First print - small water tank HELP!
Anyone here that can advise? I have a PRUSA 4 in an enclosure, brand new. I will use sketchup as familiar with it. I firstly want to print a box 90mm tall 90mm long front to back and 120mm wide. The 120mm width is to allow for the water pickup tubes from a Decent coffee Machine to drop down into the tank and to the left of it, a food safe aquarium water level maintainer float will be located. I will also want to print a lid to fit over the tank to keep dust and bugs out. The idea is that I can use my old plastic 6mm water supply hose that I used for my old coffee machine, straight into the float device, put the lid on the box with the holes already made into it. Slide the box under the machine until the water pick drops in. Turn on the water supply and never have to refill again!I need advice on what material to print in, I have three rolls of different filaments, PLA ABS and petg if I remember correctly.How thick should the bottom and walls be? What settings for the infill and slicer should I use? Same with the lid and the lip around the top of it. How much clearance should I give the lip if I want a snug fit?What setting on my printer should I use to make a waterproof box like this, anything else I should know?
this is a fun first functional thing, I can’t wait to print it! (Ps I plan on coating the inside with an expoxy to make it food safe)
Tricky for a first project - but:
https://blog.prusa3d.com/watertight-3d-printing-pt1-vases-cups-and-other-open-models_48949/
https://blog.prusa3d.com/watertight-3d-printing-part-2_53638/
Cheerio,
RE: First print - small water tank
So I can print 2mm walls and bottom of tank, solid no infill, with an epoxy coating to make food safe and water proof I should be good?
RE:
I guess water tightness isn't much of an issue if the tank will be coated by food safe epoxy anyway (which I think is critical for food safe applications). If you want watertightness nonetheless for the print itself, Calibrate your Extrusion rate properly and then add maybe 0.02 or so on top of the optimal extrusion factor. Just add a tiny bit of overextrusion.
PLA is the easiest to print and probably works if the tank doesn't get exposed to hot water (anything above 50°C), if heat is an issue, ABS would be better but it is much harder to print due to warping. PETG would be a good compromise in between.
If you want a material that is mostly like ABS but prints almost as easily as PLA, you can try Formfutura TitanX or 3djake niceABS. Both are heavily modified ABS filaments. For a beginner it might be best to try your luck with PLA though.
Regarding thickness. Maybe try 2 mm wall thickness and at least 3 perimeters.
Snug fit is highly dependent on how you calibrated your printer and filament extrusion factor for specific filaments. I would target 100µm tolernace first and make a test print to see if it is too tight or loose and then iterate from there.
If you print in any enclosure, especially with ABS but also with PETG, keep it closed even after the print is finished, for at least an hour, if you want to be on the super safe side, wait over night. So that it cools down very slowly and homogenously iniside. That minimizes warping.
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: First print - small water tank HELP!
It’s a brand new printer, so has been calibrated. Printed the test spatula. Looks perfect.
So I will printing PLA using the default settings for this printer in the slicer app. It’s for cold water, so no issues there. I was thinking about having 100% infill for the 2 mm wall walls? Would that be okay or should I try something else? I don’t think I need to worry about water leaks as I’m coating in epoxy anyway.
RE: First print - small water tank HELP!
Hi Greeny Meanie,
May I suggest that you do not use 100% Infill, but instead use lots of top and bottom layers instead.
100% infill can be a bit messy especially when the model gets tall. where as lots of top and bottom layers tend to give a much better result, that is also solid.
your proposed tank, is 90mm tall, if you are using 0.2mm layer height, you will need about 450 top and bottom layers in total,
Just in case you change the dimensions I would suggest that you specify more top and bottom layers, than the model needs, to ensure that all layers are top and bottom layers.
I would suggest 250 bottom layers and 250 top layers
prusa slicer will only use as many layers as actually required to fill the model, so ir doesnt matter that you have specifies more layers than actually required
Good luck with your print,
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: First print - small water tank HELP!
That is an interesting approach. Whats the difference between having only bottom+top layers instead of 100% infill?
What I usually do is when I want 100% infill on an object which consists of walls is to increase to number of perimeters to 10 or so. Then you get only perimeters and no infill but it is also completely solid. In many cases it is better to have a tiny bit of infill however between the perimeters from both sides. But for that you need probably at least 3 mm wall thickness as I would recommend at least 3 perimeters on each side, if you the core is not 100% solid.
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: First print - small water tank HELP!
Mind you, with three perimeters per layer as suggested by TheJiral (Assuming you are using a 0.4mm nozzle 3 inside perimeters and three outside perimeters
, there will not be any space for Infill. As you can see below, a 2mm wall with three perimeters results in five perimeters, not 6 perimeters as you might expect.
I Have left two corners square and I Have put fillets on two corners I think this would make your tank more robust and more pleasing to handle than the square corners. I put a 2mm fillet on the inside radius, and a 4mm fillet on the outer radius in order to keep the corner thickness even.
Are you using two cup mixing to ensure good mix of all components, this is essential for food safety. (Mix in one cup, pour mix into new clean cup, and mix again)
Good luck with your project.
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: First print - small water tank HELP!
Thanks mate. Im still at the sketch up stage, trying to get the corners tight with no strange anomalies. I will mix the epoxy well, so use sacrificial cups?
RE: First print - small water tank HELP!
when you mix the epoxy there is a chance of some raw epoxy remaining in the corners of the mixing cup. by tipping the contents of the first mixing cup into the second mixing cup, all of the mixed resin is transferred and filling the extremities of the new mixing cup and any unmixed resin falls on top of the previously mixed resin, where it can easily be mixed into the the remaining bulk of the resin.
this way, there will not be any uncured poorly mixed resin, after the job is complete
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: First print - small water tank HELP!
ok, I am at this stage now. Exported to slicer. I believe the prusa is delivered with PLA, there are 3 PLA in the list on the app, I believe they are all the same I presume? everything is as delivered (ready built I just put it in the enclosure)
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print settings look ok?
RE: First print - small water tank HELP!
I think I need to change my infill from 15%? but with 3 perimeters, do I need to?
RE: First print - small water tank HELP!
Added supports and 80% infill. I am concerned that I can see the inside of the top of the walls...
RE: First print - small water tank HELP!
Hi, Greenymeanie,
with 3D Printing, it is very difficult to make positive comments based on little information...
If you could save the Prusa Slicer session, the model and with all settings as you plan to use them, as a project file (File>Save Project as) then when you have saved the project file, if you could ZIP Compress the file, and attach the zip file to your next post, we can have a more informed opportunity to comment on your proposed settings
I suspect the three PLA Options are
Generic PLA
Prusa PLA and
Prusament PLA
I Have no idea which is most appropriate as I can't see the filament that you have
All three profiles are similar
Prusament = Filament actually Produced by Prusa. in house and it comes on a roll with plastic sides perforated by lots of Hexagons. Like the picture below
there will be a description of the filament laser etched onto the side of the reel, complete with a QR Code and serial number
which allow you to look at your actual reel's 'Birth Certificate' (Prusa call it "INSPECT YOUR FILAMENT ONLINE") https://prusament.com/
and when you enter your spool details you get a report including specific details like this, about your actual roll of filament. 
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Prusa PLA, is filament that is made for Prusa, outside their factory
when I have received filament, bundled with a Prusa Printer kit, it has come on a spool like this 
and I believe it has been produced by Filament PM https://www.filament-pm.com/
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the other option
Generic PLA, tends to come from places like Ebay, (Probably originating in China)
Often on non descript spools like this 
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However, If you look at the configuration wizard in Prusa slicer, there are dozens of 'Named Brands' Which you can choose from, if you have a named brand 
so, if you happen to have, say colorfab PLA, you can add those presets to your Prusa slicer configuration.
If I Don't know who made a filament I tend to use the Generic PLA filament option, and set the bed temperature to 70C
and it usually works as a starting point.
Good luck with your first print,
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: First print - small water tank HELP!
Thanks Jean, I’m super excited to get this first print going:-) The PLA I have is what was delivered with the machine. I will check the codes when I’m home shortly.I will upload the zip too:-) can’t wait!
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heres the file, no need to zip, its very small edit, I had to zip it because it did not attach otherwise
RE: First print - small water tank HELP!
Prusa PLA it seems
RE: First print - small water tank HELP!
Am i good to go Joan? @joantabb