A Simple Helical Crayford Focuser

How simple can a focuser be?

This has been a bit of a design challence for me… Just how small, how simple, can I make a focuser and yet still provide excellent usability. My latest Helix 1-14 design is my best yet.

A simple helical crayford telescope focuser
A simple helical crayford focuser

As my 3D printer design skills improve I applied lessons learned and the unique capabilities of an FDM printer to the problem of a focuser. After a bit of a journey I have arrived at a design I can consider finished. Is it the final design? I may tinker some more, but I am satified for the moment.

The design is based on a few ideas from here and there, products I have seen or used, internet postings from others faced with the same challenge. I am not one for just printing someone else’s design, I rarely do that, I want to do my own, and maybe make it better.

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2022 in Photos

With recent history having been a bit bumpy, looking back on 2022 is not too bad in out little part of the world. More than a few good memories.

  • Kailua Bay
  • PBR's with Asparagopsis taxiformis
  • Harvesting Atax
  • Raceway pond
  • Waimea Canyon
  • Kīlauea lighthouse
  • Kōloa sugar mill
  • An air compressor rusts in the abandoned Kōloa sugar mill
  • Sunset over Lawaʻi Beach
  • Charter Boat
  • Ben halibut fishing in Yakutat Bay
  • King Salmon
  • Icebergs on Harlequin Lake
  • A six inch gun emplacement
  • Total Lunar Eclipse
  • Equator
  • Masaka Road
  • Line for the ferry at Nakiwogo, Uganda
  • Kids at Kazinga
  • An older male lion (Panthera leo) in Queen Elizabeth National Park, Uganda
  • Tour vans arrive to see the lion
  • Pied Kingfisher
  • Rüppells starling
  • Marabou Stork
  • Elephant
  • The Elephant's Eye
  • Toyota Land Cruiser
  • Mauna Loa eruption at dawn
  • The 2022 eruption of Mauna Loa on the second day
  • The 2022 eruption of Mauna Loa on the second day
  • Sunset over Lawaʻi Beach

2023

As usual we rang in the new year staying quietly at home. Quietly? We may have been quiet, the neighborhood was not. I have always considered the amount of fireworks the neighborhood launches to be a rough economic indicator. Apparently this last year ws not too bad, the quantity of explosives launched over Waikoloa was impressive.

While Waikoloa was impressive, Honolulu was insane…

Our celebration? Testing a little telescope and enjoying a cup of cocoa at midnight.

With celebrations complete we shall have to see what this new year brings. There is some optimism and no complete disasters looming, which after the last few years is all I am going to ask for.

Playing Tourist

The dentist’s office is just behind the historic Moku‘aikaua Church, and just a block from Ali‘i drive and Kailua Bay. With an appointment at 9am on a Saturday morning this leads to the question… What do I do after the teeth thing? Deb is off teaching a class at the local sewing store, thus I am on my own.

Hulihe‘e Palace
Hulihe‘e Palace on the waterfront of Kailua Bay

Leaving the car in the office parking garage I decide to walk that block from the office to the bay, just walk about and play tourist for the morning.

It is a rough surf day, not bad, but a decent swell is sending water spashing over the seawall showering the occasional tourist.

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Testing a Mirror

As I have observed lately, most of the small telescope mirrors available right now are out of China, most of those produced by one company, Guan Sheng Optical or GSO. If you want a small mirror, say a 6″ or 8″ mirror, there is not a lot of choice, the mirror makers in the US generally do not do anything smaller than 10″.

Foucault knife edge test
A textbook Foucault knife edge test image on a 6″ f/4 mirror

The GSO mirrors range from decent to pretty bad, with no way of knowing what you will get when you order, just luck of the draw.

But how do you tell?

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Is it over already?

The question of the week… Is it over?

The 2022 eruption of Mauna Loa on the second day
The 2022 eruption of Mauna Loa on the second day

Eruptive activity began to wane at the end of last week,with the lava fountains diminishing, then disappearing over the weekend. Views in the webcams showed a steady decrease in activity at fissure 3 over the course of several days.

At this point no lava appears to be emerging onto the surface, with only a few dribbles left in the lava flow to be seen as minor glows across the flank of the mauna.

Oddly Kilauea, after erupting continuously for over a year seems also to have paused. There is no longer any visible lava or even a glow within the Halemauʻmauʻu crater.

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