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Gina's Mini Dome Observatory for Widefield Imaging Rig


Gina

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Now printing the middle section of the mount cover.  I've already printed the other two parts - the ends.  The top should fit the dome support fixed part when I've printed it.  More about that later...

5962470f2b3bf_MountCover01.png.e5a81c50a539d2ecb877cedcfc168684.png

596247057ed70_MountCoverMiddle01.png.80a5bf49940dd5a2b31796c6243ad27e.png

Edited by Gina
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Printing is going well but I'm not going to open the door for a clearer view for photography as that always seems to disturb the print :D   I'll take and post a photo when it's finished.

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I have a design for the fixed part of the dome support but I think I can improve it and make it smaller.  I need to sort out the arrangement for wheels to support the dome and the structure involved.  And I have yet to sort out the drive for the shutter which will be all in the rotating part with a flexible cable to the motor.

This is the current support model.

59624d6dd8f3e_DomeSupportFixedPart01.png.85c9b6d09b534ba94989986d70613758.png

Edited by Gina
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Here is the dome support and rotation drive diagram with the idea of the main fixed support being smaller in diameter than the maximum I can print in one part on the Titan printer.  That being 280mm and 5-6mm from the edge of the clear bed area.  I have yet to work out how far the mount cover wants to come up the dome base.

5962539c506c2_MountandSphericalDomeDiagram05.png.a4f4b30b61fd5d98f3722460b54814df.png

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Decided on a 260mm diameter dome support part of the casing and now printing it, hoping the filament won't run out...  First try didn't produce a brim so I added a small flange on the bottom to help bed adhesion.

59627f6de347b_DomeSupportFixedPart02.png.4918da8ee4ef43b34138aa96db9f7216.png596280b497b20_DomeSupportFixedPart03.png.09b775a8ca7da383abfcc520340c32c0.png

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I've glued together the three parts of the mount cover part of the casing.  Here are some photos.  Two of the outside and one of the inside.

596289e5ed20e_MountCover02.thumb.png.f3d3b83c556349846a417a6881e99e83.png596289cdc3750_MountCover03.thumb.png.bd1cab7e2dc5ed6e272716d5470e25cf.png596289ba86f52_MountCover04.thumb.png.69670726a12e8a6da3ca5ec79b366efd.png

Edited by Gina
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OD of mount cover = 244mm.  Thickness = 2mm

OD of dome base = 264mm.  Thickness = 2mm

Angle of mount cover = 38°.  Near enough 40° I think - from horizontal.

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Here's a photo of the dome support with short section of mount cover glued on and smoothed.  This short section will go onto the main mount cover and allow me to adjust the two parts to suit the mount and imaging rig within the mount cover and dome.

5963ee8e24d5b_DomeSupportFixedPart05.thumb.png.b06c7e07dd5301a38b780ba3513fa609.png

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  • 1 month later...

Having found another cause of my lethargy regarding astro imaging and some other activities (other than the weather), there is a very good chance that I shall be returning to astro imaging pretty soon and will probably want this second observatory to house my widefield DSO imaging rig. 

I have just moved a newly acquired Ha solar telescope into my main observatory and with the size and weight being similar to my MN190 Mak-Newt it will need the EQ8 mount.  I don't really want to keep swapping scopes on the mount even if the physical exercise is good for me :D

Edited by Gina
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  • 6 months later...

I have had medical issues since my last post that has resulted in no astro imaging but these have now been sorted out and I'm feeling much better.  A bit late for this season for "dark-side" but if I can get my EQ8 working again I plan to use it for Ha Solar imaging and maybe observing.

I am now beginning to think again at possible dark-side astro imaging for next main season and in particular the micro dome and DIY fork mount.  It's possible that my present micro dome won't be big enough (it's definitely a tight fit) and I'm building a Giant 3D printer with a much bigger print capacity than my Titan printer.  The Titan capacity is 290mm x 290mm x 325mm whereas the giant will be nearly 500mm x 500mm x 800mm with the possibility of printing not only a bigger dome but printed in far fewer parts.

Edited by Gina
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51 minutes ago, Gina said:

I have had medical issues since my last post that has resulted in no astro imaging but these have now been sorted out and I'm feeling much better.

Delighted to hear this, Gina.  Onwards and upwards! 

Tony

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  • 2 months later...

Resurrecting this thread because I now have my "GinaRep Giant Mk2 3D Printer" virtually finished and working pretty well. The print volume has come out slight smaller than I mentioned earlier in this thread but still pretty big - 430mm X, 400mm Y and 700mm Z.  The print bed is 500mm square though the heater pad is only 400mm square but reckoned to adequately cover a 500mm square aluminium plate.  This printer gives 53% extra in the X, 42% extra in the Y and twice the height of my Titan printer used for the current micro dome.

I have decided to make a larger micro dome with thoughts of being able to take a dual widefield imaging rig.  I have two ZWO ASI1600MM-Cool cameras and pairs of old SLR lenses so it would be sensible to make use of them.  Of course this will add some weight to my DIY fork mount which this setup will be using.  Regarding the mount, I have spoken to an engineer friend of mine and he see no reason why I shouldn't use 3D printed plastic for this also.  That would be good.  Any mistakes are easily rectified (reprinting rather than making new metal parts).

I am wondering if a standard astronomy dome design would still be the best though.  There are some advantages such as blocking lights from neighbours and keeping the wind off.  The down side is the complication of rotating the dome and operating the shutter on this small scale.  I shall be exercising my brain again on the designs ?

Edited by Gina
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Whatever design I use I expect to be using white (or natural) ASA filament.  ASA needs an enclosed printer and I now have my Giant printer boxed in.  ASA is virtually ABS reformulated to stand up to UV radiation and like ABS can be acetone solvent welded to glue parts together.  I have tried this with my all sky camera and it works well.

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If I go for a standard dome design I'm not sure how to move the dome to match the imager but no doubt can work it out.  I like the dome design in many ways but wonder if a clamshell design might be easier.

I should be able to simply scale the parts to make a bigger dome but the originals are on a broken computer and I have not yet tried to retrieve the data.  I don't back up absolutely everything as I generate masses of data as I design and redesign 3D printed parts.  I may have the STL files on another drive.  Another point though is that my Giant printer is not the same shape as my Titan printer so I may be able to re-arrange the design to make better use of the Giant printer.

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Been out for a nice long walk up the hill and into the bluebell woods and back and had plenty of time to think.

Advantages of Dome :-

  1. Keeps wind off the imaging rig.
  2. Shields stray light eg. from neighbours.
  3. Possibly looks better.  (Not sure about that.)

Advantages of Clamshell :-

  1. Fewer parts.
  2. Easier to make with far less mechanics
  3. Doesn't need anything during imaging session.
  4. Easy access to the imaging rig and mount.

Seems to me that the clamshell design wins on points.

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Here's a model showing roughly the volume where the imaging rig may be as it sweeps the sky.  The mount is sketched symbolically in 2D.  The range may be slightly more than this if the view is taken right down to the horizon.  The part of sphere showing the ends of the dew shields has a diameter of 380mm which is less than the capacity of my Giant printer.

1805092223_RangeofImagingRig01.png.4ca2d864bb8a84f93df2d21415097ed0.png486070305_RangeofImagingRig02.png.a5948c90d6820fc177b97647fe8b0bb1.png

Edited by Gina
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3 hours ago, Demonperformer said:

You had me at 'easier to make'!

Well, I think it's easier to make - it's certainly less complicated.

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