I’m going to start a somewhat ambitious design that involves “printed together” moving parts (think ball bearings, watch bands, etc.).
Any advice or recommended technique for designing parts that print and work together like this? I’m reviewing exiting designs but any advice from others who have designed such this is appreciated!
Ping @Daniel_Noree . Any tips?
Avoid internal overhangs of more than 45°. For example, hinges built from interlocking cones have much less problems with sticking due to dropped threads than ones made of straight pins or balls, etc.
The guy I did my MS with has been doing fun things on that principle.
@Jason_Gullickson As you need to leave space between parts, check out this thing: http://www.thingiverse.com/thing:144381 to see what´s best for you/your printer. I usually try to have a little less space between vertical surfaces than the horisontal ones.
There are some useful comments on my wrench if your up for reading thru them: http://www.thingiverse.com/thing:139268
Most of the time i use a Top Down approach when modeling projects like this.
Thanks for the tips and the awesome tools!
A CAD program with suppor for assemblies?
This may be more bleeding edge than you want but I’ve seen some prints done with a dual extruder. They print the main part in ABS and supports in PLA. You then just dissolve the PLA support and your left with perfect captive parts.
Include separate variables to XY and Z printing tolerances.
@Chris_Thompson1 and hole shrinkage based on diameter. (I don’t think I even have the option to calibrate that in these “modern” slicers anymore.)
@Richard_Collins the question is about designing, not printing.
@Marcus_Wolschon Richard was just trying to help, and honestly, I think his comment is pretty relevant.
That being said @Richard_Collins I think may have been referring to PVA, filament. Printing in 2 filaments would change the design considerable as the air gaps that are discussed earlier would be replaced by the second filament. So your suggestion was related to design. I have no experience with this yet, but we’re looking to buy some PVA filament at work, as I’ve broken many parts removing support.
@Marcus_Wolschon
I don’t mean to be mean but good design should take into account the properties of the materials being used. I was simply offering an alternative material.
@Eric_Moy You could be right, I can’t find the original post but there was a strange chemical used to remove it.
Gear bearings print easier than ball bearings and look cooler…
I have no practical experience but from what I have picked up from this forum I understand that p l a is difficult to dissolve and the material used to dissolve it is highly toxic.
On the other hand PVA is available for children to use so I would assume it’s not toxic. I understand it dissolves in water. And I think I read somewhere that if you use hot water it’s better and if you’re lucky enough to have an ultrasonic cleaner type device that makes it dissolve much faster.
@Eric_Moy @Richard_Collins @Tony_Hine_Nifty_Acce You can remove PLA support material with caustic soda (drain cleaner) - which is what is used in some commercial systems. This stuff, while certainly not pleasant on the skin, isn’t the same as dichloromethane or tetrahydrofuran which might be the nasty fume emitting chemicals Tony is thinking of.
@Sanjay_Mortimer are you talking about sodium hydroxide? Have you tried this? How long does this generally take
Thanks for the information on caustic soda @Sanjay_Mortimer
Yeah at the moment I’m running with a single extruder, so any support I use will need to be removed mechanically 