Making your own dobsonian telescope

[Piero]

What is blocking you from making your own dream dobsonian?

[Peter Drew]

Nothing.  I made my 17" and 30" Dobsonians.     🙂

[Boki Aristarh]

Only the price of big mirrors.... 🥲

@Peter I would like to see pictures of yours 30" Dob, please... 

[Louis D]

It seems like fewer Brits than Americans live in homes large enough to have a dedicated workshop, whether it be in a shed, part of a garage, or in a basement.  It really helps to have a place to store and use power tools for wood or metal working.

Australian homes rival and even best American homes for size on average.  I wonder if Australian ATMs are more prevalent than UK (and American) ATMs as a result?

[ShrewView]

Well setting aside the cost of the mirror and my dubious diy skills, its the sneaking feeling I'd only get to use it once a year with our weather. 😀

[John]

Going larger than my current 12 inch would be pointless in my current observing circumstances.

If I'd had a nice long garden with a dark observing area at the bottom and a shed for the scope I'd have a 20 inch dob rather than all these refractors. Probably not self made though. I prefer to spend my time in the hobby using kit rather than planning, designing and making it

 

 

Edited August 23, 2021 by John

[jetstream]

1 hour ago, John said:

I'd have a 20 inch dob rather than all these refractors.

😲

Ive just about fainted!😀

[jetstream]

6 hours ago, Louis D said:

It seems like fewer Brits than Americans live in homes large enough to have a dedicated workshop, whether it be in a shed, part of a garage, or in a basement.  It really helps to have a place to store and use power tools for wood or metal working.

Australian homes rival and even best American homes for size on average.  I wonder if Australian ATMs are more prevalent than UK (and American) ATMs as a result?

wheres @quaoar?

Might not be home made but very impressive

[jetstream]

12 hours ago, Piero said:

What is blocking you from making your own dream dobsonian?

I paid $1800 for my 15" vg mirror. I was quoted by a CDN company for the same size $5000.00. Glass is going way up IMHO.

[Piero]

Fair enough. Good to read that for the vast majority of members, the lack of skills is not an actual blocker. Those kind of skills are always handy to have anyway, particularly after retirement with 50-60 extra hours per week. 🙂 

Not sure, I follow the cost argument, considering the equipment of some members posting in here, but if others see some reasonable maths in there, that's excellent! 

Edited August 24, 2021 by Piero

[Peter Drew]

10 hours ago, Boki Aristarh said:

Only the price of big mirrors.... 🥲

@Peter I would like to see pictures of yours 30" Dob, please... 

Go to www.astronomycentre.org.uk,  click on 30" Dobsonian item on the information list.    🙂

[IB20]

A very small human.

[Astrobits]

Made lots, including the mirrors, up to 20".🙃

[markse68]

laziness, lack of time (or is that laziness) money and practicality (would it get used as much as what i’ve already got given it’s extra size) i guess. I’ve a beautiful David Hinds 12” mirror sitting in a box and loads of hours of design work i did when i first bought it right at start of my new hobby/passion but it’s still sat there 😞 One day…

Mark

Edited August 24, 2021 by markse68

[CraigT82]

Lack of time mostly, but also lack of interest as visual DSO observing doesn't really float my boat, especially living in a city. Maybe if I lived under dark skies. 

9 minutes ago, markse68 said:

I’ve a beautiful David Hinds 12” mirror sitting in a box

You should really do something with that mirror it's criminal for it to be sat in a box!

[DaveS]

Assumes that one wants a dob in the first place. I don't, of any size.

I have all the instruments I want, at least  for a good while yet.

[markse68]

27 minutes ago, CraigT82 said:

You should really do something with that mirror it's criminal for it to be sat in a box!

Thanks Craig for making me feel so much better about it! 😅 but you’re right- I must! and i will! Just gotta sort out my imaging rig first, oh and build my new dob base for the fullerscope, and… 😉

Edited August 24, 2021 by markse68

[DaveS]

What's the focal ratio? How about building a 12" astrograph?

[markse68]

7 minutes ago, DaveS said:

What's the focal ratio? How about building a 12" astrograph?

f5.2- would need a big mount i think

Mark

[DaveS]

Yep, wind could be a problem rather than mass. EQ8 or CEM120 territory, if you didn't want to go  Mesu / 10 Micron. An enclosed obsy would help.

[jetstream]

16 hours ago, Piero said:

Not sure, I follow the cost argument, considering the equipment of some members posting in here, but if others see some reasonable maths in there, that's excellent! 

One of the fastest ways to lose money is to sell a big dob IMHO. One of the easiest ways to get most of your money back (or more) is to sell a top refractor IMHO.Home made large dobs sell for even less than established makers scopes do.

This loss can be a consideration because some (many?) that try big dobs realize shortly that they are not for them ie room, weight, collimation etc etc. There is a nice Obsession down east-18" IRRC for $4000 asking- pick up only- shipping is very expensive and a negative for sale.

These issues might weigh on the minds of those who want to build a truss dob.

[Barry-W-Fenner]

For me its the shoddy woodwork skills and fear of however many years of bad luck you get for dropping a really expensive primary mirror! 🙂

 

I will stick with the 300p...

Edited August 24, 2021 by Barry-W-Fenner

[scarp15]

It was great to had arranged a visit Piero and to gain a full insight into your 16" dob build, it is very impressive. 

A few years ago, when Moonshane was active on this forum, he was occasionally building dobs, both for himself and others and he had offered to build one for me and at a very reasonable cost. It would have required sourcing the mirrors of course such as through John Nichol Optics. However a VX14" OOUK Dob came up on ebay and with more helpful advice from forum members I went instead for that option. Besides my wife occasionally commenting about the 'junk in the corner', no regrets really except that in the past year and a half it has been very seldom used at all.

I do admire members such as yourself and Faulksy, among others, who have built their own and having little previous knowledge or skill set. I fit into the same circumstance as others have remarked; in which I do not have the workshop, time, money, specialist tools etc. Also since most of my inspired observing time does require trips out to darker skies, having options with my other telescopes and binoculars is of equal value. For example, I cannot wait to get a chance to go on a dark sky wild camping trip again with my refractor later this year. Perhaps should we live in a more rural setting or even aspire to moving one day (no chance), then the larger truss dob build would become more viable and tempting.

[Piero]

40 minutes ago, scarp15 said:

It was great to had arranged a visit Piero and to gain a full insight into your 16" dob build, it is very impressive. 

A few years ago, when Moonshane was active on this forum, he was occasionally building dobs, both for himself and others and he had offered to build one for me and at a very reasonable cost. It would have required sourcing the mirrors of course such as through John Nichol Optics. However a VX14" OOUK Dob came up on ebay and with more helpful advice from forum members I went instead for that option. Besides my wife occasionally commenting about the 'junk in the corner', no regrets really except that in the past year and a half it has been very seldom used at all.

I do admire members such as yourself and Faulksy, among others, who have built their own and having little previous knowledge or skill set. I fit into the same circumstance as others have remarked; in which I do not have the workshop, time, money, specialist tools etc. Also since most of my inspired observing time does require trips out to darker skies, having options with my other telescopes and binoculars is of equal value. For example, I cannot wait to get a chance to go on a dark sky wild camping trip again with my refractor later this year. Perhaps should we live in a more rural setting or even aspire to moving one day (no chance), then the larger truss dob build would become more viable and tempting.

It was great to meet you too, Iain.  

Hope you will have a chance to take your telescope to dark skies soon, maybe this autumn.

Clear skies

[jetstream]

1 hour ago, scarp15 said:

or even aspire to moving one day (no chance), then the larger truss dob build would become more viable and tempting.

The mountains of BC are calling you Iain! grizzlies and all.