8" Newtonian Telescope "Leavitt" LITE (Metric) MOD-1

This telescope model seemed very interesting, and when I found the lightweight metric remix by @Aurelian_513907, compatible with the Sky Watcher Sky Adventurer GTi Equatorial mount, the same one I have, I decided that this would be my choice.

I chose to print in black PLA made with Ingeo 3D870 raw material from Nature Works because it is supposedly more impact resistant. I used a 0.4mm nozzle with 3 perimeters on all the parts. My Creality K1 Max printer can print the complete parts, without having to divide them into three parts.

The carbons rods are 12mm-outer and 10mm-inner diameter.

As I printed the parts, I noticed some difficulties and opportunities for improvement that made sense to me, but may not make sense to you. In any case, I thought it was pertinent to publish, in case it is interesting to anyone else.

The ATM from which I ordered the mirror suggested that I use a 55mm diagonal mirror, similar to the original Leavitt, and I accepted the proposal, with the advantage of reducing obstruction to the primary mirror.

I will detail the parts that I used without modifications (which must be downloaded from the respective links) and which ones I modified and are available for download here.

Weight (including primary and secondary protective cap, laser and and a 20mm eyepiece): 4100g

These parts were printed exactly as found in @Aurelian_513907's metric remix :

- metric_conversion-LTA.stl (full assemblies)

- metric_conversion-UTA.stl (full assemblies)

- metric_conversion-Leavitt_Knob_x8.stl (4 units)

This part was printed exactly as found in the @NovelTinker_388837's original model :

- Leavitt v2 - Focuser grub.stl

- Leavitt v2 - Collet nut.stl

- Leavitt v2 - 1.25 inch eyepiece adapter.stl

- Leavitt v2 - Collet.stl

- Leavitt v2 - Focuser inner.stl

Additional parts, from @dinumas_469178:

- Metric Hadley-Leavitt feet TPU (with extra support).stl

- Metric Hadley-Leavitt cap.stl

- Leavitt_lite_metric_Primary_mirror_cover.stl (this cover is very good, with a smooth and precise fit to lock and stay in place)

Parts I modified or created:

- Segments for attaching dovetail platform (from original metric_conversion-Dovetail_TubeAttachSegment.stl and metric_conversion-Dovetail_SegmentMain.stl)

I had some issues:

- It seemed to me that the screw for fixing the dovetail plate was very fragile, and that any slight tension or bending could break the small plastic pillar at the apex of the part.

- I was unable to hide the head of my M5 screws, recommended for the dovetail plate, inside this segment, leaving them exposed inside the "tube", where light would pass through and could eventually generate some artifact.

- The distance between the screws on the part was greater than my dovetail plate could tolerate. The screws ended up entering the printed part but at an angle, not allowing adequate fastening with nuts. In my case, the distance between the centers of the screw holes that worked was 19.5mm, compared to the original 22mm, which resulted in a significant difference.

- The piece that covers 1/3 of the circumference, with dovetail fastening, had a different finish at the ends than the rest of the pieces, cut diagonally, therefore with only one point for screw fastening.

My solution: a new full-circle piece with dovetail attachment and another one with 1/3 of circumference. I chose to place the larger piece closer to the primary mirror, to help with the stability of the structure, knowing that it is a critical point for the structure to bend due to the weight of the mirror. Therefore, I printed the files Extra ring dovetail 19.5mm type A.stl and Extra partial ring dovetail 19.5mm type A.stl . If you prefer to leave the piece with 1/3 of circumference close to the primary and the full-circle piece close to the diagonal, you can print the type B files. This difference between types A and B occurs due to the normal asymmetry of the pieces:

The result of these modifications:

Files:

- Extra ring dovetail 19.5mm type A.stl

- Extra partial ring dovetail 19.5mm type A.stl

- Extra ring dovetail 19.5mm type B.stl

- Extra partial ring dovetail 19.5mm type B.stl

- New knob

The metric version provides a triangular-shaped knob with three tips. However, when we use 2 knobs to tighten and fix, when the knobs are aligned with each other, it is difficult to manipulate the one underneath. To avoid this problem, I created a new, similar knob with 5 tips, to be used together with the 3-tips.

(locking nut unnecessary)

File: Modified knob.stl

- Focuser v2