v2.5 Localized Hardware BOMs

[ethanjli]

The standard Bill of Materials (BOM) for the PlanktoScope v2.5 hardware can be found at https://github.com/PlanktoScope/PlanktoScope/blob/master/hardware/v2.5/bom.csv . However, this BOM does not include ordering links, since such links will need to be different for each country. If you've customized the v2.5 hardware BOM for your own v2.5 PlanktoScope kit (e.g. by finding and adding part ordering links in your country for each BOM item), please share your custom BOM here with a brief description of the changes you made!

[ceeller]

I am in the process of localizing the BOM for the USA and will share when complete. However, I am having a difficult time locating some of the components based on the descriptions in the current v2.5 BOM.

Specifically I would appreciate help with specifications for the following line items:

• line 12 "Tube n°3" by PontonZ (what is this, material, dimensions, etc.)
• line 13 "Tube n°4" by PontonZ (what is this, material, dimensions, etc.)
• line 14 "Mini Bubbling USB" (what is this?)
• line 16 "FlowCell 300um" (is there a manufacturer?)
• line 17 "Reinforced linear stepper motor" (I cannot find the part number at the listed reseller, what are the dimensions, forces, etc. for this component?)
• line 25 "LED to HAT wires" (is there a list of the number of wires needed, gauge, length, color, connectors?)
• line 29 "Structure V2.5" (is this the case that is assembled from CNC or 3d printed components?)

Thank you for any help in identifying specifics on the above line items. I'm developing a project list at Mouser Electronics for most of the components that I'd be happy to share with everyone after we've made sure the parts are all correct.

[ethanjli]

Thanks for volunteering to work on this! Here is my understanding of the BOM (which is a very limited understanding, as my only experience with the PlanktoScope v2.5 hardware is in PlanktoScope software maintenance and as an end-user of a v2.5 Planktoscope), addressing your questions in reverse order:

• line 29 "Structure V2.5" refers to the CNC-milled parts, including the outer enclosure and internal structural parts (which are milled from some sort of bamboo plywood in the version sold by FairScope)
• line 25 "LED to HAT wires": if there is any such list of details about the cable assembly for this, I imagine it's probably in the form of not-yet-documented implicit knowledge at FairScope. Once the v2.6 hardware documentation is released (FairScope has promised to finish cleaning up their internal documentation, translating it into English, etc., for a documentation release in fall 2024, but they've been a bit short-staffed on this work relative to the size of their backlog of PlanktoScope orders to be fulfilled), it might provide some additional guidance. https://docs.planktoscope.community/setup/hardware/v2.5/assembly/#chapter-12-mount-the-led-on-part-g has photos of the cable assembly used by FairScope for BOM line 25, and https://docs.planktoscope.community/setup/hardware/v2.5/assembly/#chapter-17-connect-the-led-and-peristaltic-pump-to-the-raspberry-pi has photos of how the cable assembly for the LED is supposed to be plugged into the PlanktoScope HAT. I think we should treat this as a gap in the BOM - so if you are able to determine a good length and the correct JST connectors for the cable assembly, this could be a useful contribution to improve the existing hardware documentation.
• line 17 "reinforced linear stepper motor": I don't know how this is sourced or whether a part number exists for it. The v2.1 PlanktoScope hardware uses a similar motor which is available from Amazon (https://www.amazon.com/gp/product/B07VHRQV22), and I believe motor used for the v2.5/v2.6 PlanktoScope hardware is the same linear actuator, except with a metal screw nut block (the traveling element) which can be precisely screwed to a CNC-milled part instead of the nylon nut block which instead must be superglued (in a very awkward way) to a laser-cut part. At first glance, the stepper motor used for the v2.5/v2.6 PlanktoScope looks something like https://www.walmart.com/ip/Stepper-Motor-Linear-Miniature-Slide-Table-Linear-Bearing-Screw-Slider-Nut-15-Small-Motor/6064250967 , though I'm not sure whether the motor has dimensions and a metal screw nut block which are exactly compatible with the PlanktoScope's CNC-milled bamboo parts. https://docs.planktoscope.community/setup/hardware/v2.5/assembly/#chapter-11-mount-the-linear-stepper-motor-on-part-e has images of the motors used by the v2.5 PlanktoScope, for comparison.
• line 16 "FlowCell 300um" is something you'll have to assemble yourself. It consists of a rectangular glass capillary tube with 300 um of internal thickness (BOM line 2) which plugs into two pieces of PVC tubing (dimensions should probably match the tubing in either BOM line 12 or BOM line 13), and which is sealed together with the PVC tubing via heat shrink tubing (which appears to have been omitted from the BOM). I've been told that it's easy to assemble new flow cells, and I believe FairScope provides extra materials for doing so as part of their kits; however, I've never done it before and I don't know details about the part specifications (dimensions, etc.). https://docs.planktoscope.community/setup/hardware/v2.5/assembly/#chapter-21-insert-the-tubing-in-the-peristaltic-pump has photos of the flow cell.
• line 14 "Mini Bubbling USB" is an air bubbler which can be powered by USB. It is used to agitate the water sample inside the syringe body (directly upstream of the flow cell) to prevent heavier particles from sedimenting first, because such sedimentation would bias the size distribution of particles imaged by the PlanktoScope over the course of image acquisition for a sample. The bubbler itself looks identical to https://www.amazon.com/ALON-Oxygen-Aquarium-Hanging-Buckle/dp/B08CSP4HTZ/ , though FairScope also provides a simple air flow regulator device (I believe the exact mechanism and device has changed over time). https://www.protocols.io/view/planktoscope-protocol-for-plankton-imaging-bp2l6bq3zgqe/v3?step=4.3 has some photos showing the bubbler and one of the air flow regulator devices which has been used by FairScope, which resembles https://www.amazon.com/AQUANEAT-Aquarium-Control-Plastic-Regulator/dp/B08LGHWB77/ but differs from the air flow regulator included with a PlanktoScope I have from FairScope.
• lines 12 and 13 ("Tube" by PontonZ) should be some kind of silicone or Tygon PVC tubing (silicone might be better if you can find it at a reasonable price), but I'm unable to find any details. I suggest trying tubing with an inner diameter of 1.6 mm (i.e. 1/16 inch), which is what was used for the v2.1 PlanktoScope. I know the 1.6 mm diameter is compatible with the Luer fittings used in the PlanktoScope's fluidic path and with the v2.5/v2.6 PlanktoScope's fittings on the peristaltic pump. I also recommend getting some tubing with inner diameter 0.8 mm (i.e. 1/32 inch), just in case narrower tubing is needed for the flow cell. If you're able to figure out appropriate tubing diameters and lengths, that would be a very helpful contribution to the hardware documentation! I purchased my 1.16" and 1/32" ID Tygon tubing from McMaster-Carr in order to build a bunch of v2.1 PlanktoScopes (but modified to use the peristaltic pump from the v2.5 PlanktoScope design): https://www.mcmaster.com/products/pvc-tubing/tubing~/soft-plastic-tubing-for-air-and-water/?s=pvc-tubing

[ceeller]

Thank you. This is very helpful!

[ceeller]

Attached is a draft of the BOM for North America. If it looks good to you, please post it.

Thank you,
Chris
NA-region_bom.csv