Grockel grinder - truing the ways
Close
Login to Your Account
Results 1 to 15 of 15
  1. #1
    Join Date
    May 2019
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    6
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    2

    Default Grockel grinder - truing the ways

    I am going to “true” the “ways” on my grinder.
    The ways are 11-1/2’ long, about 1-3/8” wide and about 20” apart. The head travel 8’.

    First I need to assess accurately just what I have.
    Then I need to make corrections.
    I would like to map it out about ever 1 inch or so.

    So – how do I do that? I don’t think levels alone will tell me enough.
    I don’t think piano wire is accurate enough, but it is an option.
    The only thing I can think of is some form of laser or optical device.

    Of course I would like it to be as accurate as possible but I think I would be happy if I could get it to within 0.005” over the full length. A small deviation over the full distance is tolerable. Small bumps and dips in a short distance are not.

    Then how do I correct it. Is this doable by scraping? Perhaps a temporary rail trolley setup to move a grinding head over it.

    I will add a picture if I can do that as a new member without prior posts.

    It is a Gockel G30 with a 10HP head.
    The ways are covered with a strip of spring steel. The head rolls on 4 steel rollers.
    The ways are steel not cast. They have developed a small crown across the width.

    I know there is lots on information I am not including here but did not want to make it too long.
    I need to be able to do this with only putting it out of service for a week at a time. Could be multiple times.

    If there are short low spots could I fill with Belzona product or something.
    I am not a machinist but was an industrial mechanic.

    I can spend a few thousand for gear but not much more.

    Thanks

  2. Likes cash liked this post
  3. #2
    Join Date
    Jan 2011
    Location
    Fairfield, PA
    Posts
    374
    Post Thanks / Like
    Likes (Given)
    180
    Likes (Received)
    175

    Default

    How old is this machine?

    To be clear, which way are the ways/rails crowned? Along the length or across from front to back?

    The only trouble that I have ever encountered was rust and grit under the wear strips. We would occasionally pull up the strips and stone the rails, coat with oil, and re-tension the wear strips. We have had to replace the wear strips but never had to touch the rails.

    These Gockel machines are weldments. You can twist and raise/lower them easily at the mounting pads.

    If the rails are indeed worn then I imagine that the grinding head slide is shot also. They get sloppy especially if it is an old machine. There is not much there to keep the grit and coolant out of the head ways.

    The carriage rides on four bearings as you said. Also, there are four that ride underneath the rails, and there are inboard bearings.

    I cannot remember if the rails are screwed or welded on. If fastened, then they can be removed and surface ground. If not, since the grinding head/carriage is relatively easy to remove, the whole base can be sent out for grinding.

    Gockel did not scrape the rails, they were ground.

    There is a member on this site named CASH. He would have more insight.

    Bill

  4. Likes cash liked this post
  5. #3
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    10,197
    Post Thanks / Like
    Likes (Given)
    3459
    Likes (Received)
    3646

    Default

    A temporary rail trolley or the grinders trolly if the rollers are still good might hold an indicator to strike the chuck off to one side where it got little or no wear. Yes looking for how straight a path not a long taper because the whole chuck may need to be tilted.
    I dont know how the rails are attached.The wear strip might be considered perhaps just doing them.
    Should get it to better than .002 IMHO

    Might set a straight edge on the chuck and shim it dead straight then indicate.

  6. #4
    Join Date
    Jan 2011
    Location
    Fairfield, PA
    Posts
    374
    Post Thanks / Like
    Likes (Given)
    180
    Likes (Received)
    175

    Default

    You could contact Gockel America and chat with them:

    Grinding Machinery & Supply, Gockel America

    Also, the chuck trunnions and journals may be worn. The grease gets washed out quickly. Does this machine have the hydraulic chuck clamp or is it manual?

    Bill

  7. Likes Matt_Maguire, michiganbuck liked this post
  8. #5
    Join Date
    May 2019
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    6
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    2

    Default

    Hi,

    Good questions.
    How old - old - near as I can tell about 1968.
    Rail crown - this is across the width (1 3/8") - I was a little surprised by this, the wheel must have convex wear - have not checked.
    Welded - yes this machine is a weldment. Do you mean you can actually twist this machine with the jacking bolts. There are 6 of them.
    When I set the machine in place and leveled it I could not detect any twisting as I leveled it. It seems like a pretty sturdy beam.
    Head slide - yes other items need attention. Most of those I think I can deal with. Straightening 12' rail is not so obvious to me.
    Carriage bearings - as you discribe except this machine does not have any "holddown" rolls under the rails.
    I wish the rails were screwed on - no luck - welded.
    I will be removing the entire carriage but sending out the base (est 4000/bs) is not an option for me. I have to do whatever in situ.
    Scraping - I was thinking more in terms of how to remove metal not so much surface finish. If grinding is doable I think that would be more practical.

    Any thoughts on how to accurately assess rails?

    Thanks
    Glen

  9. #6
    Join Date
    Jan 2011
    Location
    Fairfield, PA
    Posts
    374
    Post Thanks / Like
    Likes (Given)
    180
    Likes (Received)
    175

    Default

    Quote Originally Posted by PassNCrash View Post
    Hi,

    Good questions.
    How old - old - near as I can tell about 1968.
    Rail crown - this is across the width (1 3/8") - I was a little surprised by this, the wheel must have convex wear - have not checked.
    Welded - yes this machine is a weldment. Do you mean you can actually twist this machine with the jacking bolts. There are 6 of them.
    When I set the machine in place and leveled it I could not detect any twisting as I leveled it. It seems like a pretty sturdy beam.
    Head slide - yes other items need attention. Most of those I think I can deal with. Straightening 12' rail is not so obvious to me.
    Carriage bearings - as you discribe except this machine does not have any "holddown" rolls under the rails.
    I wish the rails were screwed on - no luck - welded.
    I will be removing the entire carriage but sending out the base (est 4000/bs) is not an option for me. I have to do whatever in situ.
    Scraping - I was thinking more in terms of how to remove metal not so much surface finish. If grinding is doable I think that would be more practical.

    Any thoughts on how to accurately assess rails?

    Thanks
    Glen
    What keeps the carriage from lifting?

    This one is older than any I have dealt with. I think the oldest was 1984.

    I would start with contacting Gockel first. See what they have to say.

    Bill

  10. #7
    Join Date
    Aug 2007
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    2,081
    Post Thanks / Like
    Likes (Given)
    1116
    Likes (Received)
    946

    Default

    I am very familiar with these style machines, reform, gockel, toyo. Many of our wood industry customers have them and I will go into their facilities and perform maintenance, grind in their magnets and help with wheel selection.

    Feel free to PM me if you would like to talk.

    In your area is Akhurst Machinery, they sell Reform but I assume they would perform maintenance on any brand.

  11. #8
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    2,830
    Post Thanks / Like
    Likes (Given)
    1792
    Likes (Received)
    1008

    Default

    How to assess the rails? I am not familiar with these machines. But I know of two ways to accurately map out 12 foot long ways.

    One way is to use an autocollimator with a fixed light source mounted on the machine, and a mirror on the traveling part or on a slider that moves along the way. A two-axis autocollimator will let you map out the straightness in both the vertical and horizontal directions. A good autocollimator will let you measure to 1/10 of an arcsecond, which is corresponds to 70 millionths of an inch deviation over 11.5 feet.

    The second way is with a pair of precision differential electronic levels such as a Taylor-Hobson Talyvel 3, 4, 5 or 6. You leave one head parked at the end and move the other head along the way. This only measures the vertical deviations, but is easier and less fussy than the autocollimator, and provides similar accuracy, around 0.1 or 0.2 arcseconds. For a knife grinding machine with square flat ways this should not take more than a few hours. You move the level along the ways in steps of 3 or 4 inches, recording the angle at each station. Adding up the differences and subtracting the linear trend gives a graph of the deviation from a straight line.

    It is smart to do some careful measuring before you start removing any metal.
    Last edited by ballen; 12-19-2019 at 12:44 AM.

  12. Likes PassNCrash liked this post
  13. #9
    Join Date
    May 2019
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    6
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    2

    Default

    Thanks for all the good info.
    A few replies and more info.
    - What holds the head down - nothing mechanical, just the weight of the head - estimate 300lbs.
    I do find myself wondering somethings if I take too heavy of a downfeed if this is an issue, but does not seem to be.

    I should have spelled out a little more clearly that I am a small operation and can not afford some of the better methods that would give great results. I spec'ed out a laser system but it's about $40,000.00. Even renting(with shipping etc.) was more than I want to spend.
    Also I am on an island so everything is a ferry ride.
    Transporting the unit is out of the question.
    Accuracy of the work coming of the grinder meets spec. but I know it could be better so I and want to do this before issues arise.
    So I guess I am looking for good accuracy for a moderate cost. I don't need 0.0001"
    Do you know of anywhere (Canada) to rent a autocollimator or Taylor-Hobson?

    Thanks

  14. #10
    Join Date
    Mar 2013
    Location
    Surbiton, surrey, UK
    Posts
    1,635
    Post Thanks / Like
    Likes (Given)
    2015
    Likes (Received)
    1051

    Default

    Honestly for the numbers youre talking I think a 10sec level would be more than enough, be sure the bed isnt moving as you traverse the head. You could ride the level on the head inline with and across the ways to give a decent idea of twist and global condition of the ways, every foot would be enough for that. You could look for local holes with an indicator mounted to a 123 block riding the way, indicate right next to the block, could also keep an eye the level for sharp local movement. If youre concerned about the horizontal number I think a taught wire should work fine, failing that you could mic over the gibbed sliding surfaces, should be pretty close to zero the length of the bed if its in decent shape.

    Could scrape the bed easy enough as long as its not too hard, its box type ways isnt it?. Something like this?

    Id think it would be one of those occasions where you want to finish it up with a very low depth of cut as the head uses rollers.

    Cheers
    D

  15. Likes cash liked this post
  16. #11
    Join Date
    May 2019
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    6
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    2

    Default

    Thanks for posting the picture Demon73. Yes that is very close to what I have. Mine little older and maybe a bit wider probably a lot heavier.
    It clearly shows what I was not great at describing in words. The main thing being the 2 long "ways" with spring steel wearstrips.
    Can not tell if yours are removable but mine are not.
    By a "10 sec" level I take it you mean a Starrett 199Z type level or similar. I have a 98-12 but would be willing to buy a 199Z for this.
    I think I understand most of your comments. I think I will order the level.
    I have been wondering if "stepping" a accurate level along the ways would be practical or I am asking to problems with compounding errors by walking a level over 12'. Maybe if I used two gauge blocks under the level and string 12 point together.
    If I was to attempt to scrape the ways does anyone know of a source for a 3' or so long granet pallet than I could lay on the ways to blue the high spots.
    As you know the head rides on wheels so it will not span any low spots so I have to be very careful not to create any.

    Thanks
    Glen

  17. Likes cash liked this post
  18. #12
    Join Date
    Aug 2007
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    2,081
    Post Thanks / Like
    Likes (Given)
    1116
    Likes (Received)
    946

    Default

    I think you would be better off to remove the spring steel strip, remove the ways and have them sent out to be ground.

  19. #13
    Join Date
    Jan 2005
    Location
    The Netherlands
    Posts
    5,852
    Post Thanks / Like
    Likes (Given)
    280
    Likes (Received)
    1511

    Default

    I would start with removing the spring steel wear strips
    You say they cannot be removed? I say they can

    Then level the whole thing again and replace the spring steel
    Then see where you are
    Also keep in mind that the accuracy of the work also depends on the tilting magnet or clamping beam
    The grinding head needs to move parrallel with the clamping beam tilted at the requiert angle
    Straigtness is of less concerne as the knives beeing ground are flexible enough if the straightness is off graduatly


    Peter

  20. #14
    Join Date
    May 2019
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    6
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    2

    Default

    Yes of course the wear strips can be removed. I have a set ready to replace them.
    The wear is not the wear strips, it is the "ways" the wearstrips sit on.
    They are NOT removable.
    There are no other issues concerning me other the the wear on the "ways"
    There have been some good suggests on accurately assessing the wear.
    Unfortunately they are a little pricey.
    I am going to purchase a 199Z Starrett to assess the wear then rig up some temporary straight edges and build a grinding sled to ride on them.
    Open to other suggestions for assessing and grinding the ways nice and flat.

    Glen

  21. #15
    Join Date
    Jan 2005
    Location
    The Netherlands
    Posts
    5,852
    Post Thanks / Like
    Likes (Given)
    280
    Likes (Received)
    1511

    Default

    Once you have your Starrett level the whole thing again
    Is there any vissable wear on the ways???
    If not I think it is just that

    Peter


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
  •