16" f4 Orion Optics UK Dobsonian Project

[Astrokev]

Well, that's not expensive, even for me Trouble is, there are so many things I would like. If I were to keep buying odds and ends my obsy would never have the funds to get started!

Yep, as I said in an earlier post, a router would be good, but there's loads of other more expensive things on my wish-list that would get far more use. One has to prioritise.

[Moonshane]

progress update

yesterday and today I have routered the alt bearing cartwheel shapes and it went reasonably well using the template. unfortunately the collar on the router prevent the bit reaching far enough to get through the 18mm ply so I had to go as far as possible and then cut with a jigsaw. this left a nib of material to sand off.

I then glued and nailed the two pieces for each bearing and put them under some weight overnight. the glue seems to have done it's job.

today I have been sanding various areas, getting them as nice as I can and identical in terms of the circumference.

they are not perfect but not bad considering I have not done anything as complex as this before.

the bulk of the work is in the alt bearings I now know unless you just do plain circles or semis.

I want to ensure they go on the same way they have been sanded so I added A-D with a sharpie pen around the circumference so I can put them together again the same way when it comes to construction.

when the sanding is finished I'll then finish the cell so that I can put the cell, primary alt bearings, fit the focuser, secondary, finders and a medium eyepiece and find the balance point of the OTA. then I can establish the height of the rocker which will be as low as I can get away with.

I am setting myself a target for mid July and hope to meet that in good time.

[Astrokev]

progress update

yesterday and today I have routered the alt bearing cartwheel .

Which end does the horse go ?

Looking really good Shane.

[johninderby]

After looking at the bits you've made so far, and in particular those wheels, I now realise you've been having us on. What you're really building is one of these. :D

John

[Moonshane]

Which end does the horse go ?

Looking really good Shane.

I cannot believe you said that... neigh neigh......

cheers - I have just realised they have the 'made in Britain' look about them! maybe I should paint a flag on?

After looking at the bits you've made so far, and in particular those wheels, I now realise you've been having us on. What you're really building is one of these. :D

John

touche!! (or is that (Treb) touche??

[Astrokev]

I cannot believe you said that... neigh neigh......

cheers - I have just realised they have the 'made in Britain' look about them! maybe I should paint a flag on?

touche!! (or is that (Treb) touche??

LOL. Good play on words!

Joking aside, since it's mid-build, it's bound to look a little utilitarian. I'm sure the finished job will look superb.

On a related note - have you seen Penguin Pete's Octagonal OTA build just posted? Superb workmanship. My hex tube is being designed on the same lines, though I fear the quality of my build won't compete (another bit of word-play there!). Now if I only had a router.....

[spaceboy]

Probably sounds stupid but I am really getting exited to see the finished item. You are doing a great job Shane and I'm willing every thing to go smoothly in the hope to have a look through it at the peak star party. Will you be making another EQP for this scope?

[Moonshane]

LOL. Good play on words!

Joking aside, since it's mid-build, it's bound to look a little utilitarian. I'm sure the finished job will look superb.

On a related note - have you seen Penguin Pete's Octagonal OTA build just posted? Superb workmanship. My hex tube is being designed on the same lines, though I fear the quality of my build won't compete (another bit of word-play there!). Now if I only had a router.....

hi Kevin

yes, I have seen it and what a superb job. I am a complete numptie when it comes to woodwork but take it slow and things usually work out.

[Moonshane]

Probably sounds stupid but I am really getting exited to see the finished item. You are doing a great job Shane and I'm willing every thing to go smoothly in the hope to have a look through it at the peak star party. Will you be making another EQP for this scope?

hi mate

it will hopefully be ready by mid-July and certainly by the PSP.

might make a EQP if I have time as I should have enough timber left over. we'll see.

[MjrTom]

This is an amazing project, nicely done Shane.

Looking forward to seeing it in action

[Astrokev]

How's the build going Shane?

[Moonshane]

hi mate

due to my inexperience with a router I slightly messed up the alignment of the two boards making up each alt bearing so it's meant a lot of sanding - two days of sanding! It felt like I was grinding the mirror . finished that yesterday so they are ready to be drilled and put on the OTA.

this weekend I'll be doing that, fitting the focuser, finder shoes and possibly flocking the OTA.

I have some laminate for the alt bearings on order and this will be applied too if it arrives in time.

hopefully early next week, once the cell is finished I will have a chance to establish the balance point with a mid range eyepiece and I can then start work on the rocker and ground board once I know the required height.

I bought an offcut sheet of slightly bobbly laminate about 600mm square for £8. In my current circumstances I need to try and save a bit here and there. It's not ebony star but will hopefully be OK if I set it up correctly. If not I can always glue a ring of ES over the top of it with impact adhesive after keying it first.

so moving along albeit slowly.

I take the view that this is a project that once finished will be used for years and years so I might as well spend a few extra days getting it right, especially given the skies at the minute which I presume are still light although I cannot see them for clouds!

more good news is that I have secured a job which is the first step toward a brand new career after 28 years in banking. I will be the Administrative Manager in a primary school from 1/9/2011. The money is pro-rata (4 days a week and term time only) so a massive drop from my previous role but assuming I am as good as I say I am, they have indicated that I can build the days and responsibility quickly and this should increase the salary quickly too. I can also do lots of related training and qualifications (even to degree level) so this will also enhance my opportunities going forward.

Really quite positive although tightening of belts will ensure for a year or two. Now trying to get some temp work until I start and seeing an agency today so will (hopefully??) have less time to spend on the scope.

[Astrodread]

I cant wait to see your scope finished Moonshane. 16" hmmm dribble. Theres nothing more satisfying than making your own scope and then using it. You bring on the inspiration......

Many thanks

More photos please.

Pete (astrodread)

[Moonshane]

for sure Pete

There will be lots (sometimes I think too many!) as I go. I tend to photograph each finished stage (or if there are some build tips during the process I add those too).

I am off to see a professional welder today to see if he can redo the welded nuts I got someone to do on the cell as a favour. They are a slight mess but I'm not complaining, easily resolved.

[Astrokev]

Hi Shane

Thanks for the update. Firstly, congrats on getting a new job - makes you feel part of the human race again! I've just started some part-time contract work with a company I've worked with before, so that helps keep the wolf at bay for a while longer. An interview lined up for next week, which I'm hopeful about, so I hope to follow your lead in the not too distant future.

Regarding your job - bitter/sweet I guess - good for the income and stress levels, but less time for stuff you enjoy, as you say. Make the most of your spare time while you can!

You can never post too many pics, so keep 'em coming.

[SniffTheGlove]

Been an interesting read Shane, hope all goes well with the final construction bits.

Are you aim for a 1.25 or 2in focuser with this monster?

[Moonshane]

Hi Shane

Thanks for the update. Firstly, congrats on getting a new job - makes you feel part of the human race again! I've just started some part-time contract work with a company I've worked with before, so that helps keep the wolf at bay for a while longer. An interview lined up for next week, which I'm hopeful about, so I hope to follow your lead in the not too distant future.

Regarding your job - bitter/sweet I guess - good for the income and stress levels, but less time for stuff you enjoy, as you say. Make the most of your spare time while you can!

You can never post too many pics, so keep 'em coming.

cheers Kevin

spot on about how I feel re the new job. scared, excited, worried about the lower salary etc but we'll be OK, and definitely part of the human race again. went to a temp agency to fill in the gap until I start and felt like a right loser. hopefully will result in at least some work though.

hope you get something sorted out too matey - looks good!

more pics will certainly follow.

picked up a borrowed pillar drill just now so will be doing some more work over the weekend for sure.

[Moonshane]

Been an interesting read Shane, hope all goes well with the final construction bits.

Are you aim for a 1.25 or 2in focuser with this monster?

cheers Sean

I am loving the work on this. quite tricky some of it and creating the teflon supports and the clips will be a bit tricky but have some ideas.

I have a 2" dual speed crayford focuser as this scope will be made for wide field lower power viewing but with an aperture mask will also hopefully be a planet killer too.

[Astrokev]

picked up a borrowed pillar drill just now so will be doing some more work over the weekend for sure.

Mmm, pillar drill.....

Definitely on my list of toys to get.

[Moonshane]

and mine for the future. for now a borrowed one will still do the job

[SniffTheGlove]

and mine for the future. for now a borrowed one will still do the job

Search your Area's Freecycle scheme. I got my Pillar Drill and Bandsaw for free from different ads from our local Freecycle scheme.

[Moonshane]

as I have a pillar drill on loan, I had a metalwork day today and made good progress with the cell.

we had originally added some captive nuts but these were not attractively welded so I have ground them off. furthermore although in principle, four bolts per connection point means more strength in the fixing, it also meant drilling 12 more holes in the tube and lining them up etc.

therefore I have drilled 6 more holes in the cell to match the existing tube holes. this will be much more pleasing aesthetically.

I am getting an SGL friend to help with the welding of some T nuts (with the spikes ground off) onto the cell for collimation bolts and the fixing points which will all be a lot neater in the end.

I drilled all me holes and here's the cell at various stages of testing the fit etc and built up/in the tube.

obviously some bolts are the wrong way round (triangles) and the collimation bolts need trimming (just a touch) but I'll do this last.

looking good and when it's painted it will be great.

I may trim down the shorter of the connection pieces and use the off cuts for the mirror clips.

also, I'll be using the four holes in the long piece (which will remain intact) to attach some 15mm thick teflon at approx 45 degrees either side of the bottom of the mirror to act as 'buffers' to keep the mirror off the sides. Might also put one at the top for the same reason.

it's starting to look like a cell now at least.

I might have to tug and pull the connection points a little as this tube is typical of OOUK in that it is not quite round and has a large flat area.

[spaceboy]

Coming along nicely now Shane. What finish are you planning for the mirror cell ?

EDIT: DOH!!PAINT Can't see the forest for the trees sometimes. Been a long day.

[Moonshane]

cheers mate. I considered powder coating but trying to keep costs down so will probably do a smooth satin black hammerite. not sure whether to spray or brush though. any tips?

[Glen]

Blimey Shane..

Watch out faint fuzzies, no more hiding! That's going to be one beast to be proud of!

I admire you perseverance cutting the stainless steel cell supports (I used to work with the stuff, dreaded having to trim, let alone cut it) AND all the sanding of the bearings, good to see the shed/workshop/kitching table.. hands on brigade are still around. Maybe if you get tired of it (highly doubtful), a few mods and you could have one of these..

Thanks for posting your project updates - and look forward to seeing it finished

Glen

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