Page 2 of 2 FirstFirst 12
Results 16 to 27 of 27

Thread: No longer hesitant to ask a sharpening question; jointer knives

  1. #16
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    27,347
    Blog Entries
    1
    Quote Originally Posted by Stewie Simpson View Post
    So, based on your advise, If I had to grind back the cutting edge on 1 of my 12 inch thicknesser blades to remove a nick, I would also need to grind back the other blades to the same degree. That wont be happening.
    This seems to answer one of my questions. My thought was if one blade hits something and gets nicked most likely the other blade(s) would also be nicked.

    The other thought was some planers/jointers may not be so well built as to handle blades with slightly different weights. Like so many things this may effect some machines more than others.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  2. #17
    Join Date
    Jul 2007
    Location
    Houston TX
    Posts
    548
    Stewie, depending on the size of the nicks, on some jointers it may be possible to offset the knives right/left to take the nicks out of line, thus eliminating the tracks. It saves a rather massive grinding job.

  3. #18
    Join Date
    Oct 2010
    Location
    Australia
    Posts
    2,534
    Quote Originally Posted by Tom Vanzant View Post
    Stewie, depending on the size of the nicks, on some jointers it may be possible to offset the knives right/left to take the nicks out of line, thus eliminating the tracks. It saves a rather massive grinding job.
    Hi Tom. I agree with that approach and have used that in the past. My concern was to do with the notion that each blade needs to be kept exact on the amount metal removed during each sharpening.

    Stewie;

  4. #19
    Join Date
    Jan 2009
    Location
    Williamsburg,Va.
    Posts
    12,402
    Just bite the bullet for the initial apptrox $300.00 cost and get the Dispos-a blade system. The knives fit against a 1/16" thick back plate and rest in the bottom of the blade groove. No trouble to change blades at all. The blades cost $20.00 per edge-they are double edged like old razor blades. They are .040" thick,just dandy for making little tools like bench knives from. The cost PER EDGE is no more than sending them out,and you never have to buy new,expensive 1/8" thick blades after about 3 grinds.

    I MADE myself a blade holder for my 8" jointer after I had bought the system for the 20" planer and 8" jointer at work,and for my 15" Bridgewood planer at home. You won't be able to do this unless you're a good machinist. But,I'm really sold on the whole system. I never put off changing blades,and planed 450 bd. feet of yellow pine shelving with one set of blades. They were still quite good when I changed them,but I wanted a surface so smooth I'd not have to sand it. I needed to get those shelves done before I could unpack the multitude of boxes !

    Carbide blades work quite well,too,planing smoother than you'd expect,since they aren't as sharp as HSS knives even when new. But,they cost way too much for lots of people. Better to just buy the dispoz a blade outfit and be done with it.

    I used to just hate it when I sent blades to be ground,and those clowns would always grind 1/8" off!! A few of those jobs and your blades were 3/8" wide!!

    Grizzly used to sell dispose a blade,but they may not be selling them now.

    Of course,the best thing is the spiral head if you can spend the money. I would not be doing that till I get at least a 20" planer,though. Those things will plane curly maple smoothly due to the very steep angle of the blades,which really scrapes instead of cutting.
    Last edited by george wilson; 02-16-2017 at 8:47 AM.

  5. #20
    Join Date
    Nov 2015
    Location
    Vienna, Austria
    Posts
    168
    Quote Originally Posted by Stewie Simpson View Post
    So, based on your advise, If I had to grind back the cutting edge on 1 of my 12 inch thicknesser blades to remove a nick, I would also need to grind back the other blades to the same degree. That wont be happening.
    I have four sets of blades, 8 blades in total. I try to find among them couple of similar size. In this case it is not so difficult - just wait for other blades to get shorter

    Very important to have fresh sand paper for each blade. Also to start with coarse sandpaper for nicks to minimize strokes. In addition, it makes easier to keep edges parallel as well. Also I try to mirror my actions by swapping hands and directions to compensate for any disproportions in my body. But maybe I'm just being over paranoid here.

    Removing nicks takes quite some time. Took me couple of hours once, also because I started with P400 sandpaper... Fine for me since it happens once or twice per year and works as fitness and yoga for a good night sleep.

  6. #21
    Join Date
    Sep 2010
    Location
    New England
    Posts
    2,474
    I use the Makita 9820 sharpening wheel. It does take time to get good at it but after that it is all gravy. I sharpen my own 8" jointer and 15" planer blades on it. I probably take off 1/64" and they are very sharp. A few years ago I bought a 120 grit wheel and a 6000 grit wheel and those have only improved the process. I have two sets of blades for both machines and the whole set-up paid for itself long ago. I also have a honing jig that can be used alone or lipped over the Makita guide for sharpening chisels and plane irons, but I'm learning to do those by hand to a much finer degree.

  7. #22
    Join Date
    Oct 2010
    Location
    Australia
    Posts
    2,534
    This guy has a preference to work the flat side of his thicknesser blades, and not the bevel.

    https://www.youtube.com/watch?v=pxO4rY-msWw

  8. #23
    Join Date
    Jan 2009
    Location
    Williamsburg,Va.
    Posts
    12,402
    That guy in the video was funny!! Especially the kid.Always be sure to include your toddlers in your videos!!

    I guess his method worked o.k.,but he seemed to be putting a bit of convex curve across the width of the blade, which made me a bit concerned that it might not be gripped securely, and come flying out faster than the most maniacal knife thrower in the circus!!

    I HAD thought that he was going to show how to put a BACK BEVEL on the blade, though it was awfully thin to begin with. By back beveling your 1/8" thick(REPEAT,1/8" thick) knives,you make them scrape rather than cut. IF your planer has enough H.P. to make the back beveled blades remove wood,they will be scraping rather than cutting. Then,you can run highly figured wood through the planer without any tearing out !

    The Millwork Shop in the museum bought a Northfield planer that had carbide inserts different from any others I have seen on the hobby type planers. They stood up at least 1/2" high,and could be re sharpened by the usual style of overhead grinder that most commercial level planers come with.This planer cost 30 grand,though. And,I'd hate to have to pay for the new set of inserts it would need. The motor was so LOUD!!!!!!!!, they had to attempt to build a foam rubber lined plywood box to fit over it. Partially successful. The FAN is what makes all the noise. I just took the fan OFF of my 3 h.p. 3 phase converter on my Hardinge HLVH lathe. Then,I try not running it excessive lengths of time. Then I forget about it,and run the lathe as much as I want. So far, so good!! My bad and painful knees keep me from running the lathe to many hours at a time anyway. But, before I took the fan off the lathe,I could not hear the little noises from the lathe that tell me when the lathe is not cutting its best. You can adjust the speed and feed of the HLVH till you get the smoothest, most velvety surface from it. SCROLL DOWN<PLEASE




































































    Any how, if it were possible to grind a small back bevel on your blades, your planer would plane like magic. I knew a guy who did it quite accurately with his 20" disc sander, which I would also do when my 1/8" blades get dull. That will remove the nicks. Also,it would probably make the idiot re grinder take off bookoos amounts of metal to get the back bevel off, which he no doubt, would never have heard of!!

    If you are fairly skillful you could also take off just a LITTLE back bevel on your lunch box planer blades. But, you'd better only plane SMALL amounts of wood per pass after that, as the weak vacuum cleaner type motor could not put out enough power. You could try it on a purely experimental basis, and be prepared to make bench knives and marking knives from the blades if it didn't work. SORRY<MY COMPUTER IS PLAYING GAMES WITH ME THIS MORNING!
    Last edited by george wilson; 02-18-2017 at 9:59 AM.

  9. #24
    Join Date
    Aug 2010
    Location
    USA
    Posts
    5,582
    Quote Originally Posted by Stewie Simpson View Post
    So, based on your advise, If I had to grind back the cutting edge on 1 of my 12 inch thicknesser blades to remove a nick, I would also need to grind back the other blades to the same degree. That wont be happening.
    Is there a mechanism for adjusting the blades individually? If not, then you must grind all the blades equally, right? The thicknesser as you term it would be a nightmare if the blades were not cutting equally

  10. #25
    Join Date
    Oct 2010
    Location
    Australia
    Posts
    2,534
    Pat; on my machine each knife blade is spring loaded, requiring downward pressure to set the projection.

    A thickness planer (also known in the UK and Australia as a thicknesser or in North America as a planer) is a woodworking machine to trim boards to a consistent thickness throughout their length and flat on both surfaces. https://en.wikipedia.org/wiki/Thickness_planer

  11. #26
    Join Date
    Aug 2010
    Location
    USA
    Posts
    5,582
    Quote Originally Posted by Stewie Simpson View Post
    Pat; on my machine each knife blade is spring loaded, requiring downward pressure to set the projection.

    A thickness planer (also known in the UK and Australia as a thicknesser or in North America as a planer) is a woodworking machine to trim boards to a consistent thickness throughout their length and flat on both surfaces. https://en.wikipedia.org/wiki/Thickness_planer
    I've got a Rigid machine. Never removed the blades to see how they are registered. I rarely use it but now I'm curious

  12. #27
    Join Date
    Jan 2009
    Location
    Williamsburg,Va.
    Posts
    12,402
    I also have a never used but once Delta lunch box planer ,though I have my 15" Bridgewood. Why? Because those little lunchbox planers will frequently plane wood smoothly that the large planers will tear. Probably the speed of the cutterhead. Needless to say,it must be quite sharp,too.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •