Visit the following link for details:
http://www.facebook.com/StriderTelescopes
Single Arm Dobsonian Travelscope Project - CSAT
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Chanlunlun
- 夸克星
- 文章: 3847
- 註冊時間: 週四 09 10月, 2003 21:06
Re: Single Arm Dobsonian Travelscope Project - CSAT
I had used a 12 inch single arm ultra-light telescope in Komeko for star gazing. While it is very light in weight the following issues may happen to you during usage :-Steve 寫:多年前已經想造, 今年付諸實行~
Visit the following link for details:
https://www.facebook.com/#!/StriderTelescopes
1. The zenith eyepiece height is too low, you probably need a rigid tripod to raise the eyepiece height. A heavy duty Gitso is recommended.
2. Serious light leakage problem. A light shroud surrounding the eyepiece, and if used in Hong Kong, surrounding the primary, is recommended.
3. The single arm pole is not strong enough to hold the optical alignment, especially for a f/4 mirror very accurate alignment must be realized otherwise you will suffer from obvious coma in the field of view. Adding two tension wires may help but it complicates and lengthens tyhe time of setting up in the field. Moreover when heavy eyepiece ( this is a very probable case ) is added the two added wires seem to be not very helpful.
4. The primary mirror cell is not a standard spring loaded push-pull design making aligment not at all easy.
5. The telescope is an "all-open" design which means that both the primary and secondary mirror are well exposed to ambient air - they readily attract dew in humid weather such as those summer nights in Hong Kong.
6. The "all-open" design which means that both the primary and secondary mirrors are well exposed to dirts. You need to clean the optics more often and cleaning will scratch mirrors.
7. Lack of symmetirc spider making the diffraction pattern of bright stars non-attractive. Of course this is personal but I do belief that no one will deny the beauty of a neatly right angle cross style Hubble telescope like diffraction spike around a bright star.
One thing must be added - after dismantling this telescope becomes a very small package and is being extremely suitable for travelling. If all, or major part, of the above issues could be solved this Ultra-light could be a perfect scope taken out for star gazing trip.
Re: Single Arm Dobsonian Travelscope Project - CSAT
Please find my reply above in blue.Chanlunlun 寫:I had used a 12 inch single arm ultra-light telescope in Komeko for star gazing. While it is very light in weight the following issues may happen to you during usage :-Steve 寫:多年前已經想造, 今年付諸實行~
Visit the following link for details:
https://www.facebook.com/#!/StriderTelescopes
1. The zenith eyepiece height is too low, you probably need a rigid tripod to raise the eyepiece height. A heavy duty Gitso is recommended.
Yes, I prefer sitting on a collapsible chair when using.
2. Serious light leakage problem. A light shroud surrounding the eyepiece, and if used in Hong Kong, surrounding the primary, is recommended.
Yes, I have light shroud ready.
3. The single arm pole is not strong enough to hold the optical alignment, especially for a f/4 mirror very accurate alignment must be realized otherwise you will suffer from obvious coma in the field of view. Adding two tension wires may help but it complicates and lengthens tyhe time of setting up in the field. Moreover when heavy eyepiece ( this is a very probable case ) is added the two added wires seem to be not very helpful.
I have once again strengthen the structure, to minimize the coma. There is a compromise for ultra-portable telescope...
4. The primary mirror cell is not a standard spring loaded push-pull design making aligment not at all easy.
No, it is a standard spring loaded push-pull design, I have replaced the springs.
5. The telescope is an "all-open" design which means that both the primary and secondary mirror are well exposed to ambient air - they readily attract dew in humid weather such as those summer nights in Hong Kong.
"All-open" is the only way to ultra-portable, it is acceptable.
6. The "all-open" design which means that both the primary and secondary mirrors are well exposed to dirts. You need to clean the optics more often and cleaning will scratch mirrors.
"All-open" is the only way to ultra-portable, it is acceptable.
7. Lack of symmetirc spider making the diffraction pattern of bright stars non-attractive. Of course this is personal but I do belief that no one will deny the beauty of a neatly right angle cross style Hubble telescope like diffraction spike around a bright star.
This is acceptable for me.
One thing I must be added - after dismantling this telescope becomes a very small package and is being extremely suitable for travelling. If all, or major part, of the above issues could be solved the Ultra-light could be a perfect scope taken out for star gazing trip.
-
Chanlunlun
- 夸克星
- 文章: 3847
- 註冊時間: 週四 09 10月, 2003 21:06
Re: Single Arm Dobsonian Travelscope Project - CSAT
I'm glad to hear that you have solved the majority of issues. Hopefully you could bring more often this beautiful telescope to PTC or some other site to enjoy and to share.Steve 寫:Please find my reply above in blue.Chanlunlun 寫:I had used a 12 inch single arm ultra-light telescope in Komeko for star gazing. While it is very light in weight the following issues may happen to you during usage :-Steve 寫:多年前已經想造, 今年付諸實行~
Visit the following link for details:
https://www.facebook.com/#!/StriderTelescopes
1. The zenith eyepiece height is too low, you probably need a rigid tripod to raise the eyepiece height. A heavy duty Gitso is recommended.
Yes, I prefer sitting on a collapsible chair when using.
2. Serious light leakage problem. A light shroud surrounding the eyepiece, and if used in Hong Kong, surrounding the primary, is recommended.
Yes, I have light shroud ready.
3. The single arm pole is not strong enough to hold the optical alignment, especially for a f/4 mirror very accurate alignment must be realized otherwise you will suffer from obvious coma in the field of view. Adding two tension wires may help but it complicates and lengthens tyhe time of setting up in the field. Moreover when heavy eyepiece ( this is a very probable case ) is added the two added wires seem to be not very helpful.
I have once again strengthen the structure, to minimize the coma. There is a compromise for ultra-portable telescope...
4. The primary mirror cell is not a standard spring loaded push-pull design making aligment not at all easy.
No, it is a standard spring loaded push-pull design, I have replaced the springs.
5. The telescope is an "all-open" design which means that both the primary and secondary mirror are well exposed to ambient air - they readily attract dew in humid weather such as those summer nights in Hong Kong.
"All-open" is the only way to ultra-portable, it is acceptable.
6. The "all-open" design which means that both the primary and secondary mirrors are well exposed to dirts. You need to clean the optics more often and cleaning will scratch mirrors.
"All-open" is the only way to ultra-portable, it is acceptable.
7. Lack of symmetirc spider making the diffraction pattern of bright stars non-attractive. Of course this is personal but I do belief that no one will deny the beauty of a neatly right angle cross style Hubble telescope like diffraction spike around a bright star.
This is acceptable for me.
One thing I must be added - after dismantling this telescope becomes a very small package and is being extremely suitable for travelling. If all, or major part, of the above issues could be solved the Ultra-light could be a perfect scope taken out for star gazing trip.
![[Good Job]](./images/smilies/onion_d5f02ecd.gif "Good Job")
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