 3phase on ebay now for $40 USD. Shipping included!

    I just one one from the same seller, it was New in box!. https://www.ebay.com/itm/Baldor-Motor-1-5HP-3PH-575V-56C-No-Base/401788810029

    I'd buy it myself but I have 3 on the shelf as it is...
  • Ken Lau
    4
    Cheers for the heads up. Sadly I'm in the UK so can't take advantage of the offer!
  • Jeff Kushen
    31
    But you know what to look for now! ;+)
  • Ken Lau
    4
    Shhhhhh - the missus might be reading this!! :)
  • eeny
    3
    I vaguely remember Dell Webber getting a 110v 1" grinder given him from the states which he was then able to run with a variable speed setup. Is it possible you could use an inverter system on a 110v motor so that you could then use VFD?:chin:
  • Jeff Kushen
    31
    If you want a longer lasting and more reliable variable speed, i would skip the 110v and go straight to a 220v-240v motor. They are actually cheaper, the VFDs are inexpensive and plentiful, and running a 20amp 240v line from the panel to your work area usually isn't prohibitively expensive (Especially if you can do it yourself!) Including all materials, I ran my own 30Amp 240v circuit from the panel to the garage for $125. That included 50ft of 6/2 Romex cable (in case i need to bump up the breaker) a 30Amp dual pole breaker, L620 Locking plug and outlet, and 15ft of "Equipment power cable 600v wet area". Drill a couple holes, pop out a hole in the breaker box, and TURN OFF THE POWER TO THE ENTIRE BOX BEFORE ATTEMPTING ANY CONNECTIONS!!!!

    If you use common sense it's very easy and I didn't even need a permit in my area. But I DID have it inspected before connecting the power to the box.
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