I am designing a mechanism that needs to cut 3D printer filament (normal 1.75mm). That's all it does. I just don't know how to design one. I've seen automated wire cutters, but filament requires some more force to cut than the wires. Ideally, it would leave a clean cut, but that's not essential. The final design will probably use wire cutters, I just don't know what to use to actuate them. Any suggestions on what to use?
Thanks!
I think it should be fairly easy to scale up the force of any automated wire cutter design enough to cut filament. There are a lot of DIY ones on YouTube with various designs.
You could also consider using a hot knife cutter, which would require very little force. I suspect that would leave a burr on the cut ends, which might be problematic somewhere down the feed train. Not knowing barely anything about 3D printers or your application I can't say whether that's a concern. You can get commercial hot knife cutters made for cutting rope or nylon webbing or make your own. A cheap soldering iron with a razor blade tip would work well for a DIY hot knife cutter or perhaps just a piece of nichrome wire.
Just out of curiosity I have just cut a piece of 3D filament with the side-cutters I usually use for wire and it did not seem to require as much force as wire.
Post a diagram for the sort of cutter you are thinking of using.
One system I saw (back in the day) for working a shears was to spin up a flywheel and when it was up to speed engage it with the cutting mechanism - the energy in the flywheel drove the cutting action.
...R
pert:
You could also consider using a hot knife cutter...
Heat will leave a bulb on each end. Which is likely to be undesirable.
Unless there is tension on the filament when cut. In which case a tapered thread will be left. Which is likely to be desirable.
Too much heat turns the filament into slag. Which is always highly undesirable. The heat has to be controlled (a big "no" to a simple soldering iron).
An angled cut leaving a slight taper would be a good choice.
If you could push the fiber through a close fit hole in a plate and slide the cutter across the face of the plate it may result in a clean cut. Maybe a razor on a solenoid (or handle) for the cutter?
I'm hoping that somebody finds a way to 3D print with glass monofilament or copper wire laid in the print.
Robin2:
One system I saw (back in the day) for working a shears was to spin up a flywheel and when it was up to speed engage it with the cutting mechanism - the energy in the flywheel drove the cutting action....R
Similar to what Robin mentioned is to store the energy needed in a capacitor and then to make the cut, discharge the capacitor through a solenoid attached to a steel blade. A brass anvil is need to hold the filament while the blade cuts it.
Charge a large value, non-electrolytic capacitor, to say, 50 or even 100 volts dc, and discharge through a 12 or 24 volt solenoid. Very fast and powerful action, then a time to rest and cool and recharge the capacitor.
Paul