1.25" Crayford Focuser for the Travel Telescope 114mm by Anders

Update (04/05/26) - fixxed eyetube on very short version to have the thumb screw m4 insert hole in the correct place.

Update (01/05/26) - Added new very short version for the Travel Telescope V3.0 only (due to the mounting points being to close on the older version. It is 30 mm shorter over all and has 34mm of travel vs 40mm of travel on the short version.

Update (16/04/26) - Added a new base for the short version of the focuser which is compatible with the Travel Telescope V3.0 - I am currently also working on a 2" version to take advantage of the larger mount on the v3.0 telescope, may take some time though.

Update (06/12/25) - A new shorter version is now available with several refinements.

• The base height is 55.5 mm (down from 75.5 mm on the original).

• The eyetube travel range is now 40 mm instead of 46 mm to prevent interference with the secondary mirror mount.

• Two back-plate options:

  • a plain flat version

  • an extended version with a dovetail mount for a potential electronic focuser

• Various small tweaks have been made to improve strength and printability.

• The short version uses the same BOM as the original, but the 3 bar lengths are now 102 mm.

This is a 1.25" Crayford Focuser designed for the Travel Telescope 114 mm by Anders
(https://www.printables.com/model/1038495-travel-telescope-114mm-updated-version).

The design is conceptually similar to the original by aeberbach, but with several modifications to simplify assembly and fit the smaller footprint required by the travel telescope.

Print Settings

• Printed in ASA-CF (but use what you like ABS worked well for me too)

• 0.4 mm nozzle

• 0.2 mm layer height (Bambu “strength” preset)

• Auto tree supports where needed

• Print one of each part, except the knobs (you will need two)

Additional Parts List

All threaded inserts can be found in the HANGLIFE Threaded Inserts Assortment Box
(https://amzn.eu/d/bsRQrG6)

Threaded Inserts

• 4 × M3×5×4 — base (secures the front cap)

• 2 × M3×5×4 — one in each knob

• 1 × M4×6×4 — top rim of drawtube

• 1 × M4×6×4 — inside the front cap

Fasteners

• 4 × M3×20 Low-Profile Torx Cap Screws
  https://www.accu.co.uk/torx-low-cap-head-screws/14459-SHCL-M3-20-A2

• 2 × M3×8 Low-Profile Torx Cap Screws
  https://www.accu.co.uk/torx-low-cap-head-screws/14455-SHCL-M3-8-A2

• 2 × M4×12 Thumb Screws
  https://www.accu.co.uk/knurled-thumb-screws-din-464/21241-SKT-M4-12-A1

Other Components

• 4 × 3×10 mm stainless steel dowel pins
  https://amzn.eu/d/6JBGvPn

• 4 × 3×8×3 mm ball bearings
  https://amzn.eu/d/7TrIXPy

• 2 × 5×11×5 mm ball bearings
  https://amzn.eu/d/2NIgBh6

• 2 × compression springs — 6 mm OD, 1 mm wire, 10 mm length
  https://amzn.eu/d/fcodWl0

• 1 × 10×3 mm stainless/aluminium bar, 40 mm length

• 3 × 10×3 mm stainless/aluminium bars,
  102 mm for the short version, 72 mm for the very short version, 128 mm for the orginal tall version

• 1 × 5 mm × 100 mm stainless steel rod

• 2 × 5×10×0.5 mm shims or washers
  https://www.accu.co.uk/shim-washers/62871-HSHN-5-10-0-5-A2

The stainless rod and bar stock can be bought from any metal supplier and cut to length.
Note: the springs may be slightly long — you can trim them if needed. (fixxed on the new version).

Assembly Notes

I plan to create a full assembly guide later. For now, here are general steps:

1. Install all threaded inserts
   Use a soldering iron to heat-set them into the listed locations.

2. Prepare the bearing rollers
   Insert the 3×10 mm dowel pins through each of the 3×8×3 mm bearings, then press them into the recesses inside the base tube.

3. Assemble the eye tube
   Insert the 10×3 mm bars (128 mm or 102 mm depending on version) into the drawtube.
   Slide the drawtube into the base tube in the correct orientation.
   Press the end cap onto the drawtube.

   • If the locking clips feel brittle, soaking the end cap in hot/boiling water for a few seconds softens it enough to clip on safely. be careful though!

4. Build the pinion assembly
   Press the 5×11×5 mm bearings into the pinion block.
   Insert the 5 mm × 100 mm rod through them.
   Place the two compression springs into the back of the block.

5. Install the pinion block
   Carefully slot the pinion block into the base.
   Place the 10×3×40 mm bar into the front cap.
   Attach the front cap using the M3×20 screws.

6. Fit the knobs
   Place a 5 mm washer/shim on each side of the rod.
   Press the knobs on, securing them with M3×8 screws.

7. Install the eyepiece retainer
   Compress and insert the eyepiece clip into the top of the drawtube (check orientation).
   Install the M4×12 thumb screws into the side of the front cap and end of the drawtube.

Note:
With the new version, the base must be mounted to the telescope with the eyetube already inserted.
Once the pinion block and back plate are installed, they will obstruct access to the base mounting screws—so make sure the eyetube is in place before proceeding with those steps.

Finished!