You can glue the mirror but the support points need to be closer to the center. Find the program PLOP for the optimum support points, you will find that three are enough and much closer to the center than you would think. And the support plate CTE should be close to the mirror material so steel would be better. My 8 inch is glued down this way and is fine from hot to cold weather in a steel cell I made.
Cool, yeah I've seen that gluing is somewhat common practice but also prone to issues (like I encountered.) Better to mechanically hold the mirror so it can be adjusted.
Dave, I’ve just discovered your TH-cam channel from Reddit. This is such a cool project. From having only joined the amateur astronomy hobby post-Covid, I start down the recommended 8” Dob path. Jut seeing this skeleton build of the basics of a Newtonian and watching the basics of the collimation process was incredibly insightful. I only wish you had been able to add a couple cellphone images of your views. And thanks for acknowledging the pinched optics issue and resolution. I’m sure that you know that Lockwood is one of the experts. I hope that like Dobson, you’ll do some sidewalk astronomy. You build itself will garner interest and be instructional even before they take in the sights. .
it would be great if you tried another form of attaching the mirror with specific silicone for optics and mirrors, and use a "floating" method to attach again the mirror, only on 3 first points, and avoiding the perimeter of the wall. I'm designing and printing another newton, but i'm worried about silicone, because was my initial thought and I printed that part, but not glued yet.
At this point I'm modestly confident that my re-designed mirror cell resolved the pinched optics issue I was having. It's a "standard" style of mirror holding. The secondary however is still held on with a lot of silicon and I haven't been super happy with how the collimation screws are working so I've been considering rebuilding that part anyway. Do you have any info on optics-specific silicon? A brand name? That's not something I've ever come across.
Hey I was wondering what the expected shrinckage / expansion of the Abs is when used for the telescope. Does the collimation change ro would plastic be supperior to metal as a material?
You can easily Google the CTE of materials to get a relative idea, but generally plastics have a much higher CTE then metals. Its not really important though as collimation is quick and easy so if recollimating is required once or twice during an observing session that's not a big deal.
It's a pretty big jump in performance, especially for deep sky objects. You can resolve details clearly in this scope that appear as just blurs in the Hadley.
I have not but would be interested to see what it could do with planetary imaging. For deep sky objects it would not work well as it's not rigid enough to attach a proper camera. @@sheepasus
UPDATE: Project CAD files and BoM released for free on my web site so you can build your own! - designbydave.net/3d-printed-telescope/
It has a cool look to it. Such a fun project.
Thanks! Yeah I like to do things differently if possibly ; )
Really cool, I’ve been thinking of a similar design but slightly bigger to use for planetary imaging.
Thanks for checking it out and good luck with your project!
Why do you have so few views? Your channel is great!
That's kind of you to say. Thanks for checking out my channel.
Normal people don't care about looking up 😂 But I agree, it's a really good channel with cool projects.
You can glue the mirror but the support points need to be closer to the center. Find the program PLOP for the optimum support points, you will find that three are enough and much closer to the center than you would think. And the support plate CTE should be close to the mirror material so steel would be better. My 8 inch is glued down this way and is fine from hot to cold weather in a steel cell I made.
Cool, yeah I've seen that gluing is somewhat common practice but also prone to issues (like I encountered.) Better to mechanically hold the mirror so it can be adjusted.
Dave, I’ve just discovered your TH-cam channel from Reddit. This is such a cool project. From having only joined the amateur astronomy hobby post-Covid, I start down the recommended 8” Dob path. Jut seeing this skeleton build of the basics of a Newtonian and watching the basics of the collimation process was incredibly insightful. I only wish you had been able to add a couple cellphone images of your views. And thanks for acknowledging the pinched optics issue and resolution. I’m sure that you know that Lockwood is one of the experts. I hope that like Dobson, you’ll do some sidewalk astronomy. You build itself will garner interest and be instructional even before they take in the sights. .
Thanks for checking it out! I would have liked to try and share some images from eyepiece, but I've been down the astrophotography rabbit hole before!
it would be great if you tried another form of attaching the mirror with specific silicone for optics and mirrors, and use a "floating" method to attach again the mirror, only on 3 first points, and avoiding the perimeter of the wall. I'm designing and printing another newton, but i'm worried about silicone, because was my initial thought and I printed that part, but not glued yet.
At this point I'm modestly confident that my re-designed mirror cell resolved the pinched optics issue I was having. It's a "standard" style of mirror holding. The secondary however is still held on with a lot of silicon and I haven't been super happy with how the collimation screws are working so I've been considering rebuilding that part anyway. Do you have any info on optics-specific silicon? A brand name? That's not something I've ever come across.
Dude this things sweet! Liked and Followed!
Thanks brother!
Greetings from reddit! great vid, im making my first one in a few weeks so this was good inspiration
Awesome! Thanks for checking out the vid. Feel free too reach out on here or Reddit if you need any help.
Hey I was wondering what the expected shrinckage / expansion of the Abs is when used for the telescope. Does the collimation change ro would plastic be supperior to metal as a material?
You can easily Google the CTE of materials to get a relative idea, but generally plastics have a much higher CTE then metals.
Its not really important though as collimation is quick and easy so if recollimating is required once or twice during an observing session that's not a big deal.
Was für ein 3D Printer Model Please?!
I designed it in Solidworks. Considering releasing the files but need to work on my web site for that.
how does it compare to the hadley?
It's a pretty big jump in performance, especially for deep sky objects. You can resolve details clearly in this scope that appear as just blurs in the Hadley.
@@designbydave That's great. Did you take some images with the telescope as well? I'd be interested to see them!
I have not but would be interested to see what it could do with planetary imaging. For deep sky objects it would not work well as it's not rigid enough to attach a proper camera. @@sheepasus
Fabricant européen cette entreprise ??
Please send the other link for 3D Print. Because its blocked from this country .
Should be able to access it with a vpn
trouble with wordpress!! No website:: -0
Bah. I know. Sorry about that. I haven't had a chance to look into it.
Poor main mirror!
It's fixed and very happy now 🙂
Nice!!
Thank you! Cheers!