Fix Focuser Sag For Astrophotography & Astronomy

A quick, easy fix for all rack & pinion focusers (usually fitted to budget telescopes) to remove to free-play and therefore reduce sag / tilt issues that can affect cameras and eyepieces (astrophotograhy and astronomy).
This applies to both Newtonian reflectors and refractor telescopes, but not those fitted with Crayford focusers.
Chapters :
00:00 Intro
00:57 The Rack & Pinion Focuser
02:00 Tension Adjustment
03:29 Free-Play / Sag
04:40 The Fix
07:15 'Paint' Upgrades

[@dumpydalekobservatory]

Nice simple fix that does the job & you get to have a beer first to what's not to like!!

[@Cheapass-tro]

Thanks erm... Dumpy Dalek?

[@vicamaral]

r
Brilliant, instead of aluminum i used Teflon and some superlube synthetic grease with ptfe, also these focuser were good at letting stray light in, after focusing i wrapped black cloth around the draw tube, and taped the base with electric black tape, you brining back old memories with these wobbling focusers LOL. cant wait for the next video.

[@Cheapass-tro]

Thanks for that. I didn't have (notice) any stray light but that's a good tip for others reading through!

[@SybrandStrauss]

Before you do this, see if you can resolve sag by adjusting the two little screws on either side of the tensioner. They're easy to miss. I had the same sag issue, and all it took was tightening the two little screws that push onto the tension plate with some small allen keys.

[@Cheapass-tro]

Good advice. I of course had done this first step, but the play was still there.

[@BadYossa]

That's very ingenious mate. Very much enjoying your vids and your ethos!

[@Cheapass-tro]

Thanks again!

[@woody5109]

Fixing junk with junk, brilliant

[@Cheapass-tro]

I've liked that assuming you mean the focuser, not the scope!

[@grahambohl5205]

Another good video. Many thanks!

[@Cheapass-tro]

Another good comment too. Thanks for saying!

[@nigelbombs163]

Great idea. I was thinking about cutting a credit card and using some super glue. Maybe I'll try this first. After all, it is half past noon 😂 🍻

[@Cheapass-tro]

Wahey! ... Cheers.🍺

[@philgoben19]

Thanks i was having this problem where my focus was not even so only half the object was in focus due to the movement which caused the DSLR misaligned

[@Cheapass-tro]

Result!

[@kubaduch1]

Thanks mate 👍👍

[@Cheapass-tro]

Hey Mariusz. Thank you and give my love to Wales!
Also thanks for encouraging me over on FB to share my ideas. This channel was born of that nudge!

[@omelletedelastreet9969]

there are some differences between your scope and the 200p: yours has a rack and pinion focusser while the 200p has a crayford
btw where did you get your scope?

[@Cheapass-tro]

Mine's more like the old blue one. I knew the PDS had Crayfords, wasn't sure about the new P. Thanks for the info.
These were sold out of Lidl in Ireland around the 2006 mark. I bought it used last year.

[@PhotonReceiverAstrophotography]

i tired this and my focuser still sags emmensly. looks like ill be getting a low profile crayford.

[@Cheapass-tro]

Aww that sucks. Maybe something a little thicker could work? Good luck & clear skies.

[@PhotonReceiverAstrophotography]

@@Cheapass-tro i stacked 4 sheets and seems to work for now. will deff get a crayford down the line for photos tho

[@Cheapass-tro]

@@PhotonReceiverAstrophotography I would sooner put the 4 sheets as 4 single strips around the tube than in one stack, for evenness.

[@PhotonReceiverAstrophotography]

@@Cheapass-tro tried that first to no avail. focuser is cheap plastic garbage and bends easily under load. only other option I can think of is a 3d printed piece of plastic inserted into the focuser bore where it enters the scope to help guide the focuser tube down the center otherwise it just pivots on the pinion gear and tilts the tube.