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| Messages 1 - 16 of total 16 in this topic |
Banquo
climber
Amerricka
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Topic Author's Original Post - Nov 24, 2015 - 08:16am PT
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I was talking to Doug Robinson a few weeks ago and he asked if I had thought about making hammers with bamboo handles. I asked him about the Chouinard/Frost axe with bamboo handles and he said they were laid up with hexagonal strips of bamboo. Making little hexagonal strips sounds like a PITA to me. I wonder why they didn't use flat strips. Perhaps the shear strength was better with a discontinuous glue plane.
My brother, a structural engineer, has been studying bamboo for years and has a forest of the stuff at his house. So I know about the mechanical properties of the various types of bamboo, carbonization and so on but not much about the fabrication. Does anybody know how they made the strips? How big they were? What glue they used?
Perhaps Tom Frost recalls the details. Perhaps somebody can ask him about it.
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Roots
Mountain climber
Tustin, CA
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Nov 24, 2015 - 09:35am PT
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Banquo - Grossman would be the guy to ask (re: get in contact with TF).
You keep tinkering and soon you'll have the world's best hammer. I want the Signature, Uber, Platinum model!
SUP!
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Lorenzo
Trad climber
Portland Oregon
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Nov 24, 2015 - 09:54am PT
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You might also want to check out http://nwbamboo.com
Particularly their 1/8 and 1/4" veneers for glue up, or possible their 1 1/2" dimensional lumber
Pretty knowledgeable guys and will work with you.
Roberts makes a urethane product for engineered wood and flooring they recommend for bamboo. Supposed to be waterproof.
R1505, I think.
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Banquo
climber
Amerricka
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Topic Author's Reply - Nov 24, 2015 - 10:08am PT
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Particularly their 1/8 and 1/4" veneers for glue up, or possible their 1 1/2" panels.
Yeah, I was looking at their website a couple days ago. Working with pre-made panels might be the way to go. However, I want to see if I can do it myself first because making things is the point.
Guy sez to me "how much to buy one of your hammers?" I say "$100." He says "I can get a BD hammer for less than that." I say "so buy one."
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Lorenzo
Trad climber
Portland Oregon
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Nov 24, 2015 - 10:14am PT
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Bamboo became all the rage with designers around here just before I retired. The stuff I installed ten years ago is still going strong, even around sinks and such.
I believe they use some sort if induction glue-up method that would be pretty hard for a small shop.
Pretty hard on edge tools because of the silicates in bamboo.. Use carbide.
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bamboo
Trad climber
pike co
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Nov 24, 2015 - 05:51pm PT
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banquo
bamboo and engineered bamboo products are used in the production of traditional bows--I can source the materials and laminate /shape the handles--lets talk
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Banquo
climber
Amerricka
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Topic Author's Reply - Nov 25, 2015 - 11:23am PT
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Bamboo,
I'll certainly be in touch. Other than gathering information, this is on hold until the new year. I've seen the photos of your bows that you have posted but was too stupid and dim-witted to catch the obvious bamboo connection.
The handles I've made so far are pretty simple. I cut 1" x 1-3/4" x 14" blanks out of hickory slabs. I then rough the shape out of the 1-3/4" width on a band saw. Then I use a trim router to finalize the shape. The edges are rounded over using a 3/8" radius on the router. The head end of the handle is then turned down on the lathe to fit the round hole in the head or steel tube.
I am still researching impact behavior and strength of laminated bamboo. Hickory is the usual choice for hammer handles because it has outstanding impact strength. Hickory not only has high impact strength but "high work to maximum load" or toughness.
From The Wood Handbook:
Work to maximum load in bending—Ability to absorb
shock with some permanent deformation and more or less
injury to a specimen. Work to maximum load is a measure
of the combined strength and toughness of wood under
bending stresses.
Impact bending—In the impact bending test, a hammer of
given weight is dropped upon a beam from successively increased
heights until rupture occurs or the beam deflects
152 mm (6 in.) or more. The height of the maximum drop,
or the drop that causes failure, is a comparative value that
represents the ability of wood to absorb shocks that cause
stresses beyond the proportional limit.
If you look at the tables in The Wood Handbook for hickory, you can see that it has high work-to-maximum-load and high impact-bending strength which makes it perfect for hammer handles. Hickory has the highest impact bending strength listed in the tables.
See page 5-10 of this excerpt from The Wood Handbook:
http://dammerr.com/docs/Wood_Handbook_2010.pdf
The Wood Handbook says:
The major use for high quality hickory is for tool handles
that require high shock resistance.
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deuce4
climber
Hobart, Australia
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Nov 25, 2015 - 11:45am PT
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Hickory is the only way to go. Bamboo would be okay for a long ice axe that doesn't have as much impact, but the toughness of Hickory is the choice for hammers.
Its got the best "feel" too.
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Banquo
climber
Amerricka
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Topic Author's Reply - Nov 25, 2015 - 12:14pm PT
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Mike,
I actually know Craig Calfee and have worked with him on some projects. He is more of an artist than engineer although he basically invented CF bike frames.
Deuce,
I'm sure you are right but will probably make some bamboo handles as an art project. Calfee is an artist doing engineering while I am sometimes an engineer doing art.
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ClimbingOn
Trad climber
NY
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Nov 25, 2015 - 03:04pm PT
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I know very little about bamboo, but my initial concern would be vibration dampening, or lack thereof.
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Mungeclimber
Trad climber
Nothing creative to say
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Nov 25, 2015 - 03:11pm PT
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I want a cedar handle. So it smells nice.
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Lorenzo
Trad climber
Portland Oregon
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Nov 25, 2015 - 03:30pm PT
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Just stick some cedar shavings in your nose while you use that Carbon Fiber model.
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deuce4
climber
Hobart, Australia
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Nov 25, 2015 - 04:27pm PT
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I think you will find the bamboo might splinter prematrurely, unless you are using resined bamboo like in fly rods and in some architecture projects.
But worth a try!
ps. carbon fibre would be a horrible material for a handle! Too stiff!
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Banquo
climber
Amerricka
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Topic Author's Reply - Nov 26, 2015 - 07:48am PT
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Deuce,
The concrete connections in that book are interesting but don't seem practical to me.
I seem to recall that wood handles on ice axes disappeared because they could no be made strong enough to pass modern standards.
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Lorenzo
Trad climber
Portland Oregon
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Nov 26, 2015 - 09:38am PT
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ps. carbon fibre would be a horrible material for a handle! Too stiff!
Did Chouinard know that?
Carbon fiber axes have been made starting in the late 70's to the present. I think you can engineer whatever stiffness you want in a carbon composite.
I think impact resistance would be more of an issue than stiffness.
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Lorenzo
Trad climber
Portland Oregon
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Nov 26, 2015 - 09:49am PT
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I seem to recall that wood handles on ice axes disappeared because they could no be made strong enough to pass modern standards.
That could be revisionist history. Wooden axe handles started disappearing in about 1975 and the change was pretty much complete ( at least at Chouinard) by 1980. There were concerns about breakage, but no real standards I recall. Metal axes were easier to engineer reliably.
The "modern standards" and testing didn't start showing up until the formation of the European Union, and EN, ISO, standards. UIAA just followed along. And that didn't really happen until the early 90's.
I could be wrong, of course. Just going by what I recall in the literature.
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