The Carbon Fiber Advantage? Steel vs. Aluminum vs. Carbon Fiber
Вставка
- Опубліковано 30 тра 2024
- Have you ever wondered just how much weight difference there is between carbon fiber, aluminum and steel telescope tubes? In this video, I use 3 telescope tubes of nearly identical size to find out.
There is much discussion on the advantages and disadvantages of using carbon fiber for telescope tubes on internet forums - in the video I address a few of these topics briefly. There is much more to discuss when it comes to carbon fiber, aluminum, and steel...however, I am not a materials science expert, so I encourage you to leave a comment and add to the conversation - just remember to keep things civil, and cite your comments (where appropriate). Your arguments are much stronger with citations, especially primary literature (I did not use primary literature for my video as I was covering these materials in general).
That said, I hope you enjoy the test and seeing just how light carbon fiber is! Clear skies!
Thank you @StellarvueTelescopes for allowing me to include their 'Aluminum vs. Carbon Fiber' article in my video.
Secondary sources I used for the video:
SMI Composites, SMITeam: www.smicomposites.com/aluminu...
Dexcraft: www.dexcraft.com/articles/carb...
Top-Flow music, used with permission.
AgenaAstro Affiliate Link: bit.ly/3MiW5LL
AFFILIATE LINKS:
This description contains AgenaAstro affiliate links. If you choose to purchase after clicking a link, I may receive a commission at no extra cost to you. This helps me significantly in funding the channel and astronomy purchases, allowing me to produce tutorials and unbiased reviews that you can trust. If you enjoyed the information presented and/or found it helpful, please support my channel by making your astronomy purchases through my AgenaAstro link above. Thank you! - Наука та технологія
Thanks for watching! I hope you enjoyed seeing the weight difference in these tube materials. A few notes:
1) This is a general overview, thus I didn't dive into the primary literature on this topic. I am not a materials science expert. If you have information to contribute, please do so in the comments. Please keep the comments civil, and it would also help if you're able to cite primary literature.
2) Thanks to @stellarvuetelescopes for allowing me to include their article in the video. It's a good summary when it comes to telescope applications of aluminum and carbon fiber
3) General secondary sources I used for the video are listed in the description.
4) Mass and weight are often used interchangeably. They should not be. Weight is a force; found by multiplying mass and gravitational acceleration. For example, your weight on the moon and the Earth are different, as the gravitational accelerations of these bodies are different. Weight is measured in Newtons (N) in the SI system, or pounds (lb) in the imperial system. Mass is an extensive property - it is a measure of the amount of matter in an object. Unlike weight, mass does not change due to gravitational acceleration. Thus, your mass on Earth and the moon would be the same. Mass is measured in kg in the SI system, or slugs in the Imperial System. Source: Me.
P.S. I've never used slugs, but I am sure they are used somewhere!
And what about duck taped cardboard tubes? They just don’t get any love anymore.
A friend just build a 6" reflector scope with a cardboard tube. Is amazing!
If I had one that was the same size as all these other tubes, I would have included it! :D
After I wrote this it occurred to me that many (most?) of your viewers would have no idea what I was talking about. In the early days of Dob telescopes, we made them with cardboard tubes. Those among us with a little extra cash would then wrap the tube in duck tape to add to its rigidity and protection. Those of us that went all out would then shellac the tube.
I hand ground the mirrors for the three I made, a six, eight, and ten inch. Of course just about everything on them was hand made to keep costs down. The only purchased part on mine was the focuser, and many people even made those. Even doing it like this took me months to save up enough to build one, and a couple months more to build, but first light was always so special!
One of my astrophysics instructors in my undergrad had a cardboard tube scope like you describe and he did an awesome job. He brought it to an observing night and the view was great! That’s what I love about telescopes. It doesn’t matter if they’re 50 years old or new, the optics don’t change all that much (besides the coatings), and they work great! I’ve been wanting to do a vintage telescope series on my Meade Schmidt-Newtonians. Maybe I’ll have to add that to my list.
I really want one of the Celestron Comet Catchers in orange with the sled focuser. Tough to find those Schmidt-Newts in good shape though. It took me 3 years to find my SN6, SN8, and SN10!
Hey Cody, thanks very much for the enlightening dive into this topic!
Hi Robin, you're welcome, I am glad you found it enlightening!
Great info, thanks!
Hey, thanks! I’m glad you liked it.
Awesome video. Thanks 🖖🏼
Thanks, glad you liked it!
Thanks for this video it made me make up my mind I was going to get one of these up-to-date modern telescopes but I'll stick to my old aluminum I have one I use for night time in the winter I insulated it on the outside with a automotive windshield sunshade does the job does fiber optics do have a nice look to them
You can’t go wrong either way. Carbon fiber is great, but there’s nothing wrong with aluminum.
Calling the SN6 vintage made me feel way older 😂. I wrapped the tube 3M CF and made it look like a comet hunter.
Don’t feel bad, it’s really not that old, ha! You know it’s a great scope though because it’s very rare I ever see an SN6 for sale.
Quality content thanks
You bet, thanks.
I did notice my RASA 8" did cool down faster than my RC8 but the RASA was refocused way more than the RC around the same temperature fluctuations. The RC was so much lighter though and I ended up using it more than the RASA due to the weight! The Rasa also has more glass thanks to the corrector. Oh man you had 2 Comet Hunters? I had in the past tried to source one of those and you have 2 LOL. One thing I always wondered is why are most telescopes white? Is it a thermal thing? Thanks for your video, very helpful!
Yep, the carbon fiber shaves off so much weight, it is pretty amazing. The f ratio of the RASA also is something to consider when it comes to how often it needs to be focused, but yes, good observations there! My Comet Hunter is one of my favorite telescopes. My second comet hunter is mainly for keeping at my dark sky site, that way I can save room in my car and not have to bring it down with me.
I should do an updated review on it sometime. You can find used ones on CloudyNights once every few months it seems like.
Nice.
Personally iv'e never really cared much about thermals of the materials and weight etc, but i do like the scope to be solid and tight. Can't say i noticed much difference between the materials when i use them, but my rigs also fully automated. Many warned me about carbon-refractors but mine have been behaving very good! If i decide to upgrade my newtonian i think the next one will be carbon as well (I do like the looks and stiffness), or at least a higher end build overall. A good focuser / image-train is important, this often feels like more of a letdown than the optics etc.
Yes, the focuser is usually the Achilles heel of high end telescopes and almost always need replacing. I agree though, if you watch some of my older videos I pretty much exclusively buy carbon fiber when it’s offered, like my older Explore Scientific carbon fiber refractors and such. The tube weight is drastically lighter and they’re quite stiff.
What exactly does stripping them down do for testing?
To me the test would be, which one cools down faster, which one is easier to carry and set up. Which one is more stable.
Weight is important but real world is going to be a MUCH better test.
The test was all about the weight of tube materials. To be accurate the scopes had to be stripped down to minimize any variables.
Cool down time depends on several factors.. tube material, glass substrate and thickness, optical design (Maksutov corrector lens? Schmidt corrector plate? No corrector lens?) and atmospheric conditions. It’s not easily tested as there are too many variables, and hence why this test only focused on the tube materials.
SN6! Classic! I miss my sn10. Great optics, but what a porker!
Right? It took me over 3 years to acquire my LXD75 SN6, SN8 and SN10! I’m fortunate that I was able to get a manual MoonLite focuser when they were still offered and the flange, so no modifications to the tube were necessary. It’s such a big scope, but the views through it are stunning!
I also have a Comet Hunter and a few weeks back I brought it with me to a star party. In the daytime I had it pointed at the Sun for almost the whole day, I must say it did not get that hot at all. When pointed directly at the Sun the objective gets the most of the Sun's energy, the tube body is completely in line with the Sun and doesn't get that much energy. It's almost as if the tube is shaded by it's front diameter. CS
Yes, this is true - as the Stellarvue article mentions, if you're going to do occasional solar observing carbon fiber is fine. If you're doing dedicated solar observing it is best to use an aluminum tube. My point was about dedicated solar observing. I use my carbon fiber 8" EdgeHD for occasional solar observing and it also works well. That's a good point you make, thanks for the comment.
For mirrors, low-thermal expansion material like fused silica (e.g. suprasil) or even zerodur can make the focus *a lot* less temperature sensitive if a low-thermal expansion material like carbonfiber is used for the tube. So I wouldn't discount that advantage of carbon fibre for reflective telescopes.
I agree. I certainly still am of the opinion that carbon fiber requires less refocusing than aluminum as the night goes on, but it’s not perfect - nothing is. That said, I prefer carbon fiber tubes for a variety of reasons, the weight being a huge reason.
I'll stick with my aluminum
Steel? Carbon Fiber? I'll stick with rubber.