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10 Nm gear head motor

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Smokey:
I would think being back driven would be a feature in this case since you can have a hand wheel and still move the head by hand.

Nominal Animal:

--- Quote from: Smokey on November 28, 2022, 09:37:45 pm ---I would think being back driven would be a feature in this case since you can have a hand wheel and still move the head by hand.

--- End quote ---
No, that's why I use a stepper with a dual 8mm shafts: you put the hand wheel on the butt shaft of the stepper.  If the driven axis is vertical, you can make the axis of the hand wheel horizontal, which is more comfortable too.

(If you mean a hand wheel on the output shaft directly, you'll want to be able to uncouple the gearbox and motor, because they add a LOT of friction.)

No back-driving means that without input to the gearbox, the output is locked.  You cannot rotate the output (other than gearbox backlash, typically about a degree or two in NMRV's), at all: it only rotates by rotating the gearbox input.  The holding force is on the same order as the maximum output torque, often over a kiloNewton for well made worm gearboxes (as it is mostly a materials and bearings issue).  The -030s usually have an aluminium frame.

That applies only to worm gearboxes with sufficiently high ratio, 15:1 or more, perhaps? It is due to the contact geometry and friction between the pinion and the worm, so that with sufficiently high ratios, the pinion physically cannot rotate the worm – but it depends on exactly what kind of worm-pinion geometry is used.

In comparison, 15:1 planetary gearboxes can usually be back-driven.

Doctorandus_P:
I also have an (rebranded) RF30 and a long time ago I was also tempted to add a motor to the column. After some brainstorming however, I decided that automating that task was not the mayor issue, but that the bolts to clamp it are on the other side then the cranking handle.

My solution was to replace the bolts with a few pieces of longer all thread with brass nuts and add some steel tubes to make the nuts more accessible. Now both the locking nuts and the cranking handle are on the same side and this solves most of the problem.

Just in case you (or someone else) is interested, I also added the user manual.

Infraviolet:
The other option is always to stick some 3d printed planetary gearboxes infront of an existing lower torque motor, so long as they're big enough (always go far larger than you'd usually expect) and you have space enough for that then they can be reasonably efficient (even with multiple stages for 10 fold, or more, speed reuction) and will cope with this sort of torque level. The most difficult part is usually the strength of the way you join the input gear to the motor shaft, however low the torque at this point the forces occur in a very small area near the flat of a D shaft so are tricky to handle with plastic. A tiny gearbox of this sort I made took 68kg*cm before breaking, so I'd be happy to use it at maybe 10kg*cm long-term. 8Nm is about 80kg*cm, a larger printed gearbox can definitely take this. 37mm 12V dc motors to provide speeds of around 12rpm and torques around 10kg*cm are readily available in a pretty standardised size with 6mm D shafts.

Jester:
Really bad action video of the Saturn Vue wiper motor raising and lowering the head on my round column mill.

The wiper motor has two speeds, this is slow speed.

https://www.dropbox.com/s/26wb19hzack3i44/VerticalLift%20Movie-short.wmv?dl=0

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