The Peachy Printer Suggestion Thread

[DoulosDS]

".... Whatever the software determines the slice thickness to be, when the drip count is reached, the computer could raise a flag on a USB port and pause for a programmed interval before scanning the slice with the laser. The output signal would close the solenoid valve and stop the drip during the pause interval. This would allow time for the resin to flow over the previously-exposed layer and any bubbles to pop or voids to fill...."

From another suggestion: the flag signal could also trigger dunking a displacer in the print tank to raise the resin level momentarily and ensure the previously printed slice is evenly covered with fresh liquid resin. The displacer would have a tapered base to minimize waves and a time delay would be programmed for resin to flow off the displacer and any disturbance of the resin to settle before the next slice is printed. A micro controller (R-Pi?) and stepper motor would lower and raise the displacer, with a sensor to maintain the approximate depth of displacement as the resin rises in the tank, and keep the tip of the displacer just under the surface to prevent drips during the print. The displacer would begin to lower when the flag indicates the laser has completed scanning the current slice, while the drip system is running. When the solenoid stops the drip, the displacer would be raised as quickly as can be done without undue disturbance of the resin.

[DoulosDS]

There are so many good ideas on these forums! As I read, I keep getting more inspirations...

OK, the displacer would work fine, but an even better method uses a positive displacement pump, driven by a stepper motor. (I'm assuming the drip system is far more precise than the pump, but the pump is sufficiently precise for pumping repeated volumes.) At the end of the slice print, the flag signal opens the solenoid valve and the drip system begins adding brine to raise the resin to the level of the next slice. Meanwhile the pump is also adding brine by a precise number of revolutions. When the drip count is complete, the excess brine has caused the resin to cover all the previously exposed slice. The pump is then run in reverse by the same number of revolutions, returning the resin level to the height of the next slice. A short pause would allow any movement of the resin to cease before the next slice is scanned.

However, if the stepper-driven pump is sufficiently precise for positioning the resin from slice to slice, the pump can replace the dripper system. It would raise the resin enough to cover all the previous slice, using X revolutions; then lower it to the level of the next slice, using -X+slice revolutions. I think this could speed up the printing process significantly.

[NeilR]

I was thinking that the high viscosity would cause the surface tension of the resin to prevent it from covering the surface, by "grabbing" the edges of the print and not flowing over the top.

If all else fails you can use the resin you have to fill the shelled/hollow prints.

[NeilR]

Here is a fairly bad sketch of what I was going to set up for my drip system to minimize the chance of disturbing the resin layer. Using a 1" pvc pipe to contain the drips, this would also work for your dip system I would think.

Untitled.jpg

[Synchron]

Hi,
Maybe a stupid idea, but if you have this side-pipe. Would it be possible to raise the waterlevel by airpressure, maybe with co2 soda mixer cartridge, in this pipe? After that you only have to open a valve and you would come back to the original level

[amoose136]

You'd want to be careful with the gas gradually dissolving into the saline though when you create a pressure differential like that. Then it could off gas as soon as it goes around the bend and potentially disrupt the print.

[Sven.L]

attn.: Peachy Printer Staff

Pre-Ordering / PayPal

Please add PayPal to the payment options. I tried to pre-order but am left out from that possibility because you did not yet add PayPal support. I do not have a credit card I want to use on websites (the last one was illegally used by web-based thieves after I used a US-American website for credit card based payment). Please assist as soon as possible. Thanks.

[Sven.L]

Hi rylangrayston,

I replied to your private message (in regards to PayPal). Did you receive it? Enabling PayPal would be a great extension of purchasing possibilities/options for our forum members here - not everyone wants to use his/her credit card on websites, especially when having made already bad experience with that (like I did on another website).

[rylangrayston]

I agree that we should have pay pal.. I have replied to your message

[Sven.L]

Thanks, I saw it. And send a new reply from my side. :-)