Balanced mechanical parts printing
Hi,
I am prior to getting a 3D printer and I am really looking into buying a Prusa printer. What I would like to know, is it possible to print well balanced structures like flywheels with a Prusa? Is it possible to admit that the filament/material distribution is always equal in the whole piece or can it vary during a printing session?
Thanks a lot for any input.
Regards,
Greg
RE: Balanced mechanical parts printing
Flywheels? Plastic is not very dense, so if you are worried about balance questions you must be talking about very high speeds.
The prints produced by 3D printing are pretty good, but there are a few things that might affect your definition of good balance:
(1) When the printer moves from one layer to the next, there is generally a slight deformation (usually a tiny bump) from the ideal or theoretical shape. You can ask for those deformations to be distributed randomly, which probably balances them out. Or you could sand them off.
(2) If your shape requires supports, then the process of removing the supports is likely to leave behind traces of the support material that may or may not be symmetrical.
(3) If your flywheel is going to be supported on, for example, a metal shaft then the hole for that shaft may not be perfectly round due to the nature of the process of printing small holes (<1cm). Thus, when you either force a shaft into the hole or bore the hole out to fit your shaft, you may be very slightly off center.
(4) The X-Y resolution of the printer is 1/80 of a millimeter, but that doesn't mean the accuracy is that good. A tenth of a millimeter is usually a pretty good estimate of accuracy on a well-tuned printer in good condition.
RE: Balanced mechanical parts printing
If you look at some of the fidget spinner designs on thingiverse, they often include some bearings or some nuts around the outer diameter of the spinner in order to provide some additional rotational mass.
Most of the gears I've printed are less than perfect. Often I end up with a little bit of a wobble. That's not a problem with a fidget spinner or a gear toy, but could be a critical flaw in something that's very high speed.
I'd be curious to hear more about the intended use of the flywheels.
RE: Balanced mechanical parts printing
Print a few test stl , by a online company, or ask on the internet if some can do it.
If holes are not round, adjust stl after each print to adjust the stl(depends on what material you are using). Also dependence on how the hole is sitting on the print, horizontal or vertical.
RE: Balanced mechanical parts printing
Thanks for all the responses!
You guessed it right, there would be some mass attached on the outer perimeter. The goal would be to print the rotor of a magnetic motor that will hold the magnets. I would use a ball bearing in the center, so I wouldn't need to print a small hole there, therefore resolving the problem of the <1cm precision problem.
If I understood right its quite doable, but might need some tinkering and deeper knowledge of the printing/setting up process, which is totally expected and wanted to get into this anyway.
So thanks a lot again, I got my answer! 😉
Greg