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WernerKr / -Un-original-Prusa-Heated-Drybox

Code files for the heater
GNU General Public License v3.0
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Modification ideas: ESP8266; rotary encoder #1

Open maximweb opened 5 days ago

maximweb commented 5 days ago

Hi there,

I am currently in the process of upgrading my MK4(soon to be S) with MMU3 and the (un)original heated drybox. When scouting for possible modifications, I saw your very interesting mod.

I have some ideas for further modifications, which I hope are worth sharing.

Switch from Arduino to ESP8266

Your images indicate that you are using Shelly products to log the temperatures, and it somewhat looked like Home Assistant. Hence, I was thinking about replacing the Arduino with a wifi-capable ESP8266/NodeMCU. This could then push all the sensor data to a self-hosted MQTT server enabling logging and live review of the heater's performance without the need of additional Shelly hardware. (I've some working not-yet-published code for ESP8266 and MQTT, which I could contribute.)

Replace some buttons with a rotary encoder

Another tweak I can think of, vastly improving flexibility, is to replace some of the buttons with a rotary encoder. This gives significant more flexibility and allows to built an entire menu structure. In addition to setting the target temperature, this would also allow to adjust multiple settings, currently hardcoded.

I would love to get your take on my suggestions. It might take some weeks until I have all the default parts for the enclosure ready, but I am willing to contribute some code, as I have helpful bits and pieces already lying around on my harddrive somewhere.

WernerKr commented 5 days ago

I was thinking about replacing the Arduino with a wifi-capable ESP8266/NodeMCU

I had this idea too and have even bought an Arduino Nano ESP32 with Headers [ABX00083] – ESP32-S3, USB-C, WLAN, Bluetooth, HID support, MicroPython compatible But I haven't done anything with it yet.

Shelly products to log the temperatures, and it somewhat looked like Home Assistant.

Yes. The Selly plus 1 with Add-on plus is a device in Home Assistant und here I can log the temperatures of (un)original heated drybox. Why Selly? Is an independent device outside the dry box, i.e. not exposed to high temperatures, the DS18B20 sensor can measure temperatures of up to 125°C and can switch off the voltage from the heating element in the event of overheating without an additional device. It is important that the fans continue to run. The Shelly is only intended for additional security. Is currently available for recording temperatures, as I have not found any other way to record such high temperatures and transmit them for evaluation

I have tried to use the DS18B20 sensors directly now as well. They are not recognized, but they work because they are recognized by the Shelly. I haven't yet found out the reason for this.

Replace some buttons with a rotary encoder

I think this is a prerequisite for further expansion.

I think your suggestions are excellent

maximweb commented 5 days ago

I was thinking about replacing the Arduino with a wifi-capable ESP8266/NodeMCU

I had this idea too and have even bought an Arduino Nano ESP32 with Headers [ABX00083] – ESP32-S3, USB-C, WLAN, Bluetooth, HID support, MicroPython compatible But I haven't done anything with it yet.

I just looked it up, didn't realize that there is an Arduino ESP. Must have missed that, thanks. I have a bunch of different versions of ESP8266 board, though. My last attempt to MicroPython was some years ago, and I had trouble getting it work reliably. But I never revisited it since. For such possibly dangerous applications, I would always opt for Arduino (C/C++) code.

Shelly products to log the temperatures, and it somewhat looked like Home Assistant.

Yes. The Selly plus 1 with Add-on plus is a device in Home Assistant und here I can log the temperatures of (un)original heated drybox. Why Selly? Is an independent device outside the dry box, i.e. not exposed to high temperatures, the DS18B20 sensor can measure temperatures of up to 125°C and can switch off the voltage from the heating element in the event of overheating without an additional device. It is important that the fans continue to run. The Shelly is only intended for additional security. Is currently available for recording temperatures, as I have not found any other way to record such high temperatures and transmit them for evaluation

Thank you for the info, I had not really thought about the electronics overheating. Maybe I opt for moving all electronics to the outside of the box. Maybe next to the PSU.

I have tried to use the DS18B20 sensors directly now as well. They are not recognized, but they work because they are recognized by the Shelly. I haven't yet found out the reason for this.

DS18B20 can be tricky. They easily damage when connecting them in the wrong way. In addition, they are very picky regarding the value of the pullup resistor on the data line. Some reference code from one of my projects.

maximweb commented 1 day ago

I hope it's ok that I hijack this issue to report my latest findings and progress.

I've read your notes regarding the temperature distribution being poor without additional external fans.

Hence, I had a look at the duct I believe you are using.

I think the design of the duct has two flaws, which when fixed, might make the additional fans unnecessary. The original design divides the entire cross section in three even sections. The outer ones direct the hot air sideways and the central one downwards. The flaw I see in this is that the cross section of the duct includes the black plastic frame of the heater, while the air from the fans solely flows through the metal parts.

This results in most of the hot air flowing in the central section and hence downward, whereas only a small portion of air is taking the outer section directed towards the sides.

duct original flaw

Therefore, I am in the process of redesigning the duct with the following changes:

Here a sneak peek:

duct redesign sneak peek

So far, I have only printed in PETG as design test. Running the fans without heating, I can confirm that most of the air is exiting the duct sideways. As of yet, I never printed with Nylon and still waiting for my order to arrive. I hope i get this printed without warping.

PS: I also ordered an Arduino Nano ESP32. Some more printing of basic frame parts to do, before I can start coding.

WernerKr commented 1 day ago

Hi,

might make the additional fans unnecessary I think that the two additional fans have a positive effect on the air distribution, especially towards the front

In my opinion, the upper distribution is OK, It divides the heating area into 3 equal parts. The problem is the side outlet, which is much smaller than the one assigned above.

I therefore also increased the side outlets by 15mm. I have to say that I haven't been doing 3D printing for very long and don't have enough experience. I can only make changes with the PrusaSlicer using Add Part or Add negative volume.

widening the entire base of the duct, placing the side outlets further apart. I also suggested this to the "duct" creator, but he never responded I hope i get this printed without warping. With Easy Nylon form Overture (printed with 260°C) no Problem with Warping But on Strong overhangs create blobs. No need of “Supports”. I also tried using supports, but the blobs were even worse.

See attached pictures.

2024-10-08 21 36 44 2024-10-08 21 34 24 2024-10-08 21 31 27

Werner

From: Max Sent: Tuesday, October 8, 2024 6:34 PM To: WernerKr/-Un-original-Prusa-Heated-Drybox @.> Cc: Werner Krenn @.>; Comment @.***> Subject: Re: [WernerKr/-Un-original-Prusa-Heated-Drybox] Modification ideas: ESP8266; rotary encoder (Issue #1)

I hope it's ok that I hijack this issue to report my latest findings and progress. I've read your notes regarding the temperature distribution being poor without additional external fans. Hence, I had a look at the duct https://www.printables.com/model/951757-duct-for-unoriginal-prusa-heated-dr ybox I believe you are using. I think the design of the duct has two flaws, which when fixed, might make the additional fans unnecessary. The original design divides the entire cross section in three even sections. The outer ones direct the hot air sideways and the central one downwards. The flaw I see in this is that the cross section of the duct includes the black plastic frame of the heater, while the air from the fans solely flows through the metal parts. This results in most of the hot air flowing in the central section and hence downward, whereas only a small portion of air is taking the outer section directed towards the sides. duct.original.flaw.png (view on web) https://github.com/user-attachments/assets/9c83eeef-22c9-44fd-a159-7af86a19 ce7b
Therefore, I am in the process of redesigning the duct with the following changes: