swimming laserbase

Hi,

while i watched the update 13 video, i got a little question.
Is it possible to mount the laser on a swimming base?
With this, the distance between the fluid and the laser would be always the same.

The challenge is keeping it in the right orientation. What stops it rotating around the job or floating off to one side? Any sort of rail system adds complexity, cost, and friction. For a good print you need both the Peachy and the job to be fixed to solid objects, and if one of them is floating then that's an issue.

Realistically, for the standard Peachy, that probably won't happen - with a sub-$100 budget there's not a whole lot of space for extra hardware. For the fancy version (Peachy Pro) I gather that they're automatically refocusing the laser to deal with this problem.

I could see this being done with a multi-legged mount with foam ends sitting in low friction guide tubes (lube?) inside the build tank. That way as the water raised it would also raise the printer evenly (once the printers weight is overcome by the legs buoyancy). Since the mounts and tanks are not in the $100 version i'd be surprised if someone doesn't try this in their custom build TBH. Maybe one of the beta's can give it a shot ;-). Seems like a pretty cool idea to me Synchron.

If the buildtank has corners and isnt a perfect circle the first print could be “corner boats“ on which the laser unit stands. (Only an idea, i have no idea how much the stand would weight...)

I think Spelljammer's design is great.

http://i.imgur.com/iu7JYK9.png

i think the biggest problem would be here, that the riser gets jammed (? deutsch: verkantet) with the guides...
maybe this could be solved by 4 guide rollers wich are pressed to the guide bars.

@ Anuvin
WHERE do you see this design from Spelljammer ?????

We could also barrow from other 3D printing technologies and use the rails from something like a delta printer to have smoother movement between the supports/guides and the riser.

@Dino:
http://forums.reprap.org/list.php?185

Johan

@ NahojjohaN thank you, i have not take a look at that multi-resin thread by reprap.

Sorry, yeah, the multi resin thread, second page, first post by Spelljammer. Speaking of which, if you read this Spelljammer, could you share that cad file with us? I would love to add another support rail, reposition the peachy, add a floating multi-resin ring, and a motor to spin it, and see what it looks like when you try to jam it all in there.

Edit: Spelljammer was nice enough to send the file to me. Here it is, for anyone that may want it.

http://www.tijuanachristmas.com/3dprint/3Dprinter1.skp

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Originally Posted by Anuvin

I think Spelljammer's design is great.

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I totally agree.

Quote:

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I think Spelljammer's design is great.

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Totaly agree ! The beta testers will be able to test this soon !

This looks awesome but I cant help think that it's over engineering a problem that doesn't exist. How far will the peachy's laser have to travel before any errors due to focal length will be noticeable on the print? I'm guessing that for a build area of around 150mm³ there will be no notable effect.

I also guess that. However, seeing as how the Kickstarter mentions that Peachy Pro models will have automatic focal adjustment, I am inclined to think that the Peachy crew believes it may be an issue. If it is a problem, I believe Spelljammer's design elegantly solves the issue. If it doesn't have a noticeable effect on reasonable scales, it will be unnecessary. I can't wait to find out.

If the problem to solve here is maintaining a constant distance of the laser from the surface of the resin I would think using styrofoam would be hard to use to do this. The styrofoam would require a minimum fluid volume/resin height before it begins to float, which means it would not be that constant distance from resin print surface without filling the print area with that minimum volume. That means an overhead on the print time. As Synchron points out, the risers and/or guides could get jammed, or at the very least contribute friction and resistance which means this has to be included in the styrofoam's volume and the minimum fluid volume/resin height as well.

What if the styrofoam was damaged? It will inevitably lose mass, again changing the minimum resin height. If the floatation method could be produced by some pressurized structure that would be very hard to damage, the minimum height problem could be solved, and all done without guides, this might work. I'm a little baffled as to how you could overcome using guides and can't quite picture a system in which the volume of resin displaced is constant from start.