TEVO Little Monster Duet Ethernet Conversion
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I find a lot of optical endstops will work on 3.3v but to get a positive trigger you need large, black optoflags to trigger them, anything less doesn't give a solid trigger.
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My Tevo LM will be here next week. It would be nice to use these components to start with on the initial build up.
Should would be sweet to see that posting of full instructions to Thingiverse go up soon or did I miss it?Better go look again!
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There wouldn't be any show stoppers in regards to only switching the controller, but keeping the original extruder and volcano?
The only incompatibility I've thought of is that I believe that the stock optical endstops use 5V, while Duet WiFi/Ethernet expects them to run on 3.3V.
Hopefully somebody who knows more can chime in on this.
(it's probably not a big deal to take 5V from GPIO or something, in any case)
I thought of this as well, but thankfully, it appears the stock optical endstops are working just fine on 3.3 volts. Homing is working perfectly without further modification.
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Sorry for taking so long to post this, but here's the complete conversion instructions and 3d models for the conversion:
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Awesome! I have added a link on the wiki to this thread and the thingiverse entry. Thanks for taking the time to document this.
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Thank you!
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Are you happy with the dimmensionall accurancy of the printer? I have a spare Duet wifi and im dreaming of a delta Even if i got parts for a big Core xy on MGN rails on the bench ^^ Delta's Looks so cool!
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Are you happy with the dimmensionall accurancy of the printer? I have a spare Duet wifi and im dreaming of a delta Even if i got parts for a big Core xy on MGN rails on the bench ^^ Delta's Looks so cool!
I am. I've been comparing the setup to my SeeMeCNC Rostock MAX V2, which has been my bulletproof printer that cranks out my my accurate prints. So far, the TEVO with a Duet is within a 15-20 microns. Not bad for something I haven't tweaked at all compared to the Rostock that I've spent a significant amount of time dialing in over the past year.
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Seems I just have to get one
Thanks for the info Emulsifide! -
I can at least confirm that the frame seems very rigid, which alongside the large print volume was the main selling point for me.
I guess I was lucky with the controller too because I did get fairly consistent print quality with it. That said, it does crash occasionally mid-print but there's a chance you can resume the print if you don't go back to main menu and instead just turn the power off and on again. And when I say "consistent" I also mean that it seemed to produce unwanted print artifacts consistently too…
I'm pretty sure temperature sensing was off too.
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Thanks again for sharing this.
I've received my Duet Ethernet, and I am actually also waiting for some .9 steppers for the XYZ. I am a bit unsure though, on the necessity of replacing the stock 1.8 motors.. Will this actually be worth the hazzle? As I understand from the Duet documentation, the .9 ones are recommended to increase the torque on micro stepping these axes on deltas, but is there a strict need for it on the LM? Will a replacement actually give me better results down the line compared to the stock ones? (3d-hw-mod-newbie-alert)
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Using 0.9deg motors reduces the fine moire you get on prints from a delta. You can see my findings at https://miscsolutions.wordpress.com/2015/08/01/upgrading-the-large-delta-printer.
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Thanks, I will change the motors later on then.
Right now I have successfully switched out the MKS board with the Duet Ethernet.
I am amazed.. Truly. It went from a monster to being a kitten; I can sit in the same room as the printer and its sound level is like 50% of what it was. The auto leveling works fantastically, the UI makes it a treat to work with both settings and daily tasks.. Wow! Fabulous engineering! And the switch took me a few hours thanks to Emulsifide's pioneering and good Duet documentation in general. Can't get better. -
I also recommend these: http://www.ebay.com/itm/3X-NEMA-17-Vibration-Damper-noise-3D-printer-stepper-motor-dampener-screws/302320633635
Running my TEVO delta in the living room was misery prior to installing the dampeners. They work magic with this printer.
The seller on eBay sent me one defective part (the vulcanized rubber was loose) but I managed to fix it with superglue. The seller was so embarrassed that he sent me a fourth one for free, so I can at least recommend him for the upstanding service.
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I ordered my TLM kit with this exact upgrade in mind : And look, someone has already done all the heavy lifting, super awesome.
Only one question (right now): Is there any reason to get the whole kit built hooked up to the MSKBase first… or should I skip all that and just hook up the Duet directly? I ask because I haven't actually purchased the DuetEthernet yet. If I'll save a bunch of time going that route directly (straight to Duet), the I may as well order now so it's all ready to go at the same time…
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@Ak:
Only one question (right now): Is there any reason to get the whole kit built hooked up to the MSKBase first… or should I skip all that and just hook up the Duet directly? I ask because I haven't actually purchased the DuetEthernet yet. If I'll save a bunch of time going that route directly (straight to Duet), the I may as well order now so it's all ready to go at the same time…
No good reason that I could think of, aside from using it to verify that none of the parts are faulty.
What you could do in advance is modifying or swapping the connectors for compatibility with the Duet. I went the "modify" route and used side cutters and a precision knife to peel off plastic fins off the motor connectors and elsewhere where they would cause the white plastic back wall on the Duet board connectors to bend. I also replaced or split some Dupont connectors (e.g. BLTouch 1x3pin and 1x2pin to 3x1pin and 2x1pin). Be sure to at least check the wiring, as some of my kit's Dupont connectors had pretty awful crimping applied…
Be extra-attentive with the SSR (enclosed in the big black box on top, together with the PSU), and remember to generate your own PID for the hotend (and preferably the heated bed, although I skipped tuning that and just used OP's values which seem to work for me).
EDIT: You probably know, but just in case... Remember that the frame is grounded via the screwed connection to the aforementioned black aluminum case containing the PSU and SSR, so if you ever decide to relocate the PSU you have to remember to pull your own wiring from the PSU's protective earth connectors to the frame and check with a multimeter that the separate parts of the whole structure are grounded, with the most important part of course being the aluminum around and beneath the mains-powered heated bed. Checking that these parts are properly grounded is smart even if you modify nothing. I would go as far as making certain that the PSU's protective earth is in fact connected to proper pin on the back of the enclosure where the power cord is connected, and use a power cord that definitely isn't defective.
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Great info, thanks for the tips!
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I ended up ditching all of these parts in favor of genuine E3D parts, a .6mm nozzle, a Duet Ethernet controller, and a 7" PanelDue:
Hi
I've been looking into replacing the knock off E3D stuff for genuine parts myself. I keep having jams.
Would you mind specifying what you bought on the E3D website?Thanks
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I've now concluded that I seem to have been provided with a defective MKS SBASE controller board.
The MKS-SBASE controller is unreliable garbage. Mine worked for about 6 weeks.
Thank you for publishing your success. I was debating whether I should change to the Duet Wifi from the stock MKS-SBASE disaster of my TEVO. Seeing your success and the fact that Duet comes with Trinamic drivers tipped the scales.
I made a board with TMC2130 step sticks for my TEVO and these drivers made a huge improvement in printing quality and printing is nearly silent. I could not go back to the whiny sound of standard stepper drivers.
I agree with you on all the shortcomings of the software and controller combination. There are also absolutely no fail checks or safety limits for anything on this printer.
I bought my TEVO Little Monster thinking that for the price I was getting a 3D printer instead of a good mechanical frame, stepper motors, power supply, some cheap cloned parts for the extruder and hot-end. Oh, lets not forget a small chance to have all these come together as a working 3D printer.
I had small issues:
1. The BL-Touch failing and causing the printer to drive the hot nozzle into the bed, melting the liner. I wound up checking its status every print, just in case it failed.
2. One of the end stop sensors getting blocked by a loose filament, causing homing operation to think this axis is already homed and running the other two at 400 mm/s until they locked because the other carriage was low. The printer wasn't the wiser and kept grinding the belts until I turned off power.
3. No supports for the umbilical and filament coming to the effector meant that the filament got caught by one carriage during homing and could not reach home position. The printer kept going, grinding the belt.
I got it set up and running decently. Added printed mods to support umbilical and filament, added shrouds to protect the end stop sensors. However, I kept having intermittent failures with the printer just stopping once in a while but I was learning to live with it because it was very rare.
Then two and a half weeks ago (six weeks after I got the printer) I got a "filament jam". Since then I haven't been able to get it to extrude reliably and all attempts to fix the problem only seemed to make the situation worse. I haven't had the printer working since then and spend over $200 trying.
I wound up replacing all the cloned parts with genuine e3d parts, hoping it will resolve my issues and wanting to eliminate variables. As I kept diving deeper into the workings of the extruder and hot-end I realized that it was a miracle I managed to print at all with such poor quality components. I can vouch for the much higher quality of e3d components but my real issue turned out to be a slowly failing controller board reading higher temp than actual.
If it all went at once I would clue in faster but it was a slow degradation process. The hot-end thermistor channel must have gone first and caused the original "filament jam" by lowering the actual temperature at the nozzle. Finally, the bed channel also failed. Not realizing the two issues were related, I re-configured the bed and extruder to use the spare channels TH3 & TH4. It seemed to work but the actual temperature was 30 C below what the controller was showing.
This morning, just when I thought I could print again, the two remaining channels started reporting 93 C at room temperature. This is when I finally clued in that my problem from the beginning was an erroneous temperature reading by the controller and the rest of the failures were symptoms.
I am glad I now have all genuine e3d parts. I did not want to blindly replace them without doing some testing to assure myself that the change to genuine parts makes a difference. My trust in 3D parts and components has gone to zero unless I verify them myself. I used a Fluke multimeter thermocouple probe which I can trust and lowered it into the filament path. Stripping the outer teflon insulation, which keeps the red/yellow wires together, reduces the diameter so the probe fits where 1.75mm filament does. By controlling the depth of insertion I could measure temperature all along the filament path, right down into the nozzle.
I ran combinations of TEVO stock components (with the TEVO fan and fan mount) against the e3D parts (e3d fan shroud, quiet 30mm fan I bought at DigiKey) and found that with TEVO stock parts and configuration the heat-break temperature just inside the heat sink is 48 C with hot-end at 190 C. With e3D components and the quiet replacement fan it is 39 C for the same nozzle temperature.
I will place an order for a Duet Wifi and hope to have the printer working again over the weekend. I have a backlog of a few projects that are waiting on printed parts. I never expected my printer would be out of commission for almost a month after less than two months of use.
Vladimir.
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It's usually possible to convert 5V optical endstops to 3.3V. Identify the resistor in series with the IR emitter in the slotted opto switch and reduce its value by about 50%. If it's a surface mount resistor and you don't have SMD desoldering equipment then it's easiest to solder a second resistor of equal value on top of the existing one.
Does the Duet Wifi not have the ability to use the Stall detection of the stepper drivers for end stop detection?
I know this is possible according to Trinamic information and also by the Prusa MK3 implementing this exact feature.
This is definitely something I would like to use and if not available to work on the firmware enhancement to make it work.
I hate relying on the optical end stops. They are not as reliable as the trinamic stall detection because the latter will work if an obstruction stops the carriage from triggering the optical sensor.
