Modified the Decanter Centrifuge Prototype in order to test the Raspberry-Pi-Pico motor control designed by Anthony. This is work on version 2.
This work is documented here https://docs.google.com/document/d/1Eq32CS5Lr5qy8SvmcNOLg8heyqcrqfEfMRUhx3XsUl4/edit

This work was performed over the course of 3 working days at the lab.

I first built the electronic board designed by Anthony to test the breaking system based on L298N chip.
Second, I installed a DC motor instead of one of the broshless motors, as a driver, to test the breaking of the broshless.
Test was performed with Anthony being present remote, over webcam.

Then I modified the setting again, for testing the idea of driving both broshless motors using the Pico, interfaced with the motor's original drivers. The system is now ready for performing the tests, waiting for the Pico program.

today and yesterday, I reviewed the documentation for the motor driver modules, came up with a strategy to configure and drive the modules, shopped for metering pumps, decided on a fluid delivery subsystem ( use the pumps we got, hbridges we have and ideally a flow sensor, rather than a metering pump, they are too small anyway but are a good idea to investigate for the future), tried to bounce ideas off of others/gather consensus about what direction to take things in. plan is to tomorrow implement features in the firmware for pump control and information display, try to juice some alfalfa and determine what else I can do to prepare for the montreal visit, oh also organize, buy tickets etc (I am paying for the tickets because I want to go anway to see my friend's art show)

I designed and created the first part of a motor controller to control the centrifuge motors through the drivers. Not done yet. Designed things, assembled the electronics, wrote the code for the pico, tested things. assembled some fans for testing to stand in for the motor controllers

improved performance a bit more on the control system. Still not really good enough. schmitt trigger advisable

further work on the system for monitoring and controlling rpm. The pwm counter approach wasn't working out, it is more susceptible to noise for some reason and in any case it's hard to filter. I transitioned to interrupts and can use a moving filter to filter the periods as they come in, similar to how I did with previous systems.

Did a bunch of stuff to rebuild the electronics and improve the documentation of them, slow and painful going to try to work through the internet. Communicate with other team members at the meeting. We got disconnected so didn't get much else done.

Delivered the stuff to the Sensorica lab, assembled and help balance and test the system and electronics. I am only asking for 4.5 hours of time because I kind of wanted to go anyway as a little vacation. I would have had to ship the stuff by mail which would have cost as much anyway otherwise. The original idea was it was in addition to the work to be done in Cornwall, but now it has replaced that bolus of work.

ensure all bodies and stls are correct and named sensibly, review cad for errors improve google documents

Concept development, started another part printing (had some complications, sd card reader stopped working, time for that logged under experimental technician), drafted the proposed reciprocating filter separator.

Assembled the enclosure, got the screen working with the pico so we can see diagnostic info without the usb connection but concluded we sort of need it anyway, advanced the design of the electronics and firmware a little bit, got a pico and breadboard we can use ( I can't give up my other one)

meeting to decide next steps, improved documentation, decided how to pursue printing, started slicing parts

Improved CAD, double checked for errors, exported and uploaded the STLs and cad files, finalized, documented and uploaded code and electronics, next thing is to cut the pieces for the enclosure and try assembling it, I think, I don't have any hinges but should be able to do the rest, I have some 1/2 inch plywood.

I was able to make a mock- up of the brake and motor drive, pid loop and photointerrupter, and get things mostly working. It needs to be more responsive, the method of counting pules to determine RPM is too slow to allow precise rpm regulation. I will switch it to counting pulse duration instead later and try some more.

Got the rpm measurement and pid control loop working better, implemented a filter for the signal. Got regulation to within about 1% now, and there is a lot of elasticity in this system so I think with the actual centrifuge 0.1 percent is looking viable, and in any case we don't actually need it to be that accurate, as long as it clears the solids out adequately and not excessively.

I got the PID controller working with the raspberry pi pico, got the code written and debugged mostly, got smooth monitoring and regulation of the rpm of a fan using a brushless motor as a brake. We can use the exact code and electronics for the centrifuge, we will add to and modify them of course, but regulation to within about 2% was proven practical here, I think with the centrifuge 0.1% may be doable, it looks viable, anyway.

Did some work yesterday, sourced a peristaltic pump, made progress on the CAD implementing a photointerrupter system for rpm, and the enclosure, and electronics.
Note: I noticed the system is date-stamping my entries wrong. it is july 8 right now but this entry was stamped july 6.

I implemented the pid control system and connected the electronics for braking, however the braking process appears to inject too much high frequency noise to allow the RPM to be reliably detected with good accuracy using this approach. Detecting current rather than voltage might work better, I ordered some sense resistors to try that approach. I can also use the ADC of the pico instead, and possibly use the extra core of the pico to improve timing issues. However it is starting to look like an external encoder is a better idea than trying to use back emf. Indeed perhaps I should give up on back emf now. The motor controller is able to detect the rpm and position of the motor using back emf, but they use a processor running C or assembly, c is about 100x faster than micropython, assembly faster still. It may not be viable in micropython. Took a video to show the operation of the braking electronics/proposed system and that it is viable.

rigged the half h=bridge L298N modules to perform passive braking from the PWM of the Pico, and set aside for later, for use in combination with an rpm measuring system, this is large enough and powerful enough that we can use it for the main centrifuge hopefully. We can use the actual hardware I have prepared, not just the design, I will just keep it assembled until we need it.
rigged a test brushless motor to a fan, connected a phase to a rectifier bridge, divided the voltage down to protect the pico verified with the oscilloscope, trie dto measure the frequency with the pwm in peripheral on the pico. Noise is a major problem, tried a couple RC filter,s found one that seems to work, but for some reason the PWM counter is still giving the wrong frequency, I can confirm it on the oscilloscope. The next stage will be to try using the ADC and high frequency polling to try to track RPM. If that is not reliable, we must cook up some kind of encoder with the photointerrupter or buy an encoder, encoders are totally overpriced for some reason so we might as well just cook up our own in a minute.

Made a pico program to control a fan with a pid loop, using the pwm peripheral to measure fan speed, as interrupts were not accurate enough. the fan speed measurement still isn't very accurate, something is wrong. It varies by more than 10% even when I measured the signal from the fan on my oscilloscope and that's not the problem, it is the pico. I can try using the pio peripheral next, and posting on forums. If it can't be solved we can't use the pico, and will have to try using an arduino or something instead, like the teensy.

Further investigated pico, got interrupts working, got the fan tach signal working, we could use interrupts, will investigate pio later.

Investigated the use of the raspberry pi pico for use as a master controller of the centrifuge, controlling the peristaltic pump, acceleration, test run time, and rpm and relative rpm of the screw and barrel. Some technical difficulties, wrote a program to try to use interrupts to track the FG (frequency generator) output of some fans, the motor controllers for the spindle motors has a similar output to track rpm. It does not look viable. The next thing is to explore the use of the pio peripheral to monitor RPM.

advanced the cad further earlier today, added the other motor and motor mount, decided on and implemented a strategy for the rotating seal and upper drive, modified and improved things, dealt with some errors and issues with fusion.

Made some decisions on how to do things, advanced the cad, also did some research on how to do the firmware for a pico that controls both motors and a peristaltic pump

Added motor mount and motor coupler, solids collection geometry, adjusted width of tube etc., got everything in place, error free etc.

Made some decisions, did some cad, shopping/sourcing parts, plans for the show at the maker festival

shopping, considering options, some CAD, for centrifuge drive systems.

Started work on the centrifuge. Make the screw and barrel and cap, sourced o-ring that fits and bearings. We still have to decide on a drive mechanism and I would prefer to do this before doing much more CAD as it has implications and changes can be hard to make.

Did more cad on the centrifuge, it is mostly done now I think, it could still be split for printing or whatever.

Did some planning and figuring with Tibi at the weekly meeting, made a plan for the CAD work to be done on the next version of the decanter centrifuge. Tibi will do the small scale test to ascertain the potential processing rate of the centrifuge. We also discussed the intriguing possibility to manufacture the parts with SLS in metal, as Wikifactory people tell us they can get a good deal on it.

Discussed and made some conclusions on the design of the decanter centrifuge, considered self balancing mechanisms, what the barriers are and how to solve them. Decided on a plan of action: build a regular "mushroom hat" centrifuge to test the settling rate characteristics of the protein coagulate first, then if the results are promising, probably do a revision 2.0 of the main decanter centrifuge, to employ 2 metal shafts, eliminate the big bearing, keep the bearings away from the fluid, and employ direct drive (possibly, maybe not, there are issues with torque vs. speed curve matching that may require us to use pulleys. We may replace the pulleys with non-toothed pulleys or larger pulleys for better wear resistance.)

research on options for rotating seals for centrifuge, considering options for moving the physical prototyping forwards

Travelled to Montreal to deliver parts, finish parts, assemble and test centrifuge, and document it all, at the Sensorica Lab. Mission accomplished, mostly. Many changes are needed, and the manufacturing limitations are serious. also see $50 for gas and 2 hours travel time, logged elsewhere.

improve cad file with modifications to the screw, schedule progress for milestone 1, expand bom.

printing, post processing. removing support from the internal rotor is a real problem. soluble support material and dual extruders is valuable, clearly.

Improving CAD, printing.

Inspect cad model, make final improvements, export and start the prints. filament cost will be logged elsewhere.

Replaced the bearing with a bigger one, shopped for the bearing, adjusted the model to accommodate everything, double checked everything to be sure it is all ready for printing. Still need to add holes to mount that uppermost bearing plate.

improve cad model, make some design changes, shop for parts.

I did some more on the fusion cad file for the centrifuge, design and drawing.The motors still need a few more dimensions. Redrew the motors, and added and adjusted everything for the mounts that come with the motors, decided on strategy to mount the motors after considering several options, they need to be changed so the fan does not stick into the bucket.

designed and added added motor mounts, teeth to pulleys,modelled motors and checked over the cad file

Accumulated over a few days, thinking with and work providing to Anthony, who produced the CAD files.
Drove the documentation of this prototype
https://docs.google.com/document/d/1Eq32CS5Lr5qy8SvmcNOLg8heyqcrqfEfMRUhx3XsUl4/edit

implemented the planned changes:
improve seal around cap and outer rotor, I added a groove for the oring to stick to, but realized a better idea is to increase the number of bolts. It is quite a lot of bolts, but will reduce the chance of leakage issues/the need to reprint a different one. There is no ridge in the cap itsself as it appeared it would be unhelpful anyway.
-thicken cap
-check over it all for errors
-put the hole back in the inner rotor
-thicken the shaft walls. There is a limit to this. I thickened both shafts, and reduced the central hole diameter.

- I was not able to make any progress with the pulley/shaft interface. There just isn't really enough plastic there to do much and still have enough strength. I could put some very thin threads on perhaps that would be ok, yeah.

Tibi and I determined some of the details for changes/updates to the CAD model for the centrifuge, which I will make later.

Modified Extruder Pro from Precious Plastic to match the needs for Green for Good. Design modifications were done to the extrusion screw to match the required processes. A bit of work is needed to finalize the leaves crushing section. The design modifications were made to the shared OnShape model.

https://cad.onshape.com/documents/e5ffe24c901e0463cea1c3a5/w/894b77f33ef5631b42db8302/e/c285d73b693d1bab88f0a39a

Set up the working, design and prototyping documents.

Cleaned up Deliverables doc. Extracted some content and put it into presentations. Better flow, easier to read.
https://docs.google.com/document/d/1g6DbV0mSqwU6rdLqyrv5Ctw_3cHamuPZLFXwajPkN4g/edit#

Worked on Design Considerations, documented some ideas in the table, told that to Tibi.

Visited a local corn miller in Njombe and added info and pics to general considerations: https://docs.google.com/document/d/1g6DbV0mSqwU6rdLqyrv5Ctw_3cHamuPZLFXwajPkN4g/edit#

Searched and documented different techniques to manufacture screws for extruders.

Discussed a visual of the design architecture of an extruder with Bernard. He had already made a first draft, we discussed fine-tuning it.

Spent time with Tibi discussing General Design Considerations, talking notes in the cod / table.
Introduced the village corn mill model.

Spent time with Unai discussing General Design Considerations, talking notes in the cod / table.

Discussed a visual of the design architecture of an extruder with Tibi. I had already made a first draft, we discussed fine-tuning it.

Finished the Build Understanding presentation and presented at the Build Understanding meeting.

Helped Tibi with the Building Understanding presentation: feedback and formatting.
https://docs.google.com/presentation/d/1WpRGuaFrFYwCeyw-kRZSqxvARfo0OIhqLxjk1Ov_vO0/edit#slide=id.p

Worked on the Building Understanding presentation. Mayssam helped a bit
https://docs.google.com/presentation/d/1WpRGuaFrFYwCeyw-kRZSqxvARfo0OIhqLxjk1Ov_vO0/edit#slide=id.p

Worked on the Building Understanding presentation. My point of view
https://docs.google.com/presentation/d/1WpRGuaFrFYwCeyw-kRZSqxvARfo0OIhqLxjk1Ov_vO0/edit#slide=id.p

Searched info about protein processing and surveyed companies that are engaged in this field.

Processed Bruce's mined info from his doc, into the Deliverables work, structured information.

Information mining, delineating conceptual space, pile data in this doc.
https://docs.google.com/document/d/1qt48RPToG9qfQssWqH4qMcs3rPJkMqC2ZlP_K8l3ts0/edit#

Added a few organisations and documents to Diigo
Met a local artisan in Njombe (Tanzania) who can provide design considerations.

Explored concepts for shredding and squeezing leaves. Captured some examples of devices that instantiate these concepts in the Deliverables doc. Shared ideas with Tibi.

Had a meeting with Anthony to order parts and plan for the prototyping of the second version of the decanter centrifuge.
Made a BOM on the doc
https://docs.google.com/document/d/1Eq32CS5Lr5qy8SvmcNOLg8heyqcrqfEfMRUhx3XsUl4/edit#

Had a meeting with Tibi to order parts and plan for the prototyping of the second version of the decanter centrifuge.
Made a BOM on the doc
https://docs.google.com/document/d/1Eq32CS5Lr5qy8SvmcNOLg8heyqcrqfEfMRUhx3XsUl4/edit#

Meeting with Anthony to discuss second iteration of the Decanter centrifuge prototype. We used the report doc from the first tests.
https://www.amazon.ca/Adjustable-polishing-machine-fishing-12V3000/dp/B0965QSSBL/ref=sr_1_7?crid=2AY7OZ1LS49JJ&keywords=hollow+shaft+motor&qid=1654717312&sprefix=hollow+shaft+motor%2Caps%2C197&sr=8-7

We decided to iteratively go for a second design, redesign the screw, look at possibilities to only use one motor instead of two, better sealing for the barrel, and integrate other improvements ideas in the same doc.

Worked on the design roadmap with Tibi and Mario.
Glanced over some engineering papers about oil extractors.

Worked on the design roadmap with Tibi and Elie.
Glanced over some engineering papers about oil extractors.

Searching basic design parameters and discussing design with Elie, Tibi and Bernard

Searching basic design parameters and discussing design with Elie, Bernard and Mario

Searching basic design parameters and discussing design with Tibi, Bernard and Mario

Bernard: Searching basic design parameters and discussing design with Elie, Tibi and Mario

Scrum meeting with Tibi, Mayssam and others.

Design coordination meeting with Maysam, Mario, Tibi, and Elie.
We went over priorities, examples of designs.

Scrum meeting with Tibi, Mayssam and others.

Design coordination meeting with Tibi, Bernard, and Elie.
We went over priorities, examples of designs.

Design coordination meeting with Tibi, Mario, Bernard, and Elie.
We went over priorities, examples of designs.

Design coordination meeting with Maysam, Mario, Bernard, and Elie.
We went over priorities, examples of designs.

Design coordination meeting with Tibi, Mario, Bernard.
We went over priorities, examples of designs.

Writing Decanter Centrifuge testing report.

Updated the Deliverables doc, mostly the Design section.
https://docs.google.com/document/d/1g6DbV0mSqwU6rdLqyrv5Ctw_3cHamuPZLFXwajPkN4g/edit#

Updated the documentation for the Decanter Centrifuge
https://docs.google.com/document/d/1Eq32CS5Lr5qy8SvmcNOLg8heyqcrqfEfMRUhx3XsUl4/edit#

printed and re-printed the solids collector, the new one prevents us from needing to dismantle the whole thing to check or collect the solids output. This will save a lot of time. Also printed the new collars. Post processed everything. Communicated with the team a little. no meeting today. Printed the next motor coupler, went well. Mostly done stuff, all that remains has to be done in montreal, I think.

print things, overcome printing problems (curling off bed, infill not joining walls), another design revision for the motor coupler, pack for montreal, communicate and plan, changed the plan. Decide to implement the pico tachometer approach, order sensors for it, received rods checked for fit.

Planning, writing document for what to do in montreal, many potential errors caught and things that need to be done forseen, things I need to bring etc. Also received shipments of tslot and bolts and checked for fit etc.

3d printing of several parts, post processing of barrel and more on screw, printer maintenance (unclog a batch of nozzles, clean printer), buy containers from dollarama, investigate sensors for rpm measurement using the reflective sensors we have, research on cost to performance ratio of small centrifuges and screw presses, modify and reprint seal. Try to communicate.coordinate/strategize with team (no success)

source parts, printed parts, post processing, printer maintenance, cut materials to size for later use, modified CAD file to adjust clearances and changed liquid seal thing to collect leaked stuff, sliced and started printing. ordered more PLA, ordered pump, strategized, documented labor efforts and expenditures, fleshed out assembly and maintenance documentation further. Ready to print some stuff tomorrow and then most of what remains has to be done in montreal or after parts arrive, I think.

Tried several times to print things, many failures, still trying. Ordered parts, documented things tried to communicate with the team, reviewed plan, modified cad, strategized, sliced files, maintained printers, printed stuff.

did some stuff on documenting assembly and design history and future, keep monitoring printer, seems to be working now, strategizing for what to do next/tomorrow.

Contribute to the report on the testing and experimentation, advise next steps.

Continue building centrifuge. Sand down the screw. Tried it with water. helped make a pump solution. Mounted tray under it. Stopped it from wobbling off table. Experimented with distorting the structure to improve the contact between screw and barrel.
Cut and fit the liquid collector ring and solid collector.
Got fusion working on ubuntu, modified and Printed new couplers.

Made a liquid shield to reduce spraying of water issues.

Testing Decanter Centrifuge V2 with Anthony at the Sensorica lab.
Report will be published here.
https://docs.google.com/document/d/1eiORXDJ7Uac9PpiSCx6PZ2T4cYSGZGcBktK0d40TdpU/edit
This work required mechanical and electronics skills / manipulations.
Assembly and disassembly of centrifuge.
Making new juice, coagulating and running centrifugal tests.
The work was performed during 3 days, just logging 10 hours.

Big day, ran tests with coagulated kale juice. Troubleshoot, hypothesize, test, repeat. Document, take pics and video. We got close to extracting protein continuously. Got some from the barrel wall, which allows us to determine the properties of the stuff. I think simply modifying the outlet ports will yield success. Centrifuge works fairly well.

Sanded screw a ton, improve arduino code. Overcame some missing wires
Overcame some issue with driver forgetting its parameters.
Got a method to put oring on.

arrived at lab at 1 pm, got settled in, got some assembly and testing of electronics and mechanical assembly done, departed 6 pm

Got the electronics partially working with Tibi, got the motor drivers partially responding (not full throttle range yet)

inspected the alfalfa to see if it's still good, experimented with juice extraction methods that would be more efficient than bringing it all to montreal on the train and extracting it there. checked to see if flavor is ok, everything seems to be in order but I can't extract juice using my juicer. cleanup.

draw a diagram of the electrical connections, shop for flow sensors.

Improved the pico code, modified it so that it can drive the brushless motor drivers, experimented with another more responsive approach to monitor rpm. Consulted with Tibi on ways forward, how to connect things, reviewed the code with him. on hold now till tibi gets some of the stuff trimmed and assembled.

more work to get the electronics and braking system working, did some shopping for solid state relays to use in the future, considered ways forward, waited around some for the meeting to start.

did some more stuff to get the electronics working and test them out, quite slow going and difficult to do over the internet.

Tried to get the pico working and get the motors set up for the testing with Tibi. Slow going over the internet. Tested things with linux and the pico on my end to troubleshoot, problem appears to be the pico has been damaged on Tibi's end, at least it is a strong enough hypothesis to justify shipping him another pico to try.

Slow going trying to rebuild the electronics by working through the internet with unfamiliar equipment etc. Got the power stage of the braking regulator working, moved on to the pico but seems to be some driver issues or something, not clear.

Went to Montreal with the stuff, assembled and tested and got working the centrifuge as well as we could, given the lack of some parts. Got it working at 5000 rpm smoothly, looks like it can probably do the full 12,000 rpm with liquid inside it. Everything seems to be going well. Left the machine in Montreal for further experimentation.

printing, fitting parts together to verify fit, sanding, removing supports.

rescuing the bearing block with the liquid collector, liquid collector needs modification and reprinting, evaluating the design. it is quite a lot of work to dismantle, more than the previous unit even perhaps. Tried to assemble things, realize there was a problem, went back.

re-design and re-print the liquid collector ring, assemble/check for fit, ordered more screws Can do the motor couplers tomorrow, then printing is done I think.

Sanding parts to fit, printing, overcoming errors, testing, editing cad to produce a part to repair the liquids collector component (rescue a part that didn't print ok), video report posted

more printing, keep track of which parts are done, slice them in a way that makes sense, clean, load and prepare the printer, start the print, scrape the part off, post process. It's actually a lot of work. Large rolls of filament, a more reliable and streamlined toolchain etc, would all help. ordered yet more filament

Printing the last few parts, post processing etc.

Printing, post processing, did two batches and went to the store to get more glue sticks, ordered more filament, got the new sd card reader working

Printing, slicing, post processing, double checking everything for accuracy and strength. Made a quick video report on progress etc.

I cut the plywood to size, obtained hinges, brackets and screws, all compatible, and assembled the enclosure box, except for the two holes in the door as things could change yet in that regard.

started another part printing, scraped the old one off and post processed it.

Printed and post processed the screw part.

double checking things, finalizing, decided to reprint the barrel because the screw holes were a bit too big on the last one (the accuracy improvements caused the holes that previously grabbed the screw adequately to be bang on 2.9mm in diameter, which is not quite right for the screw to grab. The screw really has to grab, though. For the next revision these holes should be replaced with metal nuts.)

finishing screw, post processing to remove supports, sand, test for fit, all looks good.

reprint screw with better settings in sideways orientation

checking parts fit, dimensions are within suitable range, saving settings for future use, assemble bearings and other parts as far as I can to verify they fit

print screw in sideways orientation, remove support material, test for fit.

Re printing parts and adjusting parameters and options to achieve better accuracy. Circles appear to be much more susceptible to thermal contraction. Currently scaling objects up by 100.4 xy and using horizontal expansion of -0.1 combined with 4 wall layers and 80 mm/s print speed, 0.28 mm layer height, 70 degree build plate, skirt, most other parameters default is giving the best result. Some room for minor improvement, but probably no need to further improve. Thermal contraction appears to vary between brands of filament, but more so for circles vs. rectangular features. This variation between feature shapes is slightly baffling and a real problem. I am using PLA. Using "outer wall first" led to unnaceptable defects on the pulley teeth, however may be an acceptble subtitute for the horizontal expansion compensation factor on most parts. It leads to some under extrusion and some over extrusion on some areas of parts, it is unclear why.

printing parts, updating master document

review what has been printed, what needs to be done, add a table to the main doc, proceed with producing any remaining parts.

2 hours travel time to Montreal and back again to Cornwall. This is billed at an efficiency of 66 percent, because I also wanted to go to montreal for personal reasons.