The source code for the linear actuator and pump server are housed here: https://github.com/mtu-most/linear-actuator
Full instructions, documentation, data, and pictures coming soon....
Materials and Tools
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Procedure
- Secure motor into the motor end using 4 M3 washers and 4 M3 x 20mm socket head cap screws.
- Insert the 2 metal rods into motor end, then secure them in place with 2 M3 nuts and 2 M3 x 10mm socket head cap screws.
- Insert threaded rod into the coupler halfway, the other half should be on the motor, secure it.
- Hollow out the two ends of the carriage, with a handheld drill bit or knife to make a hole in the plastic.
- Snap the linear bearings into place on the hollowed out ends of the carriage. Then insert an M5 nut into the nut-trap on the bottom of the carriage.
- Attach the base of the Plunger holder to the carriage with 2 M3 nuts and 2 M3 x 10mm socket head cap screws.
- Slide the carriage onto the threaded rod and make sure the two metal rods fit into the linear bearings.
- After the carriage is midway down the threaded rod, thread two M5 nuts onto the threaded rod.
- Insert the two bearings into the circular slots in the idler end.
- Now slide the idler end onto the rods and secure it with two more M5 nuts on the end of the threaded rod. Push the two nuts already on the rod up to the idler end to secure it.
- Insert the syringe body into the body holders, then slide the plunger into the base of the plunger holder.
- Using four M3 x 40mm bolts, four M3 washers, and four M3 nuts secure the two holding pieces to the idler end of the pump. Put two nuts it the top of the holder closer to the carriage and two nuts in the bottom of the holder against the idler end.
- Insert the tab of the plunger holder on top of the plunger to secure it to the pump and prevent slipping when in use.
Calibration
- Plug the motor into the raspberry pi.
If the motor is plugged in the wrong way the pump will push when its told to pull.
NOTE: Do not plug and unplug the motor from the pi if the pi is plugged in to a power source.
- Using a mini-USB adaptor plug the raspberry pi into the computer.
- Plug an ethernet cable into the raspberry pi, then connect it to the Netgear wireless router. Then connect the router to the computer with another ethernet cable.
- Plug everything into an outlet and turn on the router. Look to see that your computer recognizes the network. Once it does, switch over to that network and open up your web browser. Type in the address bar: pi.local:8080.
NOTE: This is only the address if a version of Linux is in use. We have no practical way to get the address on Windows or Mac, however it does work on Windows and Mac if the name can be obtained.
- The site that is now opened is the pump control interface. Set it to a lower speed, then pull the syringe out slightly past a big marker. Then using tiny steps, push the syringe to the bigger marker so the plunger is exactly on the mark. Then push it 50 mm, and record how many milliliters it moves. Then divide the number of milliliters it went by the number of millimeters you pushed it and plug that number into the calibration window.