Servo adapter for Saurons Iris Dust gate

thingiverse

INTROAs an extension of Sauron’s excellent Iris dust gate system I designed a very small add-on feature to enable attaching a servo. By attaching a servo it was my intention to enable microcontroller operation of Closure and Opening without removing the possibility of reverting to manual operation at a later date.Huge thanks to Sauron for his design …. https://www.thingiverse.com/thing:3561833Enormous thanks UKHeliBob from the Arduino IDE Forum for his code and education in the art of Arduino/Servo programming. He managed in 10 minutes what I couldn’t do in 2 weeks !!.PARTS REQUIREDAn Arduino Uno R3 or compatibleThe adafruit 16 channel PWM Servo Shield or compatibleA beefy 5v DC power supply with at least a few amps to power the Arduino, Shield and the servosSG90 servo(s) (however many to match how many dust gates you need)SPDT toggle switch (however many to match how many dust gates you have)50mm of stiff connecting rod (extra long sowing pins are ideal)M2 nuts and boltsBUILDPrint Saurons design without the handle and using small ends only. Noting that this add-on is for the small ends only. I didn’t do one for the large end as Im using 40mm pvc waste pipe for my dust/chip extraction. From top looking down (where the iris opens turning the pegs anticlockwise) pick the most unhindered peg, that is the peg that moves without any of the iris wings passing beneath when opening. Anti-Clockwise from that is where to pick two screws to attach the servo mount.You will need cut off the peg below the mount to allow for the servo axis to sit unhindered.Attach the servo to the mount with the axis to the left with M2 nuts and bolts.Attach cable to the servo and the Arduino Sheild at servo position 0 taking polarity into considerationAttach a cable to the common and one of the other pins on the SPDT toggleAttach the toggle switch common pin to GND on the shield and the other switch lead to Digital pin 2 on the shield (do not use digital pins 0 or 1)Upload the attached code to the Arduino noting that the adjustable bits are as follows:a) Each switch is equivalent to a servo; the servo on position 0 will be switch pin 2, servo 1 will be switch pin 3 and so on, only number in this order and only if being used via the line:byte buttonPins[] = { A2, A3 }; where “A3 and A2” are the equivalent numbered digital input pins on the shieldb) The angle of open and closing can be adjusted via the line(s) :pwm.writeMicroseconds(servoNum, 1000);(generally speaking I have mine set at 500 and 2000 respectively) Note: that changing this will change for all servos. However adjustments to this the connecting rod and the servo armature should lead to the most efficient opening and closing or the iris. Test the servo and its movement without fastening a linkage.Use grease to lubricate all touching and moving parts.Once you are happy with the movement in relation to the peg, you will need to judge and fashion a connector depending on how youve set it up. I heated a long sowing pin with a blow torch and pushed it through the peg I was using first.I was looking for the widest amount of movement between opening and closing to avoid dust traps. NOTEAfter live testing in a system I discovered that stress upon the two ends of the inlet and outlet pipes put too much friction for the servo to servo to deal with so it is recommended that both 40mm inlet and outlet pipes are bracketed and mounted to the wall to give the iris unit freedom to operate indpendantly. CONCLUSIONIf you think I’ve missed anything please do not hesitate to get in touch and Ill endeavour to help if possible. Enjoy.