Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

20" f/4 Dob build

swamp thing

By swamp thing
in DIY Astronomer

Recommended Posts

  • Replies 402
  • Created
  • Last Reply
swamp thing

swamp thing

Posted
  • Author
Posted
BTW apologies Steve, I should have spotted that mate.

No worries buddy. It's an easy alteration. Couple of slight changes to the spider, and jobs a good un.:icon_salut:

TBH handy that Don spotted it before I painted it all.

Regards Steve

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted

Made all the necessary adjustments to the spider this evening. :rolleyes:

Just shows the advantages of posting your build as it goes. Saved me a lot of "oh for goodness sake" after it was painted. :icon_salut:

Also finished drilling the focuser board. This will be biscuit jointed to the UTA rings rather than screwed (will look neater). I also cut a Telrad board this will also be biscuit jointed to the UTA rings near the focuser board.

Pictures to follow. I will also post some of the altered spider.

Whilst awaiting the focuser, I may build a transport box for the UTA. This will be made of lightweight 9mm ply, lined with something. Haven't decided what yet. Any thoughts?

I may start on the mirror box too. Have decided to go with some "Webster" altitude bearings, simply because I prefer the look of ally to ply wood bearings.

I could easily make ply ones but personally like the idea of 'breaking up' the all wood look, and making it more aesthetically easy on the eye. :rolleyes:

Gonna just have a Telrad on the UTA. I will probably fit a super (small 4" or 6" newt) finder on the mirror box. As this will be easier to balance.

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted

Got the camera out and took a couple of pics to show the now parallel spider vanes.:)

The focuser and Terad boards have both been biscuit jointed on and a couple of coats of varnish applied.

You can see the advantage of the biscuit joints meaning no unsightly countersunk screws in the tube rings.

6f94e1ee.jpg

On the name board it just had to be black and green.:)

9b07e6b3.jpg

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted
What thickness steel did you use for the spider? Very nice woodwork too btw. :)

Hi

Sorry cannot really help with that as its still the spider that came off the beacon hill scope that donated the mirror.

It's also galvanised and painted so even if I could find my Vernier it wouldn't be very accurate..

I would estimate it at 1mm thick

Thanks for the kind comments.:)

Coming along nicely Steve, really looking forward to seeing the finished product. Keep up the good work :)

Cheers buddy. How's ya observing platform coming on?

Link to comment
Share on other sites
Damo636

Damo636

Posted
Posted

Cheers buddy. How's ya observing platform coming on?

Thankfully all done apart from a bit if tidying up around the edges. We were in Homebase earlier and the wife was eyeing up some new patio furniture, I was thinking more along the lines of a nice dob friendly obsy :)

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted
Thankfully all done apart from a bit if tidying up around the edges. We were in Homebase earlier and the wife was eyeing up some new patio furniture, I was thinking more along the lines of a nice dob friendly obsy :)

Now your talking:D

Some type of roll away shed? Looked like you have pretty good skies where you are.

maybe have to go on an Irish tour when my Dobs finished.:)

Link to comment
Share on other sites
Damo636

Damo636

Posted
Posted
Now your talking:D

Some type of roll away shed? Looked like you have pretty good skies where you are.

maybe have to go on an Irish tour when my Dobs finished.:)

I can put you up for a few nights Steve, no problem :).....

Even supply the Guinness....

but only if you bring the 20"

:)

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted
Will you need a roady for that tour Swamp Thing? Lol! Guinness and stargazing, what could be better!

May have to take swamp thing though. Don't think we'd get both your 12" and the 20" in the back of my little van. He's road legal but hasn't got the comforts of home yet.

I can put you up for a few nights Steve, no problem :).....

Even supply the Guinness....

but only if you bring the 20"

:)

Sounds good to me.

Sounds like I'll be doing a UK and Ireland tour when it's up and running. Better get my finger out getting swamp thing ready.

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted

Finished early today so managed to pick up the plastic sheet for the light baffle.

Now, wood and metal I can do but plastic :eek: first time for everything I guess.

Trimming this to fit was about as nerve wrecking as scope building can get. One slip and you've messed up your upper tube rings and all that work.

The plastic I decided to go with was 1mm thick and not that easy to cut it needed quite a bit of pressure on the knife. I found the 0.5mm stuff just a little too thin for anything on the actual tube assembly.

The plastic is mat finish on one side and gloss on the other.

After fitting the light baffle I replaced the spider and upper truss clamp locators.

The UTA is now finished bar the focuser and Telrad. :)

2bb3afe6.jpg

5adc3c1e.jpg

ba0ace9e.jpg

Just waiting for the Focuser and then I can start on the mirror box.

I need to know the finished weight of the UTA before I can calculate the depth of the mirror box.

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted

Cheers for the encouragement peeps.

Only a Telrad on the UTA Ibbo. I may Put a 6" RFT newt on the mirror box as a super finder later.

Star parties are definitely on the menu once this is finished.:(

I hope to tour around the country and meet as many of the SGL crowd as poss.

I'm not so much patient as just slow.:D I've so many other things on the go at the moment. Building an overland camper. (Makes the scope build look really easy) and redecorating at home.:)

Knackered TBH.

Link to comment
Share on other sites
swamp thing

swamp thing

Posted
  • Author
Posted
Are you keeping the guy who you had the scope off up to date Steve. I know one thing it is a drastic improvement over the original. Proper job!!!

Never gave it a thought Nick as he didn't build it. I think if he'd built it I would have sent him some updates.

looking great Steve! This is the most tricky bit. Once through this and it's plain sailing.

I hope so Shane. At least while waiting for the focuser I can get on with some other jobs.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.