Technical Information for Direct-Action(tm) Pallet Valve
DM-1 and DM-2 Valve Instructions
Patent # 5,608,176
rev. 08/25/97
Read Completely Before Installation
Direct-Action(tm) pallet valve action
The Direct-Action pallet valve is designed for the pipe organ industry for both new organs and restorations. It offers significant reduction in "pallet valve bounce" and "pallet valve pop." The angular motion of the pallet valve provides a gradual opening and closing rate for the pipe toehole. It also provides an environment for improved initial pipe speech and closure.
The angular motion of the pallet valve provides superior performance in high wind pressures.
The Direct-Action pallet valve comes in two models, both with 70ohm coils. The DA-M1 is used for pallet valves 3/4" and smaller. The DA-M2 is for pallet valves larger then 3/4". The DA-M1 armature is restricted to 3/16" travel with a felt bumper. The DA-M2 armature is allowed to travel a full 3/8." Prompt and responsive pipe speech is improved by using the correct model pallet action.
The pallet valve action assembly is attached to the windchest toeboard using a sheet metal screw of #8 by 5/8". The screw may be pre-installed by inserting into toeboard. This procedure is made easier with LOC-1, our clear plastic screw position locator with crosshairs and a hole through which to mark screw location.
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It is important to position the magnet so the final resting position of the pallet valve edge is near the inside armature end. Large pallet valves( > 3/4" ) will extend beyond the outer armature end when glued in place. This technique will give maximum pallet valve lift and prevent pallet valve binding against the toeboard. |
Note: Never use a pallet valve smaller than 9/16" diameter.
Note: Break the edges of windholes where the pallet valve rests on the toeboard with a 45 deg. stone or sandpaper.
Note: Use only pallets supplied by KADAK. The animal fat content in most domestic leathers will cause pallet valves to stick to the toeboard.
Note: See pallet valve size table to assist in selecting sizes
Adhering Pallet Valve to Armature
Pallet valves should be 0.285" to 0.310" in total thickness. Due to expansion of the felt while in storage, the valves may need to be compressed. This is easy accomplished by pounding them with a block of wood on a flat clean surface. Once the pallets valves are attached to the Direct-Action assembly, they will retain the correct thickness due to the armature spring tension.
With Direct-Action assembly mounted in the wind chest, lift armature away from toeboard and position pallet valve with GL-1 adhesive on it into place. Hold valve in place against toeboard with fingers and gently press armature against pallet valve. Go to Install page.
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Pallet valve positioning for pallet valves 3/4" and smaller |
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Pallet valve positioning for pallet valves larger then 3/4" |
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HINT - to facilitate magnet adjustment, place the pallet valve to be adhered under the armature without adhesive to test preliminary adjustments. Do not use the same pallet valve to adjust another magnet as the pallet valve may have a different thickness do to manufacturing tolerances. Install the pallet valve used during adjustment on the action that was measured.
Adjusting Magnet Frame and Pallet Valve
Adjustment of the pallet valve is very important for optimum pipe speech. The goal is to adjust the magnet frame to limit the pallet valve travel. The ideal adjustment is to limit the pallet valve travel to provide just enough airflow required for a given toehole size. If the travel of a small toehole pallet is excessive for a given toehole diameter the pallet valve my bounce upon closing and provide slow response. Likewise, by not providing enough travel for a large pallet valve there may not be enough airflow for the pipe.
The following formula will provide correct pallet valve adjustment, ( d / 2 )2 / d = h, where d is diameter and h is height. The pallet valve travel should be measured at the centerline of the toehole.
| Toehole diameter | 1/8" | 3/16" | 1/4" | 5/16" | 3/8" | 7/16" | 1/2" | 9/16" | 5/8" | 11/16" | 3/4" |
| Valve movement | 0.03" | 0.05" | 0.06" | 0.08" | 0.1" | 0.11" | 0.13" | 0.14" | 0.16" | 0.17" | 0.19" |
As you can deduce from the above table, the amount of movement of the armature is little. However, this is theory only and does not take surface resistance or any other factors into account. The table and formula is presented for curiosity only. These valve height dimensions are optimum and should be used as a guide. Experience will allow the installer to make adjustments by eye.
IMPORTANT - while the adhesive is fresh, immediately adjust the magnet frame and magnet pole as follows:
View the overlap between magnet pole (figure 1, B) and armature (figure 1, C) The armature should overlap pole (figure 1, B) by about 0.05" minimum. If overlap is incorrect, bend the frame (figure 1, A) backward or forward to adjust. For small valves the overlap may be more.
For reference only, Not Field Adjustable - view the gap between the end of pole (figure 1, B) and armature (figure 1, C). Gap clearance should be 0.008" to 0.013". If clearance is too close the armature may bind during operation (clicking noise), if too wide, the armature may not pull pallet valve completely open or not at all. If clearance is incorrect, do not use the magnet. Return the magnet for replacement. There is a method to correct the gap, but return is preferred.
When adjustments are complete, check to see that pallet valve is still aligned properly over toehole and seated FLAT.
IMPORTANT - The pallet valve must seat with the toeboard in
a perfectly flat position. Visually test this by gently lifting the armature away from the toeboard and then gently
return it. Do not let the pallet valve return with force. When in the rest state there should be no visible gaps
or lifting of the pallet valve edges from the toeboard. If pallet valve is not seated properly there are two options.
One, check to see that the pallet valve is the correct thickness and replace with correct thickness valve. Two,
bend the magnet frame an point A in figure 1 by moving it backward or forward. This adjustment will require that
all previous adjusting methods be rechecked. Experimentation is the only way to master this adjustment.
Adjustment of spring tension should only be made after pallet valve adhesive has cured. There are two methods to adjusting spring tension. The first method will affect pallet valve tension against the toeboard. The second method will affect the tension that holds the armature into the magnet frame.
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To adjust pallet to toeboard tension, bend the L shaped end of spring (figure 2, F). Do this by holding the spring with needle nose pliers near the corner and bend with finger for new tension. Close the bend for more spring tension and open for less. Note: it only takes a little to produce great affect in tension. To adjust armature to frame tension bend the spring wire (figure 2, E) that protrudes through the spring tag by holding the main part of the spring and bend short tag wire for new tension. The spring uses the magnet frame tag to pivot against and hold the armature in place. Close the bend for less spring tension and open for more. |
figure 2 |
Note: The spring should naturally rest about an 1/8" from the end of armature before insertion.
IMPORTANT - do not adjust the spring mounting TAG as this will affect both pallet valve and armature tension and create more problems.
Always use a suppression diode in the driving circuit. Many solid state relay systems already incorporate them.
Direct-Action Mounting Positions
The magnet is shipped with spring tension for the mounting positions shown in figure 3. To mount in first position shown in figure 4, the spring tension needs to be changed. Do not mount in the second position shown in figure 4 as this position may have potential opening problems due to friction.
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figure 3 |
figure 4 |
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Both positions OK |
Left view needs radical spring tension change. Right view may have problems |
Pallet valve mounting positions for valves 1" in Diameter and Larger
For maximum air flow past pallet valve, adhere the armature as shown in figure 5. The pallet should be mounted in an offset position in relation to the toehole. This allows the pallet to move forward when open and allow superior air flow into the toehole.
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Symptom |
Cure |
| Action does not reiterate quickly | Armature travel may be to great for pallet valve size. Reduce travel by bending frame toward valve. Pallet spring tension may be to weak. |
| Ciphering occasionally occurs | Pallet spring tension may be to weak, or pallet may not be perfectly flat just as it touches toeboard upon closing. |
| Ciphering is continuous |
Check for dirt between valve and toeboard. Check to see if pallet valve is laying flat against the toeboard and completely covers and seals toehole. Pallet valve spring tension may be to week. See 'Adjusting Spring Tension' in the instruction sheet. |
| Magnet action makes clicking noise when ACTIVATED | Check the spring tension that affects armature to frame tension. Armature spring tension will most
likely need to be increased. See 'Adjusting Spring Tension' in the instruction sheet. Check the clearance between the armature and magnet pole. They are most likely touching when energized. Even though they do not touch when moved by hand, they may touch due to bending of magnet frame. Armature to magnet pole clearance should be 0.010" to 0.016". If not, return magnet. |
| Magnet action makes clicking noise when RELEASED |
Check the spring tension that affects armature to frame tension. Armature spring tension will most likely need to be increased. See 'Adjusting Spring Tension' in the instruction sheet. Test the suppression diode, if it has failed clicking will occur. If everything checks out ok, return magnet to factory for replacement. |
| Pallet valve bounces |
Check both armature and pallet spring tensions. Most often the spring tension is too light. Pallet valve travel may be to great for pallet valve size. Reduce travel by bending frame toward valve. Pallet valve adhered to armature in wrong position. See 'Distance to toehole center' table in instruction sheet. |
| Pallet valve does not open |
Check magnet coil resistance at the relay connection. This will determine if both the coil and magnet wiring are functioning. If resistance is correct, check the armature to magnet pole clearance, and armature to magnet pole overlap. See instruction sheet for specifications. Check to see if pallet valve has a tendency to stick to toeboard. Sometime the sealer or finish that has been applied to the toeboard will have residual tackiness that keeps the pallet valve closed. If this is the case, apply Baby Power or Talc between the pallet valve and toeboard. Test the voltage at the magnet coil contacts. It must be sufficient to operate magnet. |
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