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My first piece of astronomy lathework


JamesF
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I've been wanting to tinker with Mire de Collimation to collimate my dob, but I didn't have any handy way to fit a webcam into the eyepiece holder without removing the lens. So I found a lump of waste (and not great quality at that) aluminium and turned myself an adaptor. It's nothing special and not actually even the most complicated thing I've made so far, but it's the first piece of work I've done for astronomy on the lathe since I got it all set up and started teaching myself to use it a couple of months ago, so I'm feeling a little pleased with myself.

camera-fitting.jpg

The eagle-eyed will notice that the barrel even has a slight taper below the shoulder where it fits into the eyepiece holder so it won't snag on the compression fitting :)

it occurred to me afterwards that if I get some anodizing gear I can make up any number of 1.25" extension tubes, but for the really useful stuff I probably need to get to grips with thread-cutting.

James

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Well done James, there noting like seeing a piece of metal whizzing round in the lathe chuck and your close enough to take some serious damage if you try to take of to much metal, thread cutting is something i have only done with taps and dyes, my lather does have the thread cutting option but never had the desire to make it work....

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Now you've started, you won't stop.

Don't fear thread cutting on the lathe. I did for years and only recently took it upon myself to have a go. It really is straightforward and all you need to do is think about what you;re doing and be methodical. My last threading effort was an internal filter thread on a camera nose piece and it really is rewarding to think that you can do this.

Gears still fill me with fear though!

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Looking good James, I have had my lathe for about 6 years now and still havn't had a go at thread cutting yet!

I must get on and try it.

Jason.

Sent from my LT15i using Tapatalk 2

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nice work! I find turning to be very satisfying.

My old dad had a Myford ML6 lathe in his workshop/shed. Very handy for bits and bobs :)

Oh, and that thread cutting lark is a doddle with some planning and tooling....

Mind you, when I was tinkering scrap metal prices were a tiny fraction of what they are today :(

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Mind you, when I was tinkering scrap metal prices were a tiny fraction of what they are today :(

Yes :(

We have a rule that no wood suitable for the log-burners leaves the property. I think we're about to get another that no metal suitable for turning leaves the property :)

James

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Nice one James. Won't be long before your turning out nice professional anodized pieces. Maybe it's your next career move?

Bet you want to try and interface your lathe with a PC now.......... :grin: :grin:

Alan

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Very nice James.

The eagle-eyed will notice that the barrel even has a slight taper below the shoulder where it fits into the eyepiece holder so it won't snag on the compression fitting :)

James

I noticed that, I thought it was an optical illusion until I read the rest of your post! :D

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Excellent, I'd love a lathe and the expertise to use it. An excellent start, James.

Thank you.

Although my dad worked as an engineer for at least the first ten years of his working life and had a lathe in the workshop for "playing" with, I didn't ever learn to use it. It was only at the tail end of last year when I decided I could actually put one to use that I bought my first and decided to teach myself. It's obviously not as easy as having someone there who can say "ah, well, that noise is chattering and it means you've not got the tool at quite the right height" (or whatever) or "this is how you part off and yes you do have to suppress a certain amount of mechanical sympathy whilst you get the hang of it" and to show you how to do particular jobs, but within reason it seems possible to teach yourself given a bit of reading and hanging around on the model engineering forums. It's just a fair bit more work :)

James

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Nice one James. Won't be long before your turning out nice professional anodized pieces. Maybe it's your next career move?

Bet you want to try and interface your lathe with a PC now.......... :grin: :grin:

I think I have a fair bit of experience to get first :)

Sometimes (often, even :) I wouldn't mind a complete change of career, particularly one that didn't leave me sitting at a desk for most of the day, but right now I'm working on a project for a client who is insisting that I charge them more than I already do and I think I should probably be being grateful for what I have rather than looking over the fence and deciding that perhaps it's more verdant on the other side :)

James

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A good start.

I cannot see from the pic whether you have left a shoulder at the end of the taper to prevent the locking screw from pushing the adaptor off axis. Perhaps your reference to a shoulder is just that.

Having recently joined the 2" eyepiece brigade, I have decided to make an adaptor for each one of my 1 1/4" eyepieces and leave them attached permanently, so I will then only be changing 2" fitting bits.

Nigel

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I didn't leave a shoulder, no. I'd modelled it on the barrel of the ES eyepieces and didn't see an upper shoulder on them but having googled a few more images I see that there's a very narrow shoulder right up under the eyepiece body, probably not even 2mm deep. It looks like it only shows up if you get a directly side-on image, otherwise the eyepiece body hides it. That's easily sorted then :)

James

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Nice one James :) I too would like a lathe - just a small one. But I decided astronomy gear was a better use for my limited funds. I'm also rather limited as to where to put it. My dad showed me how to use a lathe umpteen decades ago so I could probably pick it up again :D

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Nice one James :) I too would like a lathe - just a small one. But I decided astronomy gear was a better use for my limited funds. I'm also rather limited as to where to put it. My dad showed me how to use a lathe umpteen decades ago so I could probably pick it up again :D

The nice thing is that lathes haven't fundamentally changed for probably sixty years or more, so there are lots of books containing information that is still relevant even if it is old. It is a lot of money to tie up just for fun though. Even my small (and it really does have to be considered small) lathe would have been about £500 new and then there's the tooling, additional bits of gear -- chucks, tailstock chucks, steadies, measuring kit and so on. You could probably spend another couple of hundred pounds there without thinking too hard. So if funds are limited I think you probably made the right decision sticking with the astronomy :)

James

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Hi James. I've been a machinist for years. To be honest I haven't done manual machining for about 20 years (all CNC now), but when I was an apprentice a Zeus Book was invaluable for thread cutting. Pretty sure you can pick one up on Amazon. As long as your lathe has the gear setting ability a man of your intelligence will find it a doddle ;)

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Nice effort James, I can see you engineering your own moonlite focuser in no time at all. On the subject of anodizing aluminium, you might want to take a look at

video on how it can be done using a more DIY method than buying any kit. One word of warning, the guy's voice in the video might send you off to sleep, so probably best to watch it with the alarm clock set for every two minutes - though the actual instructions are pretty good.

Keep up the good work.

James

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I think that once you get a lathe and start making things it brings along a mindset of 'I can have a go at that'. Surely, you'll have some failures, but more often than not, you'll succeed. Once this happens, your confidence increases and away you go.

I'm sure that some of the things I've made could have been bought cheaper than the time and effort in making them on the lathe, but that's not really the point; there's satisfaction in making something from nothing.

On my telescope I've made all the adjusting screws on the primary and secondary, Telrad adjusters and mounts for the handsets. I didn't really 'need' them, but I've had a great deal of satisfaction in making them.

You're embarking on a great journey!

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Excellent job there.

It's great to be able to make something that is not available commercially to your exact requirements, and then modify it if needed. Not only that but it becomes cheaper as well. I have made everything on my telescope including the Finderscope ( binocular obj + old eyepiece ), Crayford style focusser with two speed knob, novel secondary holder ( which is a failure and needs to be re-designed) and I haven't spent the retail cost of these items on the bits of metal used.

( One thing did strike me looking at the taper section - and this applies to those of us who are unfortunate enough to not have access to a lathe and thus be able to make an adaptor - and that is that should it become necessary to pull an eyepiece with this taper slightly out of the focusser to achieve focus it will be liable to be pushed off axis by the locking screw. )

Nigel

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