Bench Grinder for Blades

Discussion in 'Lawn Mowing' started by jeffyr, Apr 16, 2001.

  1. jeffyr

    jeffyr LawnSite Senior Member
    Posts: 876

    I know...the RBG is the way to go for blade sharpening. It's more than I can justify though. Does anybody use a bench grinder or an angle grinder for their blades ? If so do you have a jig setup for proper angle ?

    I have been looking at bench grinders and a Delta 1/5 hp is about $50 and an off brand 3/4 hp is $20-$25. Could it be possible that the Delta 1/5 is more powerful than the 3/4 cruddy brand ?

    jeffyr
     
  2. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Posts: 4,831

    A hand held angle grinder is my 2nd choice after the RBG dedicated grinder. Delta makes a fairly good one for around $50 or less. Get a bench vise for holding the blade. I have one mounted on my trailer to this day and this is what I used to use for sharpening before I got my RBG. The vise on the trailer comes in very handy on the job for any repairs and at home, if you sharpen blades on it, it keeps your shop much cleaner sharpening them out side.

    I have tried sharpening a blade on a bench grinder and it's not my idea of fun. I would rather use a file. :(
     
  3. Skookum

    Skookum LawnSite Senior Member
    Posts: 675

    I have used a bench grinder forever now. Almost 8 years. I have looked several times at the RBG type grinders. Last time was this winter at a trade show. I will eventually get one, but I always seem to find more things I would rather have then a dedicated blade grinder.

    I do not use any sort of guide or jig. It takes a little talent and I think I have a very good eye and have just been doing them the same way for years with no problems. I took mine several years ago to a professional sharpening shop twice, that was the last time. He used a pro blade grinder. My brand new blades looked like they were 1/4 gone after he grinded them just twice on that machine.

    When I sharpen mine, I just barely take anything off, I just touch up the edge. Like I said I have had no problems in 8 years!
     
  4. mowerman90

    mowerman90 LawnSite Bronze Member
    Posts: 1,491

    Check out yard sales and get yourself an old Radial Arm Saw. (or you may already have one) Just turn the head on it sideways and get an 8" coarse grinding wheel (make sure the RPM of your motor is not more than the wheel is rated for). Then find a piece of 2x3 or 4" channel iron and bolt it to the saw table as a rest for the blade and you're in business. If the wife complains, just tell her you'll make her some wood cabinets or furniture with the saw and no one will be the wiser. Works almost as good as the RBG grinders and costs waaaaaay less.
     
  5. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Posts: 4,831

    Skookum: If you only sharpen the edge of the blade, the angle eventually gets to steep and you won't get as good of a cut. To maintain the correct angle of the blade, you need to take a bit off the whole angle of the blade, not just the cutting edge. This is where the RBG shines, it keeps all your blades at the same exact angle while getting them sharp and at slow rpm's so the blades don't get too hot.

    I think the second best way of keeping a blade at the correct angle is a hand held angle grinder.

    BTW, If your happy with the way you sharpen your blades, this is great. I'm just letting you know what to look out for. :)
     
  6. jeffyr

    jeffyr LawnSite Senior Member
    Posts: 876

    I have been using an angle grinder up until now. Easy enough. The shop I go to uses an angle grinder to sharpen hedge clippers--hooks them in a vice with the blades lined up and only takes 10 minutes. Like Skookum said though-lots of practice here.

    jeffyr
     
  7. Fantasy Lawns

    Fantasy Lawns LawnSite Bronze Member
    Posts: 1,913

    you can use a die grinder ...or a file ....or any way to get that edge ....

    the edge should be equal width (as much as possible) the length of blade area .....your motion is a long smooth one across the full length into the stone (keep the stone clean & square) ....

    it's almost like you are peeling off the top layer of the stone with each pass ...your pressure on the edge should be a constant & firm but not so hard that you lose control of the angle (don't lift it off the guide or jig)...

    the #1 problem is HEAT ...don't grinder her so hard you turn the edgin blue ....as it will be soft and dull easy ...

    I believe $ears make a jig for their bench grinder

     
  8. Skookum

    Skookum LawnSite Senior Member
    Posts: 675

    Eric,

    Thanks for the advise on the angle. You are right over time stepping up the back of the blade to the proper angle with the front is necessary.

    My point is that I feel there is no reason to do it EVERYTIME you sharpen blades. Just a small touch up on the tip is all that is usually needed. Doing it everytime takes off so much all the way across the blade. Just a touchup is enough if you are changing blades at proper intervals.

    Agree, Disagree, just another view?

    [Edited by Skookum on 04-16-2001 at 07:23 PM]
     
  9. LJ lawn

    LJ lawn LawnSite Senior Member
    from NJ
    Posts: 356

    now does anyone know WHAT angle? or proper degree blades should be?
     
  10. LeoS818

    LeoS818 LawnSite Member
    Posts: 122

    Tilt the rest on your bench grinder to hold the blade to the right angle. Start on the inside of the blade. Putting light pressure on it, pull the blade away form the grinder. With a little practice you can get a very good edge on it and retain the proper angle.
     

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