16 inch ultra light weight telescope - version 1.0
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- 夸克星
- 文章: 3847
- 註冊時間: 週四 09 10月, 2003 21:06
16 inch ultra light weight telescope - version 1.0
Dear ATMers,
I will go a Maldive trip next month and it is a big waste not to explore the extremely clean sky over there. My luggage capacity is only 15 kg (cheap air ticket…lol ) which means that the 20 inch telescope cannot go along. The next on my list is a 16 incher, that is the PTC telescope that many of you may get familiar with.
My task is to reduce the total weight of the telescope below 15 kg, with an aperture of 16 inches. The problem is that the mirror itself already weighs 8 kg. I have only a margin of less than 7 kg to work with.
So I adopted a single pole design. To further reduce the total weight I change the secondary from 4 inch to 2.6 inch, vastly reducing the weight. The focuser is also change from a metallic rand-and-pinion to a custom PVC one which has a weight of only about 30 grams.
At the same time I have to lower the center of mass of telescope as much as possible to increase stability. After a few days struggle I finally come to a result of what you see in the attached pictures.
As usual I choose 3/4 inch plywood to work with. it is cheap, strong, light weight and easy to handle. Carbon fiber will get better ( and fancier ) results, but it is very expensive and not readily available.
Star test of the finished scope was carried out last night. Although the single pole is strengthened by three taut steel cables, it still cannot display as a rigid structure as traditional struss structure. However the alignment still holds good enough if altitude angle is not less than 30 degree, which I feel should be sufficient for ordinary visual star observation. The vibration is still there but not serious. The telescope is being fully functional.
The total weight of the telescope is 14.7 kg, not counting the eyepiece and telrad. I am being very glad with the result.
The plan B of the telescope will be carried out shortly, with carbon fiber struss design. I am waiting the arrival of carbon fiber tubes. But at least I have this scope on hand now, in case the carbon fiber cannot be ready in time.
Best regards
Chan Yuk Lun
18 June 2015
I will go a Maldive trip next month and it is a big waste not to explore the extremely clean sky over there. My luggage capacity is only 15 kg (cheap air ticket…lol ) which means that the 20 inch telescope cannot go along. The next on my list is a 16 incher, that is the PTC telescope that many of you may get familiar with.
My task is to reduce the total weight of the telescope below 15 kg, with an aperture of 16 inches. The problem is that the mirror itself already weighs 8 kg. I have only a margin of less than 7 kg to work with.
So I adopted a single pole design. To further reduce the total weight I change the secondary from 4 inch to 2.6 inch, vastly reducing the weight. The focuser is also change from a metallic rand-and-pinion to a custom PVC one which has a weight of only about 30 grams.
At the same time I have to lower the center of mass of telescope as much as possible to increase stability. After a few days struggle I finally come to a result of what you see in the attached pictures.
As usual I choose 3/4 inch plywood to work with. it is cheap, strong, light weight and easy to handle. Carbon fiber will get better ( and fancier ) results, but it is very expensive and not readily available.
Star test of the finished scope was carried out last night. Although the single pole is strengthened by three taut steel cables, it still cannot display as a rigid structure as traditional struss structure. However the alignment still holds good enough if altitude angle is not less than 30 degree, which I feel should be sufficient for ordinary visual star observation. The vibration is still there but not serious. The telescope is being fully functional.
The total weight of the telescope is 14.7 kg, not counting the eyepiece and telrad. I am being very glad with the result.
The plan B of the telescope will be carried out shortly, with carbon fiber struss design. I am waiting the arrival of carbon fiber tubes. But at least I have this scope on hand now, in case the carbon fiber cannot be ready in time.
Best regards
Chan Yuk Lun
18 June 2015
- 附加檔案
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- The single pole, stabilizing beam, steel cable and the minimalist allt-azm mount.
- 8.jpg (460.5 KiB) 已瀏覽 5436 次
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- The 16 inch primary mirror, mirror box , altitude bearing, part of single pole and part of steel cables.
- 7.jpg (528.42 KiB) 已瀏覽 5436 次
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- The custom made PVC focuser. It is helical in design and has very small weight.
- 9.jpg (369.21 KiB) 已瀏覽 5436 次
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- The PVC focuser, 2.6 inch diagonal mirror and the light shield.
- 10.jpg (352.63 KiB) 已瀏覽 5436 次
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- The 16 inch single pole. Unlike the traditional PTC telescope it’s a minimalist in design.
- 12.jpg (510.46 KiB) 已瀏覽 5436 次
最後由 Chanlunlun 於 週二 30 6月, 2015 11:54 編輯,總共編輯了 1 次。
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- 夸克星
- 文章: 3847
- 註冊時間: 週四 09 10月, 2003 21:06
Hi Steve !Steve 寫:
It is a pity that did not see you bring this new ultra light weight telescope for us to have an appreciation at PTC in the past starry nights started on Monday.
I did not come because I was making the telescope on Monday and Tuesday. On Wednesday night I star test the telescope at my home.
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