FourThievesVinegar / solderless-microlab

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SPIKE: PARTS: As an assembler, I want to know whether DIY peristaltics are good and which ones are best. #215

Open sparklestheunicorn opened 4 months ago

sparklestheunicorn commented 4 months ago

At ~$30/ea in 2023, the three peristaltic pumps are a major part of the cost of the MicroLab. In addition to being costly, they are also relatively limited in terms of the number of vendors selling them to the public. It would be good to look into alternatives and their reliability.

There are a number of 3d-printed peristaltic pump designs out there (one example). An exploration of the various options and tests of their reliability would be helpful in deciding whether we think we want to encourage our users to go with printed pumps, and if so, which ones?

phaseloop commented 1 month ago

Here is the curated list of available pump designs from thingiverse and printables.

Also it's worth considering a different approach - pressing a syringe cylinder to extract given volume of liquid instead of pulling it using pump. The downside of it is the limit of syringe volume while with pump we can connect anything to the input side.

Used assumptions:

Pump designs

Editor's choice!

Heavy-duty, well designed pump with adjustable hose tension. Includes source scad files for further modifications (no other design on the list probably does that).

Uses 6 mm tubing.

Other

Easy and nice design - uses 3 mm tubing. Pump intake seems to be integrated into housing (??) which seems to be weird.

(OG design linked in this issue)

Similar design but uses less popular needle bearing

Nice and secure design but needs some minor fixes to tube guide to prevent it from moving and keep the precision.

ok-ish but tube seems to not be secured properly and there is a risk it will fall out during operations

ok-ish but the bearing mount gives me anxiety and I doubt it will work more than 10 minutes. Someone tried to adapt aluminium pump to 3d printing.

Easy and clean design but risk of tube falling out

Nice and clean design but bearings are not secured with screws and keeping pressure between pump rotor and motor shaft is the single point of failure.

sparklestheunicorn commented 1 month ago

Thanks @phaseloop! We're running this by some of the CAD design folks.

phaseloop commented 1 month ago

I have a pretty long and solid experience in FreeCAD - I would love to join discussions if that's possible.

sparklestheunicorn commented 1 month ago

@phaseloop please drop us an email at volunteerⒶfourthievesvinegar.org and we'll put you in touch.