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Thread: CS about capirons

  1. #61
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    Quote Originally Posted by John Coloccia View Post
    pushing on a rope
    LOL - I use that all the time

  2. #62
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    We'd have much better products if there were more people out there that knew maybe just a LITTLE something outside their main discipline. You know, get in the lab every now and then and actually try to use the stuff you're pumping out.
    I didn't last as long as you. In a metallurgy class we were testing rods for tensile strength. I got a little bit of a chewing for not getting a high enough fail point. It seemed making the material seem stronger than it actually is was the 'proper' way to test. I dropped out of that class soon after that and went into art and electronics.

    Every time some building or road fails and the 'experts' are baffled this test comes to mind. How many things end up being designed by people who are just reading inaccurate specs?

    One time my employment was as a drafter at a pump manufacturer. One particular product had a history of a rather violent self disassembly problem. I did a few calculations of moving part lengths and found many of them to be perfect resonant nodes of the running speed. I presented this to the head engineer and he told me I didn't know what I was talking about and resonance had nothing to do with it. I didn't stay there much longer.

    I have worked with some great engineers and some who couldn't see outside of the box let alone being able to see inside the box.

    jtk
    Last edited by Jim Koepke; 09-26-2014 at 1:14 PM.
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  3. #63
    Oddly enough, Jim, one of the more common paths to get into things like instrument building seems to be starting as an engineer or designer of some sort. I can't even count the number of people I've met doing stuff like this, and when we compare stories they're all eerily similar. These fringe, crafty sorts of vocations are like the town dog catcher rounding up all the strays. We should have our own support group.

  4. #64
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    Hah, so true. I have a career of constant negotiation with all parties to get things done. So, in my hobby I turn down pretty much everything I dislike, which makes for far fewer commissions, but far more enjoyable ones.
    Bumbling forward into the unknown.

  5. #65
    Jim and John, You guys are cracking me up. My favorite story is being called into a meeting at one of my customers because a product destined for a EU customer failed VDE emissions testing. The players were the mechanical engineer who called me, the project manager, the buyer, and the marketing manager. I proposed a solution which I knew would work and gave them a price for the EMI gasket needed. It was more than they expected and there was no budget for it. The meeting degenerated into name calling, recriminations, literal fist shaking and threats of violence between the engineering manager and the marketing guy over blame and most importantly whose budget the fix would come out of. As I was leaving I received a very embarrassed apology from my engineering contact about management behavior. All of the standard crap went on. "It's your fault for promising too short a delivery" "If you guys knew how to design and weren't incompetent..." "Why did you ship from the beta build before we tested for emissions?"
    Dave Anderson

    Chester, NH

  6. #66
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    I guess the trouble starts when people sidestep reality to build one size fits all intellectual castles in the air - and then proceed to get attached to said castles and/or make commitments/build power bases off them. The devil as the man said is always in the detail, and reality always eventually must bite.

    We're not of course immune around here to the problem either. It's for most of us the basis of the human condition….

  7. #67
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    Quote Originally Posted by Brian Holcombe View Post
    Hah, so true. I have a career of constant negotiation with all parties to get things done. So, in my hobby I turn down pretty much everything I dislike, which makes for far fewer commissions, but far more enjoyable ones.
    My father's approach taught me to listen to everyone's story no matter how crazy it may sound.

    Then if it is like some of the folks at the farmers market I direct them to the other woodworker there saying he is better set up to do that kind of work.

    A couple of times people came by that did seem a bit odd but that didn't bother me. My wife thought one woman was way out there. She almost convinced me to not bother with the woman's request, almost. The next week she came back and spent $270 with us.

    We get a lot of requests for different things. If they are not a big gamble and within my ability they get made. Often the folks may not return. Almost all of the items have been bought by others. Some have actually become regular items that sell well.

    With many things it is often possible to learn from others with whom you may not agree. Even some of the 'experts' who put me off at times have little bits of useful information to glean.

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

  8. #68
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    Dave, our sales group would regularly promise delivery of a new product at a certain based on when the customer wanted it...without consulting engineering or purchasing about design and parts availability, let alone testing prior to assembly and delivery. This was in an industry that does not tolerate failure in use. We were going to cost the salesman his bonus​ because the engineering group could not produce a new product in half the lead-time of the commercial parts, yet to be determined. My BP is going up just remembering it, and that was 7-8 years ago. Not an isolated case either.
    Last edited by Tom Vanzant; 09-26-2014 at 4:11 PM. Reason: Speling

  9. #69
    Quote Originally Posted by Tom Vanzant View Post
    Dave, our sales group would regularly promise delivery of a new product at a certain based on when the customer wanted it...without consulting engineering or purchasing about design and parts availability, let alone testing prior to assembly and delivery. This was in an industry that does not tolerate failure in use. We were going to cost the salesman his bonus​ because the engineering group could not produce a new product in half the lead-time of the commercial parts, yet to be determined. My BP is going up just remembering it, and that was 7-8 years ago. Not an isolated case either.
    I actually had this conversation in a fairly high level meeting once. Sort of explains all at once just why I was a bad fit for the corporate world:

    them: "John, report on that new feature. How long will it take?"

    me: "We can do it in 4 weeks."

    them: "WHAT??? 4 weeks??? That's impossible. You should be able to do it in a few days. We need it for a test coming up in two weeks. We need a better estimate"

    me: "4 weeks is the best, real estimate I have. It will take a few days just to do the final testing and release because what you're asking for isn't straight forward. I think it will take 4 weeks."

    grand poobah: "It can't take 4 weeks. I want this working and in the lab early next week. Period. Just do it, end of story. I want a report everyday on your status."

    me: "OK. I can give you an update right now where we are."

    few seconds of silence

    grand poobah: "Go ahead."

    me: "As of today, we've fallen 3 weeks behind schedule."

    I guess I could have handled that more tactfully.

  10. #70
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    Quote Originally Posted by Jim Koepke View Post
    My father's approach taught me to listen to everyone's story no matter how crazy it may sound.

    Then if it is like some of the folks at the farmers market I direct them to the other woodworker there saying he is better set up to do that kind of work.

    A couple of times people came by that did seem a bit odd but that didn't bother me. My wife thought one woman was way out there. She almost convinced me to not bother with the woman's request, almost. The next week she came back and spent $270 with us.

    We get a lot of requests for different things. If they are not a big gamble and within my ability they get made. Often the folks may not return. Almost all of the items have been bought by others. Some have actually become regular items that sell well.

    With many things it is often possible to learn from others with whom you may not agree. Even some of the 'experts' who put me off at times have little bits of useful information to glean.

    jtk
    I refer people pretty commonly to a local shop which has a broader range of capabilities in design aesthetic. I'm quite rigid in that I will only sell my own original design work to people. I wont copy or work in the style of another for a commission.

    I've made one piece in the Nakashima style for myself, but I would not sell it ever.
    Bumbling forward into the unknown.

  11. #71
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    Quote Originally Posted by Jim Koepke View Post
    Have you seen the video linked in some of the discussion about setting the cap iron?

    http://vimeo.com/41372857




    That sounds about the same as my understanding of this.

    If the chip breaker is set too far from the action there is too much flex in the shaving to provide any 'back pressure' on the wedging action. In effect this 'back pressure' prevents the shaving from lifting ahead of the blade.

    Another wood working phenomena comes to mind which helps my understanding of this. It is the wedging action of a chisel when cutting dovetails. The chisel's bevel causes the chisel to move toward the back of the blade when chopping dovetails. This is why one doesn't start chopping right on the line.

    This wedging force, imo, is present more in a bevel up configuration than in a bevel down set up. Please note this is just opinion and I have not taken the time to set up actual tests nor are there any plans for me to do such.

    BTW, some of the books I read about joinery when I first started in woodworking advised to start on the line. Must have been some of those non-woodworking writers George mentioned.

    jtk
    THAT'S THE VIDEO! A tad academic for my purposes and a little verbose, but that's the video I was thinking I saw before and I was trying to explain. For some reason, I thought I saw that in a dream.

    And yeah, I've heard something similar about starting on the line about doing dovetails. I saw the chisel moving backwards and started trying to counter the bevel, then just said screw it and I try to either make notches for the bevel or I just keep it in front of the line.

    BTW, Kees. . .the video Jim's linked has the narrator saying the chip is getting compressed by the cap iron. It's around 11:20. If you watch the video, you can see that with an 80* bevel, the cap iron is actually causing the wood to get compressed right in front of the leading edge of the blade (around 12:50). Also, if you watch behind the blade, you can see the wood slightly decompress and expand (though this might just be an optical illusion). I think where we're getting hung up is some minor semantics differences (I really do hate English for this) and when forces get talked about I think of it in terms of physics and specifics. I think the guilty force you might be looking for here would be centripetal force, not lateral force. The centripetal force is causing the inside of the chip to compress and the outside to decompress just due to the distance each has to travel (if you watch the video, the wood against the breaker appears to be moving much faster than the wood farther away from the breaker).

    Anyway, semantics. I'm being way too literal and thinking of this from more of a physics standpoint than anything.
    The Barefoot Woodworker.

    Fueled by leather, chrome, and thunder.

  12. #72
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    I think we are more in agreement then I thought Adam!

    That compression you see on the video is exactly what I am talking about. When you measure shaving thickness and you compare it to the actual amount of wood removed, you will easilly see a 30% to 50% difference.

    I'm not sure about the centrifugal forces though. These Japanese guys were planing at a very slow speed.

    One big difference I see with the high angle panes is the difference in vertical force. This wedging force on the woodfibers is much less in a high angle plane, compared to a 45 degree plane.
    Last edited by Kees Heiden; 09-27-2014 at 5:13 AM.

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