Hello all, I'm new to this game. Looking at getting into some 3d printing from a hobby engineering point of view. Either mock ups for water jet cutting of metal parts (some of them will need to be a moderately load bearing to test fitment) or molds for carbon fibre sand casting. And maybe a few parts direct printed.
I'm pretty good at problem solving and figuring out how to set things up but I'd rather just buy something that works. The Bambulabs ones seem popular for being ready to go out of the box and the a1 mini is tempting for being really well priced but with a limited printing size.
I'm actually not on a tight budget, just want to get value for money. Would be happy to go for the P1P or P1S models or from another brand.
From my limited research PETG seems to be the material of choice for most of these. And I think most printers can handle PETG?
Also software wise (I'm talking about design not slicer) what do you recommend? I have a bit of experience with Autocad (albiet a few years ago) which isn't massively relevant, but something that operates on those principles is probably a good start.
Hello - new to this game and looking for advice
Moderator: CrazyIvan
Re: Hello - new to this game and looking for advice
IMO the most important thing to realise is that 3D printing doesn't "just work". The issue is finding an acceptable compromise between competing demands, usually by trial and error. It's at least as much art as science, with tweaking in the slicer settings required to optimise any particular print, and designing with printability in mind. The two main issues are bed adhesion and warping.luke2152 wrote: Sun Dec 22, 2024 9:21 pm I'm pretty good at problem solving and figuring out how to set things up but I'd rather just buy something that works.
Bed adhesion is a compromise between making the first layer stick to the build plate for the duration of the print, and being able to get the model off the build plate once completed – hopefully without damaging either. Sacrificial layers can be added to the build plate (grip tape, glue stick) or in the slicer (raft, brim).
Having a heated build plate provides another dimension of tweakability: depending on the filament, it sticks when warm and releases when cold. Different build plate materials perform better or worse with different filaments.
When strain builds up in successive layers due to shrinkage, and the adhesion to the layers below (including the build plate) is inadequate, the layers lift at the edges. This is warping, which can cause splits in the model, but particularly affects overhangs because you want the adhesion between support and print to be low so you can get them apart afterwards. You can stop the bottom layers warping if you have enough bed adhesion (but then the strain can warp the build plate!).
The main remedy for warping is an enclosed print volume with heating to control the shrinkage, or even just to keep the drafts out, but the price is going up. On my simple Tina2 I partially combat warping by avoiding it in the design of the model and choosing the print orientation appropriately, including splitting the model into parts so that overhangs get printed directly on the bed, but it seriously compromises what I can achieve.
The next level of sophistication is to have multi-filament printing, preferably multiple nozzles. With two nozzles, you can print support structures in a different filament which is easier to remove – either with lower adhesion to the main filament (different materials) or by being soluble. Printers with one nozzle and a filament multiplexer waste a lot of filament by having to purge the melt chamber each change (probably twice per layer).
Another choice to make is printer geometry. Budget FDM printers move the build plate in the Y axis ("bed slinger"), with the print head moving in X and Z. The issue with that is tall thin prints wobble and can misalign or fail. Pricier units move the head in X and Y, and the bed in Z ("Core XY"), which not only stops the wobble but also makes higher print speeds possible. Some (typically "Delta") have a completely stationary bed and move the head in XYZ.
So as you see there is plenty of choice with regard to price point. Mid-priced FDM printers cluster around bed slingers with heated beds but not enclosed volumes, because those are the simplest to make. Some offer a range of textured build plates and different plate materials to suit different filaments.
Some filaments smell nasty or are even toxic and need enclosed volumes and ducted ventilation. Only PLA and TPU are suitable for an unheated bed and no enclosed volume. Some filaments require higher nozzle temperatures. Some filaments are abrasive and require a hardened nozzle.
FreeCAD. No question (or you could try the Ondsel fork of FreeCAD).Also software wise (I'm talking about design not slicer) what do you recommend? I have a bit of experience with Autocad (albiet a few years ago) which isn't massively relevant, but something that operates on those principles is probably a good start.
If your experience is 2D, you have a learning curve. 3D design for print requires careful construction to ensure the surface is completely defined, so the typical workflow is to create the design from 3D primitives by addition or subtraction – it is not a case of drawing each surface and connecting them together as you might in a conventional engineering drawing. It's almost like reproducing the steps in a machine shop: eg take a cylindrical billet and lathe a profile into it, then weld that onto a plinth of some sort.
Re: Hello - new to this game and looking for advice
Thanks for the detailed response some really good practical info there. I had hoped things could "just work" in 2024 but I guess that would be too easy!CrazyIvan wrote: Mon Dec 23, 2024 10:39 am IMO the most important thing to realise is that 3D printing doesn't "just work".
Do you have any specific recommendations model wise for beginners machines on a low/medium budget.
Re: Hello - new to this game and looking for advice
It can't and never will, simply because of the process.luke2152 wrote: Mon Dec 23, 2024 10:32 pm I had hoped things could "just work" in 2024 but I guess that would be too easy!
I have no experience of any specific machine, but from what I can see they're all much of a muchness except for the accessories available. Bamboo offers a wide range of build plate materials, for example. There are loads of reviews on YouTube, and user forums for the different manufacturers, so have a good look around for pitfalls before you decide.Do you have any specific recommendations model wise for beginners machines on a low/medium budget.
Re: Hello - new to this game and looking for advice
I just checked out the Ultimaker Factor 4 industrial printer. It has a fully enclosed and filtered temperature controlled build volume, heated bed, nozzle temperatures up to 340ºC... and costs £20k.
But they still boast only 95% print completion rate.
Go figure.