Toe Stud Module

"An engineer can do for a dime what anyone else can do for a dollar" - Anonymous


The board which holds the toestuds comes out as a single module, now that I've removed the extraneous wiring.

As shown here, the Crescendo is on the right and the swell on the left.  However with a 3 manual instrument, you want two boxes.  As the Crescendo doesn't work very well on Hauptwerk, and in the world of infinite memories, it seems a crutch, I'm using these two shoes for Swell and Choir.  Of course, the positioning is vital, so I created a dummy shoe at the right height as the Crescendo shoe.

Workarounds

The scanner I'm using takes 32 inputs (4 groups of 8) and 3 analog shoe inputs.  The mechanisms on these shoes are essentially a set of contacts engaged by a ground plate.

So I've worked around it by building a microcontroller which scans the inputs from the shoe mechanism, then outputs a PWM to create an analog voltage (which goes into a scanner which then converts it back to a digital signal).

Seems convoluted, but it preserves the simpler interface of a single MIDI combiner.  It also leaves all 32 inputs open for pistons.  I have 8 from the manual (see previous post), and 15 from the toe studs.  A side benefit is that because I'm filtering the output of the PWM, there is some inertia in the interface, which better emulates the real action of a shutter mechanism.

The previous picture shows the old crescendo mechanism, now the swell shoe.  The old swell mechanism, now the choir shoe, is connected to the digital to analog microcontroller blob attached to the board. I picked off 8 inputs from the crescendo mechanism (swell shoe), and 8 from the swell mechanism (choir shoe). You can also see the "crescendo" dummy shoe in place.

So the result is as follows

Labels are coming. Now the only module to do us the stops, and I'm waiting a couple of weeks for the new USB versions. 

Modular is better, I think

I have made a lot of progress on the console.  At this point, I'm waiting for parts.

Modularity

 I've decided that consoles are big because of the wiring used in old technology.  I've decided on 3 manuals for this console.  I believe I can make this console with the following relatively easily transportable modules:

1) Keyboard stack - This includes the 3 keyboards.  Outputs here are 2 * 4 pin cables for the keyboards, and an 16 conductor ribbon cable for the pistons.  The 4 pin cables are arranged  one for the bottom two, one for the top one because of how the scanners are designed, using the BBS-1K scanners from www.midi-hardware.com.  I've "prepared-for" the fourth manual.  installing all of the ribbon cables but not the scanner in the old Zimmer SW manual.  There's a big scratch on the keys in the center of the keyboard, so it's less than desirable.  BTW, I think "prepared-for" is organ builderese for "You don't have the money for this, and you probably never will, but I'll put this in to make you fell good about it".  So essentially, this module is done.  I have put handles on the side of the stack to allow for easier moving.

This is built such that the keyboards flip up for contact maintenance and repair 

2) Pedalboard.  The output here is a MIDI connector, and a 5V power cable.  This module is done.

3)  Pedal piston module.  I'm planning on this to have all of the pistons (10 generals and PREV on the left, 3 Ped divisionals, NEXT and Zimbelstern on the right).  Outputs here are 2 16 pin ribbon cables for the 16 pistons, and 2 2-pin cables to interface to the shoes.  Also here would be the expression pedals.  At this point, I'm thinking of just a Swell and Choir shoe - in fact, one shoe with both on it should be sufficient.

4) Stop tab rail.  Given that I only have 26 SAMs, and new ones are $33 each (plus $15 engraving), the <$12 all-in per stop cost for lighted rockers makes way more sense.  (I'll probably develop the MIDI driver circuitry just for experience)  I'm planning on 80 lighted stop tabs from www.midiworks.ca.  Two rows of 24+16 (SW, GT/Solo) and (Ped, CH).    This configuration will fully support the CUI Casavant.  They are coming out with USB interfaced modules, so I'm waiting on those.  If they get delayed (I'm an engineer, I know how this works), I may just go back to the MIDI interfaced ones, though the USB ones would make the interface a whole lot cleaner.

4a) The music desk will be attached to the stop tab rail on the top.  LED lighting strips, with separately controlled brightness, will be attached to the top (music) and bottom (key desk) of the desk.

5) A collapsable, or at least disassemble-able table with alignment pins for the keyboard stack and the pedalboard.  I'm deciding if I should hack apart the Zimmer console to use the wood, or design from scratch.

It's all about ground

The keyboards from Ryan Ballantyne feel nice, however once I started to use them, the contacts were intermittent.  Given that I put multiple contacts in parallel, it seemed incredible that they wouldn't work.  So I played with cleaning the contacts, to no avail.  Then I looked at the grounding.  The key bars are grounded through a ground wiper in back, and through the return springs.  The return springs are soldered on the bottom side, but not on the side on the key bar.  For the intermittent keys, all I had to do was solder the springs, and instantly the keys worked reliably.  I only soldered the ones that were problematic.  I may regret this later, or I may just go back and solder the rest.  Keys in soldering these 1) use flux, 2) protect the felt pads from the hot key bar - I used a small piece of wood.

Cable Dressing

As in everything else in this project, the second one is better than the first one where you are trying to figure out how to make it work.  Guess which one I did first?

Pistons

Given my experience with my existing console, the only pistons I think are necessary are generals, pedal divisionals (just a few), and NEXT.  Other controls, not necessary to be on the keyrails which are necessary are Memory 000, Memory +10, Memory -10, Memory +100, Memory -100, and system power off.  I will also add lighting controls Music Desk +, Music desk -, Pedalboard+, Pedalboard -, and Keydesk+, Keydesk1.  So to that end, I built two piston keyrails using the pistons from the Ryan Ballantyne keyboards.

Choir piston keyrail: Set, Next, General Cancel.  The good thing here is that the keyscanner that I used from www.midi-hardware.com has 64 inputs.  61 are used for the keyboard, so 3 are left over and can be used for these three pistons.

Gt piston keyrail: Generals 1-8, Next.   I'm not doing 1-10 - I'll put 1-10 on the pedal pistons.  8 pistons just look better in this group.  Next was put into the keymatrix, and the 8 generals go out to a separate scanner through a ribbon cable.

This weekends work will be in finalizing the key stack, and working on the pedal piston/shoe module. 

2 manuals, three or four?

I was able to complete the electronics to drive the stop action magnets - somewhat.  The drivers work, but the MIDI logic doesn't.  My adaptation of the Midi-Hardware LED lit switch driver to this structure didn't work.  If I move forward with this, I'll probably do the entire structure - from MIDI to SAM drivers, without a third-party MIDI interface in the middle.

As well, there are only 26 SAMs.  26 tabs is barely adequate for a 2 manual instrument, and will be entirely inadequate for a 3 manual instrument.  So I believe for now I'll abandon using the SAMs in favor of lit rocker tabs.  More on that later.

This weekend, I dropped off the pipe driver parts and electronics with Ryan Ballantyne, and was able to pick up 2 keyboards from him that he wasn't using.  The plan was to put one keyboard onto the two I had, however these keyboards feel WAY better than the plastic Zimmer keyboards that are on the console, so I want to use both of the new keyboards, and 1 or 2 of the zimmer keyboards.

But what would I do with one leftover keyboard?  Should I build a 4 manual console in this tiny shell?

They'll fit, but stoptabs will be another problem.  Options here are the sides (which have room for rows of 8 across) and a box built on the top just below the music desk.  Still working on the design here.

It's amazing what electronics have done to how the organ is built, even pipe organs.  This organ build who knows when, has 3 sets of contacts for the top manual and NINE sets of contacts for the bottom manual.  The contacts are moved in and out of connection with a key bus bar by pallet magnets, and there is a GIANT bundle of wires coming out. 

Fortunately, all of this can be removed, and replaced by scanning electronics which reside at the keyboard, allowing a cable of 4 wires to carry all of the relevant information from the keyboard to the rest of the system.  I forced the contacts in the "ON" position, and wired across 3 in the top manual and 4 or 5 in the bottom manual for redundancy.

It only takes 2-3 hours to wire up the ribbon cables, and results in a fully self-contained keyboard.  No giant cables running from it, and it can easily be unplugged and removed for maintenance or whatever.

Why am I doing this?  My wife wants to know.  Of course, she's amazed any time someone buys my Hauptwerk sample set.  It's a weird and esoteric hobby.  Maybe not as esoteric as something like making your own paper, but it's up there.

Pedalboard and Reed switches

Reed switch are a pain.  Though they create a reliable connection, the switches themselves are delicate, and it seems like magic as to what will and won't trigger them.  Sometimes, magnetism seems kind of magic anyway, so, no surprise.

As with most things, experimentation and making mistakes teaches us the better way to do things.   Initially, I set the switches crossways

And measuring carefully, just set the magnets into the pedals

But as you can see from the ones with 2 and 3 magnets in them, there's more magic in them than I at first thought.  So I found some great double sided tape in the garage (finally, a use for the random stuff that I've collected over the years), which allowed me to move the magnets until they worked, then glue them in place.

The next thing I tried was to set the switches 90 degrees from where they were.  This worked WAY better, as they were further apart from each other and had fewer interactions to worry about.

Whenever you use reed switches
1) Buy extras - the glass tubes are fragile
2) Figure out a way where the reed switches - all parts of them - are as far away from each other as is possible
3) Figure out a way that you can move the magnets around until they work well.

Video of the pedalboard in action to come soon.  It's a busy week coming up.