wheel for cylindrical grinding
Close
Login to Your Account
Results 1 to 7 of 7
  1. #1
    Join Date
    Feb 2010
    Location
    ch
    Posts
    2,045
    Post Thanks / Like
    Likes (Given)
    187
    Likes (Received)
    267

    Default wheel for cylindrical grinding

    im looking to get 2-3 wheels for an od grinder im refurbishing. the size is 250-300 mm. my supplier recommends:

    80 (grit), h (hardness), 8 (structure), no prosity data.

    the mixture is a propriatary "93a". rep sais this will grind soft and hard steels (whatever that means), so i dont have to get two wheels.

    any thoughts? im afraid the wheel will be too fine and too soft, although the stuff i will be grinding will come from the lathe usually, so just finishing, machine is manual anyway. i have no idea what the wheel is that was on there.

    for non ferrous metals he recommends:

    15c80h15.

  2. #2
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    8,611
    Post Thanks / Like
    Likes (Given)
    2558
    Likes (Received)
    2922

    Default

    80 H would be on the finer and softer side of my selection for surface grinding...but have used that wheel on OD grinders and surface grinders..

    Most likely the rep knows the machine and the material, and has other customers doing similar so a good idea to go with his recommendation for a starting point. If not getting a price break for buying three wheels you might just buy one and test that wheel for surface finish and holding up to your part.
    QT: [the size is 250-300 mm.] near 12" ...is that the part or the wheel size..
    Buying used wheels you take chances because saving great amounts of money. Buying new wheels it is best to stick with one manufacturer because the hardness factor can be better selected for the next harder or softer. for instance going from a H wheel to a J wheel, and changing the manufacturer at the same time the J may be the same hardness as the other manufacturer's H.
    Last edited by michiganbuck; 01-10-2018 at 07:43 AM.

  3. #3
    Join Date
    Feb 2010
    Location
    ch
    Posts
    2,045
    Post Thanks / Like
    Likes (Given)
    187
    Likes (Received)
    267

    Default

    250-300 mm is the wheel.

  4. #4
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    8,611
    Post Thanks / Like
    Likes (Given)
    2558
    Likes (Received)
    2922

    Default

    12" wheel....Then perhaps around 2000RPM..good for spindle bearings and for a cool part.
    Grinding method is also important. Going right and left with cross in feed is common..but for some work slow constant plunge to + .003 or so then travel left and right can save wheel and time..The wheel peripheral makes the strongest grind but few use it as much as it could be used. like going into a corner/shoulder with a dressed Od and a dressed corner/side/shoulder with turning the wheel head, many just side wheel....Yes in most cases wet is best.

    Below 10" (back in the day) we would kick RPM to 2500 but now the rule is go by the label as per OSHA...

    there are some handy grinding tricks on youtube.
    How to remove the taper from an O.D. Grinder without grinding the part. - YouTube

  5. #5
    Join Date
    Feb 2010
    Location
    ch
    Posts
    2,045
    Post Thanks / Like
    Likes (Given)
    187
    Likes (Received)
    267

    Default

    so don has put up some new vids since the last time i looked. i wonder how his slit arbor doesnt expand from being ground on centres.

    anyway, can you recommend some norton wheels (i can get those too)? soft, hard, non ferrous. not concerned with finisch too much as it will probably depend more on the machine than the wheel. 250/300 x 20/25 x 51.8 mm.

  6. #6
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    7
    Post Thanks / Like
    Likes (Given)
    2
    Likes (Received)
    5

    Default

    I get this question all the time from my customers. And my answer is always the same: just about any grit type will do. White, pink, brown, mono, NQ. And just about any wheel grade will do: H, I, J. What matters most is grit size. The very common mistake that is responsible for 80% of the burn, chatter and size-holding issues in cylindrical-grinding is to choose too-large a grit size and dress the wheel dull (with a slow diamond traverse) to achieve surface finish. Don’t go this route. Choose a reasonable grit size (or close, it’s not an exact science), and you’ll find a lot of your other problems go away. Here are some guidelines:

    Ra=32, 60 or 80 mesh
    Ra=24, 100 mesh
    Ra=16, 120 mesh
    Ra=8, 150 or 180 mesh

    These mesh sizes will see too fine. Do it anyway, and then dress with an Overlap Ratio of 2-4 (if you don’t know Overlap, take my course or watch my videos).

    We could also get into wheel speeds, plunge speeds and workpiece RPM, but the most important thing is grit size. Finally, if you’re doing cylindrical-traverse, choose a roughing traverse speed and workpiece RPM combination such that you use 50% to 80% of your wheel width each workpiece revolution. (Very relevant to roll-grinding.) I’ve gotten customers using the right grit size and traverse speed and seen their cycle times cut by 75% (and general headaches go away). But they must first understand the fundamental concepts of dressing overlap and grinding overlap. Once they do, everything else usually takes care of itself.

    I hope this helps.

    Jeff
    The Grinding Doc

    Jeffrey A. Badger, Ph.D.
    The Grinding Doc
    Expert in Grinding
    Independent Consultant
    Making grinding solutions practical & simple
    +1 512-934-1857
    [email protected]
    Welcome! - Metal Grinding Expert Classes and Clinics - TheGrindingDoc

    Take your grinding to the next level with the
    High Intensity Grinding Course
    Columbia, SC USA -- 6-8 February 2018
    hosted by S.L. Munson
    Anaheim, California USA -- 9-11 April 2018
    hosted by Rush Machinery

  7. #7
    Join Date
    Feb 2010
    Location
    ch
    Posts
    2,045
    Post Thanks / Like
    Likes (Given)
    187
    Likes (Received)
    267

    Default

    hi doc

    i have seen a lot of your vids and its the best source of info on the net for beginers and pros. you wouldnt believe how many times i impressed grinder hands with the coolant velocity stuff i learned from you.

    however, you seem to be making this simpler than it is. there are so many grains and mixtures lately, so that i would like to use the latest technology. all that stuff is propriatery to the manuf., and therefore diffucult to analyse.

    i have a real difficulty to find a wheel of the 250/300 x 20/25 x 50.8 size for od grinding. i thought i would need three: soft, hard and grey iron.

    if you can help i will appreciate it. im based in switzerland, so norton, 3m, tirolit, krebs etc. are an option.

    i undestand you want a harder wheel for od as compared to surface, because the contact is smaller and gritt breaks down easier. however about structure and porosity im not sure, controversial info from manufs., probably due to differen types of grain.

    so where do i get my wheels?


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
  •