Monday, June 22, 2015




Inserts , like pins, are available in tens of colours , shapes and patterns.

Some shapes and patterns from a old Williams book:



Some of the inserts for sale at the moment:

image Image result for playfield insert
Image result for playfield insert Image result for playfield insert Image result for playfield insert



Because I use RGB LEDs, I don’t need to have coloured  inserts, white opaque is enough. The colour of the led will set the insert colour.  The insert only need to be transparent need to diffuse the LED light, so the insert is evenly bright lighting up.

I did some experiments to try to replicate patterns of inserts in 3d printed inserts, but this is difficult. The ‘transparent’ ABS is not transparent enough after 3d printing, to see the patterns on the bottom side of the insert.

The only pattern that works good enough is a circular pattern. Circular patterns on the bottom do not work, but using a low infill (35% ) circular pattern works quite well. That is because it is close to the surface of the plastic, so it is still visible from the top.

The other insert that works well is the plain and pattern less one.

The diameters of inserts are some imperial diameter. Because I only have metric drills, I changed the diameters to metric. I used the following diameters: for circular inserts 19mm, 25mm, 30mm and 40mm for the arrow.

Here some examples

insert_plain1 insert_circle insert_star
insert_arrow inser_circle insert_worst


The result

Some inserts just printed on the Mendel90 3d printer. The heated print bed is a bit uneven due to the many layers of glue-stick on it. Occasionally I will smooth the glue with some water when it gets too rough.

For the real prints of the insert that go in the playfield, I will print it on glass coated with ‘slurry’. Slurry is ABS dissolved in acetone. Things printed on slurry get a very smooth bottom. This will make the top surface of the printed insert as smooth as glass.


You can see the patterns on the bottom of the inserts with various patterns.


I glued some inserts in a bit of plywood with normal PVA glue.  This works very well. I could not push the insert out of the wood. I am surprised that the PVA glue does adhere to the ABS plastic so well.  Later on will try epoxy glue too, see how that works..

Here the test board from the bottom. The holes are 25mm the whole depth of the hole, without a ridge like real playfields have. Possible the ridge will hold the insert even better in place. Something to try out too.


The plastic part screwed on the bottom is a LED holder. I will write a blog about that later.


I will make some pictures with the inserts lighted up.

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