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DIY Walking Axe
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Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Updated Axe Pics on 11/05/2007 19:06:16 MST Print View

I have to clean them up a bit but here they are.

Shaft 3.1 oz.
Pick .85 oz.
Adze .3 oz.

Total 4.25 oz.

Axe1
axe2
Axe3

Edited by Steve_Evans on 11/05/2007 19:09:02 MST.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
FEA Questions on 11/05/2007 19:21:48 MST Print View

Chris,
The Axe fails in two spots depending where I place the load.
In both cases I fix the tip of the pick (as per UIAA diagrams),ie. we stick the tip into a wall leaving the shaft parrallel to the wall

When load is placed pulling down on the shaft - the shaft does not fail, the pick fails at the inner radius closest to the tip.

When a load is placed perpendicular to the shaft (towards the wall)at the lowest point, the edges of the holes fail -obviousy the ones at the top...but the connection stays strong.

Hope that explains something - I'd post the pics, but I don't have the software handy right now.

Not sure if you have seen the UIAA standards, but they are fairly rugged. This axe would turn to powder before it even came close to passing.
Steve

Edited by Steve_Evans on 11/05/2007 19:25:16 MST.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: Carbon on 11/05/2007 19:34:27 MST Print View

Kevin, carbon? if it's free I'll take it! :)

Actually, I was chatting with a guy who worked at a golf store regarding getting some thicker diameter carbon material - he was recommending a graphite shaft for my needs. Until I have them both "in stock" I won't know.

As for the epoxy question. Yep, Chris is quite correct. There are some extremely tough ones out there. Some of it is even machinable.

Maybe "Rev 2" will have the carbon shaft...wonder what I could get the axe down to...Sub 3oz?

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Finished my Axe on 11/07/2007 21:49:17 MST Print View

Final weight is 4.30 oz. I just tacked it together because I think I can make a much better one if I put some more thought into it...but here's some pics. Not the nicest looking, but there is potential for Rev 2 to look much better...

weights
For comparison...
compare

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Finished my Axe on 11/08/2007 02:45:33 MST Print View

Hi Steve

I would be interested in a test under load. I suspect you may find two areas of weakness: the holes in the shaft, especially at the top end, and the lack of reinforcing around the head of the shaft.

Now, V2 ... :-)

Cheers

Sam Haraldson
(sharalds) - MLife

Locale: Gallatin Range
DIY Walking Axe on 11/08/2007 06:31:21 MST Print View

Steve -

Fine work, my friend. Hopefully v. 2 can include the carbon fiber shaft discussed previously.

Roger -

Note a few posts back in this thread that Steve did put the axe design to a simulated load test.

- Sam

Christopher Plesko
(Pivvay) - F

Locale: Rocky Mountains
Re: Finished my Axe on 11/08/2007 07:53:18 MST Print View

What about doing an I-beam style head? That would require milling the piece or as a secondary operation but it could increase the pick's stiffness quite a bit.

If that makes no sense let me know and i'll try to get a few minutes to model one up in NX.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: DIY Walking Axe on 11/08/2007 11:29:15 MST Print View

Roger: your suspicions are correct - and the axe is weak in general. Anticipating it would have these weaknesses, I concerned myself with weight more then anything when designing it...and it was more of a "what material do I have on hand/when can I get on the machines/what is possible with my skills" (ie. I had personally never cut aluminum with a plasma cutter before - I think that's why my stuff had such terrible burrs) You'll be happy to know that V2 is already being researched (Carbon Fiber and 7075 should do the trick)

Sam: Thanks...and yes, the next one is going to have a carbon shaft (the ones at macqc claim a tensile strength of 650ksi!?!) - if anyone has a line on carbon shafts let me know...Kevin?

Chris: Since I personally can't TIG weld (the reason this axe is tacked), I'd have to get the guys to do it for me, so I had originally thought of making the pick and adze from "T" bar (was that what you were thinking?) so it was one piece and the top could have the cross member tapering to the front...but none was readily available. Machining it wouldn't be a problem, but in my next design I want to use 7075 for it's higher strength. Not sure, but I think blocks of it woud be dang pricey. Yep, I know it's not theoreticaly weldable...but I'm getting mixed reviews and working on it. Any first hand experience on this?

A recap on the loading the axe can handle - I'll put together some better simulated tests which are more representative of the UIAA tests and share for those interested - new design only though...the old one is embarrassing...

Edited by Steve_Evans on 11/08/2007 11:37:27 MST.

Christopher Plesko
(Pivvay) - F

Locale: Rocky Mountains
Re: Re: DIY Walking Axe on 11/08/2007 12:03:15 MST Print View

I was thinking something like out of billet yes. Expensive? Maybe for production but for 1 offs I've done it plenty of times. Esp combined with a CF shaft you could design the whole piece around an epoxy fit up with the finished shaft. The combined loading (your original thinking with the T) would strengthen and stiffen up the pick and adze since they wouldn't just be relying on weld area for reinforcement.

Then again you could repeat the original design and just make the pick section much thicker to start relatively speaking and machine the front and pockets in the back. From the top looking down you'd be "triangle-ing" down toward the head of the pick.

Probably doesn't make a lot of sense without a picture but I just grabbed a quick look at the head of my BD Raven Pro last night for ideas.

FWIW I can tig weld aluminum. Never worked with 7000 series. I know it's weldable (i've seen welded bikes with it) but I don't know if it's easily weldable.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: DIY Walking Axe on 11/08/2007 13:06:11 MST Print View

I should have been more specific...I can TIG weld...but I'm not a welder...it's a crapshoot most of the time (ie. best left to someone else). ;)
I do like the idea of the one piece head (I just looked at the Raven Pro) as it would be easier for ME to manufacture the axe (no welding). I'm going to work on it a bit tonight and see how it looks/works. I think I had a bit of tunnel vision chasing after the Helix's design.
I use "expensive" in terms of what the material for my current axe cost...really $0. My local suppliers don't carry 7075 (been there before ) and I have to order full lengths if I need it. Mcmaster ripoff sells it but for the size I would need it would probably run me $100 bucks or so. I'll have to take a look around. I'll probably do a prototype out of 6061 but run the analysis with 7075.
I see the bikes made of 7075 and my camp axe is 7075 so I know it's weldable, but I've always been told it isn't. Maybe a special process? I'll probably just get one of the guys to try it if I go down that route.
Good input Chris - much appreciated.

Edit: Just looking again at the Raven Pro, the handle looks very comfortable to hold - perhaps it is the way to go. I only mention that because one of R. Caffins observations when testing his Helix was that the head's edges were noticable.

Edited by Steve_Evans on 11/08/2007 13:10:07 MST.

Christopher Plesko
(Pivvay) - F

Locale: Rocky Mountains
Re: Re: DIY Walking Axe on 11/08/2007 13:16:21 MST Print View

I admire you're work and speed. I'm so busy I rarely get beyond the CAD/3D modelling stage lately.

Keep us posted on how it goes :) It'd be fun to make my own ice axe so maybe after collaborating on a few of your versions I'll knock out my own. I'm sure I could take over the CNC for a few hours :)

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: DIY Walking Axe on 11/08/2007 14:02:38 MST Print View

Hi Steven

> Roger: your suspicions are correct - and the axe is weak in general.
I think I will get a swelled head. :-)

> You'll be happy to know that V2 is already being researched (Carbon Fiber and 7075 should do the trick)
Hum ... you have access to a plasma cutter and TIG welding? Maybe you should think about titanium - that would be a first I think. You can get small quantities of Ti from www.titaniumjoe.com - I buy from him.

> pick and adze from "T" bar
Yeah - interesting idea!

> Welding 7075
Yeah, very heat-sensitive stuff, but mainly at the highest tempers. You can electron-beam weld it I believe ...

Cheers

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: DIY Walking Axe on 11/08/2007 15:23:08 MST Print View

Roger,
I considered Ti, but it's soooo heavy :) - I believe 60%. Not sure if I could achieve sub 1 oz with it ;)...however, it is significantly stronger (140 ksi or so), so it may be the best option - Good idea RC. I'd have to weld it up - no way I'm machining the head from a block of "gold".
The 7075 (about 85 ksi) is easy to work with, and I can anodize afterwards. I'll try to see where the sweet spot is regarding strength.
If I stick with the "T" bar/block idea, I'll have to use aluminum. Ti would be a PITA to machine.
Funny you mention the electron-beam welding, even my welding buddy had to look that up! - however, we don't have the capability so I most likely won't go that route.

Any idea where people are buying carbon shafts these days?The golf store ones are too thin - ditto with arrow shafts.

Edited by Steve_Evans on 11/08/2007 15:23:59 MST.

Ryan Longmire
(longmire) - MLife

Locale: Tejas
CF tubes on 11/08/2007 17:26:35 MST Print View

try here:

http://www.graphitestore.com/items_list.asp/action/prod/prd_id/99/cat_id/34

I dont know enough about CF to guess what OD/ID would be strong enough for this application. price would be ~$60-70 per shaft (roughly).


edit: this place might be better:
http://www.carbonfibertubeshop.com//index2.html

Edited by longmire on 11/08/2007 17:33:52 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: DIY Walking Axe on 11/08/2007 18:53:46 MST Print View

Hi Steven

Yes, Ti is heavier than aluminium, but the 6AL-4V Ti alloy is much, much, much harder! I am machining both at the moment. The 7075 goes smoothly; the Ti wears the milling cutters! (Thinks ... I can buy carbide cutters ... at a price!)

I am not surprised you don't have e-beam gear: the comment was actually meant as a joke. Very much Mil stuff.

Cheers

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: DIY Walking Axe on 11/08/2007 19:09:22 MST Print View

Hey now...not many people have Nuclear Reactors - we own 8 in Pickering alone...no joke. :) opg.com

Thinking of going with www.macqc.com for the shafts...anything cheaper?

Edited by Steve_Evans on 11/08/2007 19:12:13 MST.

Paul Tree
(Paul_Tree) - F

Locale: Wowwww
too late? on 11/08/2007 20:58:02 MST Print View

sounds like you have moved to carbon, so maybe some of these suggestions are moot. Also, I noticed on your adze, perhaps add metal to grind a bevel for the chopping edge. Anyway..

1. No holes close to the head.
2. First holes are smaller.
3. Alignment of holes is offset.
4. Adze is elongate, extends over top of shaft.
5. Adze is notched into pick.
6. Adze is curved for comfort.
piolet3

Edited by Paul_Tree on 11/08/2007 20:58:52 MST.

Christopher Plesko
(Pivvay) - F

Locale: Rocky Mountains
Re: Re: DIY Walking Axe on 11/08/2007 21:10:54 MST Print View

That macqc site is cool! I need to spend some quality time there.

Functional Ti/carbon b rated axe? Goal: Ligher than a BD Raven ultra with similar usability. Price would be out of this world but quite sexy. Revision #10? ;)

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Ti/carbon "B" rated axe... on 11/09/2007 06:19:07 MST Print View

Chris...I'm on it - I'm dedicating my cottage weekend to it. I need to get some specs on that carbon. I'm curious to see if the carbon shafts would pass the UIAA standards. The fatigue tests scare me the most...50,000 cycles...my arm is going to be tired ;)

Paul - Thanks for the suggestions - adze to be chamfered. Regardless if I'm now going with a carbon shaft, keep them coming.

If we pool our ideas, we should be able to come up with the worlds lightest and most useful Ti/Carbon ice axe for the same price as a small car. :)

Edited by Steve_Evans on 11/09/2007 06:21:10 MST.

Christopher Plesko
(Pivvay) - F

Locale: Rocky Mountains
Re: Ti/carbon "B" rated axe... on 11/09/2007 08:35:28 MST Print View

A thought on the carbon stuff real quick.

A lot of the technical ice tools have carbon shafts these days. Often they'll carry a B rating instead of a T rating but at least a B seems to be attainable with a carbon shaft. Now using a straight up round shaft may not be as good as a shaped rectangle/oval shaft but given the nature of one-off/limited production, oval shafts may be out of reach at the moment.

Such a fun topic!