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Goat willow for a refractor tripod?

ATM DIY equipment mount refractor tripod
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#1 mr.otswons

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Posted 03 August 2019 - 08:19 AM

- here in Norway, I have a bunch of goat willow, (also known as **** willow). The heartwood is known to resist moisture very well, and has been used for fences in the past. Would that be a good material for a tripod? I like to use locally sourced materials.

Of course fur and spruce, we have that, birch as well. But the willow has some nice colour and play in it. Plus the water and rot resistant qualities.

 

PS: the other name for willow, is going to be censored I guess..



#2 Stevegeo

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Posted 03 August 2019 - 08:26 AM

I have read about your willow, if you can get a piece that's killin dried  .. you'll probably find it unsuitable .  The wood is known to slit easily and break .. I know it's common your way . But consider another choice . Preferably a good hardwood . 

 

 I own a tree farm here in NY  and read up on this species .. 

Steve George 

Area 3751 observatory .. otisco ny . 


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#3 Cotts

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Posted 03 August 2019 - 08:53 AM

Gordon Lightfoot is here to help....

 

Dave


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#4 Garyth64

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Posted 03 August 2019 - 09:27 PM

In the other thread that you posted this thought, I replied and said, "**** Willow", but that got censored.  So I retyped it as "PussyWillow".

 

Maybe another wood would be better.


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#5 mr.otswons

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Posted 04 August 2019 - 08:21 AM

Garyth64, as you said in the other post, (was unsure if that thread was alive, so posted twice), just make one.

 

Steve, maybe there is some test to do on the material, for strength and rigidity. as Paul Sellers often says, there is no two pieces of wood alike. One spruce can be tougher then another oak.

 

enough talking then for my part.

Thanks!



#6 KLWalsh

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Posted 04 August 2019 - 09:05 AM

Maybe cut it into thin strips, then bond them together using a good exterior grade adhesive like a resorcinol epoxy, to make the boards for the legs.

#7 Stevegeo

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Posted 04 August 2019 - 10:26 AM

This wood has properties that are undesirable for almost any constuction...  

 

Think about it, if it were that abundant (which it is) and IF it were that great....why isnt this used for furniture, buildings etc...

People from the past have gone done this road before, and learned a few lessons from it.

 

Find anothe material....



#8 Xeroid

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Posted 05 August 2019 - 09:22 AM

Just my opinion but Maple, Ash, Cherry hardwoods are good for tripod legs. Good damping, low vibration, supports heavy scopes.

 

My home built Cherry tripod easily handles my 10+ kg Astro-Tech 130mm. The eyepiece tray is required and makes the tripod rock solid.

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#9 don clement

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Posted 05 August 2019 - 02:22 PM

https://archive.org/...6-pdf/page/n53 


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#10 luxo II

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Posted 06 August 2019 - 08:39 AM

Your willow is not a good choice.

 

For this application you need a hardwood that has very high strength in compression and tension, and is also durable. Spruce would be better, while in my country I would use a eucalyptus, possibly jarrah, karri or even redgum which are all extremely strong hard timbers.


Edited by luxo II, 06 August 2019 - 08:41 AM.


#11 davidc135

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Posted 06 August 2019 - 12:07 PM

Why not give it a try and see. If the stiffness of a beam increases as the fourth power of thickness and width then a 20% increase in these dimensions will double the stiffness of the tripod. Not sure of the durability though.  David



#12 calypsob

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Posted 06 August 2019 - 01:10 PM

Willow is pretty soft. Id recommend you look for some hornbeam, beech or hard maple maple for some solid legs.



#13 don clement

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Posted 07 August 2019 - 03:56 AM

IMO geometry is more important than material for tripod rigidity.  I did not use wood for my tripod but a wood tripod could benefit from some of the things I did based on ideas in the S&T "gleanings" article by John J. Brooks.  BUMP One thing I did was to  connect the legs from leg to leg using stranded cable under tension. Each leg was pre-loaded  inward by using a stop on tube below the triangular plate at the top and bending each leg inward. This way all connectors have no play.

 

Don

 

Tripod top showing stops

 

TripodTop.jpg

 

Top view

 

TripodTopView.jpg

 

Tripod pre-tension wires from leg to leg

 

TripodLegPretentionWires.jpg

 

flattened tripod

 

TripodFlattened.jpg

 

Setup on tripod for total solar eclipse in  Casper, WY

 

TotalEclipseSetUp.jpg

 

 

 


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