Elvira House of Horrors Crypt Facade by grabul

Last crawled date: 3 years, 3 months ago

Replaces the crypt front plastics of an Elvira House of Horrors Stern pinball machine with a 3d printed facade. The print consists of five skull heads having leds in the the eyes.
The dead head signboard is iluminated from behind by the existing led in the crypt.
(Note: it seems that the download all button doesn't work, please download the files separately)
General:
The leds are 3mm and connected to the GI (general ilumination) of a node board of the pinball. I recommend to use larger series resistors (>=470 Ohm, details see instructions below). The power consumption is therefore very low (<20mA for all 10 leds!) so there is no risk to damage the node board. But In any case I do not take any responsibility for any possible damage. Use and build the mod at your own risk!
All parts a printed with black filament, except the skulls are printed in white. But since you have to paint it anyway you can use any filament color you have available.
Instructions:
First of all: One should already have experience in soldering and a certain basic understanding of electronics to be able to build all together. The wiring is very fiddly due to the small dimensions. Also we have to use enamelled copper wire which is harder to solder. Sometimes it is not easy to remove the enamell.
The original plastics is completely removed and replaced by the 3d printed facade.
The 3d print consists of several parts: the facade, the dead head signboard, 5 skulls and 4 mounting nipples are printed separately and then glued together. For a precise bonding there are corresponding adhesive engravings in the print.
In the mounting nipples you have to press a nut to srew the facade with the rest of the crypt.
The mounting nipple exists in two versions: one for 3mm nuts and one for unc 4-40 nuts. If you have unc 4-40 nuts available the you can use the original existing screws. Otherwise you need 3mm screws in black color to replace the original screws.
For the 3 skulls mounted on the stelas there are 3 tiny cover plates available to glue from behind to close the soldering area.
As an option you can also print the gate, but I didn't like that anymore, because it is too coarse and doesn't fit together with the movable counterpart of the mechanics in the crypt. In the end I simply photographed the original and printed it with a color printer on paper and glued it on (all-purpose glue).
First step is to paint the parts with acryl paint.
Before you start painting you have to pre-treat the 3d print with a plastic primer. It is important to mask all glue dots with masking tape, otherwise you cannot glue the parts together anymore. Use a plastic glue for gluing.
I printed all parts with a black filament so I have black contours at places where I don't apply any acryl paint.
Once you have painted everything you can start with the electronics. First wire the skulls on the stelas. I used 0.35 mm enamelled copper wire everywhere. The three upper stelas have a small channel on the backside through which you have to thread the wire. Then lead it through the front opening and solder the skulls. Inside one skull there are two 3mm leds, which are connected in series. Be aware that you check the polarity of each led and connected the anode of one led with the kathode of the other! (one leg is longer than the other, this is the anode).
The opposite leads (an anode and a kathode) have to be soldered very close together. The remaining two outer connections are soldered with one enamelled copper wire each. When the skull is soldered on, then carefully pull both wires back from behind until the skull has reached 1-2mm at the glue point. Do not glue until everything has been wired and tested.
Solder and fit the skulls for the signboard in the same way, do not glue them yet.
The signboard must still be specially prepared: From behind a self-adhesive window foil (green) is stuck over the lettering. The foil is matted so that the illumination from behind is even. The best way is to put a white layer over it with airbrush, but it also works with white acrylic paint and a brush.
Each pair of the leds of one skull must be connected in series with a suitable series resistor. Since the 3mm led are quite bright I use for a red led pair (at the stelas) a resistor of 560 Ohm and for a green pair 470 Ohm (at the dead head signboard). The resistors are located on the back side underneath the signboard in extra recesses. You have to use ¼W resitors so you can press them easily in the recesses.
In the free space below the resitors you have to put a cutted piece of stripboard: two tracks are needed for + and - connections. First solder two wires (red for +) and (black for -) on each the tracks of the stripboard and thread the wires through the hole of the left side of the facade.
Then you can connect each wire pair of a skull to the stripboard. Take care about the polarity of each skull.
Before you glue the skulls, the sign and the skull cover plates on the facade check the electronics and apply 5V to the leds. If you have no laboratory power supply unit then you can use 3 AA batteries in series.
Do the first check NOT in the pinball machine otherwise you can ruin the node board if you have a short circuit in your wiring!
Cut the gate printed on paper so it fits into the free area on the front side beneath the dead head signboard. Glue it with an all purpose glue.
The last step is to protect the paint with an transparent acryl varnish spray.
Happy printing and please let me see your version especially how do you have painted the facade.