Results 1 to 7 of 7

Thread: Do Neg Hook Dado Blades Lift Workpieces?

  1. #1

    Do Neg Hook Dado Blades Lift Workpieces?

    I have a dado blade set with a negative hook angle and I'm wondering if that causes any more lifting while feeding a workpiece, than normal? My boards feel like they want to lift while feeding. I've been looking at a Forrest Dado King and that looks like it does not have the neg hook. I know both are great dado sets, so no need to tell me you love yours, cause I'm sure I'd love a Forrest, but that neg hook makes me wonder about the lift.

  2. #2
    Join Date
    Feb 2003
    Location
    McKean, PA
    Posts
    15,595
    Blog Entries
    1
    I don't know if a negative hook angle makes the board lift more, but any time you make a cut on a TS with the blade very low there is a tendency for the wood to want to lift. Dado blades are nearly always used at low heights and they make wider cuts so the lifting effect is more noticeable.
    Lee Schierer
    USNA '71
    Go Navy!

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Please Contribute

  3. #3
    Makes sense Lee. Thanks. I thought maybe the net hook might add to the problem, but I guess it doesn't. Thanks for the input.

  4. #4
    Join Date
    Jun 2006
    Location
    The Hartland of Michigan
    Posts
    7,628
    Not sure about a table saw, but a neg hook with a RAS would work great.
    Never, under any circumstances, consume a laxative and sleeping pill, on the same night

  5. #5
    Join Date
    Apr 2007
    Location
    Columbus, Ohio, USA
    Posts
    3,441
    I have never seen the question asked with respect to a Dado set, but, this is what I know...

    The higher the hook angle the more aggressive the cut. With an aggressive cut (higher hook angle), the blade will pull into the wood or pull the wood cutting faster. This can also make it more difficult to control and therefore potentially less safe for certain operations. This is why you have a negative hook angle on miter saw or sliding saw (so the blade does not pull itself into the wood). On the other hand, you have a positive hook angle on a rip saw.

    Off hand, I think that you will generate more heat with a negative hook angle if for no other reason than you are probably cutting more slowly.

    So, do I expect more tendency to lift with a negative hook angle; ummm, in "guess mode" I would say yet because it is less likely to "pull" the wood into the blade. It might be easier to control the feed rate, however.

  6. #6
    Join Date
    Mar 2003
    Location
    Upland CA
    Posts
    5,548
    Don't want to hijack the thread please, but as far as RAS are concerned, my experience is that negative angle teeth don't seem to make much difference. I have a Freud Super Dado set with negative teeth, and safety bumps, which seems to pull about the same as my Forest Dado King with angled rake, and no bumps. Tested back to back. Perhaps someone else has had a different experience?
    Rick Potter

    DIY journeyman,
    FWW wannabe.
    AKA Village Idiot.

  7. #7
    Just based on simple physics a negative hook blade is going to lift more than a positive hook. By how much or whether its appreciably detectable who knows. The teeth are entering the work to keep it in compression for the first 50% of the cut (or slightly more).

    Id imagine when sharp it'd be imperceptible but as the blade dulls (no different than a positive hook blade) the work would want to lift more.

Posting Permissions

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