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Fozzie

Completed - fixed height hardwood tripod

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Hi All,

So it's been about a year since I started the last tripod build,  and I enjoyed the accomplishment and the use of the tripod on the Vixen GP that much that I've decided to give it another go for the EQ5 tripod/SkyteeII mount I have laying dormant at home.

The plan is for a fixed height tripod, of approximately 1400mm with a section size of 75mm x 30mm.  This will be a much heavier duty tripod than the last, as it has no moving parts and is intended for use with the skyteeII, especially if I get another Newt or heavier scope.

The design is based around the Tak EM200 SE tripods, fixed height, strong, wooden..  Although I will be added a few extra bits to push wood working skills a bit more.

the loose plans are as follows

 556784271_FixedHeightTripodplans.thumb.jpg.414f1cc3f4d04f86e325dc1de69e941c.jpg

I'll use the same rubber spiked feet as previous and I've selected a different wood, as the Sapele wood I previously used after 3 teak oil coats and a year of life under the stars has really darkened up to a deep, deep, mahogany effect.. Looks great, works great, but I fancy something lighter this time round.

I've chosen another African type,  Iroko Wood, which although doesn't take treatment/preservatives overly well, should look (hopefully something) like this when oiled, which is the only finish i'll be applying.

iroko-wood-worktop-3050-x-650-x-40-6732-p.jpg.7e4e260c56bc622ce634e812c8722673.jpg

Should be picking the timber up this week, which has cost me around £62, I've got left over fixings from last time, so I think this should be comfortably under £100.

Will need to by a Chain, rubber feet and inserts..

Will keep updated on progress.

Ta

Fozzie

link to the previous build FYI

 

Edited by Fozzie
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I've actually just added a berlebach spreader to this, so it'll end up costing around a wee bit more, but the spreaders are great bit's of kit and really add to the overall stability.

So check list of items.

  • Wood - Got
  • berlebach Spreader and fixings- Got
  • M8 85mm long Bolts, wing nuts and washers - Got
  • Thread Insert M10 20mm deep - Need
  • Rubber feet - Need
  • Chain and Fixings - Need

Next job is to take the old metal legs of the EQ5 and pack them in the loft.

I've also been offered some off cuts of the Iroko so I can test the finish I want to apply.  The Iroko is quite an oily wood (apparently although I've read differing opinions) a bit like teak, so oils don't overly take.  I want this as natural as possible, and it looks like the best finish might just be a light Oak stain followed by a few coats of UV protector.. but that's for permanent out door furniture, which this wont be.. so we shall see.

Will post pictures of the wood when it lands

Ta

Fozzie 

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First  rethink of the tripods..

Looking at the EQ5 hub, after I've taken the metal legs off it's quite different to the vixen GP hub.. so I'll need to rethink how i attach the legs. 

Two options I can think of.. firstly notch the top of the legs so that they fit between the brackets, or cut grooves and adjust the position of the bolts by a few mm over wise the outer leg bits will snag, it will only leave 10mm cover on the wood.. should be enough though!

20180627_205008.thumb.jpg.e7f5374a78df9557a06e5b216caa868a.jpg

Will draw something up tomorrow.

Ta

Fozzie 

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The Iroko wood is here and I've got a piece with beautiful grain running through, i suspect this is cut in a different plane to the othe pieces, it'll make a great north leg..

The pieces are 1600mm long, the chap at the timber store cut me some longer pieces so I can test finishes on them before I apply to the main legs once I've worked them..

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20180629_211323.thumb.jpg.7bf333b013dba5fb4c8bbac986e413b6.jpg

Few more bits in the post for next week and were good to go!

Ta

Fozzie

 

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So I'm messing around with the off cuts, after setting the height to 1350mm of the legs.. that's a extra 100mm over the sapele tripod.  

I'm testing different wood finishes however because I have two pieces of sap wood and one heart wood the final appearance of the legs is going to vary drastically.. the heart wood will be the north leg I think.

So the finishes are

Teak oil

 

OSMO red ceder uv protection

OSMO light oak uv protection 

Ive also got some clear OSMO uv protection which I'll try later on.

Here's the impact..

Untreated cuts

20180701_163445.thumb.jpg.7dd3b734d24ca986f837e8d141e082fe.jpg

Treated cuts, teak oil bottom, oak at the top

20180701_170708.thumb.jpg.e1d3c2720f96a445fdcdfc6330e7609e.jpg

The heart wood is the darker.

It's almost a shame it's not 3 of a kind...

Still though, nice wood..

Ta

Fozzie

Ps it's defo the same wood... look at it and on, you can see where it's been cut..

20180701_172324.thumb.jpg.4f8406c75eedcb666a29d7f0ae342806.jpg

Edited by Fozzie

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Call me old fashioned, but I really wouldn't start from here. :wink2:

If that cast, white tripod top is your intended donor I'd be putting the legs OUTBOARD of the lugs.

And fit a LARGE METAL spacer BETWEEN the lugs to stop them snapping right off the casting when the cross bolts are tightened.

 

The best tripods are very wide where they join at the top.

A spreader in the middle can NOT stop rotational torque applied at the top when you move the telescope.

It can only limit leg spread and provide somewhere to collect dew and dust on your exposed eyepieces.

 

Think of each tripod leg as an inverted isosceles triangle with the base at the top.

The wider the base of a triangle the stiffer it becomes laterally = vital torque resistance.

The struts [legs] are ONLY put in tension and compression instead of literally bending.

The wider the space between the bearings the smaller the potential slop using simple geometry.

 

Stand on one leg and then try two. Two legs provide the vital triangulation for lateral stability.

Your legs are put in simple compression to resist toppling over sideways.

Bring you feet closer together and the stability drops.

 

Ideally, hinged tripod legs should lock naturally against a flat surface up at the top.

Were it me I'd be trying to emulate the lightweight, PORTABLE, folding piers you see under AP mountings.

Hugely wide hinge spacing [triangle bases] mean broad triangles mounted on large diameter, hollow cylinders.

Of course these are designed to fold for portability but the geometry is well worth studying.

 

Drilling will not provide you with an accurate hinge bearing in wood. Or not for long as wood is sensitive to moisture.

Cones are good because they will tighten to remove all slop.

 

Spherical rod end bearings are relatively inexpensive for what they bring to the feast.

[Think Go-cart steering components rather than cars]

These can be bolted individually OUTBOARD of the tripod head lugs.

This removes the danger of snapping off the lugs and maximized their spread.

Bore the legs lengthways and epoxy the fixing nuts into the end of the wooden legs to allow some adjustability.

Rod ends come in right and left hand threaded models with hexagonal aluminium arms.

 

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The original Celestron C8 tripod was one of the best ever made, I doubt whether its stability/weight ratio has been improved upon.   ?

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Not so much old fashioned, but vastly experienced i suspect!

Thank you for the response, to be honest a few bits are totally beyond me, but i'll try and comment back as you took the time to write up your thoughts.

3 hours ago, Rusted said:

Call me old fashioned, but I really wouldn't start from here. :wink2:

If that cast, white tripod top is your intended donor I'd be putting the legs OUTBOARD of the lugs.

And fit a LARGE METAL spacer BETWEEN the lugs to stop them snapping right off the casting when the cross bolts are tightened.

That’s correct, the EQ5 tripod hub will be the “donar” hub as you call it. The legs are intended to fit around the lugs as shown, so they will be both “outboard” and “inboard” of the lugs.  Teflon Washers will provide packing to prevent any looseness and stresses from snapping the lugs off when tightening the cross bolts.  These bolts will be high tensile M8 85mm long.  The top of the tripod legs will be 75mm. 

3 hours ago, Rusted said:

The best tripods are very wide where they join at the top.

A spreader in the middle can NOT stop rotational torque applied at the top when you move the telescope.

It can only limit leg spread and provide somewhere to collect dew and dust on your exposed eyepieces.

 

I’m not in any way shape or form an engineer, and reviewing your blog, your engineering and DIY skills are obvious for all to see.  Whilst I understand this comment, that the mount will still experience rotational torque, would that not be a feature of all mounts, or is this a specific warning to my proposal?

I’m hoping that having the tripod legs, square to the donor hub and sturdy enough will overcome these forces, the spreader will aid by controlling the legs, adding to the overall resistance, and prevent the legs from any twisting motion, better than say a chain.. 

3 hours ago, Rusted said:

Think of each tripod leg as an inverted isosceles triangle with the base at the top.

The wider the base of a triangle the stiffer it becomes laterally = vital torque resistance.

The struts [legs] are ONLY put in tension and compression instead of literally bending.

The wider the space between the bearings the smaller the potential slop using simple geometry.

 

As I’m at 75mm wide already, the only way to increase the stability would be to reduce the height (length of legs) so increasing the height/width ratio.  Again, I’m no engineer but do we think 1350mm high legs are too much/unstable?

3 hours ago, Rusted said:

Ideally, hinged tripod legs should lock naturally against a flat surface up at the top.

Were it me I'd be trying to emulate the lightweight, PORTABLE, folding piers you see under AP mountings.

Hugely wide hinge spacing [triangle bases] mean broad triangles mounted on large diameter, hollow cylinders.

Of course these are designed to fold for portability but the geometry is well worth studying.

 

Those are great mounts but way over engineered for my skill set and requirements..

3 hours ago, Rusted said:

Drilling will not provide you with an accurate hinge bearing in wood. Or not for long as wood is sensitive to moisture.

Cones are good because they will tighten to remove all slop.

 

The iroko wood has a 25year lifespan, very durable and is extremely resistant to both water and oil based preservatives, I’m hoping it will take a while for any water damage or rot to effect hinge.  Providing I can drill accurately enough, I’ve access to a pillar drill that will do the job, then hopefully this will be ok, with out the need to sleeve the hinge with a metal tube.

3 hours ago, Rusted said:

Spherical rod end bearings are relatively inexpensive for what they bring to the feast.

[Think Go-cart steering components rather than cars]

These can be bolted individually OUTBOARD of the tripod head lugs.

This removes the danger of snapping off the lugs and maximized their spread.

Bore the legs lengthways and epoxy the fixing nuts into the end of the wooden legs to allow some adjustability.

Rod ends come in right and left hand threaded models with hexagonal aluminium arms.

 

That’s a good way of fixing   that I’d not considered before, if the above hinge fails I’ll absolutely look in to that.

Again, thank you for the response, hopefully mine hasn't "dumbed" it down too much, but my endeavours are to simply replace the tripod legs that came with a generic EQ5 in to something that ultimately looks better and might offer a bit more stability and vibration dampening.

As always.. feed back warmly welcome!

Ta

Fozzie

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Don't underestimate yourself, Fozzie. 

It's good to see anyone willing to have a go at a bit of ATM.

I'd better explain myself:

I was afraid you'd put a long bolt through both tabs of each leg.

This would put enormous strain on the tabs which might give way.

If you are sandwiching the tabs with wood then use a short bolt per tab.

If you can find room to fit them in or can sneak a nut in between them.

You could sink a nut into each "inner" leg then put bolts in from the outside if it's tight.

A picture is worth a thousand [of my] words. :wink2:

tripod top lugs.jpg

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16 minutes ago, Rusted said:

A picture is worth a thousand [of my] words. :wink2:

tripod top lugs.jpg

Oh I see.. no that's not what I was planning on..

this is more representative..

1107373638_mountfix.png.9c0a6c89ebc08f510f50918398af2032.png

the entire top of the tripod leg will be solid, clamping the two tabs, using large Teflon washers to close gaps, spreading the load.. acting a bit like the metal spacer you originally noted. 

ta

Fozzie

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@Fozzie. Some images to illustrate what myself and @Rusted mentioned earlier. These are a couple of tripods I made from aluminium stock but could just as easily been made of wood. The tripod tops are 9" diameter and the splays at the top of the legs are 8". It's virtually impossible to twist the tripod top by hand and damping is excellent. I'm sure your tripod will be as good as any of the currently available wooden tripods judging by the appearance of your previous work.  ?

002.JPG

003.JPG

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9 hours ago, Peter Drew said:

@Fozzie. Some images to illustrate what myself and @Rusted mentioned earlier. These are a couple of tripods I made from aluminium stock but could just as easily been made of wood. The tripod tops are 9" diameter and the splays at the top of the legs are 8". It's virtually impossible to twist the tripod top by hand and damping is excellent. I'm sure your tripod will be as good as any of the currently available wooden tripods judging by the appearance of your previous work.  ?

Thanks Peter, those photo's demonstrate very accurately the inverted triangle @Rusted has been discussing. 

I guess this is the only bit out of my control, shall we say, as I've chosen to use a pre-manufactured hub from an EQ5.  Maybe next time I could look at turning a tripod hub out of wood to so I can increase the overall width of the tripod top. 

I guess part of doing this, especially with the vixen hub, was because I couldn't afford a off the shelf wood tripod, and I wanted to demonstrate what could be done/achieved with "relatively" common components, such as tripod hubs like the EQ3, EQ5 and old GP etc. 

I've got to say I've enjoyed having something else to do on an evening when the kids and football is done (read while the wife is watch love island), whether the fixed height tripod is as good a result as the last one though will remain to be seen, but from test samples of wood I've done, it should look the part at least!

Ta

Fozzie

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Fozzie,

The problem with your spanning and filling between the lugs is that wood always shrinks as it dries.

I'd be considering a solid aluminium spacer but the problem is getting it in there.

Why not leave out the central "filler" section of timber altogether and add a sturdy 'ally' spacer instead.

Properly done the central metal spacer will add to the structural integrity of the lugs and look "pretty" too.

As if you had a solid metal extensions, the full width of both lugs, attached directly to the central boss.

Just like the Vixen in your image above but even wider. Just as it should be on every tripod.  :thumbsup:

 

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22 hours ago, Rusted said:

Fozzie,

The problem with your spanning and filling between the lugs is that wood always shrinks as it dries.

I'd be considering a solid aluminium spacer but the problem is getting it in there.

The Iroko is not overly prone to excessive movement once dry, heck it has less than 5% shrinkage from original to kiln dry state, but I take your point about general shrinkage over time providing movement between the lugs. 

Now I could get some M8 metal spacers at 35mm long, with a rough M10 o/s diameter.  If I over sized the hinge drill I could tap this into the centre part of the tripod leg, with washers taking up the remaining slack.  That would provide the stability and leave the wood to shrink around the spacer over time.  The only issue here is it would be a 10/11mm hole rather than 8mm leaving not much coverage (less than 10mm of wood) surrounding the hinge.

Standoff.jpg.1f6d58f303bf812e20a418f54db4ad9c.jpg

My issue with removing the centre part of the wood/tripod connector is that the legs would then only be secured by 10mm thick wood either side, which would leave me concerned about breakage of the wooden legs at this point.

I'm leaning towards keeping the tripod legs as I've drawn to avoid cutting to much out and weakening the leg too much at this point.

Something to think bout, but i'm leaning towards either this M8 sleeve or just sticking with the original and watching for shrinkage of the hinge over time which could be taken up with nylon washers..

22 hours ago, Rusted said:

Just like the Vixen in your image above but even wider. Just as it should be on every tripod.  :thumbsup:

Don't I wish it was... when I started this I wrongly assumed as the EQ5 is a clone, the tripod hubs were identical to one and other..

thanks for the thoughts gents, keep them coming!!

Ta

Fozzie

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Morning All..

Tripod build update and an important warning first off if you decide to work with an "oily" wood like Iroko.

WARNING..

I'd been warned that Iroko wood dust was or had the potential to be irritable so I got a dust mask from work and impact glasses for routing and drilling..

Yesterday I spent the morning routing the various element's, dust mask and glasses on as my PPE. Last night I was weezing and looking my voice.

Any dust is bad.. this iroko dust is so oily it's like Lilly pollen, it sticks to everything and is so fine the dust mask was bright yellow and clearly when working with it you need to be open air or have better dust extraction.. there was A LOT of dust to contend with.. it's taken me all morning to clear out the garage and hoover it..

So H&S  advice.. make sure you wrap up safe and have the correct equipment even for jobs at home..

On to the tripod.

So far I've cut out the foot section, routed the chamfer's and radius of the hinge, cut out the 37mm holes and inserted the spike feet.  It's by no means perfect and I've found the wood has a habit of splinting annoyingly with will need a bit of sorting..

Only thing to do now is the hinge drill, the tapering of the feet and a bit of decorative routing to the face of the legs..

So far, I'd go a strong 7 out of 10.. learning some new tools and skills here as we go..

Ta

Fozzie

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20180708_104000.thumb.jpg.97d9f503ade9eae2a611d3c27558c4c4.jpg

 

 

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Mmmmmmmm the spreader chain is maybe a bit over specified.. ?? it'll take 160kg before it gives though.. which is nice

20180713_202724.thumb.jpg.89b601dd2f23d13781465d515afa9699.jpg

 

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Last bits routed and drilled the hinges..

Just waiting on a different chain than above.. then it's down for the stain..

Otherwise... voilá!

20180714_123622.thumb.jpg.d9a541926b2ea7216905b5e03c87f050.jpg

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thanks

fozzie

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Stained with a mixture of OSMO oil  and teak oil..

5ml OSMO red cedar uv protect oil

20ml  clear matt uv protect oil

25ml teak oil.

Left for 30mins then wipe with cloth to remove excess, now drying..

Looks nice..

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20180714_135055.thumb.jpg.46854bb4c802f6fb0f7c1799d912bc2d.jpg

ta

Fozzie 

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Looks fabulous dizzied. Watch out Berlebach!! :) 

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Fabulous build Fozzie. What is the chain for? Is it to secure the tripod to a secure robust post in the garage to stop anyone stealing it, because it is a beauty :)

Steve

Edited by sloz1664
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On ‎14‎/‎07‎/‎2018 at 14:03, Stu said:

Looks fabulous dizzied. Watch out Berlebach!! :) 

Dizzied? lol, my wifes nick name came from an auto correct issue.. changed here family name from Wardle to Waffle... it stuck..

23 hours ago, Peter Drew said:

Beautifully made. (As expected!)     ?

Thanks Peter

 

23 hours ago, sloz1664 said:

Fabulous build Fozzie. What is the chain for? Is it to secure the tripod to a secure robust post in the garage to stop anyone stealing it, because it is a beauty :)

Steve

Thanks Steve,

A slightly more appropriate chain has turned up now, will fit it tonight.. just as a back up if anything gives, it'll stop the legs spaying too far.. if im honest I don't trust my DIY after some appallingly bad floating shelves I put up, that also fell down again!

that big chain is now holding a friends 6ft driveway gates closed for extra security.

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2 hours ago, Fozzie said:

Dizzied? lol, my wifes nick name came from an auto correct issue.. changed here family name from Wardle to Waffle... it stuck..

Dizzied, tee hee, I hate autocorrect Fozzie  , Fozzie, fozzie ...... how strange, now it has stopped doing it!! :) 

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27 minutes ago, Stu said:

I hate autocorrect

Me too..  My phone once changed International to irrational as I typed in a hurry and didn't spot it.. 

Biggest issue was I was talking on social media with the wife and her friends about international women's day... that sort of autocorrect malfunction will get you in the dog house no doubt about it! 

Still costing me now that one I think..

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