3D scanning

[Smouser]

I have some small items I would like to scan with a 3D scanner if it is viable.

The goal is to be able to 3D print very accurate copies of the originals.

Who are the 3D scanning boffins lurking on this site?
Is it even realistic/possible to scan items accurately enough to replicate at home/via a hobbyist?

See the items below I would like to get scanned.

 

[ajlelectronics]

Well I bought quite an expensive one, but never really got anything like I needed from it. The model that they supply as a sample was about the only thing that worked for me!

 

[Onoff]

Well I bought quite an expensive one, but never really got anything like I needed from it. The model that they supply as a sample was about the only thing that worked for me!

I'll give you a tenner for it...

 

[Onoff]

£20 then...

 

[Mart63]

I have had a 3D scanner at work for years but never got particularly good results with it. We have just purchased a Creality Otter, but not had time to test it out yet. To be honest we got the best results with a free phone app called Kiri Engine. You have limitations with the free version, but we still got a very high level of detail. You do have to take a lot of pictures with it that are then processed in the cloud. I'd definitely give it a try, it might be good enough for what you need and also free. I don't think the paid version was terribly expensive.

 

[Onoff]

My lad managed with his phone, a then Moto G4, 5, 6? Took a hundred or so photos. Some clever algorithm filled in the missing bits.

Real ornament on the left, scan on the right:

https://flic.kr/p/2ncjpz8

Render:

https://flic.kr/p/2ncjymi

Model:

https://flic.kr/p/2ncitsm

Print:

https://flic.kr/p/2ndAqk5

 

[daedalusminos]

Yes it is possible it depends what sort of results you're after and how much post processing required.

I generally use the scanned model to create a parametric model.

 

[hotponyshoes]

I've messed around with them a bit.
For something like the cow head (no critical dimensions and hard to draw) they work fine.

For something like the parts in your photo, it would be quicker and more accurate to measure and draw from scratch.

 

[Smouser]

I have had a 3D scanner at work for years but never got particularly good results with it. We have just purchased a Creality Otter, but not had time to test it out yet. To be honest we got the best results with a free phone app called Kiri Engine. You have limitations with the free version, but we still got a very high level of detail. You do have to take a lot of pictures with it that are then processed in the cloud. I'd definitely give it a try, it might be good enough for what you need and also free. I don't think the paid version was terribly expensive.

I heard we also have a 3D scanner (unknown condition\age\accuracy) at work but allegedly they don't have the software. There MIGHT be a possibility that I can borrow it for a week at some point to try and have a go at home.
I am not particularly interested in taking 100's of photos to try and render the pieces.

I would rather try to use a 'proper' 3D scanner / send them to a hobbyist on here to scan for a few beer tokens.
'Professional' 3D scanning services online look to be rather expensive.

From my limited 'research' it seems that the newer and more expensive scanners improved significantly over the last few years.

 

[Mart63]

Another option would be to make silicone rubber molds and then use a fast casting resin like Xencast P2 or P6. Xencast is available from Easy Composites. Silicone rubber from DWR Plastics.

 

[Ali]

I've messed around with them a bit.
For something like the cow head (no critical dimensions and hard to draw) they work fine.

For something like the parts in your photo, it would be quicker and more accurate to measure and draw from scratch.

This. Ideal for organic shapes (used widely in dental and medical worlds), but for something with typical engineering geometry you’re wasting your time unless you have a spare £500K or so.

 

[Smouser]

Another option would be to make silicone rubber molds and then use a fast casting resin like Xencast P2 or P6. Xencast is available from Easy Composites. Silicone rubber from DWR Plastics.

Mmm, that might be an option.
However, if I am going through the trouble of casting, is it not better to then just cast them in metal?

Who are the casting boffins on this site?

 

[Mart63]

How about making molds in high temperature resistant silicone rubber (DWR Plastics) and casting with pewter (again DWR Plastics) or KA Low Melt Alloy (Tiranti)

 

[Agroshield]

See the items below I would like to get scanned.

A scan is like a photograph: a raster item. When you zoom in too far, it does the equivalent of pixellating.

A 3D model made using measurements is a vector item: it is perfectly defined at every scale.

Why, in particular, do you want to scan those cams? Even with a £20k scanner, the results will be less accurate than measuring and drawing them.

95% of the shape you can measure using calipers. The other 5%, the cam profile, you do using a dial indicator and rotary table.

You have reminded me I need to upload the rest of the information to your Brierley thread. I will snap a picture of the fixture I used (I could send you the one I used but it is easier to make it in place once the RT is centred under the machine spindle than to align a pre-made one).

 

[Bki26]

Could always diy a cmm setup lol

https://www.reddit.com/r/ender3/comments/hbe5ud/i_turned_my_ender_3_into_a_manual_coordinate

 

[jmp49]

That article should be titled "I turned my Ender 3 into a (manual) coordinate measuring machine shaped thing which to non technical people looks good"... Or are we back to people printing to 0.01mm tolerances in plastic and measuring it with digital calipers territory...

 

[hotponyshoes]

Could always diy a cmm setup lol

https://www.reddit.com/r/ender3/comments/hbe5ud/i_turned_my_ender_3_into_a_manual_coordinate

I've got a cmm arm, it's great for what I use it for but I would imagine taking any more than a dozen measurements at any one time would be tedious.

Something like the 3d printer mod with an auto-scan mode would be ok but it will still just give you a drawing with loads of points (each with an amount of error) that you have to join together somehow.

There may be other, better ways but, for the parts in the first thread, I still think it would be quicker and more accurate to draw them from scratch.

 

[Agroshield]

...it will still just give you a drawing with loads of points... ...that you have to join together somehow.

If you have a file with a million (x,y,z) coordinate triples in it, it is about four lines of Python and 2 seconds run time to make an STL mesh out of them. So that bit in and of itself is not so challenging.

But a mesh is a mesh - difficult to modify and difficult to scale because it is 'raster' (discrete) rather than 'vector' (continuous).

As you point out, it is getting those million points of data in an efficient way that is hard to do without expensive automatic kit. Again, as you say, an engineering-type object is generally better drawn from scratch.

 

[hotponyshoes]

If you have a file with a million (x,y,z) coordinate triples in it, it is about four lines of Python and 2 seconds run time to make an STL mesh out of them. So that bit in and of itself is not so challenging.

Easy once you are set up to do it..
I was referring to the op's first post, doesn't sound like he has a 3d scanner so the time spent selecting one then finding/installing software etc...
Quicker just to draw.
Although if he plans to scan loads of various things in the future it might well be worth looking at other methods!

 

[jmp49]

I've got a cmm arm, it's great for what I use it for but I would imagine taking any more than a dozen measurements at any one time would be tedious.

Something like the 3d printer mod with an auto-scan mode would be ok but it will still just give you a drawing with loads of points (each with an amount of error) that you have to join together somehow.

There may be other, better ways but, for the parts in the first thread, I still think it would be quicker and more accurate to draw them from scratch.

For your portable arm (faro, romer etc), you can get laser scanning probes that mount on pcmm arms, and they are a lot more accurate than the stuff we're talking about in this thread. I have a perceptron laser scanner mounted on a pcmm that I'm working on the perceptron side to get going. The idea is you sample higher precision ordinate points such as bearing mounts and holes and dowels etc with the probe providing definite points to a high tolerance, then use the laser part to scan profiles and shapes to go into a mesh.
These are often use these in production line quality inspection with the laser scanner to check profiles and probed points with the probe & for reverse engineering stuff. But they're not hobby kit prices either. As soon as anything has that level of precision, the price reflects the amount of work and care that has to go into it of course.