Focus/Zoom Motor for Camera

A geard stepper Focus or Zoom motor for motion control, follow focus etc. Standard 0.8 Module gears and 15mm rod attach.

Weighing in at only 135g and costing about 10€ to build, while using a 12v bipolar stepper motor, this is a really affordable way to test out focus or zoom motion control using off the shelf motion control systems.

While the 3D printed bevel gears keep the cost down, they definitely affect the longevity and accuracy of the system, however good repeatable results can be achieved. The results also depend a lot on the lens used, with cinema lenses offering better results due to increased focus throw and often smoother focus ring movement, however here I am using the kit Canon EF-S lens with decent results.

If you make this FZ motor, I'd be happy if you post a Make with your results!

BOM

Geared Stepper Motor

2x625zz bearings

1xM4x20mm Hex head bolt with nut

1xM5x50mm Hex head bolt

5xM3x6mm bolts

4xM2x6mm self tapping screws

Tools

3D Printer - Bambu lab A1 mini is a good choice to get started, they can be found for about 150 Euro on the secondhand market.

Allen key wrench set

Needle nose pliers

Consumables

Printer filament - PETG

Super glue

Note: some links are Affiliate.

Print the plastic components, download on Printables here.

PETG is recommended for all parts except the two bevel gears, ideally they should be printed in NYLON, ABS or ASA, but PETG or PLA will also work but will likely not last as long.

Using 3 M3x6mm screws, attach the motor to the body

Insert/screw the M5 bolt through the Lens Gear until the head is flush with the gear.

Insert the two 625zz bearings into each side of the gearbox, it should be a tight fit so some force may be required, ensure you push the bearing in evenly without putting force on the dust seal as this may damage the bearing.

Push the drive gear onto the motor shaft and secure with a spot of super glue.

Slide the gearbox onto the body (either way) and fasten with the remaining 2 M3x6mm screws. It should be a fairly snug fit.

Place the focus gear inside the gearbox and screw the M5 bolt through until the lens gear is flush with the body. This is definitely the trickiest step, care must be taken to avoid back-driving the motor as this will put unnecessary strain on the bevel gears. Use the needle nose pliers to carefully grip the gear.

Once the Bolt is all the way through, fasten the lens gear in place with either the grub screw or some glue.

Note, the lens gear may be attached to either side.

Using the 4 M2x5mm self tapping screws, fasten the lid onto the gearbox

Insert the M4 Nut into the body and push the M4x20mm bolt into the thumbscrew then screw onto body.

Congratulations, assembly is now complete!

The FZ motor attaches to standard 15mm rods, pictured I am using an L-Bracket and a 3D printed rod holder.

Attach an appropriate cable using the following pinout:

Yellow = A+

Orange = A-

Blue = B+

Black. = B-

For motor control, an Arduino can be used, alternatively, I use and can recommend the Frame MoCo (if not shown on website, send him an email) as an off the shelf budget solution, or if your budget stretches, the PINE motion controller from Blackforest Motion offers a some advantages (ie 4th Axis) at a reasonable price. Both of these systems support various capture modes (Timelapse, realtime etc) through a bluetooth phone app.

This motor is far from perfect, and the accuracy and longevity will greatly depend on the quality of the bevel gears. I plan to create a version 2 with a NEMA8 stepper motor and a brass worm gear set, while this will increase cost it should offer significant improvements while reducing backlash.

If you need focus gears, I use and recommend this free site to create them