DIY perfect, seamless Lens Gears for Follow Focus

Here's what you need:

Gear Parameter Calculator
The certificate seems to be invalid by now, but it's safe to use as long as you only type in your gear-needs :)

GearDXF software

Autodesk Fusion 360

Also, you need some calipers or a strip of paper to measure the diameter of your lens. That's it! Easy, fast, cheap and great :)

Big shout out and thanks to Rob for teaching me how to do this! :)

[gregelisara]

Thank you for this very useful video. I'm on a mac and managed to do everything just using the free version of Autodesk Fusion 360 (maker version) - no need for GearDXF.

In Fusion 360, select the add-ins option then "Scripts and Add-ins". In the sample scripts provided when you install Fusion 360, select the SpurGear script and run it (I used the Python version, but the C++ version looks identical). When the script starts, change the "Standard" option from "Metric" to "English". Enter the diametral pitch of 31.75 and the number of teeth you need. I set backlash and root fillet radius at 0, and changed the gear thickness to 10 mm. Set the required hole diameter then click "OK"


That's it. Model generates and you're good to export the SLT.

[wolfcrow]

Nice one! With a database of STL files for accessories anybody can build their own.

[MaghoxFr]

very cool setup with the knob FF for focus and the lever for zoom. Great video.

[djackindabox]

Very nice, well-done step-by-step. I was about to order some of the Helicoptersean ones, but I'll try this first.

Thanks a lot !

[geekdomo]

thank you for this, exactly what I was looking for. I used Tinkercad as my free cad program & simplify3D as my slicer. Gears came out great! Thanks

[jaspertermors]

Thanks so much for this tutorial Lucas! Will try this on my SMC Takumar and Contax Zeiss sets soon :)

[AbdelElAsrivisuals]

Awesome Lucas! I think I will do this to all my photo lenses to fit the same diameter. Thanks a lot!

[DocMicha]

you could directly use the spur gear add-in in fusion 360

[combatwombat]

Great to see you made such a useful video from our very long Facebook chat of explaining how to do this :-) Well done!

[Hoss_]

I just tried this, the newer version of GearDXF is different and does not work correctly, I went to the calculator and type in 91mm and .08 like you said, got 112 teeth, then went to gearDXF and entered in 112 teeth and 31.75, but could not enter in 81mm, it reset it to 78.84mm. I managed to find an old version and it worked, so not sure what the difference is, Just wanted to let you know. thanks

[mrtobycook]

This is incredibly helpful! Thank you!

[nickcastetter]

The Gear Parameter calculator you linked to says it's no longer available. Any other suggestions for how to find how many teeth I need? Thanks!

[Vladislav]

Good advice and awesome idea! Thank you ^^

[SRG-Learn-Filmmaking]

I wonder why this approach is not more common. It's hard to find more than a couple of vendors who make this kind of seamless ring (although some managed to make them elastic). How your prints stand the pass of time? Are they still going?

[Vautksch]

Wow danke! Damit wird mein Set Nikon AI Festbrennweiten ausgestattet. Thx!

[fangshizhu]

Hey Lucas, thanks for the great tutorial! I have a question with the GearDXF though. I am trying to create a follow focus ring for Sigma 18-35 mm f/1.8. The diameter of the lens focus ring is ~77mm. So, adding +10 mm ring thickness, using the gear tooth calculator, the parameters should be:

Diameter: 88mm
Pitch: Mod 0.8
Tooth count: 108
Diametral pitch:31.75

However, when I try to design the ring profile within the GearDXF, I could not input those numbers accurately. After inputting the Diametral Pitch as '31.75', the software automatically changes the number to '31.8'. Also, after inputting the Bore Hole Diameter as '77 mm', the software automatically correct the number to '75.24 mm'. Any idea what the reason might be and how to address this?

[samadhiproduction]

Hi Lucas Pfaff thanks for the tutorial. wery unerstandable but cant runn GearDXF software on any computer I tried. Any help please?

[felixpopp]

Sehr cooles Video. Werde es mal ausprobieren

[tuckerkanderson]

Are you going to do an update on this video Lucas?

[FlyingJackalope]

The "Gear Parameter Calculator" link is dead. Is there a similar calculator online anywhere else?