Hi all,
I'm resurrecting a XYZ DaVinci as a RepStrap machine. I bought it for USD15 without a hot end, virtually unused.
The proprietary 'bearings' allowed 1mm slop vertically in the X and Y direction, with the head mount wobbling uncontrollably.
Background and info at end of post. I am familiar with Arduino and C++. (trained industrial engineer - process engineer / metallurgist as well as trade qualifications.)
Reusing a 12V DC power supply.
Retrofitting a RAMPS board/Arduino Mega 2560 combination to the above to replace their board.
I was wondering if I could ask your advice on the following (RAMPS questions first.)
(1) I was going to power the Arduino Mega separately through a 5V supply on the Vin pin. Will this avoid overheating the RAMPS/arduino without removing the D1 protection diode in your experience?
(2) Is a separate MOSFET board a nice to have or a necessity? I assume that being 12V power supply, the current draw is going to be higher than a 24V feed to the bed.
(2a) Is somebody able to recommend a MOSFET board as suggested in the RAMPS FAQ (working 12-14 hour days at the moment. starting 10 minutes ago)
(3) Is it possible to address the SD card on the 12864 LCD display through the ribbon cables on the display header on the RAMPS board?
(4) Has anybody set up an external interrupt on pins D 20/21 (or ATMEL 2560 pins 43/44 on the physical chipset ) to use as an emergency stop (was going to get the bed to drop 20mm if so). The RAMPS sketch I've seen has these as the I2C pins - do I need to use these to communicate with the SD card. Fallback: Is it better just to wire the power supply to the arduino in parallel as a kill switch?
(4a) Are there any other traps for young players that I might have missed in the above?
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Now the RapStrap questions:
(5) The unit is being used where stepper motor noise is audible. Do the TMC2208 stepper drivers give substantially lower noise?
(6) Which is the most accurate out of the TMC2208, 4988 or DRV8825 stepper drivers? I am now full time teaching practical subjects in COVID lockdown. When I get this working, it's first 100 jobs will be earring designs and jewellery designs for an all girls school through a 0.2mm nozzle for definition. It's easy enough at the moment to do it once and do it right.
Sorry for the length of the post, but...
I'd appreciate any advice and opinion you can provide.
Regards,
A
(moderators - trust that this is OK to post all within this forum - if it is better placed elsewhere, please feel free to move it..)
Background:
I am going to reuse the following:
Frame of the XYZ DaVinci machine.
Power supply. 240V, 50Hz in. (or is it 230 V here locally now?) 12VDC, 5V DC, 3.3VDC out from memory.
Steppers - NIDEC KV4239 (JST-PH connectors - the board has DuPont connectors, by the look of the photos.)
Bowden feed unit.
Maybe, the optical limit switches in some directions (others need to be scrapped/replaced with mechanical limit switches.)
Have bought the following:
E3D V6 clone hot end
Linear Bearings.
DR8825 Stepper Motors.
Mega 2560 / RAMPS 1.4 / LCD12684 (https://www.ebay.com.au/itm/312970444335)
MicroSwitches
Separately (on slow boats from overseas - might be here in Nov, have bought a RAMPS 1.6 and a Taurino Mega board.)
Edited 3 time(s). Last edit at 09/19/2021 08:39PM by Andrew_F.
