Peter Rust Rusty Pete Show full post »
JonD
Hi  Coaster,
Excellent post.  Many thanks for sharing your experiences.  I suspected that simple photogrammetry scanning  would come with some serious "issues" especially for our types of applications where we require precise and unambiguos accurate .stl files for slicing and printing.  

So yes,  still awake,  and very keen to hear more about your experiences with  the Einscan and SLA printing. 
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Peter Rust Rusty Pete
hi Coaster
welcome to the forum
Thanks for the input, and l am sure that l speak for others when l ask you to please continue with your advice.
Pete
More than one way to skin a cat ðŸ˜‰
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Bunkerbarge
Interesting to see at the Great Electric train Show this afternoon that there seems to be more and more vendors offering items in 3D printed format.  I saw some very nice coach kits and I bought a lovely little kit of an 00 scale lever rack for detailing the insides of a signal box.  Lovely detail but rather expensive.
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AHJAY
I am interested in your scanner experience...

Ahjay
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Coaster
Thanks for being so welcoming everyone, and it is good to know that my observations and experiences  may be of help to others.

So onto the scanning bit.After coming to the realisation that photogrammetry was not really going to be suitable for what I was doing, I looked more closely at scanners. What a minefield! There are a lot out there, and it is hard to compare as they all seem to be slightly different both in the way they work, scanning accuracy, scanning size and some are portable (handheld) and some desktop.
The first one to get my attention was the Next Engine, from the US. Despite ordering one and sending several emails, nothing much happened.They seemed to be having some sort of mid life crisis and couldn't supply one, despite still advertising products for sale.
Next was the David SLS3, a German scanner which by all accounts produces excellant results but, despite Teutonic thoroughness, appeared to be a pain to set up and use.
Quite expensive too, and not versatile, requiring recalibration every time it is moved.They were taken over a couple of years ago by Hewlett Packard and the scanner is now known as the Structured Light Pro S3. Incidentally an American company called Physimetrics have their own brand Phy-Scan scanner at a better price, and appears to be identical.The base priced unit is ok but the optional second camera and turntable are recommended(of course) which quickly ramps the price up.I have bought products from Physimetrics, they seem to be  a reputable company.
as an aside they have 'industrial' digital cameras, which look like a little box with a lens on the front.No knobs, dials etc just the basics. The photo booths that companies use to scan people use 50 to 70 of these cameras, all fired simultaneously to 'freeze' a moment in time.
There are lots of scanners, from tiny tabletop units , conversions from Xbox motion sensors right up to industry standard units at industry prices.
The two main types are Structured Light and Laser- they work in similar ways but Structured Light seem more affordable (if that is the right term.....)
I have just bought an Einscan Pro 2X Plus scanner, upgrading from an Einscan Pro Plus which I have had for 2 years.
It works by shining a structured light onto the item to be scanned, the light is reflected back to the sensor and the point cloud is generated by triangulation to produce a 3D image. 
The new scanner is quicker , can scan a bigger area but resolution is about the same. The big difference is ease of use, the new software is brilliant!
I have the optional Industrial Pack, a flash name for an automated turntable.There are 4 modes- single scan, auto with turntable(which has registration targets on it), free scan rapid and free scan HD.
I rather naively thought that buying the scanner would be 'the silver bullet' but not so.There are limitations, most of which can be overcome but it has taken a little while to get good results.
Ok so we want to scan something. It has to be light-ish in colour, preferably have some texture or defining features, non reflective and must not move! Also a dimly lit room is good, sunshine or even daylight  is no good at all so you can't scan outside.Another major drawback is that I have a desktop PC not a laptop, and the scanner only works while connected, so at the moment it is not mobile.Also it uses mains power, admittedly to power a transformer which drops the voltage but there is no battery pack available yet.
I had fabricated some model components and wanted to scan them. Think what happens when you shine a torch at something-the back part is in shadow.
The scanner is doing exactly the same thing, so for that reason a fixed setup using a tripod to mount the scanner and an automated turntable makes life easier .Generally 4 runs of 12 to 18 scans will cover most things.I have a couple of bases made up from black styrene sheet to support parts to be scanned, black does not scan. Really. Anything black is invisible to the scanner, so this saves a lot of editing to remove 'outliers' which otherwise would be included.I generally scan an item, turn it 180 degrees then flip it and do two more scans, turning between.
It is important to get as complete a scan as possible, because when you come to create a mesh during processing, the software will fill any missed bits with what looks like something an apprentice welder might produce at his first attempt. (apologies to apprentice welders!) It is possible to clean it up later but just more work.
For bigger items I have only used the Rapid mode. A garden statue was easy, it is of  cast concrete and very textured.By textured I don't mean the surface finish, but it is an item with all the surfaces varied so the scanner can easily track as it scans.
Conversely a smooth, flat or featureless item will fail. Easily remedied by adding 'targets', little self adhesive markers in a random pattern so the scanner can find its way around.
This is starting to look like an advertisment for Einscan, sorry about that but it is the only one I have any experience with.I have seen Artec, and Creaform scanners being demonstrated at an engineering expo a while ago, but they are aimed at industry and priced accordingly.(I registered and attended  the expo. I'm a painter by trade. The only piece of machinery familiar to me was the coffee machine😁
I will take some photos of the subjects  tomorrow to compare  with the scan results , and also  some to show how the scans actually print.
I'm new to this posting thing, should I have started a new thread or just carry on with this one?
Cheers Trev
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AHJAY
Thanks. It is an interesting subject. The Einscan is one I am looking at so very interested to see the comments. Have you compared results betwen laser and white light scanning - or is the real world budget difference too big?

As to the thread, up to you. Perhaps a thread for scanners separated from printers would be useful though.

Cheers, Ahjay
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Coaster
Hi Ahjay,

Yes the professional grade laser scanners are very expensive, one I saw being demonstrated was $25,000 and that is the budget model, $60,000 for the next model up. They looked very nice though.....

Cheers Trev
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