[F360] tooth profile orbiter gear?
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Hello CAD-wizards,
I made an orbiter gear with the add-on "helical gear plus" in fusion360. But it seems, the tooth profile is just a cutout of a spur gear?
Is that, how it should look? I expected a involute profile...
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@o_lampe I highly recommend shwivel’s add-ins for gear creation. They cost a little, but are far superior to any of the ones I’ve seen available. You can set all manner of tolerances, pressure angles, and module. They are available in the autodesk store.
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I found this drawing of internal gears and it looks quite similar. I'm halfway relieved, that it seems to be good enough to try.
0.2mm nozzle is ready to go
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@o_lampe in the past I've gone to Stock Drive Products - Sterling Instruments, sdp-si.com to download gear profiles. Internal and external spur with a wide selection of tooth counts and module/pitch. Belts and pulleys too. Register and download to your hearts content
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@3dpmicro
I wish they had 'ready to print' design. Sometimes changing the dimensions to add a 'fudge factor' is harder than designing it from ground up. But it's a good source for CNC. -
@o_lampe Here's an example of the interactive tool (before it generates the gears based on the input). As you can see, you have a LOT of options, from straight cut to helical, to herringbone.
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and here's what the result is (for added enjoyment, the result is actually animated with joints, so you can spin the gears.....
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The 8th attemp was a success. Dialing in a 0.2 nozzle is harder than I thought.
Herewith I proudly present the drive gear I'll design my "sherpa mini" spinoff around.
The motor is now closer to the COG, which I believe is an advantage for the Delta effector it will sit on.
The gears meshing really good, except for the teeth were the seam was.
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@nuramori
the idea is to avoid planetary gears. Because I couldn't manufacture the planet-shaft. With a rotating orbit gear, I have almost the same gear ratio, but lower partcount and hassle. Furthermore, the motor is closer to the center as the orbiter (no offset from gearbox) or sherpa mini ( in Z-direction).Your assembly shows a NEMA17 motor, spur gear and a planetary gear...how much can you extrude with that monster?
(and how fast are retractions?) -
@o_lampe You're reading it wrong - it's a Moons NEMA11, not a NEMA17, and it's extremely light. Aside from the mosquito liquid (that's a heavy beast), all of the assembly, plus electronics (toolboard), parts cooling fan, and motor was 270g. It IS a planetary approach, with a final ratio of 18:1 The offset allows me to lower the extruder very close to the hotend, and the motor sit on top of the MGN carrier, so the moment of inertia is low. The gears are MJF printed with GBPA12 (glass filled nylon 12), and after a year of almost daily use, exhibit no wear at all.
My retraction speed is 85mm/s, and I typically run it at 120mm/s
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Watch for scale