Camel(fish)back straight edge

  1. pressbrake1

    pressbrake1 Forum Supporter

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    essex england
    Yes thanks, tempted as it’s half the money a casting will cost
     
  2. Brad93

    Brad93 M J B Engineering

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    Didn’t think of it that way.

    It’s probably only 3 or 4 foot though isn’t it?
     
  3. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Wow. How do you ensure it doesn't flex, or bow if not supported enough.
     
  4. Maker

    Maker nEw mEmBeR

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    Presumably as it's a parallel not a straight edge, it would be fully supported by a machine table when it's in use?
     
  5. pressbrake1

    pressbrake1 Forum Supporter

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    Because it’s a very strong structure and cast iron doesn’t like to flex.
    Everything is plastic but cast iron is one of the least plastic
     
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  6. pressbrake1

    pressbrake1 Forum Supporter

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    A76AA4FA-4ACB-4DD3-85B6-E1BFA1F986AE.png 7CBAD593-DDE7-4BB7-8D88-CAE72A3F8253.png 50369EAC-72D8-492A-B4F8-42636E2BCBA0.png
     
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  7. Matthew Tinker Member

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    56
    Location:
    93300 Aubervilliers France
    I doubt it will flex significantly more than a fish back, it's an "I" beam, probably heavier than a fish back. I have a 72inch one this shape that I checked on the diagonal of my 36"x36" surface plate, over 49" or 1.25m the sag was less than1/100mm, under 4/10 of a thou. for scraping a lathe bed, that's acceptable for me! By the way, my 72" straight edge weighs 40kgs!
    Cheers, Matthew
     
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  8. Brad93

    Brad93 M J B Engineering

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    That’s not bad for cast aluminium 8 tenths over that length
     
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  9. pressbrake1

    pressbrake1 Forum Supporter

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    Bearing in mind that’s machined not scraped!
     
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  10. Brad93

    Brad93 M J B Engineering

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    That is impressive.
     
  11. pressbrake1

    pressbrake1 Forum Supporter

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    There shouldn’t be sag as I’m guessing 49” support points should have been very close to the airy points.
    40kg isn’t too bad my windley bros 72” fishback has got to be 70kg plus!
     
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  12. Matthew Tinker Member

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    56
    Location:
    93300 Aubervilliers France
    It's supported well outside the Airy points! I compared the difference between the straight edge lying flat on the surface plate and raised up at the extremities with blocks. 1/100mm is OK. I know the weight of my straight edge is 40kgs as it was weighed transport, it's a bear to wield single handed!
     
  13. pressbrake1

    pressbrake1 Forum Supporter

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    Prototype squares
    EC210E88-8E27-4611-9A4A-D1890A02373F.jpeg B633F0C2-7E7E-401B-8712-E1D915953D87.jpeg
     
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  14. pressbrake1

    pressbrake1 Forum Supporter

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    18” and 30” which I sent to USA , gentleman posted pictures of them painted BCC8978E-B80B-437D-B792-7536CE061B62.png
     
    Shox Dr, Seadog, Dr.Al and 2 others like this.
  15. atomant48

    atomant48 Forum Supporter

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  16. pressbrake1

    pressbrake1 Forum Supporter

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    2,884
    essex england
    12/18” and 18/24
     
  17. pressbrake1

    pressbrake1 Forum Supporter

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    2,884
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    Squares all fettled waiting for machining .
    Foundry properly pulled my trousers down on these. There again they would be 1000s from Taft pierce or windley
    A6932A75-3ECF-430E-B1DD-F29AE38C9565.jpeg 4E9020B4-B3C9-4ED9-9148-F78882315B47.jpeg 7D7FBB4F-61AD-4009-A40F-5F28F0D03C34.jpeg 47844372-1605-4DA5-9830-B415876C4B80.jpeg
     
  18. mike os

    mike os just a little insane.....

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    sexy
     
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  19. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Very nice. I picked 2x 2’ high squares off ebay about 10yrs ago. He messed up and put £40 buy it now, instead of starting bid.:clapping:.

    cast aluminium with a steel face with tee slot, so not as nice as yours. But easier to pickup:clapping:
     
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  20. Munkul

    Munkul Jack of some trades, Master of none

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    Those are absolutely beautiful :)

    Are they cost effective to sell, then? I couldn't justify it, I don't have the need... but someone surely will!
     
    pressbrake1 likes this.
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