MagneTicFocuser [MTF]

DIY focuser for astrophotography with a magnetic flange

This is a simple, inexpensive focuser with a magnetic flange for quick and easy assembly without tools. When I was looking for a cheap way to get a focuser, I came across a project on GitHub called TicFocuser-NG. This is an INDI driver for a Pololu TIC Controller. This controller is a small, compact circuit board with a stepper motor driver and a controller that is addressed via MicroUSB. The advantage of this solution is that you don't need an Arduino or Raspberry Pi to control the stepper motor driver, everything is on a board that is smaller than the area of a NEMA17 motor. Another advantage is that you can also focus your telescope manually when you remove the MTF. This usually does not work with a purchased focuser. For under $100 you get a solid focuser that is also extremely energy efficient with only 0.012W (12V/1mA). This focuser is for astrophotography with the INDI driver TicFocuser-ng https://github.com/sebo-b/TicFocuser-ng

BOM [MagneTicFocuser]:

1x STEPPERONLINE 17HS13-0404S-PG27 1x Pololu Tic T500 4x M3x6 for fastening the geared motor 4x M3x10 for the connection between housing and magnet plate 2x M2x8 self-tapping for attaching the controller 2x M4x10 grub screw for the clutch 4 N45 neodymium magnets 9x5 (4 more for the flange on the telescope) 1x barrel connector socket 5.5x2.1 for 12V DC 4x heatset inserts M3 5x6 (I have the VORON compatible heatset inserts) Superglue to stick the magnets in place JST connectors 4-pin for stepper, 2-pin for 12v

Motor settings:

My settings in the Tic Software for the stepper motor are: Current limit: 1mA (yes, it works!) Step mode: 1/8 step (for maximum resolution and less vibrations on accel/deccel) Max speed: 8000000 Max accel: 80000

Assembly:

Notice: I have detailed instructions with photos on my blog (german): https://astrophoto.lionbit.com/3d-druck/22-magneticfocuser Here is an English translation (google translate): https://astrophoto-lionbit-com.translate.goog/3d-druck/22-magneticfocuser?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp Quick assembly guide: You have to melt 4 heatset inserts into the red magnet plate and then glue in the 4 N45 9x5mm magnets with a drop of superglue each. Remember, the magnets stick out 1mm, so don't try to press them in flush, that will go wrong. Screw the magnetic plate to the housing. For this you need the 4 M3x10 screws. Shorten the motor leads and crimp a JST connector to the end. Solder 2 JST sockets on the Pololu Tic Controller. 2-pin for 12V power, 4-pin for the motor. Solder a cable to the 12V socket and crimp a 2-pin JST connector at the other end. Pay attention to the polarity! Don't forget the shrink tube ;) Now plug the 2 JST plugs into the sockets on the controller and screw the controller to the cover with 2 M2 self-tapping screws. Place the motor in the housing, paying attention to the motor cables, they only fit into the recess provided in the housing. Screw the motor with 4 M3x6 screws. Slide the cover with the controller into the housing until it clicks into place. Finally, the coupler must be placed on the motor shaft. You will also need 2 M4 grub screws for this.

Parts for the Scope:

Hexafoc Focuser: https://www.printables.com/de/model/251958-mtf-mount-for-hexafoc Baader Steeltrack: https://www.printables.com/de/model/251975-mtf-mount-for-baader-steeltrack Happy printing!