Am I at a Dead End?

[RussG]

OS: macOS 10.16
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24366 (Git)
Build type: Release
Python version: 3.9.7
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.3
Locale: C/Default (C)

As a total Newbie I thought I would see about making a container and a 3D print of it. As I go along I am learning about all the criteria that need to be met and the obstacles to overcome. I’m wondering if I can go any further with my project.

The attached FreeCAD file and screenshot show my container as developed, so far, but I thought it far enough along to start investigating ways to go about getting a 3D print made. That’s not looking like such an easy thing to accomplish, for me, right now.

I don’t have a 3D printer, and even if I were in a position to have access to one such as the Prusa i3 MK3 my container would be too large for it to print at the size I want it. I’ve begun looking at 3D printing services and even tried to get an online estimate, but found myself faced with choices I needed to make in order to get an estimate such as the kind of 3D printing technologies and materials which are currently out of my knowledge sphere. I can get some help from such services during business hours, I’m sure, and will pursue the route next week, I expect.

Meanwhile, in this post I am asking for thoughts and advice as to methods and avenues I might pursue towards getting a 3D print of my container—if it is even worth pursuing. I’m not in a position to spend a great deal of cash on this project. I have no idea yet what kind of costs I might be looking at with commercial services and I am hoping folks here have a better idea of what I am facing and perhaps avenues I might investigate. What would your experience suggest about trying to get a 3D print made of my container? What might a commercial 3D printing/prototyping service charge? Are there other alternatives available? What should I be looking at and thinking about?

Thanks.

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Feeder 05.07.22 Constrained v1.21.FCStd

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[edwilliams16]

My printer has a useable volume of 254 * 254 * 254 mm, making it mid-range as printers go. Your model would fit diagonally across the bed, but not quite vertically. For your reservoir part, vertical would be a good printing orientation as it would not require supports.
(3d printing builds vertically, layer by layer. You can't print in mid-air, so you have to print breakaway supports under overhangs. These tend to spoil the surface smoothness and have to be accessible to be broken away. This limits overhang angles to about 45 degrees.)
You have modeled it as multiple bodies. If printed that way it would require gluing. That works fine, but I would model some flanges to increase the gluing surface areas.

The simplest material to print with is PLA (polylactic acid). It makes nice prints, but its greatest disadvantage is that it has a relatively low melting point. It will soften around 50C, a temperature routinely reached inside your parked car, for instance. It is quite hard, but somewhat brittle.
ABS plastic was the most common alternative. It is serviceable up to about 85C. Long skinny parts like your reservoir could be tricky to print as temperature gradients cause it to curl - probably making a temperature controlled printer enclosure a necessity - which many printers (like mine) do not have.
Many have switched from ABS to PET (and PET-G) plastic, the stuff your plastic drink bottles are made of, when PLA will not suffice. It's temperature tolerance is about the same as ABS, but is somewhat less finicky to print, depending on the model.

My only experience with a commercial service, before I built my own printer, was a failure. The price was reasonable, but he was unable to print some gears out of ABS, because of the afore-mentioned curling problem. (To be fair, I tried later and I couldn't print them either.) I ended up cutting the gears out of Acrylic with my bandsaw. They weren't very smooth, but good enough for my application.

[chennes]

Without knowing the critical elements of your design it's hard to answer in general, but I'd argue that 3D printing is not a very good manufacturing technique for that particular design, especially if it's supposed to be larger than a standard consumer model print bed. The image you show is a bunch of flat planes: I'd make it using a CNC mill or laser to cut each of the faces, and then stick them together with material-appropriate fastener or adhesive.

[Shalmeneser]

Btw, your 1st sketch is ... unreadable, unusable.

[RussG]

Btw, your 1st sketch is ... unreadable, unusable.

That's odd. I'm guessing it has to do with settings somewhere in FreeCAD as to what is displayed and what is not. I don't know the interface well enough to specify. That's not what I see. I just downloaded the file I posted and it (Sketch: Reservoir) looks like this, to me when I open it:

Screen Shot 2022-06-08 at 8.18.01 AM.png (102.47 KiB) Viewed 629 times

[thomas-neemann]

..

these ticks control the display

Bildschirmfoto_2022-06-08_17-47-40.png (119.62 KiB) Viewed 600 times

[TheMarkster]

If it's a feeder (bird feeder?) to be outdoors, then PLA could be out because it will degrade with UV exposure. ABS is more UV resistant, but prone to warping during printing, particularly with larger prints. If the object is too large for the printer, then the only option is to print it in smaller pieces to be assembled later. Smaller pieces are also less prone to warping. Acetone makes a great glue for ABS because it acts as a solvent. I have found the joints to be quite strong. Ed's suggestion of flanges for larger surface area at glue joints is a good one.