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DRUM PEDAL PROJECT
• Nowadays, most drummers use a double pedal. Both beaters are attached to the kick-drum. The right bea...
DRUM PEDAL PROJECT
• There are basically 2 types of double pedal. The cheap ones, light but suffering from serious rigidit...
SOME OLD SKETCHES
One way to reduce the mass of the long shaft of the left pedal is to eliminate
the shaft completely by b...
DRUM PEDAL
This left drum pedal is
built from scratch. It
includes a single arm
ultra rigid frame of T-
6061 aluminum allo...
Bonded carbon, carbon ribs, aluminum pedal
Shaft details
Fully adjustable
linkage, machined
T6061 alloy. Note
the Aluminum...
RETURN
TO
MENU?
PEDAL PROJECT-2
• The pedal described earlier functioned very well and my son used it for several years until I
purchased ...
PEDAL PROJECT-2Gain
Offset
Pot
The signal from
the left pedal is
transmitted to
the servo
actuating the
beater
The prototy...
PEDAL PROJECT-2A
• The servo used in the proof of concept did not have the required
torque/speed capabilities required for...
PEDAL PROJECT-2
Rotary Solenoids
Servo
Solenoid and servo
combination
This prototype uses 2 solenoids to
improve the accel...
PEDAL PROJECT-2
PEDAL PROJECT-2
DETAILS
Solenoids
Servo
PEDAL PROJECT-2
PEDAL PROJECT-2
DETAILS
Servo
Power
6VDC
Servo
Servo PWM
Signal
RETURN
TO
MENU?
PEDAL PROJECT - 3
SEMI-ACTIVE PEDAL – CONCEPTUAL DESIGN
PEDAL PROJECT-3
In rock music, the drummer
applies pressure on the
pedal using his thigh and
calf muscles aided by the
wei...
PEDAL PROJECT-3
The pressure on the pedal
propels the beater forward,
stretching the return spring.
2
A WEAK springs allow...
PEDAL PROJECT-3
As the drummer releases the
pressure on the pedal, the
spring returns the beater to its
original position ...
PEDAL PROJECT-3
The STIFFER the spring, the
BETTER. The best solution is using
a very stiff spring and provide
assistance ...
Thin Flexible
Carbon Fiber
Plate
PEDAL PROJECT-3
The entire assembly
moves down when
the pedal is
depressed
The heavy oran...
Thin Flexible
Carbon Fiber
Plate
PEDAL PROJECT-3
The entire assembly
moves down when the
pedal is depressed
The yellow whe...
Thin Flexible
Carbon Fiber
Plate
PEDAL PROJECT-3
The inertia of the
orange wheel and
the torque of the
motor propel the
be...
Thin Flexible
Carbon Fiber
Plate
PEDAL PROJECT-3
The beater has
reached maximum
extension
Slight
Pressure
StiffReturnSprin...
Thin Flexible
Carbon Fiber
Plate
PEDAL PROJECT-3
The entire assembly
moves up as the
pressure is released
As the drummer
r...
Thin Flexible
Carbon Fiber
Plate
PEDAL PROJECT-3
The stiff springs
returns the beater
to its original
position and assist
...
Thin Flexible
Carbon Fiber
Plate
PEDAL PROJECT-3
In an instant, the drummer
is ready for the next hit on
the kick drum. Th...
PEDAL PROJECT-3
CONCLUSION
1. This design is simple. It does not requires complex electronics
such as servomotors, sensors...
RETURN
TO
MENU?
Drum pedals
Drum pedals
Drum pedals
Drum pedals
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Drum pedals

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Ideas for design of passive and semi-active drum pedals

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Drum pedals

  1. 1. DRUM PEDAL PROJECT • Nowadays, most drummers use a double pedal. Both beaters are attached to the kick-drum. The right beater is connected to the right pedal by a short linkage and the left beater is connected to the left pedal by a short linkage and a long shaft including 2 U-joints. Both beaters are connected to the frame by a return spring. The system pedal/shaft/linkage/beater/spring forms is equivalent to a torsional harmonic oscillator with a natural frequency: • 𝒇 = 𝟏 𝟐𝝅 𝒌 𝑰 where K is the equivalent torsion coefficient and I the equivalent moment of inertia. • Because of the added mass of the long shaft and linkage of the left pedal (higher moment of inertia) do not respond as well as the right pedal. It is slower and increasing the torsion coefficient makes it more difficult to operate.
  2. 2. DRUM PEDAL PROJECT • There are basically 2 types of double pedal. The cheap ones, light but suffering from serious rigidity issues and questionable durability and the expensive ones, with all ball-bearing construction and (sadly) built like a tank as, it appears, that the more massive they are and the more appealing they are to the customer. (A drummer joke?...) The moment of inertia increases resulting in a slower pedal. • The ideal pedal would have a pedal/shaft/linkages/beater’s shaft of zero mass with the total mass of the moving assembly concentrated into the beater head. • In addition, the geometry of the linkage is very important in the way the pedal feels. • The goal of the project was to design, fabricate and assemble a left pedal of minimum mass with adjustable geometric linkage.
  3. 3. SOME OLD SKETCHES One way to reduce the mass of the long shaft of the left pedal is to eliminate the shaft completely by building a single-foot double pedal. One beater is actuated by the heel and the second beater by the ball of the foot. This would be very useful for a LEG AMPUTEE drummer. Interestingly, someone beat me to it last year and a small company began to commercialize such a pedal. Sketches for unusual linkages with poor man kinematics (i.e. paper and pencil)
  4. 4. DRUM PEDAL This left drum pedal is built from scratch. It includes a single arm ultra rigid frame of T- 6061 aluminum alloy, a pedal of carbon fiber on an ultra-light aluminum frame, a light weight, fully adjustable, all ball bearing linkage and a shaft of large diameter of thin wall perforated aluminum tubing. This was my first project using a milling machine (non CNC alas, and all in inches!)
  5. 5. Bonded carbon, carbon ribs, aluminum pedal Shaft details Fully adjustable linkage, machined T6061 alloy. Note the Aluminum fasteners
  6. 6. RETURN TO MENU?
  7. 7. PEDAL PROJECT-2 • The pedal described earlier functioned very well and my son used it for several years until I purchased for him, last Christmas, a double pedal from Axis ($780, Ouch!), the only properly designed pedal on the market in my opinion. • The shaft connecting the left pedal to the beater is a large part of the problem. So, why not eliminate the shaft completely? With this in mind, I decided to investigate the possibility of an electric pedal. The left pedal becomes a sensor capturing the motion of the foot and the signal is used to propel the beater.
  8. 8. PEDAL PROJECT-2Gain Offset Pot The signal from the left pedal is transmitted to the servo actuating the beater The prototype worked well. However, the servo is not powerful enough, limiting the intensity and speed of the drummer. The motion of the left pedal is captured by a potentiometer connected to a modified servo tester wit adjustable gain and offset
  9. 9. PEDAL PROJECT-2A • The servo used in the proof of concept did not have the required torque/speed capabilities required for “spirited” play, even though this servo was one of the most powerful analog servo available from the RC Hobby community. • Larger servomotors exist (CNC milling or routing application for example) but such expensive components were beyond the scope of this project. We experimented instead with a combination of servo and solenoids.
  10. 10. PEDAL PROJECT-2 Rotary Solenoids Servo Solenoid and servo combination This prototype uses 2 solenoids to improve the acceleration of the beater. Bench Test Stand
  11. 11. PEDAL PROJECT-2 PEDAL PROJECT-2 DETAILS Solenoids Servo
  12. 12. PEDAL PROJECT-2 PEDAL PROJECT-2 DETAILS Servo Power 6VDC Servo Servo PWM Signal
  13. 13. RETURN TO MENU?
  14. 14. PEDAL PROJECT - 3 SEMI-ACTIVE PEDAL – CONCEPTUAL DESIGN
  15. 15. PEDAL PROJECT-3 In rock music, the drummer applies pressure on the pedal using his thigh and calf muscles aided by the weight of the lower leg. 1
  16. 16. PEDAL PROJECT-3 The pressure on the pedal propels the beater forward, stretching the return spring. 2 A WEAK springs allows the drummer to hit the drum head QUICKLY with sufficient force and minimal effort.
  17. 17. PEDAL PROJECT-3 As the drummer releases the pressure on the pedal, the spring returns the beater to its original position and provides lift to the pedal assisting the drummer in lifting his lower leg. The drummer must lift the entire weight of his lower leg using his thigh muscles. This is the most limiting factor in term of playing speed. 3 A STIFFER spring allows a QUICK return of the beater and provide more force to the pedal, helping the drummer lifting his leg QUICKER with less efforts.
  18. 18. PEDAL PROJECT-3 The STIFFER the spring, the BETTER. The best solution is using a very stiff spring and provide assistance to the drummer through external power for the forward motion. The drummer must lift the entire weight of his lower leg using his thigh muscles. A very stiff spring will help the drummer lift his leg quicker. 4 FORWARD action requires a WEAK spring and RETURN action requires a STIFF spring. HOUSTON WE HAVE A PROBLEM!
  19. 19. Thin Flexible Carbon Fiber Plate PEDAL PROJECT-3 The entire assembly moves down when the pedal is depressed The heavy orange wheel is continuously powered by a high speed motor StiffReturnSpring STEP-1
  20. 20. Thin Flexible Carbon Fiber Plate PEDAL PROJECT-3 The entire assembly moves down when the pedal is depressed The yellow wheel connected to the beater shaft contacts the orange wheel powered by the motor Slight Pressure StiffReturnSpring STEP-2
  21. 21. Thin Flexible Carbon Fiber Plate PEDAL PROJECT-3 The inertia of the orange wheel and the torque of the motor propel the beater forward despite the stiff return spring StiffReturnSpring STEP-3 Slight Pressure
  22. 22. Thin Flexible Carbon Fiber Plate PEDAL PROJECT-3 The beater has reached maximum extension Slight Pressure StiffReturnSpring STEP-4
  23. 23. Thin Flexible Carbon Fiber Plate PEDAL PROJECT-3 The entire assembly moves up as the pressure is released As the drummer releases pressure on pedal, the yellow and orange wheels are decoupled Pressure Release StiffReturnSpring STEP-5
  24. 24. Thin Flexible Carbon Fiber Plate PEDAL PROJECT-3 The stiff springs returns the beater to its original position and assist the drummer lifting his lower leg StiffReturnSpring STEP-6 The entire assembly moves up as the pressure is released
  25. 25. Thin Flexible Carbon Fiber Plate PEDAL PROJECT-3 In an instant, the drummer is ready for the next hit on the kick drum. The cycle is complete. StiffReturnSpring STEP-7 The entire assembly remains in the up position until pressure is applied to the pedal
  26. 26. PEDAL PROJECT-3 CONCLUSION 1. This design is simple. It does not requires complex electronics such as servomotors, sensors, microcontrollers, etc. 2. For professional drummers kick-drum speed is critical especially for rock/hard-rock/metal types of music. 3. It takes years of hard work to master this skill. 4. Drum pedal technology has not changed for the last 60 years. It has only evolved with better materials and tweaking the geometry. The biggest advance was the introduction of the double pedal in the 70’. BIG DEAL! 5. No active drum pedal have ever been developed. 6. The biggest and only challenge in the design is the clutch. The force for clutch engagement must be user adjustable and the clutch must disengage when the beater hits the drumhead. Not that easy to do well but not that difficult either. 7. THIS WILL BE A REVOLUTION. THIS WILL BE THE NEW PARADIGM
  27. 27. RETURN TO MENU?

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