Cab Head Update (with some general advice learned from over a decade of cab use)

[scottacus]

I built my pin cab called "Multiball" over a decade ago and I was never completely happy with the head.  I used a three screen setup with a small DMD TV and a larger screen for the backglass.  Quite a few months ago I built a ZeDMD and held it to the front of the head with butcher twine for about nine months just because pulling the head apart and rebuilding would be a lot of work.  Here's a summary of the update and what I've learned over the last dozen years about cab design...

In the last couple of weeks I took on the task of updating the head.  I found a 32 monitor that was 1/10" too wide for the head so I used a router to cut a recess in the inside sides to allow the monitor to fit in.  I then designed a holder for the monitor arm in F360 along with two angle brackets, printed those and used a maple cross beam to support the monitor.


 

I then took a sheet of polycarbinate and masked and painted the back with black paint to make an opening that restricted the viewable area to an aspect ratio that matched most backglasses.  You can use any paint you like because since the paint is on the back, the glossy front of the poly will make the finish high gloss black.  This is a great trick to use on things like arcade monitors and pin cabs.

 

When I first started out in VP I stretched playfields and BGs to fit my screens but later realized that not only was I distorting the artwork but changing the way games played.  This sheet of poly does two things.  First it restricts the viewable area to a nice aspect ratio and second it puts a clear glossy finish in front of any BG artwork just like on a real pin.  I think the addition of this makes a somewhat subtle but huge difference in appearance.

The DMD and speakers were done as a separate sub assembly.  Here my biggest advice is to put in threaded studs to slide into the speaker mount openings and hold the speakers down with nuts rather than trying to hold the speakers down with screws inserted through the mounts into some sort of grill.  My speakers have a 3D printed ring that holds LED strips for lighting the speaker grills as well.  Trying to hit holes in a grill through a speaker slot, past the lighting ring, through the back glass panel and into an external grill was a bit of a challenge.  Mounting on studs eliminates all of that.



I designed and printed new external speaker grills that had a low profile so that they would not interfere with the head laying flat on the side rails when the head was folded down for transport.  Another lesson learned over the years is make sure that your head can sit in both the upright and folded positions without having anything interfere with these positions.

One thing that really bugged me was that I used an external subwoofer speaker grill and a surface mounted arcade on/off button on the bottom of the cab.  This meant that I could not slide a lift cart under the cab for moving it around without first putting 2x4s that spanned the cab so that the lift cart did not crush the grill or button.  I picked up some decorative stamped metal grill and recessed the power button in an old air vent hole so now I can use the lift cart without any problem.  HUGE improvement.
 

Here's what the new head looks like.



The photo doesn't do justice as to how bright and colorful the ZeDMD is.  Massive improvement over the old TV.

And the entire cab.



Quick tour of photos shot while the playfield TV was up.  The cab runs on Pinscape and has 10 contactors, under playfield speakers, head and under cab LED's, five flashers, side addressable LEDs, shaker motor, knocker, chime unit, lighted buttons, plunger with CCD and plunge button.



Details on how to make grills like on the speakers or the enclosure for the power supply can be found here.
https://pinside.com/pinball/forum/topic/one-way-to-make-custom-parts-with-grids-and-grills-on-them

One last thing, if you have anything that uses PWM that can make an audible sound and is not run at 100%.  Consider adding a bit cap across the input to smooth out the PWM and eliminate any "growl" that might occur because of the square wave PWM.  You can see one on the shaker motor and the fan on top of the head has one as well.

 

[bord]

Love the black bezel around the screen. Stretched backglasses are a real pet peeve.

[scottacus]

Thanks!  Not only does the clear poly set an aspect ratio that is close to the real thing but it eliminates the step off from the front of the backglass plate to the tv screen and also puts a high gloss finish over the bg art.  Two things that all real pins have.  Putting clear poly over the ZeDMD makes it really look like an old school plasma DMD only brighter and in full color.

[JFR1]

16 hours ago, bord said:

Love the black bezel around the screen. Stretched backglasses are a real pet peeve.

Ha!! One of the first pics I posted of my cab back on Vpin, had the Air Aces bg stretched. Bord politely mentioned that there were ways to resize. 

Thanks for the continued amazing contributions you two provide to the community.