How to trim abrasive cut-off wheel
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 25
  1. #1
    Join Date
    Jul 2006
    Location
    rochester, ny
    Posts
    1,831
    Post Thanks / Like
    Likes (Given)
    365
    Likes (Received)
    509

    Default How to trim abrasive cut-off wheel

    Broke a little piece off the wheel I use on a chop saw to cut HSS shaper knife stock. Doesn't seem like a good idea to use it as is, wondering how to make it round again?

    It was a pretty pricey wheel, $50, cut really fast, prefer not to have to replace it.

    It's not reinforced (dope slap!)
    Attached Thumbnails Attached Thumbnails img_1608.jpg  

  2. #2
    Join Date
    May 2011
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    1,613
    Post Thanks / Like
    Likes (Given)
    153
    Likes (Received)
    846

    Default

    A garbage can...there's no real safe way to do it.

  3. #3
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    9,274
    Post Thanks / Like
    Likes (Given)
    3155
    Likes (Received)
    3333

    Default

    You can dress with a silicon carbide carborundum stone, use a roller abrasive dresser like a cracker jack mini or just use it with a careful infeed to the part.

    Problem is the you can’t ring test such a wheel so all methods are dangerous. But the last method the least dangers.

    I would box it in as best I could with not much big effort, perhaps put on an old jacket, wear gloves and face protection and carefully feed it into a cut off part.

    On a surface grinder would only feed on the grind side/not the climb side.

    I have done such and found a new wheel out of the box is as likely to blow as a chipped wheel.

    Yes fire it up and let it spin for a minuet or half before using. *I would use it but take no responsibility for your using it.*

    Handling such wheels is tricky. I like to keep them on a wood stub wall hanging with a thin (1/4") plywood cover sheet.
    Wheels are difficult to hold-the-wheel for tightening so a way to hold fast the spindle is best.

  4. #4
    Join Date
    Nov 2007
    Location
    marysville ohio
    Posts
    9,011
    Post Thanks / Like
    Likes (Given)
    2565
    Likes (Received)
    5969

    Default

    Quote Originally Posted by plastikdreams View Post
    A garbage can...there's no real safe way to do it.
    You are going to repair then stand in front of it at 3000+ rpm.....yeah good plan. 50.00 wheel........Thousands at the hospital, hmmmm. seems like a no brainer to me.

  5. #5
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    9,274
    Post Thanks / Like
    Likes (Given)
    3155
    Likes (Received)
    3333

    Default

    Two out of three say scrap it ..so I guess they win.

  6. Likes woodchuckNJ, MetalCarnage liked this post
  7. #6
    Join Date
    Mar 2009
    Location
    Eureka, CA
    Posts
    3,617
    Post Thanks / Like
    Likes (Given)
    689
    Likes (Received)
    1189

    Default

    Richard,

    Don't have any insight into your current problem but I'll say this...I have cut bazillions of moulder knives in D2-HCHC using a chop saw with a run of the mill abrasive wheel and it works great. Unless your HSS is a whole bunch tougher than D2, maybe give the abrasive wheel a try.

    Stuart

    https://www.amazon.com/Metal-Abrasiv.../dp/B0070OJS7K

  8. #7
    Join Date
    Apr 2011
    Country
    AUSTRALIA
    Posts
    105
    Post Thanks / Like
    Likes (Given)
    31
    Likes (Received)
    37

    Default

    On a weekend with all shops shut, I had a similar problem a few years back with a thin surface grinder wheel.
    I put the wheel on a slow speed grinder with a quick and dirty arbor spacer, I stood well aside and dressed it gently at 790rpm. Once the diameter was below the broken bit, I put it on the surface grinder and dressed it true - gently and carefully. It was fine after that.
    Mind you, I never trusted it and I wouldn't do it when the shops are open or the job wasn't in a rush....

  9. #8
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    3,845
    Post Thanks / Like
    Likes (Given)
    668
    Likes (Received)
    1673

    Default

    Im my younger years I'd have just pressed on with it.

    Sent from my SM-G930R4 using Tapatalk

  10. Likes Rob F. liked this post
  11. #9
    Join Date
    Nov 2018
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    153
    Post Thanks / Like
    Likes (Given)
    27
    Likes (Received)
    102

    Default

    I routinely repair chipped and cut to smaller size abrasive wheels and grinding stones on wterjet cutter. On thin abrasive cutoff wheels takes a minute or less to cut a new circle. I use the centre of the wheel as referance point for the waterjet cut and then true the wheel(s) with diamond. Even if you do not have a waterjet cutter, taking it to a shop that has is usually less than the cost of new, or special size, wheel.

  12. #10
    Join Date
    Aug 2012
    Location
    California, Central Coast
    Posts
    2,700
    Post Thanks / Like
    Likes (Given)
    2078
    Likes (Received)
    972

    Default

    Used to be we would break chunks out of the chop saw blades with pliers to cut hard material. seemed to slow them glazing up. If saw has a guard I would run it, just stand to the side.
    You could also use an angle grinder to "dress" it.

  13. #11
    Join Date
    Aug 2014
    Location
    bainbridge island
    Posts
    1,044
    Post Thanks / Like
    Likes (Given)
    196
    Likes (Received)
    252

    Default

    for what its worth an 8" aluminum oxide grinding wheel at 3600 rpm scares me. you've got a 14" wheel rated for 3800 rpm. that's equivalent to 29,700 rpm for a 5" angle grinder, mine runs not even half that speed, or 1/4th the centrifugal "hoop" stress that disk is rated for.

    if you're using that disk at 1750 rpm, i would continue to use it. and if you're worried about it blowing up then you need to quit thinking that an undamaged disk won't blow up.

  14. #12
    Join Date
    May 2017
    Country
    FINLAND
    Posts
    1,503
    Post Thanks / Like
    Likes (Given)
    432
    Likes (Received)
    692

    Default

    Quote Originally Posted by Rob F. View Post
    Used to be we would break chunks out of the chop saw blades with pliers to cut hard material. seemed to slow them glazing up. If saw has a guard I would run it, just stand to the side.
    You could also use an angle grinder to "dress" it.
    I wouldn't run any sort of disk in a chop saw without guards, broken or not.

    Diamond wheel on a angle grinder would cut the excess off in a haste. Either "dress" or carefully slice from the side while spinning the chop saw by hand.

  15. #13
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    6,243
    Post Thanks / Like
    Likes (Given)
    1486
    Likes (Received)
    4357

    Default

    Try some of these, or a similar reinforced wheel: https://www.amazon.com/IVY-Classic-4...ustomerReviews

    $13, not likely to fail like your unreinforced wheel did, get a few other brands while you're at it to do comparisons. Ditch the broken wheel, or place it on a hook with a note saying "This is why you don't buy unreinforced chop saw wheels".

  16. #14
    Join Date
    Sep 2015
    Country
    UNITED STATES
    State/Province
    Tennessee
    Posts
    454
    Post Thanks / Like
    Likes (Given)
    234
    Likes (Received)
    349

    Default

    Quote Originally Posted by Wlodek View Post
    I routinely repair chipped and cut to smaller size abrasive wheels and grinding stones on wterjet cutter. On thin abrasive cutoff wheels takes a minute or less to cut a new circle. I use the centre of the wheel as referance point for the waterjet cut and then true the wheel(s) with diamond. Even if you do not have a waterjet cutter, taking it to a shop that has is usually less than the cost of new, or special size, wheel.
    The problem with that is there could be a crack you don't see all the way to the arbor hole. I had a friend who lost an eye to a wheel that let go after it was damaged.

  17. #15
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    13,471
    Post Thanks / Like

    Default

    Quote Originally Posted by Rob F. View Post
    Used to be we would break chunks out of the chop saw blades with pliers to cut hard material. seemed to slow them glazing up. If saw has a guard I would run it, just stand to the side.
    You could also use an angle grinder to "dress" it.
    Angle grinder and no need to spin the cut off wheel fast....just rotate it against the angle grinder.

  18. #16
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    9,274
    Post Thanks / Like
    Likes (Given)
    3155
    Likes (Received)
    3333

    Default

    I would by hand notch an aluminum oxide wheel with notches about an inch apart but nicely spaced and perhaps 1/4" deep using a cut off wheel . This to make the wheel act a couple letters softer for surface grinder work. SG are safer than OD, cylindrical and TC grinders because the SG wheel faces a safer direction.

    I often used a a heavy sheet metal 10" x 14" (perhaps 12 gauge)that I would place between me and the work on a SG or TC grinder, Mostly to control the dust and coolant but it also to gave me some more protection.

    We had a cut off wheel set up on a Cincinnati #1 TC grinder with having a compound angle vise, With that we would do simple cut off chops and angular cuts to rough cut most any odd angle to rough shape cutting tools and steel parts going to a milling operation. That method saved many hours. Coming into parts at angle took a some care needing a very slow in feed to get a start in the part, some times needing a little cross feed so the wheel would get straighter for the plunge.

    Cant remember notching a cut off wheel but likely would have done that if I felt the need, likely would use a diamond wheel for that notching.

    Still it is not good to tell others to do odd things on grinders. Guys who grew up with senior grinder hands learn methods to do such things in a safer way..That is not for the new guy or guys who might not know or be willing to do the drill every time. Dumb things can get someone killed...like leaving the T wrench in a chuck or putting a wheel on a spindle with not dressing it, some guys just cant/wont do the drill.
    Last edited by michiganbuck; 04-01-2019 at 08:46 AM.

  19. #17
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    3,845
    Post Thanks / Like
    Likes (Given)
    668
    Likes (Received)
    1673

    Default

    Quote Originally Posted by Rob F. View Post
    Used to be we would break chunks out of the chop saw blades with pliers to cut hard material. seemed to slow them glazing up. If saw has a guard I would run it, just stand to the side.
    You could also use an angle grinder to "dress" it.
    Yup, the welder's helper would gash the wheels.

  20. #18
    Join Date
    Jul 2006
    Location
    rochester, ny
    Posts
    1,831
    Post Thanks / Like
    Likes (Given)
    365
    Likes (Received)
    509

    Default

    Thanks for the replies, not surprised many suggest just replacing it. I broke that little piece off by trying to pick it up holding it there, not realizing it wasn't reinforced. The machine is full guarded, and I wear a face mask when I use it, so still tempted to trim it back. I use it very infrequently these days.

    I bought the wheel from C.G.G. Schmidt Co, the outfit that makes woodworking knives and cutter heads, they sell it specifically for cutting hss knife stock. It cut like butter, WAY faster than all the other cut off wheels I tried, and with no heat, well worth the cost.

  21. #19
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    9,274
    Post Thanks / Like
    Likes (Given)
    3155
    Likes (Received)
    3333

    Default

    QT[ still tempted to trim it back.]

    Using it carefully is the safest way to trim it back.

    if you are worried.. is there any way you can stand well out of harms way and from there slow feed into a cut off operation..
    what are you using it on..perhaps a large chop saw like machine..
    Agree such a wheel is often way better than a reinforced wheel.

    It is good to wear a dust mask for any abrasive grinding.. even heavy sanding by hand.
    Last edited by michiganbuck; 04-02-2019 at 08:19 PM.

  22. #20
    Join Date
    May 2006
    Location
    Seattle
    Posts
    1,789
    Post Thanks / Like
    Likes (Given)
    33
    Likes (Received)
    324

    Default

    Many years ago I worked at a place that build prefab metal buildings which went on barges to Alaska. They had a 20" abrasive saw. I busted a little smiley into it the same as you did. I young and scared of losing my job and I just kept cutting with the same blade. After cutting parts for a few minutes, smiley was all gone. I'm still here.

    I vote for keep on using it. Cutoff wheels are not like surface grinding wheels. Cutoff wheels are reinforced to keep them from cracking and coming apart.

    Just my opinion, worth exactly what you paid for it. If you follow my advice and kill yourself, please don't complain to me! :-)

    metalmagpie

  23. Likes michiganbuck liked this post

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
  •