---Build an Organ instructions 2
Continued from previous page (29th dec 2007)
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This Pipe Organ has now been sold on e-bay
It plays very well off both keyboard and / or midi filer (supplied).
THIS IS HOW IT WAS BUILT.
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Fitting the chest Magnets / Diodes + wiring etc- .
You will need "two" 1N4007 diodes for each chest magnet (see photo).
I use 6's x 3/4" Black Japanned Slotted Screws to mount the magnets.
DON't use screws with a tapered head.
Check each magnet before actually fitting, make sure there is at least 1mm gap between the armature and the lever (photo),and the spring is fitted correctly.(photo).any other adjustment is made after the magnets have been fitted.
Fit the 1st Magnet,when the screw is tightened the small "Teeth" on the magnet mounting will dig into the wood, after the screw has been fully tightened make sure the pallet can be lifted by at least 1/8", if it cannot , then adjust as follows.You can also adjust the "lift" by screwing in or out, the felt & leather pallet.
The mounting bracket can be bent slightly, BUT follow this procedure --.
Using a pair of reasonably strong "long nose" pliers, grip the mounting bracket "below" the hingepin,then pull the actual coil on the magnet UP slightly, now check the amount the pallet opens. For minor adjustments you can screw or un-screw the pallet.
DO NOT BEND THE MOUNTING AT THE HINGE
This will cause the hinge to "stiffen" and it may stick,Just make sure the chest magnet works freely.
Do this for all the magnets.
Solder the Supression diodes across the magnets terminals, make sure the ( + ) positive end of the diode faces the mounting screw.( The positive end is the one with the silver "ring" around the diode.)
Also solder the "blocking" diodes, "negative to negative" as shown on the photo below.The blocking diode is necessary to block any feeds from the other rank finding their way "back" and operating the solenoids on this rank.
Fit the common positive wire, this goes to each solenoid coil of rank 1.
Rank 2 has its own common positive.
The ends of these two common positives go to two seperate switches , these are the STOP switches.
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The Midi Decoder used gives out Negative "pull down" signals and these are connected to the diodes on the negative end of the solenoids.
I use 64 note midi Decoders supplied by www.j-omega.co.uk , They come with "Full" installation instructions.
The power supplys I use have multiple voltage output, although a single supply of 12 volts D.C. is OK.
I use 12vdc for the decoder and 17 to 18 vdc for the Chest Magnets.
This is the AIRFEED pipe.
windchest underside
windchest to , (note marking)
rackboard mounted (note the pillars) I have used 6.
Rackboard Pipe holes
tapered grinder, & Rotary rasp.
Inside the windchest,note the markings and centrelines
Again, inside the windchest.
bottom cover for the windchest (MDF)
diodes fitted to the magnets.1 suppression, 1 blocking.
the GAP here should be around 1mm
The Magnet spring, (This is the positive end of the coil)
Note the "teeth" on the magnets mounting plate. and the cheesehead Black screw.
If needed, Bend the mounting plate using long nosed pliers HERE.
30th DEC 2007 -All 100 magnets fitted to the main windchest
100 Magnets fitted, There will be a seperate Bass winchest with another 24 magnets.
All main winchest magnets fitted with diodes 31/12/2007
Note Polarity of diodes, also the positive common feed wired to the rear of the solenoids.This braided wire connects All the solenoids for 1 rank, each rank has a seperate positive common, these go to the stop switches, so you can switch on or off each rank.
The 4 -25pin "D" type plugs ALL now wired to solenoids.(1st JAN 2008)
All main winchest wiring now done (sorry it's a bit out of focus)
Testing completed 2nd jan, found 1 solenoid not working,and 3 of the pallets under a pressure test leaked.removed the windchest bottom, found one diode fitted incorrectly, and reseated the leaky pallets.All now OK.
wiring ready for electrical testing.( essential,before fitting windchest bottom),Any faults or mistakes should be found and remedied before continuing. (1st JAN 2008)
Decided to fit a 4' foot stop and a 2' stop. More details of this combined Power supply / Midi decoder / Diode matrix and multiple switches will follow on the next page later this week.
There are also 61 small relays on this unit
These are the solenoid coils for the two64 note Multiple Switches.
5th Jan. Electronics now completed & Tested. I will publish the circuit diagrams of this complete unit when I have the chance to do so. It is complicated and all the diagrams are "In My Head" at the moment.
The 12 wooden BASS pipes (C3 to B3)
4 of the Metal Bass pipes (C4 to D#4)
The Bass winchest will carry both the Waldflute & Principal pipes. 12 of each rank, it is built in exactly the same way as the Main windchest.
The other 8 Metal Bass pipes mounted on windchest top. (E4 to B). I will be using "support" rails approx 2/3rds of the way up all the pipes on the bass chest.** Below is the Bass chest with pipes mounted.
