3D Printing:
DC motor for direct drive mount

Contents:

1. Introduction & links
2. To be continued

Note:
I take no responsibility or liability for what are written here, you use the information at your own risk!

1, Introduction & links:

Introduction:

Most mounts today include gears, gears have backlash and are very expensive when made of high quality. More interesting with a mount without the gearboxes for R.A. and DEC axis, a direct driven mount by brushless electric DC motors. The motor isn't very complicated, my idea is to 3D-print the motor.

A slow rotating motor with high torque is best solved with an axial motor with permanent magnets and brushless.

To get the position of the motor with high accuracy, better than 0.2 " it's need of a very high resolution angle sensor. They are complicated and expensive. Most of them consist of a magnetic tape wrapped around a disc and a magnetic sensor.

I start with links to collect information. Maybe there will not be more than this. Interesting readings anyway. I study a lot of physics many years ago, but don't know much about electric motors more then how to use them.

An impossible dream ? I don't think so:

• https://www.youtube.com/ watch?v=-6ikMRXNs9s (RC Plane with 3d-printed Motor and 3d-printed Propeller, Christoph Laimer YouTube)

Design of axial electric motors:

Here are links to design and physics about direct axial electric motors. Most of them of high power design and must be scaled down:

• http://webfiles.portal. chalmers.se/ et/ MSc/ DubarChristian.pdf (Design of an axial flux machine for an in-wheel motor applicationn, Christian Du-bar Chalmers)
• https://www.linkedin.com/ pulse/ design-build-axial-flux-motor-tobias-krieger (Design & Build an Axial Flux Motor, Tobias krieger)
• http://web.mit.edu/ kirtley/ binlustuff/ literature/ electric machine/ design Of AxialFluxPMM.pdf (Design of axial-flux permanent-magnet low-speed machines and performance comparson between radial-flux and axial-flux machines, Asko Parviainen)
• https://www.designworld online.com/ innovative-design-comes-to-electric-motors/ (Innovative electric motors sport axial designs, Leland Teschler Design World)
• http://e-hike.net/ sites/ default/ files/ article/ file/ motor_4275224.pdf (Design of Axial Flux Permanent Magnet Brushless DC Motor for Direct Drive of Electric Vehicle, N. A. Rahim Á Hew Wooi Ping)
• https://www.emworks.com/ ckfinder/ userfiles/ files/ Axial Flux Motor.pdf (Axial flux electric motor, Juan Sebastián Lasprilla HincapiéAndresdavid Vargas SandovalJosé Zuluaga Parra EMWorks)
• https://backend.orbit.dtu.dk/ ws/portalfiles/ portal/ 117047343/ Session 3 Applications presentation.pdf (Design and fabrication of axial flux ferrite magnet brushless DC motor for electric two-wheelers, Fasil, Muhammed; Mijatovic, Nenad; Holbøll, Joachim; Jensen, Bogi Bech; Almunia, J.; Seoane, A.;Altimira, R. Backend orbit)

High resolution encoders:

• https://www.linearmotiontips.com/ how-do-magnetic-linear-encoders-differ-from-optical-versions/ (How do magnetic linear encoders differ from optical, linear motion tips)
• https://www.rls.si/en/ products/ linear-magnetic-encoders (Linear magnetic encoders, RLS)
• https://www.posic.com/ EN/ products.html (Encoders, Posic)
• https://www.machine-dro.co.uk/dro-interfaces-cables-and-spares/spare-parts.html (Reading heads and Magnetci tape, Machine DRO)

Other links:

My other links related to direct drive mounts:

• ../../links/ links-astronomy-direct drivemount.html (Direct drive mounts)