Is anyone working on combining low resolution 3d printing of soft, shrinking PLA/ABS with high resolution CNC milling and hard(or flexible,…) , accurate casting?
Some expensive 3d printers for jewellery/dental seem to combine printing and milling of wax with lost wax casting.
Very high detail, many materials and everything except the casting happens inside the machine. Clean like a 3d printer.
Search for Lost pla Casting. There was a Video in my Stream a few days ago.
I know it. It is still limited to the accuracy of home 3d printers.
Using that process for polyurethane or rubber would also be terribly wasteful and messy.
That’s why I’m learning on a large “desktop” CNC in my printcave since a few month.
3d printing is not the ultimate answer.
3d printing soft thermoplastic is useful, clean and portable but very limited. That’s why I’m asking for people who may or may not work on combined approaches.
Casting urethane for example gives a pretty wide range of material properties, even approaching injection molding.
But 3d printing alone is not accurate enough to make a mold with a perfect glossy or grained surface finish.
Replacing the roughing step in 4 or 5 axis CNC milling with 3d printing of a material that doesn’t melt in milling could be a super flexible yet fully automated process in an enclosed machine that doesn’t fling around dirty shavings or need you to stock blocks of source material.
i read that website. that was really cool !! (http://3dtopo.com/lostPLA/)
if he had some band sander, a rough sand will make the surfaces flatter i guess?
But the part will loose all dimensional accuracy in the process.
And you can’t sand complex undercuts.
@Marcus_Wolschon Aware of this?
http://store.qu-bd.com/product.php?id_product=45
For all the fact that there would be a manual tool head swap, at least the design accommodates for milling then FFF as opposed to the reverse. Assuming they can deliver on what they promise of course. Linear motion design looks appropriately CNC capable…
+Tim very cool.
Their choice of VFD and Spindle look very serious but I’m concerned about the build volume, mechanical stability and strength of their X, Y, Z steppers.
Probably more light then medium duty milling on very small parts.
But an incredibly interesting development.
However I don’t see any mention about an automatic tool swap and tool height calibration between 3d printing and milling or different milling cutters.
If the device was lightweight (wich I doubt given the Hitachi VFD and water cooled spindle) it would be a perfect mini CNC+3D printer combination for travelling.
errrm all the tech talk i read on their page is interesting. but as long as there is no video on a working prototype = they have not really proven anything. their accuracy speak of 1/32 stepping @ 0.0001" is a very tall order. if it does work, i like to see some dial indicator proof
. 1mill is 0.001" = about 25microns, they are talking about 2.5 microns. i really like to see some proof that it really is 2.5microns
.
my gut feel is that there is too much talk and nothing solid.
Perhaps positioning accuracy without considering tool runout.
@3roomlab . Those numbers work on paper: Assume 0.9 degree step angle, that gives 400 steps per rotation. They state 0.0001" per step. So, where the ball screw lead is x, x/400=0.0001" giving a value of 0.12, close enough to. 1/8". Roughly equivalent to a 1204 metric screw. No reason I can see why that wouldn’t work.
with correct choice of gear/pulley, + ur suggestion of 400step/rev + their spec of 1/32 stepping, it is possible to hit 2.5 microns easy, i managed 6.7um on a crappy test gear on 1/16 step 200step/rev. even more easier with a nice ball/screw assembly. i am just saying, we all know the theory, lets really see some proof they actually did it 
… measured with a dial indicator
with 1um accuracy
i am a strong believer in fine accuracy and repeatable results
Fair enough. WRT videos, here’s one of them speed testing the FFF version - http://www.youtube.com/watch?feature=player_embedded&v=8UliNaajy5o
This one is belt driven rather than Ball screws as with the Milling version.
@Marcus_Wolschon Excellent Blog post there, see you found a video of it working too :). One of the things I find most exciting about the project is their commitment to keeping it open source. That way, one might take their schematics and develop a metric variant for instance. I’m a great fan of Aluminium profiles and I’ve been toying with the concept of realizing the frame design with extrusions (suitably re-enforced of course) and sourcing all the relevant Linear motion hardware etc from China. No doubt the’re be some components I’d have to have manufactured, but the idea of a reprap-style CNC bot is very compelling. Particularly as the QU-BD folks are utilizing reprap electronics and (it appears) firmware. Perhaps this is misplaced optimism, I’m interested to hear your opinion as you’re already a milling machine owner.
I’m not sure yet.
For 3d printing you want a clean, heated bed.
For CNC work T slots and lots of space. It won’t stay clean.
Replacing the roughing step with 3d printing, then refining the surface and small features with 5 axis CNC milling could be a useful combination.