Traditionally scale RC aircraft canopies are vacuum formed over a former that is CNC machined or carved. Originally I intended following this tried and tested with a canopy on a personal project, but printing the former.
That changed when I was @Michael_CurryTachikoma hollow print with its 1mm thick walls and thought it would be worth a go. I had to redesign the canopy with SLA printing in mind, but the end result was well worth it.
I printed it with clear v1 resin, at 0.1mm layer heights. Ideally I would have liked to print it at 0.5mm to save the amount of post processing, but that’s not an option at the moment with my printer.
As long as the weight is OK, it will be more than adequate for the flying prototype. Even including the 2.5 hours clean up and sanding, the process has save a good 10 hour of work. Better still I don’t have to stress about the amount of time lost when trying new iterations. For me, as a designer, this is one of key advantages of 3D printing…. love it!
@Michael_Curry, yes all by hand and little rushed as it was more of a proof of concept. I’m sure if I spent more time on it I could get it a lot better.
The finishing process was very similar to that used by the FormLabs guy who did the magnifying glass… sorry can’t find the link.
The pictures have created some excitement among FFF users and the RC modelling guys. A couple of them have suggested using jewellery polishing rouge with a dremel for the final finish.
@Steve_Johnstone impressive results, I’m loving seeing your lamp refract in the canopy. You’ll have to get that photograph when you have it out on a sunny day
I’ve also found this to be true - particularly with thin-walled parts, the resin is much more likely to warp right after printing. Once post-cured, the strength of the resin more than doubles, meaning that it’s easier to sand, paint and handle the part (although the flexibility logically diminishes, so it’s easier to snap a part in two). I’m particularly impatient, so it’s particularly satisfying to see someone who has mastered finishing.
Thanks a for sharing your workflow - I’ve never thought to apply automotive lacquer followed by wet sanding. I can’t wait to try it out. Make sure to keep us in the loop as this develops!
Ideally I would have given it another clear lacquer after the last wet sand and then straight on to cutting / polishing, but I really need to keep the weight down. I’ve since redesigned the canopy so the all the glass sections are 0.5mm instead of 1mm… very thin wall.
I’m on my 8th attempt to get a complete print and appreciate that I’m getting near to the limits of the printer. I’ve got one v2 canopy that has a small hole that I repair need be.
I’m in that situation where I can’t for-certain blame the failures on the lases issues as I’m a newbie with SLA printing.
I’ve just started printing a test mold that I will finish in the same way, but don’t need to worry about the weight. I’ve previously printed FFF mold in ABS for casting urethane foam parts and I’m keen to see if I can do the same on the Form1+. It would be awesome if it works as it would allow a whole new level of achievable detail.
I’ve whole series of videos on my workflow for 3D printed FFF, ABS molds and casting urethane foam, if anyone’s interested. I do go on a bit so fair warning
I’ve successfully used a dremel with jeweller’s rouge to polish part of a piece. There is some merit to the practice, but you have to do a fair amount of sanding to get rid of the layer marks first as it’s unlikely to make much impression. I use Blue rather than Rouge though.
I’d say that the jeweller’s polish is best saved to the end, after you’ve given up on wet sanding but before you apply mineral oil or protective varnishes. It’s good for adding that last bit of sparkle to an already beautiful piece.
@David_Miller, I have a small ultrasonic bath. I’ll see if I can print a small part in the coming few days and try it out with IPA. I’ll post the result in a separete topic as this is Steve’s topic and i’d like to keep it clean/ontopic Hope the ultrasonic bath still works. Haven’t used it in years!
@Alex_Vermeer, I’ve often wondered about trying a ultrasonic bath with the IPA as I’ve ofter read about how harsh IPA is on the cured resin. My thinking been you wouldn’t need to soak your part for as long .
Hope the ultrasonic bath still works. Haven’t used it in years!
