Parts Required:
- Two copper wire spools (red and black) of size 16 AWG
- Female XT30 connector (check Dephy actuator to confirm you’ll solder the proper connector side)
- Dephy battery connector (the red connector shown in Fig 1). Please contact Dephy to purchase this item.
- Battery housing
- Two Black-Oxide, M2 x 0.4 mm Thread, 8 mm Long
Important:
Before starting to solder the wires into the battery connector, it’s important to insert both wires through the wire routing hole to the side of the battery connector.
The wires need to stick from the marked side to the unmarked side.
Locate “+” and “- “signs on the connector. You’ll need to solder to these two holes. Red goes to the “+” hole and black goes to the “- “one.
Ignore the glue on the connector for now.
What to do:
Grab the two ends of the wire spools that are inserted through the battery housing and insert some short shrink wraps into the wires then start the soldering process. See Solder Through-hole Components for info on how to solder. Once done soldering, apply heat on the shrink wraps using a heat gun as a proper way to insolate the exposed parts of the wires.
Important:
Make sure once you’re done soldering you have clean solder and that the wire is only touching the through-hole it’s soldered to. If the wire touches any other holes on the connector board, damage will occur to the battery (we lost one expensive Dephy battery due to this). Once done soldering, please use hot glue as shown in Fig 3 and 4 to make sure the wires don’t touch anything as they’re being strained once you start installing the connector to the housing.
The hot glue is applied as a electric isolator.
What to do:
Bolt the connector to the battery housing (Bolts should make their own threads into the plastic housing).
What to do:
Install the battery housing on the ankle and knee to mark the length of the wires needed to plug in the XT30 connector into the Dephy actuator before soldering the XT30 connector.
Once you cut the wires to size, start soldering the wires to the XT30 connectors (Red to the positive “+” side and black to the negative “- “side).
See how Soldering XT30 connectors.
Parts Required:
1 x 4 Position Rectangular Housing Connector (vendor: Digi-key Instruments, part no: WM1722-ND)
1 x 14 Position Rectangular Housing Connector (vendor: Digi-key, part no: WM17001-ND)
14 x 26-28 AWG Crimp (vendor: Sunrise Instruments, part no: WM2023-ND)
1 x Loadcell (vendor: Sunrise Instruments, part no: 3564F)
1 x Strain Gauge Amplifier (vendor: Dephy, part no: 6ch)
1 x Surface Mount (vendor: Digi-key, part no: WM7608CT-ND)
Tools:
1 x Crimping Tool by Molex (vendor: Digi-key, part no: WM15815-ND)
1 x Wire cutter
What to do:
1) Cut 11 cm of black loadcell cable using a wire cutter
2) Strip 4 cm off of the insulation of the black load cell cable
3) Take wire off
4) Match input and output channels of the loadcell to those of the strain gauge amp.
Schematic for the loadcell
Schematic for the strain gauge amp
Connection table (Explains how to connect the loadcell to the strain gauge amp)
5) Put 26-28 AWG crimp to all ends of the loadcell cable using the crimping tool. (Video showing how to crimp)
6) Insert the crimped wire into the housing connectors:
For the 4pins connector in the strain gauge amplifier, we used 4 Position Rectangular Housing Connector and 26-28 AWG Crimp.
For the 14pins connector in the strain gauge amplifier, we used 14 Position Rectangular Housing Connector and 26-28 AWG Crimp.
7) Insert the housing connectors into their corresponding surface mounts in the strain gauge amp.
Parts Required:
1 x 10ft. 26AWG wire (vendor: McMaster, part no: 2674N21)
1 x Shrink wrap
1 x 20 Position Rectangular Housing Connector
1 x 6 Position Rectangular Housing Connector
6 x 26-28 AWG Crimp (vendor: Sunrise Instruments, part no: WM2023-ND)
6 x 28-32 AWG Crimp (vendor: Sunrise Instruments, part no: WM3670TR-ND )
Tools:
1 x Wire cutter
1 x Crimping tool
1 x Hot glue
1 x Heat gun
What to do:
1) Cut 4 wires (26AWG) to 30cm each
2) Expose 1mm wire from both ends.
3) Put 26-28AWG crimp on one end of all the wires using the crimping tool (these will be used to connect to the strain gauge amp) (Video showing how to crimp)
4) Put 28-32AWG crimp on the other end of all the wires using the crimping tool (these will be used to connect to the motor)
5) Place the wires with the 26-28AWG crimp to 4 Position Rectangular Housing Connector
Schematic for the strain gauge amp
6) Now we will separate the wires into 2 groups and place shrink wrap to cover all exposed wire
Group 1: Put side with 28-32AWG crimp to 20 Position Rectangular Housing Connector (these will be used to connect to the motor)
Schematic for the motor
Group 2 (i2c, SCL): Put side with 28-32AWG crimp to 6 Position Rectangular Housing Connector
Schematic for the motor
7) Use hot glue at the intersection of crimps with the housing
8) Repeat for all housings
9) Use heat gun to shrink the shrink wraps
10) Plug all the cables to their corresponding housings of the motor (Refer to the schematic called “Harness”)
Parts Required:
1 x p002_pyramid
1 x p1016_distalBase
1 x loadcell (vendor: sri, part no: M3564F)
3 x M5_10mm_low (vendor: McMaster, part no: 93070A121)
6 x M5_12mm (vendor: McMaster, part no: 93395A304)
4 x M3_8mm_low (vendor: McMaster, part no: 92855A309)
Tools:
1 x 2 mm allen
1 x 2.5 mm allen
What to do:
1) Connect pyramid to the loadcell using 3 x M5_10mm_low screws using a 2.5mm allen to get the configuration below:
2) Connect the loadcell to the distalbase using 6 x M5_12mm using 2mm allen to get the configuration below:
3) Flip the assembly and connect it to the knee using 4 x M3_8mm_low screws using a 2.5mm allen to get the configuration below.
Parts Required:
Voltage Regulator
What to do:
1) Connect pin 1 on the voltage regulator to the positive(red) wire of the battery and pin 2 on the voltage regulator to the negative(black) wire of the battery.
2) Connect pin 3 on the voltage regulator to the positive (red) wire of the pi and pin 5 on the voltage regulator to the negative(black) wire of the pi.
Ordering Components:
The components required for the E-Stop can be separated into three categories: manufactured, prefabricated, and miscellaneous. All of these components can be found in the E-Stop Bill of Materials. Due to recent supply chain issues, the MOSFET required has occasionally been out of stock. A suitable replacement that can be ordered internationally can be found here.
1) Manufactured components
- PCB
In order to order the PCB, this ZIP folder containing the necessary Gerber files need to be uploaded to OSH Park’s website. Please make sure that the option for “2 oz copper, 0.8 mm thickness” is chosen.
- 3D printed parts
In order to order the 3D printed parts, these STP files need to be downloaded and uploaded to Shapeway’s website. I highly recommend versatile plastic as the printing material. Printed using selective laser sintering (SLS), versatile plastic is a durable nylon plastic.
2) Prefabricated components
Please refer to the E-Stop Bill of Materials on which prefabricated components to purchase. These prefabricated components consist of SMDs for the PCB and connector components (e.g. the cable that connects the switch to the board, bullet connectors, etc.).
3) Miscellaneous components
Please refer to the E-Stop Bill of Materials.
All of the files needed to make the E-Stop and additional files can be found here for your convenience.
Important:
Attach every SMD using solder paste and a hot air rework station. 340 °C worked well for me (do not expose board to hot air for too long or you risk damaging SMT components).
Parts:
1 x E-stop board
1 x Fuse
1 x Mosfet
1 x Power Indicator LED Blue
1 x TVS Diode
What to do:
Solder each part to its correct place. The Fuse attaches to the F1, the Mosfet attaches to the Q1, the Power Indicator LED attaches to the D2+, and the TVS Diode attaches to the U1.
a) Aux cable with section of braid removed and outer insulation stripped
b) Ground sheath separated from white, black, and red conductors
c) Ground sheath strands combined with heat shrink and white, black, and red conductors stripped
What to do:
Cut into aux cable and you will see four conductors inside
1) Ground sheath composed of stranded wires (may be combined already)- connected to base pole on the male connector end
2) Black insulated wire- connected to pole next to base pole on male connector end
3) White insulated wire- connected to pole next to top pole on male connector end
4) Red insulated wire- connected to top pole on the male connector end
For each side of the aux cable, combine ground sheath strands into one insulated wire by using shrink wrap
This is how the aux cable should look after it is stripped and grouped correctly and how it should be soldered.
The white wire goes into one of the two Switch through holes and the black wire goes into the other Switch through hole. The ground sheath goes into the positive D1 through hole and the red wire goes into the other D1 through hole.
What to do:
Using the male connector side of the aux cable, solder the four conductors to the DPDT switch’s pins (using pins 1 and 2 on one side and the diode pins):
1) Ground sheath goes to positive diode pin (one without red dot) and red wire goes to negative diode pin.
2) White wire and black wires go to pins 1 and 2, order does not matter.
3) Shrink wrap the DPDT switch appropriately.
Image above shows shrink wrapped DPDT switch
What to do:
Attach actuator leads to appropriate MMI terminals on the board.
Then attach ground BM1 wire to DC power source.
Then finally attach Positive BM1 leads to batteries.
After everything is connected, to cut power to the actuator, simply depress the switch button. The aux cable is wired so that in the scenario where the DPDT switch is not connected to the board, this scenario is equivalent to when the DPDT switch IS connected to the board and the switch depressed (i.e. disconnecting the DPDT switch without depressing the bottom will also cut power to the system). This serves as an alternative method of disconnecting power to the system in the situation where pressing the button is not feasible. The DPDT switch is placed inside a handle for comfort and to prevent damage to the switch soldering.
There is no danger associated with only inserting the male connector of the aux partially into the female connector. The only downside is that if the male connector is inserted 75% of the way, the 86.6 kOhm resistor (R1) is subjected to a larger voltage; however, this additional voltage does not lead to the resistor exceeding its power rating.