From 29e6eedab7ba279610c5397b4d6e3aa7ecb611f5 Mon Sep 17 00:00:00 2001 From: Pontus Borg Date: Wed, 24 Jun 2020 22:07:38 +0200 Subject: [PATCH] README.md updates --- README.md | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/README.md b/README.md index de7d704..2b2a2d0 100644 --- a/README.md +++ b/README.md @@ -1,26 +1,24 @@ # Huvud 3D Printer toolhead board -A very small 3D printer board for use on a toolhead. It is designed to be used with Klipper firmware. +A very small 3D printer board for use on a direct drive toolhead. It is designed to be used with Klipper firmware. +Klipper has the awesome feature to be able to use multiple MCUs connected to the host over a (relatively) high latency connection. Using CAN bus it is possible to chain many small board using just a pair of twisted wires and power. A good solution for multiple head 3D printers. -![Image of Board](Board.jpg) +![Image of Board](doc/Huvud0.4Render.jpg) Features: -* TMC2209 stepper driver -* STM32F103 72Mhz MCU +* CAN bus. +* One TMC2209 stepper driver for the extruder * Two MOSFET drivers fans * One bigger MOSFET driver for a hotend heater * Thermistor input * One endstop -* CAN bus -* USB +* STM32F103 72Mhz MCU +* USB, for flashing firmware Main power is 12-24V. 24V is preferred to keep the currents low All done in KiCad and open source. - -Change ideas: - -* Find a better heater mosfet, our 3.3V Vgs is on the low side for that chip. +If you are interesting in helping out, testing or eventually using this board feel free to contact me at glpontus@gmail.com. --- @@ -67,6 +65,19 @@ I have done thermal stress testing of the board. It can run a big stepper at 1.5 I'll very soon order another 20-30 board to send out to brave beta testers. +--- +## 2020-06-24 + +Ready to manufacture some more prototypes + +Among many small tweaks the heater mosfet is changed to a different one with better Rds at 3.3V Vgs. If I limit the board to 24V and a 40W heater it could use the same small mosfet as for the fans. + +Unfortunately JLCPCB are out of TMC2209 so I'll have to find a different prototype house that has them available. Perhaps one with 2oz outer copper layers for better thermals. + +CAN bus is surprisingly robust. I have tested it through a 50m roll of ethernat cable, various sketchy test setups with star networks, breadboards, close to EMC sources etc. It always works. The Bosch engineers did a good job almost 40 years ago. + +--- + # Can Hat ![Can Hat](CanHat.jpg) @@ -74,3 +85,6 @@ As a sub project to this board I have developed a little power and CAN distribut With some more thought put into it I think it will be a good complement to the Huvud tool board. +--- + +