First Focuser Prints

So! The first parts arrived. As someone who’s been doing graphic design for over 20 years, receiving my first 3d-printed parts completely recaptured the excitement of seeing my first 2d work coming off the press. Real things are real, which is why you get excited when you experience the original photons from Jupiter hitting your eyes, even in the era of insanely detailed images from Juno.

In clockwise order from upper-left: drawtube, drive block (with stainless bearing shafts already inserted), drive plate, and focuser shaft retention block. There will be some adjustments. The focuser shaft holes are too tight. The main focus knob retention cavity is too tight. The drive plate holes are too tight. Ironically the thing I totally nailed was the diameter of the drawtube. It feels absolutely perfect, and I can’t imagine improving it. Satisfying perfect amount of friction as you slide an eyepiece in. (Beginner’s luck 100%.) The Siebert eyepieces are slightly larger diameter than the Explore Scientific 2″, but both feel great. The bearing assembly cavities seem to be just right too. I’ll know more when the bearing assembly jig arrives and I can test the bearings.

Onyx has a really beautiful surface finish out of the box, another great benefit of this material.

The drive plate is a little too flexible in plain Onyx. Maybe print density is a factor, maybe adding some continuous carbon fiber will stiffen it. It is cheap to print even with continuous carbon, so this might work.

As you can see, the Siebert Optics 34mm Observatory Series fit perfectly into the drawtube with an extremely satisfying sound and feeling.

Lots of success here, can’t wait to print some unit tests off of this.

Leave a Comment