Material and printing quality for small mechanical parts

Hello,

I'm working on project, which smallest mechanical assembly consist of 9 parts with common scale 40x40x50 mm, smallest part is 32x32x9, pins around 4-2.5mm, driven by 3 small 200 steps bipolar stepper motors 20x30mm with 24-35V power to accelerate mass about 50-200g for each part, with short and high speed movement around 5 messages per second from control application with Arduino Due microcontroller

I need advice about material like PLA, ABS or maybe something else, correct printer and printing method to get strong parts able to support short range of movement degrees, mostly less then 180 degree, but with high speed, manage with weight of parts and have a high resolution to be able maintain a mechanical movement process in such small assembly

I do not own any printer yet, and don't have any kind of practice with it. In the future, I think to get ZBOT or Ultimaker, not sure, which one is a proper choice in my case. But for now, to order 3d models printing for someone else, first of all, I need to find proper solution with material, printing method and desired quality

Any advice, guide or example would be very helpful

you haven't mentioned your budget, but your requirements may be somewhat extreme for the typical FDM printer. The 2.5 mm pins are going to be very challenging to create if you require any strength. It's easy to snap off a 2.5 mm pin of only 3 mm tall by touching it with a finger.

I would suggest to create your models and submit them to an online 3D printing service that supports FDM, SLA and also SLS printing, and among those three methods, use as many of the different materials as you can afford. SLS printing uses fifty micron nylon powder which makes a fine granular non-layer type structure, typically very strong and well suited for mechanical parts. SLA printers use a resin which is cured with ultraviolet light. Resin parts can also be strong, but sometimes brittle.

I believe the money spent to determine the best final result will give you the confidence to purchase the appropriate printer for your purposes.

good luck

Quote:

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Originally Posted by fred_dot_u

you haven't mentioned your budget, but your requirements may be somewhat extreme for the typical FDM printer. The 2.5 mm pins are going to be very challenging to create if you require any strength. It's easy to snap off a 2.5 mm pin of only 3 mm tall by touching it with a finger.

I would suggest to create your models and submit them to an online 3D printing service that supports FDM, SLA and also SLS printing, and among those three methods, use as many of the different materials as you can afford. SLS printing uses fifty micron nylon powder which makes a fine granular non-layer type structure, typically very strong and well suited for mechanical parts. SLA printers use a resin which is cured with ultraviolet light. Resin parts can also be strong, but sometimes brittle.

I believe the money spent to determine the best final result will give you the confidence to purchase the appropriate printer for your purposes.

good luck

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Hello

Thank you for answer

Well I'm trying to get desired result, which probably must determine budget, because I'm not quite sure about prices at all

So if I have to use SLS printing, then what the material I've to use?

I found a lot of informative topics about PLA and ABS difference, as well as Nylon Polyamide plastic, Hips, Pva and Resine

it is difficult to draw a conclusion without a practical result, but seems like to get durable and accurate parts, I should use Nylon

Then what should be the correct choice to get small size printer for small parts mostly about max 100x100mm able to print Nylon in high resolution, and easy to use, for price about 1300-1500$

Unfortunately, SLS printers are more than US$5000.00 I am inclined to agree that you should use nylon and the SLS printers will give you the best accuracy and detail. You may find it to your advantage to use a 3D printing service that offers SLS in nylon, especially if you have reasonable quantities. FDM printers use a flat plane for model placement and one would expect for production reasons to fill up the plane of the bed with as many models as possible.

SLS printers use the entire print volume. Un-sintered nylon powder from the build chamber is affected by the process and much of it has to be discarded, although a new mix with a small proportion of previously heated powder can be used. If you have many parts, they are "stuffed" or stacked or packed in the build chamber, reducing the powder loss, making high volume production more cost-effective.

I have an SLS printer kit that is not yet fully assembled. Coincidentally it has a 100mm cube as a build chamber.

I hope you meant 100 x 100 mm in your last post! (smile)

What software are you using to create your models?

Quote:

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Originally Posted by fred_dot_u

Unfortunately, SLS printers are more than US$5000.00 I am inclined to agree that you should use nylon and the SLS printers will give you the best accuracy and detail. You may find it to your advantage to use a 3D printing service that offers SLS in nylon, especially if you have reasonable quantities. FDM printers use a flat plane for model placement and one would expect for production reasons to fill up the plane of the bed with as many models as possible.

SLS printers use the entire print volume. Un-sintered nylon powder from the build chamber is affected by the process and much of it has to be discarded, although a new mix with a small proportion of previously heated powder can be used. If you have many parts, they are "stuffed" or stacked or packed in the build chamber, reducing the powder loss, making high volume production more cost-effective.

I have an SLS printer kit that is not yet fully assembled. Coincidentally it has a 100mm cube as a build chamber.

I hope you meant 100 x 100 mm in your last post! (smile)

What software are you using to create your models?

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Yes, maximal part size mostly 100x100 mm, edited, not meters :) so seems like I have to order SLS with nylon

I'm using Autodesk Inventor. For scale example, one of parts from particular assembly, stl print screen:

Attachment 11872

It's good that the program you are using will support STL files. So many programs generate files that cannot be sliced. Your attachment did not come through as valid, however.

Quote:

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Originally Posted by fred_dot_u

Your attachment did not come through as valid, however.

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Well, sorry, as I'm newbie, I'm not able to post link with image, and by some other reason does not loads image, maybe something wrong with my browser

Anyway, thank you for answers, now I know basic direction

Please post your progress for us to enjoy and perhaps learn.

Quote:

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Originally Posted by fred_dot_u

Please post your progress for us to enjoy and perhaps learn.

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I found online 3d printing service "sculpteo", I'm trying to figure out with given options, I have selected with bold text below, not sure if I've properly checked material Nylon PA12 100-120 and maybe I have to use Multijet Fusion process. I need strong parts that are comparable in density for example to old kinder surprise toys, I have one here with pin and structure same size with my part, this plastic is ideal by consistency

Process:

SLS (Plastic)
Multijet Fusion (Plastic)
Polyjet (Resine)
CLIP (Resine)
Colorjet (Multicolor)
Laser Melting (Metal)
Casting (Metal)
Binder jetting (Metal)

Material:

Nylon PA12 100-120 (White)
Nylon PA11/12 (Gray)
Nylon 3200 Glass Filled (White)
PEBA 2301
Alumide (Metal Gary)

Finish:

Raw
Polished
Dyed regular
Matte Painted
Glossy Painted
Dyed with Color resist
Dyed with Color touch
Smoothing Beautifier

If you're sure that Polished will not change the dimensions of your part and that such a setting doesn't add cost to the production, it seems to be a good choice. Glass Filled may be stronger, as it would imply the addition of tiny glass fibers akin to fiberglass material. It's starting to get out of my direct knowledge zone.

Quote:

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Originally Posted by fred_dot_u

If you're sure that Polished will not change the dimensions of your part and that such a setting doesn't add cost to the production, it seems to be a good choice. Glass Filled may be stronger, as it would imply the addition of tiny glass fibers akin to fiberglass material. It's starting to get out of my direct knowledge zone.

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I found SLS printing guide, it says all holes should be larger than 1.5 mm diameter. My minimal size is a 2.5mm, maybe I will change it to 3mm, but what I am trying to figure out, is a hole and pin size compatibility, mostly I need free rotation and cylindrical sliding. For example, if I have hole 3.2mm, my pin is 3mm, but I'm not sure, if it is not too little or not too much, how nylon behaves in this case

3.2 to 3.0 millimeter is 200 microns and that's very close fit. I think a fair approach would be to ask the service provider for a reference figure.

pet-g would work as would ninjateks armadillo. I've m
Made gears with 12 teeth, 1mm thick and 8 mm diameter. That was from pet-g - couldn't bend or break them just using my fingers.
And those were the large gears for that particular project :-)

Don't see any reason at all you can't make this yourself. Without pictures I have absolutely no clue what you are actually making :-)

But glass filled nylon is both strong, stiff and durable.

Curious, what printer have you used to make these tiny items? It now pops into my alleged mind that lado could have inexpensive success using a printer with a smaller than "standard" nozzle. A genuine Prusa with a 0.2 nozzle might give strong tiny features with nylon or petg and save a bundle of money.