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Curved Clips: Cut on the wheel or the platen?

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Patrice Lemée, Apr 2, 2012.

  1. Patrice Lemée

    Patrice Lemée

    Aug 13, 2002
    Here is a small clip I put in using the 10” wheel and working vertically. Not my forte and a real pain to get it all symmetrical in all directions and from one side to the other.

    [​IMG]


    On another thread, Fred and Raymond suggested doing it on the platen, horizontally of course. But if I am not mistaken this will result in clip basically like this (B) instead of the wheel cut clip (A). Pardon the crappy drawing. :(


    [​IMG]


    So how do you end up doing it yourself and what's your preference?
     
  2. jonnymac44

    jonnymac44

    Sep 27, 2007
    Patrice, I've used both the flat platen and an 8 inch wheel to do some of mine, but I do them horizontally so my results may be different. Either way, I know they're tough to get just right.
     
  3. NickWheeler

    NickWheeler

    Dec 3, 1999
    Radiused platen... :)
     
  4. Fred.Rowe

    Fred.Rowe Dealer / Materials Provider Dealer / Materials Provider

    May 2, 2004
    Split the belt and it can be done on either the wheel or the platen.

    What cad program are you using?:)
     
  5. Josh Dabney

    Josh Dabney

    437
    Nov 23, 2008
    I ground a few clips like that Pat. I had good success by making a platen out of 1" square tubing that mounts right to the angle iron mounts for the standard KMG platen.

    The skinny platen allows flat grinding the tight curve without chewing up your grind like will happen with a 2" wide belt.

    [​IMG]
    [​IMG]

    It only took a few minutes to drill and tap the tubing for mounting. I wasn't concerned with durability of the platen over the long term when I made it as it was experimental at that time but it worked well for me. If I were going to use it alot I'd make one with 1" square solid so I had lots of thickness to surface grind it back to flat or radius the the face of the plated as Nick suggests.

    Hope this helps buddy- Josh
     
  6. james terrio

    james terrio Sharpest Knife in the Light Socket Moderator

    Apr 15, 2010
    I haven't done very many, but I found that what works best for me is to rough them in on the edge of the platen and clean them up with files. If you're cutting them after HT, this may prove problematic.
     
  7. jdm61

    jdm61 itinerant metal pounder Knifemaker / Craftsman / Service Provider

    Aug 12, 2005
    Draw filing, anyone?;)
     
  8. NickWheeler

    NickWheeler

    Dec 3, 1999
    My radiused platen idea came directly from my friend Mike Vagnino. It's just a piece of some 5/16 or 3/8 tool steel (I think I used O1, it was whatever was in my "too short for a knife, but too good to scrap" tool steel bin at the time ;) :) ). Drilled and tapped it to bolt up to the KMG flat platen tool arm. I'd guess the radius is equivalent to a about a 6" to 7" wheel (keep in mind, the radius is oriented so that it's round from side to side, not top to bottom).

    I have a dedicated tool arm for mine. If I didn't, I would have just drilled a couple/few locater pin holes in the existing flat platen and pressed mating pins into the radiused platen, and probably JBweld a few rare earth magnets in it too... this way you could just slap it on and yank it off as needed.

    We all love Josh, so I really don't want this to sound mean or snobbish or anything :foot: :eek:, but the problem FOR ME with a flat platen (even a narrrow one) to grind curvy clips, is it will cause the bottom end of the clip grind to "trail out." If you look at Josh's second photo you can see what I mean- there's a nice, clean clip grind following the profile of the blade, and then right at the tail end of the clip, the bevel actually kicks back the other way. Yes, that's agressive nit-picking, but that's how I make a living. Sorry Josh. :eek:


    There's been a lot of guys, for a whole lot of years, that grind them on a wheel with the knife pointed down. I have done it, but I get too nervous when I can't see what I'm grinding.

    If I had a horizontal grinder with the right tool rest (TW-90 or the Fellhoelter) I'd use that with a contact wheel. But I don't... :( Yet. :D
     
  9. Patrice Lemée

    Patrice Lemée

    Aug 13, 2002
    Thanks for the feedback guys.

    Fred, this was expertly :barf: done with Inkscape.

    Exactly my feeling Nick. Curved platen on the top of my "jig to make" list. Thanks.
     
  10. Daniel Fairly Knives

    Daniel Fairly Knives Full Time Knifemaker Moderator Knifemaker / Craftsman / Service Provider

    Jan 9, 2011
    I hear that Jim Bowie did it with CNC powered by burning mountain lion oil.

    This is somewhat off subject but I have noticed when cutting in clips (the few I have done) that a straight clip starts to get a small curve to it after a bit of grinding. The other day I was wondering if that may be some of the reason behind curved clips... I hear they are a nice shape to blacksmith as well. My thoughts are that in older times many designs were influenced by the manufacturing process and the clipped blade may be one of them. (just a wild guess)
     
  11. kc custom

    kc custom KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Apr 20, 2005
    That elusive clean one cut pass without being able to see 100% of what you're doing. Although
    smaller than what most of you guys are doing-"drawn" a vertical upward pull my favorite a 10" wheel.
    "Cut" horizontal even pass while looking down at the swedge. Favorite wheel 8" or smaller. Now do
    the same to the other side and get them symetrical. Them %&#* swedges!
    Ken.
     
  12. james terrio

    james terrio Sharpest Knife in the Light Socket Moderator

    Apr 15, 2010
    Probably partly that, and partly the fact that a sharp concave edge cuts like crazy. Chicken or egg? I have no idea... :confused: either way, it works :)
     
  13. Josh Dabney

    Josh Dabney

    437
    Nov 23, 2008
    Nick- Comments like yours are greatly appreciated ! You clearly described your issue with a flat platen AND offered a complete explaination of your method.

    I think many times more experienced makers such as yourself refrain from commenting on something like this for just the reasons you mentioned so I thank you for taking the time. For those of us who've grown past our newbie stage and have settled in a bit it gets more and more difficult to continue to progress as a maker but detailed replies really offer the best oppertunity to keep us challenging ourselves with better execution.

    No apologies necessary !!!! I'm actually quite pleased my post instigated a "teaching moment" we can all benefit from. :D

    Pat will skip the "skinny flat platen" route and I'll skip the "radiused platen" route and go forward learning the "horizontal and a contact wheel" route.

    Great stuff ! Thanks again - Josh
     
  14. jonnymac44

    jonnymac44

    Sep 27, 2007
    When Brian Fellhoelter was in the process of making his new horizontal/vertical grinder he agreed to sell me his current horizontal grinder. This is one of the jobs I'm most looking forward to trying with it once it arrives and I get it set up.:thumbup:
     
  15. Fellhoelter

    Fellhoelter

    Dec 29, 2005
    And it work like a champ Jonny !
     
  16. Ed Braun

    Ed Braun

    140
    Jan 14, 2012
    Please pardon the low quality pics...as always....for all the effort I put in, I need to take better care in photodocumenting work..
    Here's a Benchmade 158 CSKII I repaired over the weekend for a Fla sportsman who broke the original tip off--To keep it from being an obvious repair, the only other Benchmade series that would match the handle and have a stronger clip was the 510 Rant, which I then emulated here.
    Here's what I started with after the customer had tried to fix it himself:
    [​IMG]

    I start by grinding the flats to the clip riding high on an 8" contact wheel, roughly about that last 2" of surface as the belt comes into contact with the wheel at a 90*. I could do it off the bottom of the wheel, but I lose visibility--I can keep tabs on the grind riding high by peering off the side since little less than 2" of blade is actually touching the belt.
    I then flip spine down, just letting the tip ride and feeding the blade forward to move the clip back and so the middle bows as desired. In cases where I want a thin middle to the swedge, I'll then switch off to the flat plat and use the 2" wheel or my small attachment 1.25" wheel. Here's the repaired blade:
    [​IMG]
    [​IMG]

    Hope this helps Patrice.

    Edit: As to the blade's patina, the customer had asked me to give it an acid etched finish.
     
  17. Phil Dwyer

    Phil Dwyer KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Feb 28, 2006
    Have you guys seen the grinder at Wilmont that flips horizontal? On the youtube video on their site, I believe starting around 4:05, Chris grinds a swedge with it horizontally.
     
  18. Patrice Lemée

    Patrice Lemée

    Aug 13, 2002
    Well Jonny, now I hate you. :p;)

    Thanks for the tips Ed.

    Phil, now you know I HAVE to anodize my grinder wheels! Darn you! :D
     
  19. jonnymac44

    jonnymac44

    Sep 27, 2007
    Yep, Chris makes some really nice machines!

    Brian, glad to hear it:D

    Sorry Patrice:eek:
     
  20. NickWheeler

    NickWheeler

    Dec 3, 1999
    Josh- Thanks for taking that the way you did. You always inspire me with your open minded and "defenseless" approach. I always have it in mind that even someone who knows nothing about knives could, even accidentally, give me a great idea.... but I definitely need to work on the part about not being offended by some other makers' comments. :eek:

    I don't draw file my clips because I like to do them post hardending, and can typically start sanding them with a fairly fine sand paper. BUT, there are times when one just doesn't want to cooperate, and when that happen I use a draw filing motion--- but with a piece of steel that I slap PSA paper onto and cut trim the paper so it's flush to the edges of the bar. I use a 1" wide bar for straight clips, and a little 5/16" wide bar for curved clips.


    On a side note, oftentimes many of the issues a fella is having getting his clip grinds even are stemmed from his blade not being straight, evenly tapered, and with a centered edge.

    It all goes back to my Dad's house framing days mantra- "Start square, stay square." :)
     

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