My 16" f4 dobsonian telescope

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Piero Great Britain
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My 16" f4 dobsonian telescope

#1

Post by Piero »


In June 2020 I started off the construction of my 16" f4 reflector, named after the star: Nunki in Sagittarius. The whole building took 10 months as I could only work at the weekend.

All the photos for this project can be found here: https://photos.app.goo.gl/DAZ8CqeRtJGe83jF8 .

In general, building this telescope has been an incredible experience. This was my first wood / metal project. I would highly recommend to make your own telescope if you can.

Here are some key features:

- mirror cell: based on Kriege's design using a Glatter sling cable for lateral support. This was designed using Plop software;
- mirrors: the primary is a Lightholder mirror with 1.5" thickness and coated by Spectrum Coatings in Florida. The secondary is a 3.5" Antares;
- UTA: the spider was installed with "+" orientation (as in John Pratte's design). The spider and secondary mirror holder are from Astrosystems. The secondary dew heater is also from Astrosystems. The focuser is Feathertouch FT2015BCR. I use two finders: an Antares VS60 RACI finder and a Rigel red dot quick finder;
- lower and upper truss attachments and connectors were made by me, based on the design of John Pratte and concepts in Highe's Portable Newtonian Telescope book;
- the mirror box is relatively shallow (11" deep). Joints are tongue and groove like in Teeter's design;
- the trunnions were designed after studying the beautiful 22" f4 dobsonian telescope designed by Friske on CN forum. There is some geometry regarding the upper curve and the cutoffs of my trunnions, but this is only due to my OCD, rather than added functionality;
- the rocker box is also quite shallow. I used doweling joints for this;
- light shroud was made by Heather Teeter

Other data:
- Metal was stainless steel 316 (also the MC apart from the triangles), aluminium 6082T;
- Wood is Baltic birch plywood: 15mm for UTA, MB; 3x12mm for trunnions, 2x15mm for RB side boards, 15mm for RB front/back boards, 2x12mm for RB bottom board and ground board;
- UTA struts are 1" diam, 1.6mm thick;
- Trusses are 1" 1/8" diam, 1.6mm thick;
- FRP + 1/4" virgin teflon was used for both altitude and azimuth movements;
- Lower / upper truss attachments and connectors, MC triangles use 1/4" thick aluminium.

Thanks for looking
Piero
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Last edited by Piero on Thu Aug 26, 2021 2:39 pm, edited 1 time in total.
16" f/4 home made reflector with Lightholder optics, 12" f/6 redesigned reflector with Nichol optics, Takahashi FC-100FT f/7.4, Tele Vue-60 f/6
22mm TV Nagler T4, 12.5mm Docter, 9-7-4.77mm APM XWA
24mm TV Panoptic, 9 mm TV Nagler T6, 21-9mm Nikon MC1 zoom, modded VIP Barlow
30mm APM UFF, 25.1-6.7mm Zeiss DiaScope Vario zoom
AOKswiss AYO II on Berlebach UNI 19, Hawke Frontier ED X 8x32
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NGC 1365 Australia
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Re: My 16" f4 dobsonian telescope

#2

Post by NGC 1365 »


Hi Piero, fantastic looking scope, congratulations for completing it in a reasonable time frame, and great workmanship, hope to see some observing reports with this scope.
Ivan
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Graeme1858 Great Britain
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Re: My 16" f4 dobsonian telescope

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Post by Graeme1858 »


That's a lovely looking DOB Piero.

Regards

Graeme
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ASI1600MM Pro, ASI294MC Pro, ASI224MC
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APM 11x70 ED APO Binoculars.

https://www.averywayobservatory.co.uk/
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Re: My 16" f4 dobsonian telescope

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Post by 10538 »


Nice work Piero! That’s a beautiful scope! I’m looking forward to seeing your first light reports.
Ed :Astronomer1:
Scopes: Orion 14 inch f/4.6 Dobsonian w/MoonLite focuser. Meade LX200 Classic 10”w/AudioStar and MoonLite focuser, Criterion RV6, Orion ST80A w/2” GSO micro focuser.
Eyepieces: ES 5.5mm 100*, 6.7mm 82*, 11mm 82*, 14mm 100*, 18mm 82*, 20mm 100*, Meade 9mm XWA 100*, 24mm UWA 82*, 56mm 50*, TV Delos 6,8 & 10mm, Panoptic 24, 27 & 35mm, 17mm Nagler, Powermate 2X, Baader 6mm Ortho, Paracorr II.
MISC: William Optics Binoviewer, Revolution 2 Imager, Orion Skyview Pro Mount, Skymaster 15x70, 20x70, 25x100 Binos, HoTech Collimator, Kendrick Dew System,Catsperch Chair.
Messier 110 Complete/ Messier 110 Sketches Complete / Herschel 400 Complete / H-2 and H-3 Complete
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“Starlight, I hear you calling out to me so far away” Jeff Lynne ELO.
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Re: My 16" f4 dobsonian telescope

#5

Post by Piero »


10538 wrote: Thu Aug 26, 2021 12:16 pm Nice work Piero! That’s a beautiful scope! I’m looking forward to seeing your first light reports.
:text-thankyouyellow:

The telescope has already seen the sky in the past 4 months.
It allowed me to see the central star in M57 for the first time.
For the time being I've tested it on some galaxies in Hercules and Pegasus, and of course on a few globulars, including some of the less known in Ophiuchus.
It also works very well on planets. I've only tested it on Jupiter and Saturn, but the delivered views were breathtaking.

I hope to observe them again under decent seeing conditions and spend more time observing their moons at high power.
16" f/4 home made reflector with Lightholder optics, 12" f/6 redesigned reflector with Nichol optics, Takahashi FC-100FT f/7.4, Tele Vue-60 f/6
22mm TV Nagler T4, 12.5mm Docter, 9-7-4.77mm APM XWA
24mm TV Panoptic, 9 mm TV Nagler T6, 21-9mm Nikon MC1 zoom, modded VIP Barlow
30mm APM UFF, 25.1-6.7mm Zeiss DiaScope Vario zoom
AOKswiss AYO II on Berlebach UNI 19, Hawke Frontier ED X 8x32
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Re: My 16" f4 dobsonian telescope

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Post by helicon »


Great scope Piero. And a fantastic build.
-Michael
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8 on Celestron Heavy Duty Alt Az mount, KOWA 90mm spotting scope
Binoculars: Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Various, GSO Superview, 9mm Plossl, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: My 16" f4 dobsonian telescope

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Post by Bigzmey »


Excellent! Great job Piero!
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
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