Solder paste dispenser for less then $5

thingiverse

Solder paste dispenser. Its a try to create a solder paste dispenser using cheap components from aliexpress. I've got my inspiration from https://www.thingiverse.com/thing:384680 and design it from a scratch. The biggest improvement is the plunger system. You'll need: - arduino pro mini ($1.5 delivered) - stepper motor with a driver board 28BYJ-48 ($1.74 delivered) - 5mm to 5mm coupler (1$ delivered) - M5 nut - M5 threaded rod 73mm long - power jack - tactile button - wires - some self tapping screws You'll need a serial adapter to program arduino. Notes - connect the coupler so that threaded rod will push against the shaft of the motor; - if You have to, adjust the plunger scale so it will go in to the housing without any drag; - since the uln2003 have almost 2V dropout, use at least 7V power adapter to power the motor. I use mine with 9V, but works also with 12V; - I've design it for a working length, so I can put new paste in and extrude all of it. Should work with any solder paste, but I use it with aliexpress MECHANIC XG-Z40 ($3.5 each) - do some failing on the plunger and the socket, so its smooth; - wiring you can figure out from pictures and arduino sketch - glue the m5 nut in the plunger, so it wont come out during retraction. If the socket is to tight, heat up the nut. Some throwbacks: - its uncomfortable to hold. The motor is mounted far of where you hold it, so its unbalanced. - if there is a lot of solder inside syringe, then the pressure builds up and need much more retraction so solder wont drip out after releasing the button To improve - change the coupler, so the whole body would be shorter, possibly some elastic hose would work fine - shorten to body, and move motor closer - maybe change the design so it would be half the travel, and after dispensing half the paste , take the paste out and place an extender for the plunger. That way the body could also be shorter. - add a potentiometer to change the speed/retraction length. - design custom PCB - adjust screw hole size and depth, all holes for PCB mounting. - software could use some improvement In the end it improved the work to apply the solder for project for which I don't have a stencil. Designed using Fusion 360 http://a360.co/2A1AaFL