Sara Kit Certification
- 1 Build Space
- 2 Main Checklist
- 3 Electronics Checklist
- 4 Build
- 5 Kit Build
- 6 Sara Comments and Improvements
- 7 Links
Make a copy of:
One can study the time lapse in detail to understand the build time. This time lapse should span about 7-8 hours. Rework time was about 1.2 hours.
Details of Steps Taken in Video Above
- Mount all pulleys
- Make all carriages
- Make motor pieces and finish 1 axis at a time.
- Add end stops to axes as you go.
- Mount axes on frame to verify them, except X axis (if waiting to dry)
- Make heat bed
- Make heat bed mount
- Make X axis
- Mount control panel
- Assemble extruder
- Mount X axis - fitting it in and making sure it slides easily
- Mount heat bed mount (without heat bed at this point)
- Do cable chain and wire routing
- Mount belt plugs (this should be right after X axis to test axis tightness)
- Mount heat bed
- Attach control panel
- Make all connections to control panel
- Test print, tethered to Cura (10 mm cube)
- Test print via SD card (3D Benchy) (not shown)
- Production test print - 16 motor pieces - File:Universal axis motor side.stl (not shown)
Recommendation for axis builds:
- Put pullies on motors
- Make all carriages
- Start with motor piece - put long bolt and nuts under motor
- Mount 2 halves WITH BELT INSERTED ALREADY
- Put in the 7 bolts and screws on other side. Keep loose.
- Insert 2 rods
- Insert carriage (don't worry about bolt correctness. Keep loose.
- Idler - put on 2 bearings halves
- Put belt on
- Close the sandwich for idler
- Tighten bolts (bolts have to be on the correct side)
- Insert idler on rods - TIGHTEN IDLER SIDE HERE TO THE FINAL TIGHTNESS
And comments. Time of build is in minutes. Negative sign marks time of rework (not build time).
- 15:42 - Start. Unpack. Weld frame. Set up camera. Includes going from house to workshop. Time: Frame: 37 Frame only is 21 minutes with travel according to video above.
- 16:19 - Axis assembly start. Y + Z rear. Missing tool: tape spacer. Time: 7
- 16:26 - Error warning: set screw allen wrench short side wore out mid way. Got another one. Time: -2
- 16:28-16:34 - Cleaning out idler pieces . Time: -7
- 16:35 - Tape on bearings. Not needed in practice. Time: 3
- 16:39 - Finished bearing insertion for all axes. Time: 2
- At the beginning, also glued the extruder holder on x carriage so it has time to dry.
- 16:56 - Y left finished - Time: 28 . Technique: belt was inserted during clam-shell build on both axis end-pieces.
- 17:03 - Z back finished - Time: 7
- 17:15 - Y right, Z front done - Time: 12. Total for all axes outside of X - 47
- 17:23 - Y left and Z back axes mounted on frame. Time: 8
- 17:29 - Y right, Z front hung on frame - Time: 6
- 17:32 - Thermistor and PEI fix - Time: -3
- 17:35 - Glue PEI. Time: 13
- 17:48 - One heat bed nut was too small on the inside. Got another. -10
BREAK at 17:58
- 18:53 - Nut catcher holes in idler pieces were droopy, reamed out to fit nuts. -2. Note that this is important only for X axis and bed mount - as the Y and Z don't use the nut catchers.
- 18:55 - Z platform start.
- 18:58 - Z platform done (without bed attachment still) Time: 3
- 19:10 - X axis done. Time: 12.
- 19:15 - Y endstop glued on Y axis. Both endstops inserted into holders and one glued in. Time: 5. Started power supply.
- 19:18 - 5 power supply screws came off. 1 was lost. Power supply power cord zip tie loose and below power supply. Power supply cord fixed to the top. Replaced screws. Time: -4
- 19:22 - Started control panel. MOSFET dangles forward. Need third hole for MOSFET?
- 19:37 - Control panel done. Time: 15. Notes: MOSFET very close to RAMPS. difficult to plug in USB cable.
- 19:39 - Extruder sensor did not fit in extruder sensor holder. Reamed. Time: -1
- 20:10 - Extruder finished - Time: 32
- 20:21 - X axis mounted - Time: 11. Started cable chain. Missing hole for cable chain. Hole drilled. Time: -8. Also, drilled hole in plastic end piece (this neds to be designed into file to avoid drilling)
- 21:18 - Finished cable chain. Moving to belt pegs. Time for cable chain: 49. Cable chain means assembling cable chain pieces, threading all the wires through, and zip tying to cable chain.
- 21:33 - Belt pegs all inserted and all axes tensioned at one time. Pace slowing down late in day. Time: 14. Also, Most belt pegs were too large. Used smaller ones from inventory. Time: -1. Gluing bed to bed nuts.
- 21:50 - Glued bed to platform. Includes mixing and application time for JB Weld Kwik Weld. Moving onto control panel mounting. Time: 17.
BREAK at 21:55
- 22:12 - 1 power wire on back of RAMPS broke off. Second power wire - one wire broke off inside terminal. Resoldered with solid 12 gauge house wire. Did not fit in terminals, so I shaved some off with a knife. time: -18. This is a recurrent problem. Replace power wires with solid 14 gauge house wire, except for MOSFET wires. When bending these wires, hold wires with both hands to bend.
- 22:30 - Mounted control panel. Note: way over time. Fought the difficult hole locations for a bit of time. Edges of plexiglass were broken on 2 sides - this should be 10 minutes or less under normal circumstances, but took 25 minutes. So I call this: time: -15. Time: 10.
- 22:50 - Made all of the wire connections, plugged everything in, while routing wires neatly and zip tying. Time: 25. (includes 5 minutes before break)
- 23:10 - LCD location incorrect. Removed LCD and used spacer to free up interference from cable chain. Time: -12. Note: could have redrilled location in plexiglass, but didn't want to risk breaking plexiglass late in the night.
- 23:22 - Spool holder holes too small. Reamed first with drill, did not work, so used heat gun to soften plastic, then they went on correctly. Time: -14. Time to actually put on rod holders: 2
- 23:38 - Motion testing. One stepper cable was broken. Replaced with new one after testing broken one on a working motor. Time including replacing one broken wire: 22.
- 0:00 - Printing sample cube. Successful first print with first guess of -1.4 z offset. Didn't have to touch babystepping. Probe triggered correctly without requiring initial probe height readjustment. Time: 5.
- 0:05 - Ran a test print of motor piece. Beginning of production tuning.
- 316 minute total build time - not counting any rework steps. Note 1 hour for build of 5 axes from kit.
- Rework total time: 97
- Total break time: 72
TOTAL - 485 minutes, or 8.1 hours
Tips and Tricks
- To level print bed for mounting - press down all the way until the bed mounting idlers both rest on the frame - thereby using the frame to determine a perfect parallel to the ground.
- For the extruder, insert the thermistor and heater cartridge only after the heater block is screwed into the extruder body. This allows the thermistor and cartridge to be placed in a position that allows for their easy removal for servicing of the hot end, such as replacing nozzles or other work. This also allows for the cable chain to be built in parallel - instead of having to wait for axis and extruder mounting. This allows a 2 person team to work in parallel on the cable chain - by working on the cable chain separately from the rest of the machine. For example, one person can be mounting the controller and bed, while the second person can be assembling the cable chain.
- With the optimized cable chain routing, it turns out that a heat sink extender is not needed for the 13" frame, and the extruder motor extender is not needed either. Once we add the print cooling fan, that wire will need to be as long as the z probe wire.
- 2 top half circles of carriage pieces all had extra plastic on them. Needed cleaning.
- Thermistor head was on top face, not in hole:
Overall kit evaluation is this based on Kit Certification#Evaluation
5 is perfect. 4 - good, but not perfect. Any score of 3 or lower mean that a printer would not be built successfully. 2 means that a part was missing. 0 means not done.
- Kit Prep
- 5 points per completion step for 15 pictures. Verification of pictures via build by OSE staff. 49/75
- 5 points per completion step of 10 additional pictures of electronics prep - 41/50
- Keeping accurate time on your main document - 5 points. 4. Not done in one sitting.
- Keeping accurate time on your electronics document - 5 points. 5
- 10 points - comments on improvement suggestions. 5
- Time: measured, must be under 4 hours.
- Embedding of main spreadsheet with links on your kit certification page - 5 points. 5
- Embedding of electroncics spreadsheet on your kit certification page - 5 points. 5
- Embedding of workspace setup document on your kit certification page - 5 points. 2. Not updated.
- Embedding of Build Certification on your kit certification page - 5 points. 5
- Packing kit - 5 points. 3. Corner opened in box.
- Shipping kit - 5 points. 5
- Printing bonus - 10 points - if no cleaning/reaming is required for any kit parts upon the kit verification build. 0
- Kit perfection bonus - 10 points if no rework is required upon the kit verification build. 0
- Kit completion bonus - 10 points if no parts are missing upon the kit verification build. 0. JB weld flew out?
- Build - Quality of 3DBenchy print. 6 hours or under. See detailed procedure at Build Certification.
- 5 points for every picture of Build Certification (about 25 pictures or more if needed)
- Keeping accurate track of time - 5 points
- Quality of 3DBenchy - 5 points for picture set, for the best set of 8 pictures
- Time lapse video of the entire build is presented at 10 second interval using OpenCamera app, uploaded and embedded. - 20 points. Upload of timelapse to a video site and embedding as the 5th asset on your kit certification page
- Bonus - 10 points if babystepping correction succeeds in achieving a successful print on the very first attempt.
- Production print - 50 points - verifies that everything is tight and printer is ready for shipping.
Sara Comments and Improvements
- Nut catcher area of printed pieces has since been improved by running an external fan during printing
- Bed holder nuts are sometimes too small -- but can be forced on using a hammer or similar tool
- More careful packaging procedures should be implemented - to protect delicate wire connections
- In preparing this kit, the power supply screws were left loose after removing cables following electronics testing. Noted that these should be partially retightened to withstand transit
- Sara Kit Build
- Kit Certification
- Current Material inventory - 
- 3D Printer Logs - for parts production