Skip to content

Laser Fabrication, 

a

Soldering, 

a

Electrical and Mechanical Components

 

 

 

 

Objectives

  • Complete your tape follower vehicle, in preparation for Lab 5 (PID Control and Tape Following)

  • Practice your electronics soldering skills

  • Continue work on laser cut parts/files for your Gesellenstück  

 

 


Lab Part 1 – Mech Construction of Tape Follower

 

Continue to build your Tape Follower.   You are expected to finish construction as described in the video by the end of the lab.  

 

Links below are from “Labs and Lectures” page.

 

Your completed Tape Follower will also have two QRD sensors, two motors, and one TINAH attached to the follower.   Instructions for motors and QRDs are listed below.

 

Once fabrication is completed, start playing with your tape follower: Write some basic code to turn on the motors. See if you can make it run in a straight line. Write code to use the TINAH display to see useful information from your QRD sensors about if, when, and how much they are detecting black tape. 

 

 

Lab Part 2 – Soldering and Desoldering

 

1.   Plan on approximately 45 min of time to practice these skills.   There are 2 irons for every 4 people, so you are expected to share.   

 

2.  Review the following videos for soldering

 

 

3.  Gather materials for soldering practice

You can find most of these materials at the “Wire & Solder” table.

  • one used PCB (should have old components already soldered in the board)

  • one piece stranded-core wire (black or red or green or white)

  • one piece of solid-core wire  (blue or orange or yellow or grey)

  • one 8-pin socket

  • about 1 foot length of solder.

 

4.   Practice some soldering setup skills

Try each of these skills to ensure you are comfortable handling the equipment.

 

A. Clean and re-tin your solder tip Your solder iron tips should already be clean and tested, but if solder does not melt onto the tip use Solder Iron Tip Tinner (kept at the front of the lab near the electronics components.). Weller tips have several coatings. Some tips are old and need just a small amount of rubbing with emery cloth to remove oxide layer, but try to avoid doing this.

 

B.  Watch as the rosin boils off the solder.     Occasionally bubbles up enough to end up on hands and eyes.  

 

C.   Use side cutters to trim long wires on back of PCBs.     Notice how far clipped items can fly from the boards, watch out for people around you.    Use the 3rd Hand tool to hold the board in place if necessary.

 

5.   Practice soldering a variety of components together

You will show a collection of items to a TA for completion.  Here is a suggested list of things to try:

  • solid-core wires into the PCB

  • stranded-core wires into the PCB   (check for loose strands!)

  • 8-pin sockets into the PCB (solder 1 corner pin first, then ensure the socket is flat on the PCB, then solder the remaining pins)

  • put two stranded-core wires together to form one longer wire.  

  • coat one stranded-core wire with excess solder.   Feel how much stiffer and more brittle the excess solder makes the wire

7.   Practice Desoldering

 

A. Watch videos of desoldering   You can use two different methods, the desoldering tool, and solder wick

B. Remove 2 wires from a used PCB (stranded or solid) from a used PCB.

C. Remove one BJTs. See if you can remove it without clipping the leads from the BJT or destroying the component

 

7.   Keep your soldering and desoldering parts for a TA/instructor to inspect as a milestone.

 

 

 

Lab Part 3  – QRD and Motors 

  

1.    Watch the video to see the QRD and motors.    Tape Follower for ENPH 253

 

2.    Solder the QRD  (1 for each person) 

A.  Required materials

3 pieces of  8″ stranded wire, of 3 different colours

male header pins

one 330 ohm resistor

 

B.   Cut male header pins to correct number of pins.    It is plastic, so you can use your side cutters.  Be careful, as you may accidentally cut adjacent pins in the header and parts may fly into your face.  Return extra pins to bin.

 

C.   Assemble sensor using solder, hot glue, and heat shrink tubing.    For the QRD, you will be including an appropriate resistor (330 ohms)  inside the QRD wire as shown in the sample and  in the diagram here.  

 

Mark the resistor value on the  outside with a label.

 

 

 

 

3.   Solder the Motor (1 for each person) (~15 minutes)

NB:   Since this step is relatively straghtforward, you may use one of the motors which has been soldered and hot glued for strain relief from last year.    Check the bin.  Use two pieces of stranded-core wire, approximately 8inches in length.

 

You can use the screw terminals on the TINAH motor outputs to attach the motor.

 

 

 

Lab Part 4 – Inspect connectors and PCBs for the course

 

There will be a selection of connectors on tables in the room.

 

You are encouraged to try using each of the connectors.   Try not to waste attempts, as each connector varies in price from reasonable to not reasonable.

 

    • Quick Connect Terminals  

    •  Deans Connectons (for TINAH and battery)  

    •  IDC connectors for ribbon cable

    • MTA-100 Connectors (single-wire connections to board)

    • Wire Nuts

 

    • PCBs and Wire

    • Polarization on 8-pin socket

    • board-to-board vs. board-to-wire connections

    • PCBs for 253 (Boris and Natasha).

 

Milestones

Show a TA/Instructor the following:

  • your assembled tape follower, with motors, QRD sensors, and TINAH mounted.

  • a selection of soldering and desoldering work done by both team members.

 

 

Additional Videos

  • Video: how to use a battery drill, and how to care for drills.

  • Video: knurling: potentially relevant to fix gears to shafts.

  • Video: how to use epoxy. 

  • Videos about bending: Herehere and here.

  • Video: spot welding.

  • Video: designing a sample robot chassis in Solidworks

  • Video: preparing a Solidworks file for the waterjet (=how to make ORD)

  • Video: how to use the waterjet cutter

  • Video: how to use the laser cutter (older version: PDF how-to)

  • Video: how to solvent weld PMMA (aka Plexiglass, aka acrylic)

  • Video: clean up! Yes we know, you don’t really need a video for that.

 

End of Page.