18" Inch Dobsonian telescope

General Composites Discussions Showcase
#1

Hi guys,

before 5 month a customer come to my laboratory and was interesting to create a very big Dobsonian telescope. The first part will be around 22" and the second part around 19". This project was for me a very interesting to implemented. So the first think to start the progress was to find or create the mold. The customer provide me all the necessary help to make this project alive. So after a small research in the market we decide to use a big tube that usually used to create columns for buildings.

#2

We think many times to create molds but the cost will be too high. So we decide to just apply all the materials directly on it.
Honestly that was not a good idea. The tube material was made form a very strong paper but I didn’t realize the power of my vacuum system. The first tube was completely destroyed.

So we start again from the beginning and we add inside the tubes some skeleton to avoid this problems.

#3

On the upper tube we apply over 3-4 layers carbon fiber 2x2 4k of 380gr. After finish all the necessary procedure the final product was really too lightweight (about 1.2kg) and final dimension about 80cm by 19". In the second tube the problem was to create a very strong pipe to integrate all the extra parts of the telescope, such as mirror mounts etc. So we apply 2 layers of the same type of carbon, 2 layers of poly and another 1 layer of carbon fiber. The final product was really too strong and the total weight about 4-5 kg.

#4

Below you can see the upper tube at the procedure time :tongue:

#5

The lower tube we didn’t leave it in carbon fiber surface, we just painted in matte black to reduce too much carbon pattern :D.

Both tubes created in matte surface to avoid light mirroring.

#6

So after the products was finished we start to add all the telescope parts.

Below you can see the results:

#7

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#11

…and finally…

#12

Problems:

The problem that we face on this project was when we applying the layers. Because one project like this demands a very strong vacuum procedure we fail very easily. My opinion? Next time when a customer asking to repeat again one project like this there are two ways to do it. 1st to create new mold (2 pieces probably) or 2nd to use a very strong skeleton inside to avoid Squeezing.

#13

BUT EVERYTHING NOW IS BEAUTIFUL and in the next days I will provide some photos of the outer spaceeeeeeeeeee.

#14

Looks awesome as always. How does the joint look ?

#15

In the middle of the telescope is one aluminum base that join the upper with the lower tubes. This made it through CNC procedure.

#16

I ment the joint of the carbon in one tube. Like a v patern or something like that.

#17

Very very cool

#18

Got any pictures of the moon with this??

#19

Or bag through the inside of the tube so the vacuum is pressing on both the inside and outside. Getting the inner piece out is always fun. The other option is just leaving the inside piece in.

Either way, this looks amazing! Nice work!

#20

Thanks guys!!!