an "adult" project

  Not everything I work on in my shop is boring, ie; industrial or houseware repairs etc.  This project is an oscillating pump (push-pull) for a sexual massage device, it's a DIY clone of a machine which costs over $900 to buy new. O_O

 The pump proper is a re-purposed manual bilge pump for small boats.  I removed the valves, blocked one port, and removed the handle.

 The motor is a brushed DC gearmotor, 1/16 HP, 180V max, 300RPM max.  The original brand name machine uses a 90V Bodine, I'm using a Leeson, both are excellent brands.  Many engineers I know consider Bodine to be the premium/Cadillac brand of gearmotors.  But you will get a very well made, very long life unit from any name brand.  The voltage it runs on doesn't matter so long as you have the ability to smoothly vary the supply voltage with a good motor controller.

 The motor controller I am using is a Minarik (a popular name brand in small motor controllers) XL3025A PWM speed control, but unfortunately, the only one I could find cheap that was even close to useable... had a maximum output voltage of 130V.  Eventually I will want to replace it to get the max speed available from the motor (cheaper than replacing the motor!) but it's not a high priority.

 The proof-of-concept version I built used a $20 "router speed control" (just a basic minimum-part-count dimmer circuit with parts capable of tolerating inductive kickback) together with a full-wave bridge rectifier and a filtering capacitor.  Compared to that lash-up, the professional speed control has much better performance, some fancy capabilities mostly not useful in this application (such as braking or acceleration / deceleration rates), and much longer life / higher reliability.

 I had to machine a few parts of course, notably the crank-wheel and the part where the pushrod connects to the pump (where the manual handle was originally attached).

 The power entrance has a fused receptacle for a standard IEC cord, a power switch, and some noise filtering parts to keep electronic "hash" created by either the motor (which in theory ought to be filtered out by the speed controller) or by the switching of the controller itself.  I'm an amateur radio operator, and all forms of PWM control including light switch dimmers generate so much noise that they cause us "hams" to break out in hives.  I already had the power entrance module lying around with the switch, receptacle, and a common-mode choke, to this I added a CorCom RFI filter as well as a high voltage rated .01uF capacitor which, together with the choke, will add noise filtering AND help prevent spikes from the powerline from nuking my fancy speed controller:

 The more prurient details from projects like this will have to be found on Fetlife if you're into that sort of thing; this isn't that sort of blog. ;D