April 23, 2026
Description
By popular request, here is a focusing solution for the V3 Allsky Housing design.
Fully compatible with the existing housing - this Focusing Sub-Assembly is contained within the camera cone design (PiHQ & ZWO). Thickness of the gear set intended to avoid warpage and ensure heat resistance in all climates. Fits standard ⌀28mm CS lenses.
Classified as experimental whilst durability tests are completed. User feedback welcome to further optimise the design and compatibility with commercially available lenses. Basic software commands linked below. Please see compatibility Table below.
No.
Solution based on 28BYJ-48 Stepper Motor and ULN2003 Driver available from many online retailers, sold as a Kit. This is the primary component of the focus set-up - check the following links as Example - Amazon.it Amazon.com. Available through other resellers.
M3 Screws and Inserts required for Assembly, as well as GPIO Jumper Wires for electrical connection to the raspberry pi board.
I welcome suggestions for any additional lens sizes to be evaluated - or adjustments to improve coverage of the commercially available lenses. Spur and pinion gear options included.
CS LENS | ||
2.5mm (Ø28mm x ≈17mm) | 2.8mm (Ø28mm x ≈17mm) | |
V3 PiHQ | Printed & Tested | Printed & Tested |
V3 ZWO | Designed from Drawing | Designed From Drawing |
Basic forward/backward and debugging commands uploaded to github
Motor driver requires 6 free GPIO pins on your raspberry pi (5V, GND, IN1-4)
13 Mar 26 - incorporated compliant mechanism to secure tolerance match aganist 28mm CS Lens
4 Apr 2026 - Updated Shaft and Pinion to have Keyed interface to avoid slippage/over tightening. Options for an M3 and M2.5 screw fixation of Pinion & Shaft included.
4 Apr 2026 - Included .Step File of Pinion, Gear and Shaft
License:
Standard Digital File License
ChrisE
