Printout with finish

[kurtm]

Hi everybody,

I need 3D printed details for a low-volume product. I would need around 50 pcs/year.

I have tested a lot of printers, especially printers that is said in tests to have good quality such as Ultimaker 2+, but I have not found anything that is OK yet.

The thing I need is a small case for electronics with windows for LEDs. Ideal would be a 2-material print with the LED window in transparent material. But I would be happy with a single material with holes where I put in LED windows. I would prefer to not do any surface treatment on each piece.

The material should be something that will last for many years. I have used ABS in most prints. I feel uncertain about PLA, but there may be other materials that will work.

What I want is reasonably regular surfaces. It doesn’t matter if the layers are visible as long as there is no big variation X/Y from layer to layer. But it seems that if there is a disturbance in a layer such as a hole, this will cause things to happen all around that layer.

I suspect that this has to do both with the slicer and the position accuracy. I am attaching pictures of a 2 material print with LEDs, same with the LEDs out and one with 1 material. The black is ABS in all photos.

It would be very nice with some suggestions about hub and/or printer and/or material.

Best regards

Kurt Mirdell

[cobnut]

Hi Kurt, you really should be able to find better quality than the items in the photos with something like an Ultimaker 2+ or many other printers. Do you know what settings were used for these examples? I’ve printed several items with holes with a precise required dimension and they’ve been spot on.

One other tip would be to print onto glass as this will give the bottom layer a nice glossy smooth finish which looks great for the control surface of a device.

[Perry_1]

Those are simply not good prints. This is a result of several things, including the fact that they are just not good prints.

Since printers is an ambigous term, I will refer to Persons and Machines…

If the person is not good with ABS settings and such, this will be the result. The ABS is shrinking differently when the layer with the holes is being printed, than not, and that is why you are getting the warping in that area. A good person will not produce prints that look like that.

The issue is not that most machines print layers differently when there are holes, the issue is the person setting up the print is not doing a good job, or the machine they are using is not good at printing. But a person who knows how to handle ABS and has a good machine will give you a better print.

Next, consider PLA. Yes, theoretically, ABS holds up better than PLA in heat (a slight difference), and works better when the item has a hinge, because ABS can take a few more bends than PLA, and ABS cannot be shock broken as easy.

But the differences are so minimal, that I would advise you to directly go to PLA. ABS is a material designed for extrusion molding, so it is specifically designed to shrink from the mold. As such, it is more prone to warping and shrinkage while being printed. PLA crystalizes as it cools, and as such, is more exact to the original digital model. For an electronics case, PLA is often a more perfect material, and unless this is an item that will be in an automobile, or direct sunlight, or has a hinge, or is going onto a quadcopter, I would recommend PLA for a perfect, durable, long term item that prints without shrinkage or warpage.

That being said, I would still suggest that the ABS print you are showing was done poorly, even an ABS print should be better than that, by alot. It is simply a poor print. (even so, I would still recommend PLA)

Finally, I can’t be sure how large the print is by the pictures, but it looks extremely small. As such, it seems to me if you need 50 in a year, 3d printing is a good option. I can print small parts inexpensively, as I have some printers with several print heads that can print at once. Or, if you want to print in small batches as you go, such as when orders come in, than 3d printing is a great solution. Also, if you see yourself making changes as you go, 3d printing is a great solution. But just as an FYI, if you know you will be using 500, then you want to go with extrusion molding.

If you want to discuss this further, or if you want to share your model with me so I can advise you further, contact me https://www.3dhubs.com/cleveland/hubs/perry. You can upload the model for a quote or just start an enquiry.

[kurtm]

The dimension are is 29 x 13 x 23.6 mm. Layer height is 0.1 mm.

[Arthur_13]

Some times it’s good to use resin casting for small volume.
Make a best finish on one model, create silicone mold and cast black resin with same finish over and over.
Check https://www.smooth-on.com/, they have all you need and for finishing 3D printed parts to.

[3DMatters2Us]

Hello. Have you considered SLA over FDM printing? The FormLabs printer I use can go down to 25 microns in resolution. The prints will look much better than the examples in your photos. It cannot do multiple materials in the same run. However, (as someone else suggested) if you print the lens for each LED as a snap-in piece, they will look much better. In clear, the SLA prints from the FormLab can be polished very clear (of left frosty for a more diffused lighting effect). I’d be happy to quote you on an example if you like. When you look at my hub, you will see examples of some really small items with incredible detail. Have a great day. Todd.

https://www.3dhubs.com/concord/hubs/3dmatters2us

[Regulus3D]

I Agree the quality of the prints in the photos are simply poor even for an Ultimaker 2. The printer I use produces really nice smooth prints from the off, One thing though, you will not get great transparency using translucent filament, I don’t think it will allow enough light through for the LEDs- I see that it appears you have 3D printed the LED windows in place. You will get a better finish by sticking with one material, I suspect the disturbance may be caused by the led window material you have introduced (as it may not be the same as the body - Let me know If that is the case)

I can also print these for you if your interested - drop me a quote see https://www.3dhubs.com/oxford/hubs/thomas

What size is your enclosure? Is there any IP ratings required for the enclosure? (Dust/Water ingress?) What is the expected lifespan for the product? and does it need to be rugged? - These questions help to determine the material requirements - If a certain amount of ruggedness is required - go with ABS, After all its an industry standard material for Electronic enclosures.

Hope that helps?

Tom

[Regulus3D]

Surely the cost of SLA will out be so much more than FDM?

[Enza3D]

Kurt,

As Perry said, these prints really don’t display the quality that ABS is capable of. ABS is finicky in comparison to PLA, but can be printed nicely if the printer operator knows how to compensate for for the issues that commonly arise from using ABS (warping, de-lamination, etc.). A hole or gap in the model should not affect the final result all that greatly; 3D printing is not nearly as accurate as machining or molding will be, but a hole designed to a certain specification should be able to be printed be reasonable accuracy (generally +/- 0.4 mm).

For the transparent window, you’re probably better off printing small transparent squares and just popping them into the case once it is done printing. However, you’d get better visual clarity and a more professional looking product using small cuts of acrylic or Plexiglass for this instead of printing them. For the actual material of the case, unless you are exposing this to sunlight, the difference between PLA and ABS will be minimal for you. I prefer PLA for electronics casings simply because of how much more accurately it prints details, and how much nicer it is to work with. If you really want the material properties of ABS, you could try printing with PETG. PETG is much nicer to work with than ABS, but is closer to it materially than PLA is. What is the end application for this? Is it encasing electronics outside (quadcopter, RC car, etc.), or is it just a nice housing for something you developed that designed for indoor use (print server, Pi housing, etc.)?

[Enza3D]

It most definitely will be. I think printing in SLA only makes sense here if he wants to use them to cast a mold out of silicone, then just make as many as he need by polyurethane or epoxy resin casting them.

[Enza3D]

While molding and casting is definitely the more efficient way to go (will also be more consistent), it might be difficult for an inexperienced caster to cast this particular model. This won’t be a one part mold; he’ll need to do each half separately and join them, which isn’t hard, but from his pictures it looks like there’s holes elsewhere on the model (besides the LED window) that will need pins in the mold to cast properly. Center marks could be added for these locations and the holes could be drilled fairly easily instead of casting them and then it’s just a simple two-part mold.

I do think this is a better way to go than trying to print 50 of these a year, but it will require a bit of learning and work on Kurt’s end. Although I suppose he could just find someone to make the mold and cast them for him.

[3DMatters2Us]

On average, it is more. However, it sounds like he wants to move from a prototype over to something closer to a production ready part. Getting a master using SLA, then going to a silicone mold does make sense. The overall costs would be less with a production run of 50+.

[kurtm]

Thank you very much for all your answers.

The detail is for a product that should be used indoor. Lifespan would be 10 years or more. The electronics is battery operated, and there are no demands for IP rating. There are 4 other details in the product, one similar, the three others simpler. So my total is 5 different details, 50 per year of each. 50 per year is an estimate.

I also believe that best method would be to 3D print the details in one material and then add laser-cut acrylic plastic for LED windows. But it would be nice if it could be done as a two-material printout.

The printouts in the photos are not made on an Ultimaker 2+, but I have made printouts on one that was better but still had many similar defects.

I got an offer in Sweden for casting in polyurethane that was rather expensive. As I understand it, you need vacuum equipment to make casting reasonably good. But it certainly is a possibility.

To do injection molding, I would need 5 tools (it might be possible to put several details in same tool). I don’t want any draft, so the tools will be expensive,

The suggestion to use PETG sounds interesting. I am also thinking that with next order request, I can add photos of how I want it to look and how it shouldn’t look. I have printouts that looks nice on one side.

Best regards

Kurt Mirdell

[Arthur_13]

Thanks, also it’s always good to learn some simple technology for makers.

May the youtube be with you.

[Enza3D]

Having a company polyurethane cast will be more expensive than 3D printing at first, because of the cost required to make a mold, but after that it really shouldn’t cost much more. I’d solicit a few more offers if you can and make sure you’re not being price gouged a bit by them. The nice thing about molding, is once the mold is made, it’s really only the cost of the object material and the company’s time that’s left to pay, unlike 3D printing where the cost and time more or less stays the same per part regardless of how many you print.

For the volume you’re doing, injection molding will be overkill (and much more expensive). If you were talking making more than 300 or so over a short period of time, then injection molding makes sense because the cost/part balances out.

PETG is really nice stuff, I actually just placed an order to get some more of it after how well using the samples from my printer manufacturer worked. It produces really nice prints, and isn’t that expensive either. I’d suggest looking at some other co-polymer filaments and seeing what you think of them (PETG is a co-polymer as well) as compared to ABS; Colorfabb XT, MadeSolid PET+ and Taulman T-Glase are some well known ones.

[Oscar_svensson]

Hello Kurt!

The print quality in the attached pictures looks quite bad for most printers, especially ultimakers and such.

I would say that your best, and simplest option, would be to find someone who can print your part from PETG, since that material doesn’t have the same issues with shrinking as ABS does. As for the windows, the best way would probably be to laser-cut them in truled plexi which would diffuse the light so that the whole window light up equally instead of having a dot in the center.

I’m based in stockholm to, so if you are interested, contact me on my hub (https://www.3dhubs.com/stockholm/hubs/svensson-d-sign) and I’ll print a sample and cut some plexiglass for you.

Best regards

Oscar Svensson

[Enza3D]

No problem!

[Henrik_Petersen]

[xpandedreality]

Hi Kurt,

my 3D shop at Sveavägen in Stockholm can help you. We are working with solid blocks of real materials, like aluminium, wood and platsics, to make end products in small runs. And if you need prototypes, we make those with FDM 3D printing.

Give me a shout via my Hub if you are interested!

Best
/Lamin