lumpy darkness

Observation notes (with equipment details), photos, sketches, reviews, software tips, random thoughts, by an amateur astronomer.

SATURDAY, JULY 13, 2019

polar axis cap 3D print

My Vixen Super Polaris mount was missing the cap for the upper port of the polar axis. Rather than buy one (if that is even possible), I decided to make one.

 

3D printed Vixen SP polar axis cap

 

This project, while very simple, helped me complete my very first three-dimensional printing project.

 

technical info:

  • very simple design
  • precisely measured to fit inside polar axis hole
  • flanged sides on the cylinder to allow some flexing
  • made with Polylactic Acid (PLA) filament
  • white colour would be easy to see in dark

build costs:

  • 3D print courses at TPL - free
  • 3D design software - free
  • 4 grams of PLA consumed - less than $1.00
  • properly fitting cap to block dirt and water - priceless

time (the non-renewable resource):

  • lesson time, learning 3D design courses: 5 hours
  • getting comfortable with 123D: 8 hours
  • cap design time: 1 hour
  • print time: 15 minutes
  • effectively, from design to installing: 2 days

references:

  • TPL Digital Innovation Hub web site
  • 3D apps from Autodesk (123D discontinued)
  • G-code Analyzer web site
  • Thingiverse maker web site

lessons learned?

  • Make the gaps in the petals wider. Some were filled in where the printer overran...

things I might add or change:

  • Thought about it at the time but was in a hurry... Add a graphic or logo or something to the face.

 

 

FRIDAY, JULY 12, 2019

the long story

Circa 1990. Bought my SP-C8 telescope used, sold on consignment. As is. The first telescope purchase was so exciting and overwhelming at the time that I didn't know what was missing per se. But then, I would have been told, as is.

Over the years I developed a deep knowledge of the Vixen Super Polaris equatorial mount. And I learned of the damaged and missing elements. One of which was the "upper" cap that covered or filled the sky-ward port opening for the polar 'scope. Never received it.

Sep. 2006. While considering all the issues with my mount, I found a neat exploded diagram of the Vixen SP. It showed the caps and covers.

Early on I tried to prevent moisture and debris getting into the field lens of the polar scope. I found that the plastic cap from the 35mm film tube fit well inside the opening. Crude but it worked.

Spring 2015. I took my first 3D printing classes at the Toronto Public Library, specifically the Digital Innovation Hub at the Fork York branch. I was keen to start making my own bits and bobs for astronomy (and other) projects.

Took the second course. Received my certification.

My first forays into 3D part design was for other things, many of which were large and complex. Asked around for some advice.

Considered maker spaces near my new home. Put off by one; felt a bit of sticker shock with the others.

Autumn 2017. I realised one day that I'd be near the Reference Library for a bit so I decided to try a 3D print run. But all my projects were not suitable. I considered something simple and fast. Reviewed ideas in Evernote. The scope (no pun intended) for the cap was perfect.

I quickly took some measurements, designed the cap in 123D, read my course notes, converted the file, and saved it to a stick. The next day, in the library, we loaded it up. The Ultimaker 2 printer was finicky so we switched to the fast LulzBot. In 12 minutes I created a new object. It was very exciting.

It fits perfectly.

 

 

THURSDAY, JULY 11, 2019

items needed

Tools, equipment, software, etc. used.

  • computer resources
    • AutoDesk 123D software (discontinued)
    • Slic3r app, to make the G-code
    • Cura software
    • interwebs
    • Evernote
    • scanner, for digitising the course handout
    • USB memory key stick fob drive thing
  • printer
    • LulzBot
    • 4 grams of white PLA 0.6mm
  • tools
    • calipers
    • X-ACTO knife, to trim

 

And I used a digital camera to photo-document things...

 

 

FRIDAY, JULY 12, 2019

blog links - the build

Scattered through the blog proper are detailed reports and updates on the build with some posts showing photos. Reverse chronological order.

  • discovered a cap on Thingiverse, 8 Apr '18
  • fit perfectly in mount, 16 Nov '17
  • showed off the new cap, 15 Nov '17
  • printed cap on TPL printer, 15 Nov '17
  • quickly designed cap, 14 Nov '17
  • looked into local maker groups, 31 Mar '16
  • asked RASC member some 3D printing questions, 28 Mar '16
  • took first 3D printing course, 2 Apr '15
  • registered for course on 3D printing at TPL, 17 Mar '15
  • long mount issues article, 3 Sep '06
  • SP-C8 purchased, 1 Dec '90

 

 

 

 

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