DIY Walking Axe
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Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: add me to the list on 02/05/2008 15:42:00 MST Print View

No problem Derek. 2 it is.

You'll be happy to know that I put much more thought into the head this time around...including measuring my actual swing radius! I'm no mountaineer, so all input is welcome.

I've already cut the pick and adze, waiting on the shaft from Kevin and just need to machine the ferrule and spike.

Steve

Derek Goffin
(Derekoak)

Locale: North of England
radius of gyration on 02/06/2008 06:46:20 MST Print View

I am keen on your axe because I expect it to be tougher and blunt less, than a Helix because of the titanium head. I would prefer a design that is a lttle better in every way than the Helix (price excepted) so I hope it will be at least as strong as the helix and a little lighter.
I have a degree in Ergonomics rather than hard engineering and I am a carpenter so I have used a traditional adze a lot.
Concerning the swing radius of the adze head. When cutting slash steps I was taught to swing from the shoulder with a straight arm. However with such a light axe I would have thought the optimum technique would be more wristy than that. The swing radius depends on how you use it. I would have thought the worst error would be to have an adze head too curved for the users action. So I think I would work the adze swing radius on something near a swing from the shoulder.
Concerning the pick point placement: ideally someone has a computer programme which can put in the position of masses and work out the radius of gyration. Otherwise it is educated guesswork. I would have thought that using the pick point was a very wristy action and the centre of the swing radius will be near the hold position. With a theoretical weightless shaft and all the mass concentrated at one point then the radius of gyration is the radius of the mass from the swing centre.If the mass is a real life sphere the radius of gyration will be a little further out than the C of G of the sphere, because we are talking 2nd moments of inertia and the mass further out has more effect. To remember back 40 years to A level physics the radius of gyration of a uniformly distributed shaft with no head rotated about one end was an exact fraction 3/4 or just maybe 7/8 of the shaft length. Whilst of course the C of G would be 1/2 length
If we think that a traditional ice axe has become right through use. I would predict that this markedly different adze with a relatively weightless shaft would have a radius of gyration further out than tradition is used to.
If you test axes to find the C of G I guess a wooden handled one will have a C of G well inboard of the head, whilst your prototype will have a C of G almost on the head. (I sort of feel that the spike weight should be discounted because it is very near the swing point). If the C of G is almost on the head then it is much more like a sphere of mass on the end of a weightless shaft. In one model(the uniform shaft) my guess would be the radius of gyration might be half the distance from the C of G to the outer end, in the other (weightless shaft) it would be just beyond the C of G. I would use the C of G position to determine the proportion of each model involved. If you drew such a radius of gyration on a drawing of your axe I think the point should be on the arc.
I hope thst helps, or at least gets people who remember their physics better than me to put me right.

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Re: Ti/Carbon Ice Axe - Revision 3 on 02/09/2008 21:43:15 MST Print View

I'll try to get a picture posted or emailed to you. You can email me at kevin@backpackinglight.com or ksawchuk@gmail.com when the axes are ready.

Paul Tree
(Paul_Tree) - F

Locale: Wowwww
how does it do for arrest on 02/10/2008 17:03:05 MST Print View

Hi Steve, I am wondering about actual tests in self arrest? That and self-belay are my main uses.

Hope you have plenty of hard snow and ice there! Turned out to be a good winter here.jakes view west

Derek Goffin
(Derekoak)

Locale: North of England
ice axe design on 02/11/2008 01:57:25 MST Print View

Steve,
I imagine you are changing the design of the axe to stop it filling with snow. I have a multi use purpose for a short aluminium tube up the hole in the spike. I hope your new "plug" is going to be removeable.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: Ice Axe Design on 02/13/2008 05:34:17 MST Print View

Paul,
I can't comment on the performance of the new axe as it is not yet complete...and as you know, the last one is now broken. Not to worry, it shouldn't be much longer. Not a bad winter here either, just got back from a 3 day snowshoe trip and we have had about 30" snow in the past 10 days.

Derek,
The new design had the axe plugged at each end, but I changed the design slightly to allow for easier manufacture and to use material I had on hand. If the axe does have plugs, they will either be removable, or optional - depending if I can get them back out.

Derek Goffin
(Derekoak)

Locale: North of England
how are things going on 02/20/2008 05:14:02 MST Print View

Steve,
Any news on production/ testing of the next prototype?

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: how are things going on 02/20/2008 06:13:08 MST Print View

Derek,
I have been away from the office for the past two weeks (returning only briefly), but it worked out well as I have been waiting for material. Long story short, I have all the Ti, received the carbon shafts, had the pick and adze cut, and picked up some new tooling for the project. I think late next week we should see a finished product. I'm documenting everything nicely for an easy read.
Steve

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Re: Ti/Carbon Ice Axe - Revision 3 on 03/02/2008 13:23:51 MST Print View

Aluminum Head Wear Picture this is after only 3 days of minimal use:Worn/Chipped tipNotice bend in adaze

Second picture shows bent adaze from using it as "officially" advertized.

Edited by ksawchuk on 03/04/2008 18:02:45 MST.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: Re: Ti/Carbon Ice Axe - Revision 3 on 03/04/2008 10:55:20 MST Print View

Thanks for the pics Kevin - let's hope the Titanium holds up to abuse a bit better. :)

I'm going to anodize and assemble the axe this week.

Derek Goffin
(Derekoak)

Locale: North of England
3rd prototype on 03/11/2008 09:40:10 MDT Print View

we are all agog

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: 3rd prototype on 03/11/2008 11:28:45 MDT Print View

Almost finished...I just have to cut the shaft to my length and bond the head and spike. :)

Derek Goffin
(Derekoak)

Locale: North of England
3rd prototype on 03/25/2008 09:43:28 MDT Print View

Any news Steve? sorry to pester. Take it as enthusiasm to maybe save myself 500 grams.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: 3rd prototype on 03/25/2008 21:22:56 MDT Print View

Pester away my friend! :) I'm excited too!

The axe is complete, came in lighter then expected (not by much though) and is ready for my controlled tests. I took it out this weekend, but didn't get the right conditions for much use other then a little chopping when removing my tent pegs.
I plan to put it through the UIAA tests this weekend to verify it's strength.
I've documented the process with great detail and it should be available for reading soon. ;P

Derek Goffin
(Derekoak)

Locale: North of England
Re: Re: 3rd prototype on 04/07/2008 05:10:54 MDT Print View

has it been through the strength tests successfully?

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: Re: Re: 3rd prototype on 04/07/2008 06:32:26 MDT Print View

The tests were completely this weekend - I simulated the UIAA specs and have a solid number for each requirement. I think it will be of great interest to those that followed this project.
I'll be compiling my data this week!

Edited by Steve_Evans on 04/07/2008 06:34:34 MDT.

Derek Goffin
(Derekoak)

Locale: North of England
3rd prototype on 04/07/2008 06:36:59 MDT Print View

great well done

Derek Goffin
(Derekoak)

Locale: North of England
publishing results: 3rd prototype? on 04/17/2008 15:20:49 MDT Print View

ready yet?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: publishing results: 3rd prototype? YEP on 04/17/2008 15:28:19 MDT Print View

Hi all

Yes, the results will be published, and in some detail.

Steve has written a full MYOG article on this project, and it is now going through the pipeline. Lots of details and lots of pics. Not sure yet when it will be published, but watch for it.

I do remember someone saying that if article X was a 7/10 on the difficulty scale, he didn't want to see one which was 10/10. Well guys ... :-)

Cheers
Roger Caffin
Senior Editor for Technology

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: 3rd prototype on 04/28/2008 14:26:48 MDT Print View

I've had a few inquiries, so I thought I would mention that I am just waiting until the article is published. This way, you can judge for yourself if it is something you want. That being said, I think most will be impressed with the results. :)