Mount and Reservoir Discussion

[Toasterboy]

Hey folks, with the Peachy printer hitting 1.0 and hopefully shipping soon, let's talk about reservoir, build area, and mounting options.

I'm planning to use straightwall industrial containers for my build area. I have a place in my shop where I can mount the printer to a wood beam and the build area can sit on a shelf below it. For the reservoir, my plan is a Costco milk jug or two. Also planning to mask off the area with cardboard to shield against stray UV. I'm also considering mounting the printer on a milk crate (can do both to have options).

I got several sizes of this for my build area:
http://www.globalindustrial.com/g/st...all-containers
Looking forward to trying the 24x22.5x14.5 one and printing some larger items. Has anybody tested printing larger items?

From the videos, looks like Rylan is using Montana jars. I assume that straight vertical walls help make the z-level consistent (i.e. no variance due to container shape). Montana jars seem to top out in size around 2.5 gallons. Besides industrial crates, and Montana jars, what else works? Containers with actual straight, vertical walls are uncommon as most things are designed with a taper for stacking.

What are you all planning to use?

[jontelling]

I'm glad you've started this thread, I thought about it but felt I was spamming a little.

For the build container I'm thinking a science lab beaker, they have straight sides and a very small curve at the bottom.
Anything for the salt water container.

As for the build area, it will be nice to know the projection degrees on the peachy, after all that will give you both the heigh to build width ratio.

I'm looking to use the same sort of thing as used in the videos for the build base, maybe something with a tighter mess, but not too much more.

Still unsure how I'm going to project it from UV light and build the peach support, maybe some orange plastic film around an cheap wooden frame.

[rylangrayston]

Hey Great Thread guys
Ill just make a bunch of points

- if your dripping ( ie not using a pump hack or something) keep it SMALL and tall , like 2 litres, if you dont then prints take a long time or should i say a cubed time
The smaller the printer the faster you print, the quicker you solve problems.
- The standard setup that we recommend you get working first uses 2 liter pop bottle for the bottom resivour
- We plan to let you tell the software the top and bottom dimensions of your container so that it can solve
- To block uv light we will make an orange plastic film available in our on line store, by the foot.
- put an old towl under your printer and surrounding aria, so little drops of salt water and resin don't make a mess.

lets see what else can i say on this topic...
We will be making instructions for a standard setup, and while im totally all for the wild variety of ways people will customize there peachy printers, I really think
that everyone should start out by building a standard setup first! There is just so many things to learn because of how unconventional the peachy is.
Once you get a standard peachy printer setup working in only takes a min to transfer the parts over to your awsome uniqe setup, and I guarantee the knowledge you gain
printing in a standard setup will save you lots of time.

having said that here are some things to consider for your none standard setups.

- the standard dripper can do about 2 liters per hour.
- pic a container that is rigid enough that the side walls dont bow out as you fill it with water.
- slightly tapered containers still work, we print in 1 litre yogourt containers all the time. ( the taper squashes the tops of your taller prints a bit, but maybe your just having fun and you dont care)
- pick something clear so you can see the printing happen
- dont print in something that you might eat out of ever again ( because resin is really spicy in a chemically bad kind of way )
- What ever your setup be sure to post It in the forums! that way we all learn together, and who knows maybe peachy printer will sponsor your project

[Chayat]

I'm interested to know what has been learnt about the base for a print. You seem to be using a bit of wire mesh has there been experiments with mesh size, orientation and the like?

[rylangrayston]

I'm interested to know what has been learnt about the base for a print. You seem to be using a bit of wire mesh has there been experiments with mesh size, orientation and the like?

basically any porous bump surface works great, we have printed on aluminum window screen and the 1/4 mesh you see in our recent videos.
very early on ( befor the crowd funding ) i printed on the rocks you get for a fish tank.... i would just fill the bottom half of a jar with rocks and every print came out with about 10 pebbles attached.... it made starting the printer again a breeze.

as for what dosent work
flat smooth surfaces... in the crowd funding video some of our prints were done on the iner surface of an aluminum can that we cut open... you could blow those prints off there bases .. it was annoying but it looked smooth and didn't distract the eye from the action in the shot.

[Toasterboy]

How big of a build area have you actually tested?

What is the maximum deflection angle for the peachy like? I'd like to get an idea of how high the printer needs to be mounted as related to desired build area dimensions. (i.e. height above top of build area container).

If it works (even if somewhat slowly) with the dripper for larger volumes (i.e. 2'x2'x2'), then it could make sense to look at ways to increase the fill rate of the build container (a pump hack, or whatever, to make the print times less painful). Maybe something involving a pair of motorized ball valves and a continuously running small pump to facilitate "scaling up" the drips for larger containers. With an adjustable size holding reservoir between the valves (i.e. with a diaphragm or something like a syringe + stepper motor so it can be controlled, and with open air overflow so the holding tank always fills to the exact correct volume), it might be fully automated (just enter the build volume size in the software and it can solve for the correct settings), and provide extremely consistent Z on the scaled up "drips".

If the printer angle is narrow, it may make trying to print a lifesize canoe require an impractical mounting height though=)

And with napkin math, at 2 liters per hour, something like the ~24"x22.5"x14.5" build area I suggested above would only take about 64 hours to fill (if I calculated correctly), which isn't that much worse than print times I've heard of for other large build area printers. Definitely would want to look at increasing the fill rate if I try to print at that size though...

This thread is insightful. You've been fantastically open about the details of this project and it's been fun watching as you have brought the Peachy to life... Thanks!

[Toasterboy]

I did some more napkin math.... if the pump/holding tank/ valve setup is calibrated to drop ~.35ML for each "drop", that would correspond to about 1 micron Z in a tank sized 24"x22.5"x14.5". So...a modified syringe with the valves I described would work pretty well for that volume. Seems like you could maintain extremely fast print speeds simply by scaling up the size of the "drops" in larger containers.

So how wide can we make the deflection angle on the printer? It would be cool if it can be made wide enough to accommodate mounting the printer on the ceiling and then printing into a vat on the floor.... it could probably scale to printing car sized objects easily enough.

[jontelling]

....... then it could make sense to look at ways to increase the fill rate of the build container.........

I'm not sure this is the case, bigger build area, bigger build therefore more resin to cure, as with all lasers the power is limited this means the laser will take longer to cure each layer. Which means it needs to be kept slow.

If the current limiting factors on build speed are related to the moving the mirrors (slow and steady to avoid vibrations etc) then you can up the Z-axis speed. If the laser is the limiter then the z-axis will need to be kept just as slow.

I could be totally wrong though…

[Toasterboy]

I'm not suggesting scaling up the fill rate with small containers; only for large containers. Keep the fill rate proportional to what works in small containers. They used water drops in the design because they are consistent in volume and provided an extremely cheap , easy to sense z mechanism.

Rylan mentioned in another thread that they are working on a software modification to allow the laser to stay on continuously; right now it shuts off and pauses waiting for the z level to reach the desired level between layers. That suggests that the z-level rate is a strong limiting factor. It's also a good question what the deflection speed performance of the laser is. The videos are sped up, but they seem to show the laser moving fast enough so as to appear to be a continuous line... I would expect the surface dynamics (i.e. the interface between water, resin, and laser) to behave similarly to the small scale build reservoir; I expect you would need to account for additional travel time on the laser for curing for larger objects, but that should essentially scale linearly with the surface trace path length. It seems like the z-level rise rate is the larger limiting factor in a large container. Using a calibrated valve system for z-filling essentially makes it digital, and with digital 2-way control, it could be software controlled rather than depending on sensing the drip rate. It only makes sense with containers above some size threshold though, as it's harder to calibrate and deliver smaller water volumes approaching water drop size, making the drops a better choice for small containers.

Certainly you will use more resin on larger objects, although with hollow shells, that is still pretty economical.

Perhaps this a is a feature that the Pro could explore. I'm definitely going to play around with this concept though. If only I had the printer in hand. I missed the original Kickstarter window and ordered my Peachy through BackerKit. =)

[Toasterboy]

Aha, didn't know about peristaltic pumps. One of those would work great and be much cheaper than I was thinking.