Here's what I've been building for the past few months:

Ultimaker-like gantry, bed on Z with dual leadscrews. A flexible shaft worm driven extruder on a hacked-up Titan Aero. One-handed nozzle swaps. Duet 2 WiFi. Some other bells and whistles.

Read more about it here: https://eleccelerator.com/hephaestus-my-own-3d-printer/ , it's a long page, printed out it covers 70+ pages

We got about three possibilities here:

• burnt PCB trace or otherwise bad connection caused by high current
• dead MOSFET, meaning we replace the MOSFET
• dead GPIO, you are screwed if this is the case

Have a look at the schematics

FAN0 is controlling TR5, which is the MOSFET. The MOSFET is a PMV40UN2, so go download that datasheet. Locate the "D" pin, which is the Drain pin of the MOSFET. This pin should be connected to J25, which is the fan connector. Use a multimeter in continuity check mode to see if D is connected to the NEGATIVE SIDE of J25 at all. If it is not then you likely put a lot of current through a PCB trace and caused it to break somewhere. But it also means you might be able to fix it by simply soldering a wire between the D pin and J25. This covers the first possibility.

There are two resistors near TR5, R24 and R42. I would do another test now, measure the voltage where R24 meets R42. Turn on FAN0 (using gcode), the measurement should be around 3.3V. Turn off FAN0, the measurement should be around 0V. If it doesn't do that, then you are boned, because the GPIO is not working.

If it does work in the previous test, then great. It means the microcontroller can still control that pin. Next step is to simply replace the MOSFET. If you can get one, then great. They are listed on Digi-Key at $0.57 each, shipping should be about $4 to most of USA. You've got no excuse.

The package of TR5 should be a SOT23, which is large enough that you can cut the legs off with a knife (being careful not to damage the PCB underneath). Once the legs are cut, use a soldering iron to move the remaining half of the leg off the PCB pad. After that, solder in a new MOSFET. You might need to watch a few tutorials on surface mount soldering first but trust me it's easy, you just need the proper tools, like a tweezer, thin solder, and a pointy soldering iron tip.

Appendix: If you can't buy the exact part but can get something else, then make sure it has the appropriate ratings. I would focus on the following ratings: (follow along in the PMV40UN2 datasheet if you are wondering how to find these specs)

• V_DS rated more than 24V, the PMV40UN2 is rated for 30V, look for 30V or more
• V_GSth should be something lower than 2V, the PMV40UN2 is has V_GSth between 0.4V and 0.9V , don't go too low, 0.4V is pretty damn low to me
• R_DSon should be low, under 100 milliohms preferred, looks like PMV40UN2 is about 50 milliohms in normal use
• I_D, which is the electrical current rating, go for greater than 3A. PMV40UN2 is specced to handle 3.7A continuously at room temperature

Mind if I jump in and suggest simply using a remote desktop application? I use Chrome Remote Desktop, which uses my Google account. Works anywhere in the world and on any OS, including Android.

I have used extra fan pins to control a bi-colour LED.

I have a single script file for starting a print and a single script file for ending a print, I could easily have different colours for those four statuses you mentioned by writing the LED commands into the scripts

this is not really reading the status, it's more about how you are always in control of what status you are in, because you wrote the gcode files that run before/after every print

of course this won't turn on the LED red just because you've manually enabled the bed heater without actually starting a print... but for 99% of use cases, it works

edit: another idea is to just intercept the communication between PanelDue and the Duet with a microcontroller, or rather, make that microcontroller poll the status of Duet via UART commands. This will get you much more information, but requires a lot more hardware.

@mrehorstdmd said in Finished my first DIY: Hephaestus the 3D Printer:

Looks great, but I cringe every time I see those spring tensioners on the belts...

Yea my friend said the same thing, I can easily design another plastic block that have a midway split to give it a non-springy tension.

The sliding blocks do have a screw to tighten the belt but they are at their limits already. It's way too difficult to assemble the gantry if I attempted to bring the belt in another tooth.

If you are about to tell me that the spring style tensioners are not actually doing anything because they are on the other side of the belt, that's not the case here, because the pulleys on the non-driven ends are actually not secured to the rod (set screws removed), so the tension actually transfers through the whole belt and not just the bottom half.

@phaedrux said in Finished my first DIY: Hephaestus the 3D Printer:

Great splash screen on the PanelDue.

I don't suppose you have links to the STLs of the dragon and lion statues you've shown printed?

https://www.thingiverse.com/thing:305752

https://www.thingiverse.com/thing:1351967 (modified by me with ThinkerCAD to be support-less, I got rid of the dangling ball, added a base, gave the teeth a rod-like supports, printed at an angle, with the "make overhang printable" setting in Cura enabled), modified model by me is here: https://www.tinkercad.com/things/jQfYaCHhxO1

M564: Limit axes
Parameters

Hnnn H1 = forbid movement of axes that have not been homed, H0 = allow movement of axes that have not been homed (firmware 1.21 and later)
Snnn S1 = limit movement within axis boundaries, S0 = allow movement outside boundaries

You are missing the H0

Personally I think you'll get away with just using Adobe Illustrator/Fireworks/Inkscape to redraw it all. It doesn't have to be exact. You got like 4 main screens to replicate and a few modal dialogs. It sounds like a pain in the ass... but you really only need to do this once, and then replace text and colours in the elements. It's a lot more forgiving when you make a mistake too.

Otherwise mount a GoPro in front of the actual LCD, and have instructional videos instead of just pictures. I'm sure you've already thought about this one

A few really "fun" technical approaches:

• modify PanelDue firmware to send LCD data out the USB port (as a CDC virtual COM port), write Python script (or whatever language you want) on PC to capture and render data from USB serial port
• modify PanelDue firmware to be compiled with Visual Studio, and replace the LCD functions with functions that draw into a WinForm element. You'll want to replace the touch screen functions with WinForm click events too. (replace Visual Studio with QT or something if you want)

Both of those approaches are overengineering, but the second one might be nice for Duet's own QC purposes.

I have two Taranis RC radios that run OpenTX. You can emulate every single thing on it from the PC.

I got as small board from Amazon that was a ESP32 with a OV2640 camera integrated, and has a USB-C port for power and flashing, cost about $20 on Prime 1-day. Apparently the same setup can be obtained for under $10 if you order from China (eBay/AliExpress/etc)

The software setup was pretty easy, I've worked with Espressif chips before so it was extra easy for me.

• install Arduino
• install the Espressif toolchain either by using the Arduino board manager or by using a few git commands (instructions from Espressif's github)
• install CP210X drivers
• downloading the code from https://github.com/geeksville/Micro-RTSP
• put that code as a library in the Arduino libraries folder

EDIT: uploaded example of sketch folder, showing where the sketch and libraries are located, change contents inside wifikeys.h with SSID and password https://github.com/frank26080115/HephaestusConfig/blob/master/other/esp32cam_sketchbook.zip

• put the example code in a sketch folder
• setup your own WiFi network credentials in the example sketch code
• hit compile and hit upload (selected board target is M5Stack-Core-ESP32
• check your router to find its IP address
• go to http://x.x.x.x/ to view your video stream, http://x.x.x.x/jpg for a static image
• setup DWC to load http://x.x.x.x/ or http://x.x.x.x/jpg , if you choose the live stream, you need to check the "stream" checkbox

then it looks like...

(uh... can somebody please fix the sizing of the dialog when the image is rotated? thanks)

cheaper and less complicated than a Raspberry Pi, cheaper than really any WiFi camera out there that DWC would support. horrible camera though...

@dennishall said in Duet webcam:

I haven't yet done this as I'm probably going to figure out how to make use of my AruCam(s), but here is a setup that seems to have worked: https://forum.duet3d.com/post/90344

by the way that setup works with a continuous stream, not just a still image, with the live stream you need to set the URL without the "jpg" and enable the iframe feature in Duet Web Control

edit: i edited the original post to have a line saying how

I think the best course of action is to have RRF only output one message, and subsequent identical messages are suppressed.

This should be a rule of thumb for any system that can possibly generate messages from a function that have automatic retries.

I have a printer, running great for a few years, it uses a PT100 sensor on the nozzle. It's the E3D brand purchased from Filastruder, so it's the one that comes with Molex Micro-Fit connectors. I use the included pigtail so to avoid doing my own crimps.

A long time ago, I had problems when the print would halt due to a sudden spike in temperature. That was identified as a problem with a bad crimp with the included pigtail. It was easy to fix, I cut it off and used soldering to splice in a new one. And things were fine for another year or so.

This week, turning on the printer, the nozzle seemed to show temperatures about 20 deg C higher than ambient. Wiggling the Molex connector seems to make the temperature drop back to room/ambient.

Everything is zip-tied down neatly with no flex during motion

Questions:

Are the Molex Micro-Fit just that unreliable? Or, does it have some sort of lifespan and I am exceeding its expected lifespan?

A 20 degree C offset, what does that translate into in terms of additional contact resistance (in ohms)? I am having trouble finding specifications raw enough for me to calculate this.

Thanks!

I recently got a FLUX Beamo laser cutter. It's got a Raspberry Pi and a STM32 inside. The software ecosystem is pretty closed up, no G-code in or out. However, the Pi's microSD card is easily accessible and FLUX left some old outdated source code on there, outdated but enough for me to be able to convert their "FLUX Task" files into G-code. (not the other way around, no G-code to FLUX-Task, but I conjured up "human readable F-code" with some Javascript converter I wrote and I can edit FLUX-Task files now)

I found something interesting: The way they send over monochrome data to the STM32 not as a series of G-code, but instead, for example, [0xFF, 0xFF, 0xFF, 0xFF] would represent 32 pixels (4 bytes, 8 bits each). At 0.1mm per pixel resolution, that is a black line 3.2mm long. If you do [0xAA 0xAA 0xAA 0xAA], it would be a dithered line 3.2mm long. Of course more bytes can be sent for longer lines. After a line is done, it shifts 0.1mm down the Y axis and starts another line.

Anyways, I thought that was pretty cool. Maybe you guys want to implement something like that? How do other systems do it?

Hmm... My Duet WiFi has a microSD card, and BMP files are pretty easy to parse. It might be even easier if you just allowed the user to engrave a BMP file directly, given pixel resolution and starting coordinates.

Thanks guys

the 6mm rods were a cost-down from using a linear guide rail right in the middle. I am not familiar with the performance of rail bearings and how they'd handle roll loads, and both research and just intuition says it'll handle roll loads worse than moment loads.

Would a single 12mm wide x 8mm tall linear guide rail for the X axis suffice? (MGN12H, only one bearing race on each side, also probably Amazon quality)

I see there's a torque rating for these for roll loads, but what about play/backlash?

And are you serious that dual 8mm rods across 300mm is still not good enough to handle a Hemera? My other printer is two 8mm rods in a cross configuration (like an Ultimaker 2) with a Titan Aero and it's fine, although the belt configuration is much tougher than CoreXY.

@pipersw the belts are not on one plane, please use the 3D model and rotate the view.

Why must the belts be perpendicular on the bottom? I'm following the layout on the CoreXY website, which has the belts criss-cross

Actually, don't most designs cross the belts?

EDIT: I found this page https://greghoge.com/portfolio/large-format-3d-printer/corexy-gantry-system/ , but the advice there does not apply, my belts are not rubbing each other, they are on two different planes

...wait... this means there have been people who actually had belts rub together? That's insane lol aren't they going to turn into bandsaws on each other?

Hi

My previous printers have all been Ultimakers and Ultimaker-like machines. I have dabbled in designing a CoreXY printer. While I'm 99% sure I did everything right, even modeling the belts, I'm wondering if I'm missing something... Can somebody please take a quick peek?

Link to 3D model, open it to explore it in 3D, rotate, isolate parts, etc. Hosted on Onshape, opens in your browser, no downloads required

There are 12x8x400 mm linear rails on the sides for the Y axis, two 6mm diameter rods for the X axis with LM6LUU bearings on the carriage. Extruder will be a Hemera. Pretty standard 2GT belts and pulleys, secured with M5 screws. Most of the 3D printed parts will be 4mm thick to minimize flex.

I understand that the higher pulleys will suffer more from any flex in the M5 screw mount, that's why they are not stacked, there will be nuts that ensure the M5 screws are always perpendicular to the plastic.

Nothing ground breaking, I just rather design my own stuff instead of looking at other people's designs. What do you think?

Thanks

@mad3dhatter said in Recommended extruded motor:

@frank26080115
HI frank, My name is Justin. I am curious about your flexible system an d what type of flexible shafts you are using .

The first printer is a Ultimaker 2 upgraded with Flex3Drive https://flex3drive.com/flex3drive/f3d-um2/

The second printer is a custom built printer using some gears from eBay and the flex shaft from McMaster-Carr https://www.mcmaster.com/5910K92

The Flex3Drive I also hacked up to use the same shaft from McMaster-Carr, the old shaft was removed, replaced with a short piece of solid shaft so that it protrudes out the top, and then the new shaft attached to the solid shaft. The new shaft is thicker so it lasts longer.

Mind if I jump in and suggest simply using a remote desktop application? I use Chrome Remote Desktop, which uses my Google account. Works anywhere in the world and on any OS, including Android.

@zapta said in Cheap WiFi Webcam: ESP32 + OV2640 camera:

Frank, can you post an amazon link? I see there many similar cameras and would like to make sure its exactly the same as yours.

Also, do you see still images or actual video?

https://smile.amazon.com/gp/product/B07DVD4J7N/

both still images and actual video. http://1.2.3.4/ for video, http://1.2.3.4/jpg for still image

@bearcattd said in Duet webcam:

@frank26080115

I think I am close...which board do I choose in Arduino? the ESP32 board file added 40-50 new boards.

Thanks!

M5Stack-Core-ESP32 works for me, there's no clear instructions on this so I guessed it, since M5Stack is the seller.

@dc42

PLEASE make the enter key look like a fingerprint icon and do a scanning animation when we press it