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Monday 27 July 2015

Blender to STL file Export

This weekend I had some problems with the latest version of Cura 15.06.02. Cura is used to convert the 3D model files in to a format suitable for a 3D Printer.

All my models imported very small and often crashed Cura 15.06.02 but still worked in Cura 15.04.

It took some investigation but eventually I worked out that it was because Blender was exporting to the wrong scale for Cura. Cura always assumes millimeters (mm) but the older version of Cura used some guesswork when models were ridiculously small therefore hiding the flaw in the files.

There is explicitely no scale in the STL file format:

I have reported this to both sets of developers and they can work out if they need to make any changes to be more user friendly.

I have found a way to export to the correct size and have gone back and re-exported all my STL files, previously posted on this blog and on the YouMagine site.

To Export to STL from Blender 2.74

This is only applicable if you are working in Blender using the Units options set to Metric and the scale set to 0.001. Most people would do that when working in millimeters.

In these circumstances, do not use the very convenient tool box Export button if you use the Blender 2.74 scale options to display the measurement units.

Regardless of the options selected the above does not export to the correct size when scaled units are used!

Use the full menu Export, so you get the following options:

By default, 'Scene Unit' is enabled. Just disable that.

The resulting Export, should now be the correct size.

My Choice

For future models I am going to turn OFF the Blender units and just remember that whole units represent mm.

I need to experiment a bit before I know for sure how well that will work in Blender.

Thursday 23 July 2015

Little Gate

I have finished and installed the gate I 3D printed a few weeks ago.

With a few finishing touches to the ground and bushes round the gate it blends in on the layout.

I masked off areas to avoid the PVA glue and scatter grass making a mess in the wrong places.

Sunday 19 July 2015

50th Birthday BBQ

Shelley arranged a great day yesterday for my 50th birthday.

We had a few friends and family round for a barbecue lunch in the garden.

Linda, her husband, Rob and their two waitresses, Megan and Jo, did an excellent job setting up, cooking and serving us all.

Even the cats were having a good time.

The weather was perfect, warm and sunny with a slight breeze to keep us cool.

I had setup a Scalextric. That turned out to be very popular. Shelley gave out "clear round" rosettes to anyone who completed two laps without coming off.

Gwen's mum,  Gloria,  was one of the first up. She'd had practice at Christmas so knew what she was doing.

Much to my surprise and delight, Don bought me an Audi R8 and Andy and Lisa bought me a Mini with another to follow. When I got a moment I put some digital chips in so they could be tried out. The Audi stuck to the track very well but the Mini held its own.

By the end of the day the Mini no longer had it's spoiler and a wing mirror and the R8's fin was only held on one side. All easily repaired.

I got 50 boxes of Smarties from Keith and Vanessa and a T-shirt from Lee and Lisa with an appropriate theme :-)

When everyone had gone, there was only one thing to do...

In Car Phone Holder

When Andy bought Joe, his Land Rover Defender 90, it came with a 3D printed phone holder on the dashboard.

That holder was designed for something like an old iPhone 4 perhaps even a 3. His HTC One phone did not fit.

I took some measurements and came up with my own design that fitted in the same size hole in the dash.  Andy had some specific requirements and knowing where the phone displayed things on the screen, he pointed out some critical sizes to make the phone usable in the holder.

On my first attempt I made a mistake with the width so it would not fit. This was not a bad thing because based on seeing that first prototype I was able to incorporate some better ideas.

I thinned down all the uprights, reduced the thickness of the top ledge and adjusted some of the angles so they print without supports. The most significant design change was that I made the charger plug hole in to a wedge shape to grip the charging lead. A separate cover goes round the connector and fits in to the wedge.

The small two part wedge holder for the charging lead can be redesigned and adjusted to whatever shape connector needs to fit it. The body of the phone holder remains unchanged.

The second print fitted the phone perfectly.


Blend file
STL file for the phone holder
STL file for the USB connector
Licence attribution


Friday 17 July 2015

Scenic Views

The greenery is dry, the grub is vacuumed away and the track is back down.

I've squeezed in so much track there are not many flat areas to park cars. On this corner where there is some space I've cut a couple of slots so the guides of the cars drop down and the wheels stand naturally on the ground.

I have a few more ideas for little touches to add more detail but the big work is all now done.