Wednesday, 26 August 2015

Netfabb - On Line Cloud Service ...

A recent comment regarding mesh repair on my STL to STEP blog entry reminded me I was going to record some steps on STL mesh repair using MeshLab, beyond those detailed here in a previous post. By accident, in checking for additional background material on STL issues, I came across Netfabb Cloud.

Netfabb STL Repair Cloud Service
I have been using Netfabb Basic (now version 6.3) since first getting involved with 3D printing. I was introduced to it by FabLab in Manchester, my first exposure to 3D printing. Finding it a particularly useful tool, any development is of interest. The free portion of the cloud service is intended for non commercial use only. Which happens to fit nicely with my most of my current usage. Do keep this in mind though if you intend to consider non commercial application of the service. Netfabb's web page on their cloud offering and client base is also quite interesting.

Presumably as this is the first time I have attempted to use the service, it asked me to log into the Microsoft cloud service. As I predominately use Windows at home (mainly for the children) the server prompted me with my Microsoft account details. It also wants access to other details of my Microsoft account, as far as I  have discerned to date, being no more than I have already supplied Netfabb.

Following the logon process, I was invited to upload a file. I elected to load Thing 64549. I didn't expect significant repairs; however as I have used this file a number of times it seemed like a good starting point.

The service was indeed simple to use. The welcome screen details the steps the service will walk you through and as there are only three steps, with no options apparent. It seems to be a case of it's either going to work or it isn't!

Once a file has been processed, perhaps a further over simplification, on the down side. There doesn't appear to be a status report of what the process has done to the file in the repair process! I think its a first for me, an application hasn't reported on the changes made following processing. I tested some files with known issues and found no status reporting. I haven't tried constructed test error STL files at this point. Below is what I was expecting to see, based on the Netfabb website:
Screen From Netfabb Website

Interestingly the cloud service stores uploaded files, I couldn't find details of how many files would be stored. To use the service, web access has to be available of course and the ~3 Mb file uploaded took around a minute to process. So no noticeable improvement over the locally installed version. Perhaps the file wasn't large enough to allow demonstration of any processing improvement. As there was no status report, I can't tell if its done 10 times more in the same overall time.

As my 3D print server is currently a Windows XP machine, I could see this service being useful on my system or with Linux based print systems such as a RASPI. Certainly, it would be cool to push models through the service seamlessly.

Here's a section from the Microsoft description of the service:
"The Model Repair Service is a solution tailored for the business process of 3D Printing and Additive Manufacturing. It is designed to automate and manage large volumes of 3D-model data to let you focus on the value adding processes and applications of your business.

The Model Repair Service can automatically address a large amount of tasks that normally would be handled manually and will reduce your costs while improving your speed of handling, quality and review of the data.

The Model Repair Service can import and export files on a number of 3D formats including STL, OBJ, 3MF and others. The server software evaluates incoming files for errors and determines main properties of the files.

File analysis:

    Main dimensions, volume, surface area, outbox volume
    Number of triangles, border edges, shells and holes
    Degenerate faces and self-intersections


If desired, Microsoft-netfabb Cloud Services will automatically repair the files with a success rate of >95%.

Repair functions include:

    Stitching triangles
    Closing gaps
    Close holes
    Repair invalid orientations
    Remove self-intersections
    Remove shells with negative volume
    Remove double triangles
    Remove tiny shells
    Triangle reduction

API Connection

The API Connection enables the Model Repair Service to import and export files and file data to and from a user defined database. This is an essential function for production management, pricing, and quoting.

It will be interesting to see how the service develops.

Finally below are screen shots of the steps followed:

Initial NetFabb Cloud Service Page

NetFabb Cloud Service - Microsoft Cloud Service Login

NetFabb Cloud Service - Account Access

NetFabb Cloud Service - Upload Action

NetFabb Cloud Service - File Selection

NetFabb Cloud Service - Upload Progress

NetFabb Cloud Service - Download Ready

NetFabb Cloud Service - File History
NetFabb Cloud Service - Terms And Conditions Point

Sunday, 2 August 2015

Huxley #710 - NinjaFlex First Production Parts ...

Here are the first production parts printed on Huxley #710 using NinjaFlex Midnight.
Huxley #710 NinjaFlex printed parts.

There are three printed parts. Two end protective bump caps and a flat elastomer seal. The seal is 0.5mm think (two layers) and is the thin black line you can see running down the side of the case. At this thickness its not fully opaque.

I am pleased the seal printed so well, it also serves to accentuate the lines of the box so other colours will have to be checked out when I have the funds to acquire some more NinjaFlex.

The seal has additional functions, such as applying a spring force to the PCB to keep it in place. The rib that runs along the PCB in the image below applies a force to the PCB holding it nicely in place.

The holes in the end of the case allow for mounting brackets to be fitted using captured M3 Nuts in the case. The elastomer boot has holes to allow access to the captive nuts and to allow the antenna connector to pass through.

The NinjaFlex in the image below was printed on Borosilicate glass and you can see the beautiful finish on the surface of the seal. The opposite face is textured as you would anticipate for a printed part.

Huxle #710 NinjaFlex Gasket Seal

Saturday, 1 August 2015

Huxley #710 - Does NinjaFlex...

NinjaFlex is a flexible filament based on a Thermoplastic polyurethane. Unlike the PLA normally used in Huxley #710 this material has a low hardness of 85A Shore. Making it possible to make soft buttons, bump stops, vibration isolation mounts, stretch covers and shoes (apparently).

Huxley #710 Does NinjaFlex
 I used Talpadk’s Blog and the NinjaFlex website to start configuring Slic3r rev 1.2.9 for Huxley #710.

The short story being, I could not get the higher print speed settings recorded in Talpadk's Blog to run for me. Either the feed would fail or large blobs were evident on the surface of the part. After a DOE, consisting of 20 printed parts. I ended up with a much slower print speed and very short retraction that produced very acceptable results. The NinjaFlex shown is Midnight, which is brightly lit so I can see the state of the print.

The printed part exhibits good tensile strength and elasticity, especially for a part I have printed myself. My eldest son was unable to break the part ~110N! Although it did suffer permanent deformation of ~30%. For an elastomer part this is usual, so the achieved performance was very pleasing. (For scale, the print is 20 mm square, 1.0 mm thick  and 4.9 mm high. Given it's a soft part and I don't have optical measuring equipment, there is large uncertainty in the measurement. However it seems very close to the nominals of the test part, the wall thickness and shrinkage are very acceptable.

Huxley #710 uses a bowden extruder, so the short retraction length surprised me. I suspect this is due to the low feed rate keeping back pressure in the extruder down. Back pressure might arise as a soft filament is somewhat compressible and has a tendency to buckle. Talpadk's higher temperatures will reduce the viscosity, allowing higher feed rates. However, I kept the feed rate low primarily as higher feed rates caused the filament to jump out of the filament feed mechanism too frequently. A tweak to the clamp bracket might reduce this by forming a feed groove. As I am busy designing and printing, the current settings seem like a good compromise.

Nozzle diameter 0.50 mm
Filament print temperature 220 C
Glass bed surface temperature 40 C
Print speed 8 mm/s (all layers currently)
Traverse speed 150 mm/s
Retraction speed 5 mm/s
Retraction distance 0.4 mm
Layer height 0.4 mm
Perimeters 2
Print outer perimeter last