Team Meetings
Meeting with Adam
- Update
- Is there a large desire to go directly from pellets to a printed part?
- General advantages of extruding with pellets:
- Lower cost of operation
- Mixing and matching pellets for new blends
- Instead of a polyjet, what about a polyblend?
- Advantages of directly extruding pellets
- Improved material properties
- Making our own filament:
- Can interface with any printer
- Lighter print head (bowden is lighter than direct drive because the extruder motor is on the frame)
- Controlling the diameter can be difficult
- Last team to use pellets to filament made a module 6 feet long, system was really big a. PID loop b. Temp, thickness, c. Existing pid controller, have tuning option d. Prof. Sestito was brainstorming with Adam! Take machine that did spooling and do a PID controller, rejected because CS heavy
Adam is interested in simulating being a manager.
Assume user is competent enough to build the Ender 3 from the instructions.
- Unknown bracket geometry of Ender series is holding up the purchase of the printer
- Logarithmic spiral geometry, google conversations
- Research tree
- Daniel talked with his dad, learned they use name brand pellets
- Mikey playing golf, get samples?
- Call creality to figure out
- Purchase by october 1
- Sent email to creality asking about brackets
Pellet Printer Team and Customer Meeting. Attendance: Mikey, Blake, Ethan, Timothy, Kay, Daniel, Adam.
- Adam showed us the previous senior design group’s filament making machine
- We had considered turning pellets into filament as a solution to our project so he said he’d bring it.
- Gave Adam a recap of our project progress
- Logarithmic screw that allows for retractions.
- Off-the-shelf hotend that we found that might fit a screw inside.
- Could also modify a more basic nipple.
- 3D printer farm that Adam has found.
- Adam is getting us connections.
- TH3D studios founded by Tim Hoogland
- Casey Kerrigan’s pellet printer
- Adam suggests that we reach out to her, we aren’t a competitor after all.
- RobotDigg logarithmic screws are fairly cheap and were used by the previous senior design project that melted pellets.
- We are allowed to machine things, but ideally we would use easier materials to get.
Team meeting
- Blake:
- Mikey: Free pellets? Reaches out, put in contact with Mark, gave insight, company, interest form, free pellets, order some pellets ourselves
- Tim:
- Ethan: Printer Level, Benchy attempt, sent connect invitations to Dr. Kerrigan and expert
- Kay: Custom J-head possibility
- Daniel:
- End of October
- Have a plan to get a prototype by the end of November.
- What will the prototype tell us? If screw geometry works
- What will calculations tell us? Cost, power to melt, torque
- Dr. Kerrigan design recommendations from patent
- Blake
- Daniel
- 10 quizzes
- Next Tuesday: Hazard analysis (Tim and Ethan are writing, Blake and Kay are reviewing)
- Pick method
- Figure out sizing
- Amazon barrel and screw, just use small pellets
- Custom J-head with custom screw
- Custom J-head with COTS screw
- Custom J-head with drill bit
- COTS from Harfington, parker hannefin, misumi, ect.
- All custom machined parts (like mahor v4)
- Buy white PLA 4-5 mm
- Buy white PETG 4-5 mm
- RoboDigg Bit and Barrel
- Coffee Grinder
- Buy white PLA 1-2 mm (CANNOT FIND)
- Buy PLA Filament
- Ethan puts together buy form for Tina
- Modify robodigg screw to have 6mm diameter (look at Kerrigan patent for best diameter)
- Buy screw
- Daniel Test Plans from SDRD
- Record steps we have taken so far (Mikey)
- Contact Kerrigan’s Shoe company (Tim)
- Kay Follow up with Nick to modify head
- Follow up with Campbell for auger bit
- Follow up with Adam for auger bit
- Aluminum bit for custom machining (for now)
- Ethan worst case scenario analysis for melting plastic, also find torque maybe
- Updated Adam on our purchases
- Grinder - sort of works, it’s a process
- Pellets - PLA is too hard to grind well, PP might be better
- Robo Digg screw - small, our processed pellets do fit though.
- Pellet processing
- Espresso maker is a whole process to get the pellets to a small enough size.
- It does get small enough after grinding, then blending.
- Need to test it more
- Heating element - Stock creality heat block that we can modify
- J-Head guy is ghosting Kay.
- It would be perfectly acceptable for us to design our own screw and or barrel, according to Adam.
- We should send him a screw we want machined and he’ll see if any of his connections can machine it.
- Update Adam on the custom screw
- Some pellets get stuck, some don’t. Ideally we would have the screw be 2mm bigger.
- He understands and approves the custom screw design as being a good solution
- Custom barrel brainstorming
- Adam wants to make sure that our heat block is where we want it before we machine it to avoid extra time machining and cost. Make it adjustable maybe.
- Gave an update on the hopper system
- Very rough right now, probably would work but it’s hefty and bulky
- Going to go through design iterations
- Remote extrusion system through the flexible shaft
- Need a longer shaft if it’s going to work
- He gave a suggestion about machining the barrel to avoid the plastic melting when the fans turn off.
- Feedback from Adam
- Overall he’s happy with our progress and approves a prototype to be built.
- He has found nearby machine shops with the required tools, need to provide Adam with the correct CAD once we finalize the screw design.
- Updated Adam with current design plans
- Corrugated tubing
- Pellet intake teapot
- New screw and barrel designs
- Mounting solutions
- Custom heated insert
- Potential spinning barrel solution, no screw needed
- We have an OPR on Jan 25, and Milestone 1 on Feb 1
- Update on the screw
- We bought two screws, long lead time so want an extra
- Might have to sand down to get to a better finish
- Adam couldn’t find someone to machine, so 3d printing is the best option
- General updates on the progress of our printer
- Barrel is in progress, having trouble machining it. Working on a new design
- New hopper plans, use the extrusion bar
- More new tubes
- Mainly waiting on barrel because everything is built around it
- Once barrel is done, can print out of plastic to start working before the metal one is machined.
- Update on ceramic resin, not viable for many reasons
- Update on the time study
- Adam approves of the time study format, says it’s nicer than what industry does.
- Overall Adam is happy with our progress.
- Updated Adam on the screw sizing
- Slightly too big because designed around math, not real world sizings.
- Using thermal epoxy to adhere the heat block to the barrel
- Heat block will be machined, will see if we can drill it out by hand.
- Update on the many tubes we’ve bought.
Adam told us about the verification process of his job and what needs to happen to get a product to pass audits. Off topic but interesting.
- Showed Adam our new extrusion system
- Excited to see our progress and the fact that our screw actually extrudes
- Adam is confident that we are in a position that if he has his child soon, we don’t need his supervision or meetings. Basically, he believes we can finish this project on our own.
- Might have to do that if he gets super busy with his family
- We need to improve the mounting system, make an extension for the limit switch.
- Also need to get the hopper working.
Overall, he is pleased with our progress, and excited that we have a working extrusion system.
Held virtually
- Gave Adam an overview of our progress
- Almost done, just have to put it all together
- Need a better fan to cool the upper areas down
- Just basically a progress report, he’s happy, we’re happy, everyone is happy.
- His kids are cute.
- Informed Adam of the future design presentations, he might be able to make them.
- Planned out the next meeting kind of.
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Use PLA or PETG, not PP. For PP, you need packing tape and it peels up. See the Benchy.
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Hard to find PETG and PLA pellets in small quantities – please supply the next team with them.
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Printer loses heat very quickly, remake the heat block into something smaller, shorter barrel
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Extruder stepper needs a gearbox
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Threaded heat cartridge and thermistor, please! Makes assembly much easier.
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Screws could stand to be smaller. 10-32 screws might be a little overkill.
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Purging is hard. We don’t have a great system for that right now. Improve purging.
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We didn’t use the hopper much, we didn’t need many pellets for testing. It does work well, though!
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The printer experiences Z-wobble, we think. The prints are a little wavy. See the benchy.
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NOTE: We flipped the wires on the extruder motor to make it spin backwards. The helix on the printed screws go the wrong way. The CAD is fixed now, so future builds won’t need this. This is a quirk of the machine the Vinyl Velociraptors worked and and it’s important you know about it.
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Adding an autoleveling feature would make development easier. Cuts out the busywork of manually leveling the bed. CRTouch auto leveling sensor. There might be better level sensors out there (As of 5/8/24, the CRTouch is our best recommendation).
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You may need to sand down the printed screws if you print them again. They come out with tolerances comparable to casting. Our screws were too big (We designed the screw before selecting the barrel, so we turned down their outer diameter) and the sides are very smooth. This may enhance performance on the screw that may not be seen in other screws that are made the right size the first time.
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A cost-effective way to get the heat block threaded onto the barrel would improve the usability of the printer.
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Adam has a google drive folder of the pellet printer project. He is going to make a GitHub repo and put it up on Reddit.
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Name of the extruder is the Raptor Extruder Module.