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RAMPSXB: An Expansion Shield for RAMPS

Posted by SZiv 
RAMPSXB: An Expansion Shield for RAMPS
August 22, 2017 07:33PM
Alright, I've been using printers for a while now, but I feel like I should give something back to reprap, so here's this!

Anyone remember the E3D Kraken? I was dying to get one but I didn't really have a way to tack on 2 more extruders, heaters, and thermistors. Same issue with the Reprap.me full color diamond hotend. In addition, I use RAMPS exclusively, and I felt the need for suppression capacitors like the ones on the RAMPS 1.4.2, as well as the breakout for the full graphic smart controller, and some more 12V/5V rails. I always find myself needing another fan, a way to control lights, or attach that darn HC-05 chip with a voltage divider.

So I fired up EAGLE and put together this board, the RAMPSXB (RAMPS eXpansion Board) which attaches to the AUX pins of the RAMPS control board like a shield, and adds all this functionality, at the cost of 3 of the 4 servos and the max endstops. It was designed to be cheap, just like the RAMPS board, and, aside from production of the boards, the rest of the parts are either pin headers, SMD resistors/caps, and the FETs. All the circuits are the same as the original RAMPS, so it should be as simple as defining pins in firmware.





Board:
Top:


Bottom:


Schematic:



The bottom power traces are exposed so they can be covered in solder and used for something like a second heated bed, although I doubt the 3.5mm terminal blocks can handle it. I also don't know if the processor will have a heart attack running 4 more of everything, but at least in my preliminary testing it seems to work. It only seems to run on Repetier, because Marlin doesn't look like it plays well with more than 5 extruders, but I haven't really tried.

Anyone with experience in board design have any other issues, suggestions, or ideas that I can add or fix with this? I'm DM'ing a mod to see if I can get an account for the wiki so I can do a full writeup there.

Github with all the source files here: [github.com]

Edited 3 time(s). Last edit at 08/22/2017 07:47PM by SZiv.
Re: RAMPSXB: An Expansion Shield for RAMPS
August 23, 2017 12:15AM
both thumbs up!

I do use RAMPS exklusively too, as all the 32bit boards are much to expensive for me, and/or do not have the possibility to change the stepper driver, if I burn one.

Well I see, my next project will be a diamond hotend for my delta XXL, as soon as I'm able to buy a RAMPSXB..
Damn. Just got ready - and you give me another project eye rolling smileysmiling bouncing smiley
Re: RAMPSXB: An Expansion Shield for RAMPS
August 23, 2017 03:13AM
Clever way to expand RAMPS!
Although I doubt, Marlin will be able to chew Delta-kinematics and 5 extruders in satisfying speed.
Cartesian kinematics and 20x4 char LCD will be best.

Are there many modifications on RAMPS to make it work with RAMPSXB? There must be a workaround for the HC05 voltage divider?
Is it 24V capable?
VDX
Re: RAMPSXB: An Expansion Shield for RAMPS
August 23, 2017 03:36AM
... I'm using ArduinoDue's with Marlin4Due firmware for my faster machines - either with the RADDS-board (12V or 24V, 6 motor drivers original, expansion boards with 2x or 3x motor drivers + WiFi) or with our own "proffessional" RADDS-compatible board with 24V I/O's, but only 4x motor drivers ...


Viktor
Re: RAMPSXB: An Expansion Shield for RAMPS
August 23, 2017 06:25AM
Quote
VDX
... I'm using ArduinoDue's with Marlin4Due firmware for my faster machines - either with the RADDS-board (12V or 24V, 6 motor drivers original, expansion boards with 2x or 3x motor drivers + WiFi) or with our own "proffessional" RADDS-compatible board with 24V I/O's, but only 4x motor drivers ...

I am curious why Marlin4Due (that is no longer maintained) instead of MK4duo?
Re: RAMPSXB: An Expansion Shield for RAMPS
August 23, 2017 06:52AM
It is 24V capable (assuming you get 30V rated PTC fuses) In part because I wanted a 24V bed and heaters (off the Xcool smiley, but also to be able to run 12v fans and led strips (off the main board).

The HC-05 was corrected with a small voltage divider on the arduino TX pin right on the board. It takes two oddball resistor voltages, but it works, and connects directly to the pinout on the HC-05 so you can plug it directly into that socket.

As for delta kinematics, I doubt this will be able to crunch numbers fast enough. You might try something like the RE-ARM (https://www.kickstarter.com/projects/1245051645/re-arm-for-ramps-simple-32-bit-upgrade), but I dont know what the pinout looks like. I use only Cartesian, so I never ran into this issue.

It's also missing some little things you might expect because I just ran out of space. There's no diode to protect against reverse polarity on the input, so don't mess that up!

I've got a wiki page for it here ( [www.reprap.org] ), and as soon as I figure out the markup language I'll put down some of the building instructions and usage.

Edited 1 time(s). Last edit at 08/23/2017 06:58AM by SZiv.
Re: RAMPSXB: An Expansion Shield for RAMPS
August 23, 2017 06:53AM
Quote
SZiv
(http://www.reprap.org/wiki/RAMPSXcool smiley,

it emojied my url! [www.reprap.org]
VDX
Re: RAMPSXB: An Expansion Shield for RAMPS
August 23, 2017 07:12AM
Quote
newbob
Quote
VDX
... I'm using ArduinoDue's with Marlin4Due firmware for my faster machines - either with the RADDS-board (12V or 24V, 6 motor drivers original, expansion boards with 2x or 3x motor drivers + WiFi) or with our own "proffessional" RADDS-compatible board with 24V I/O's, but only 4x motor drivers ...

I am curious why Marlin4Due (that is no longer maintained) instead of MK4duo?

... did some modifications with the Marlin4Due-firmware and it's running OK for my applications (paste-dispensing, laser-engraving, CNC-controlling) ... if I'll get some time, maybe try to adopt MK4duo too ...


Viktor
Re: RAMPSXB: An Expansion Shield for RAMPS
November 28, 2017 09:39AM
Great Idea. Can you fix Ramps-FD? This started as a great way idea but abandoned there is a great need for cheap 32 bit boards like ramps1.4 is to 8 bit.
Re: RAMPSXB: An Expansion Shield for RAMPS
November 28, 2017 09:55AM
If you're willing to explore new-ish firmware Klippy seems to get incredible performance out of 8bit hardware. I wouldn't give up on your Mega/RAMPs setup until you at least check it out. I agree there is a gap in the lowcost 32-bit market.
Re: RAMPSXB: An Expansion Shield for RAMPS
November 28, 2017 10:10AM
The RAMPS-FD is unlikely to be fixed because even if it was corrected (which it actually was, in V2), the manufacturers will just sell V1 and market it as V2. From a manufacturing standpoint, it would be better to make another board altogether.

I've mainly spoken about it in random facebook groups, but I am planning to make a board that uses the Arduino Mega footprint, and adapts a ESP32 module (like a $10 NodeMCU), level shifts it, and controls a stock 5V RAMPS board with it. It should only be a few pin headers, and maybe a IO expander and level shifter, so it should be pretty cheap, cheap enough that a $10 NodeMCU + a $10 RAMPS + this board should be less than most 32 bit boards out these days. The RAMPS board has its problems, but due to it's mass produced nature, it is dirt cheap, and so long as you dont abuse it, it actually does a decent job. The issue I'm having now is that the Firmware for the ESP32 is far, far in beta, and more importantly, I cant find a standardized board size (I'm looking at the basic square NodeMCU, but even those seem to have different pinouts). Still working on developing that, but its in the works.

In the meantime, I've got this board here: [github.com]

It's still in testing, and I'm waiting on the first set of boards, but it doesn't fix the main issue with the RAMPS-FD, which is actually a problem with the due, where the I/O pins swing high when the board starts up. That could theoretically be fixed in firmware, but no one has bothered to do it, and with the ESP32 being a good 3 times and 1 core faster, I see the Due being left behind as soon as the ESP32 takes over.

Edited 1 time(s). Last edit at 11/28/2017 10:12AM by SZiv.
Re: RAMPSXB: An Expansion Shield for RAMPS
November 28, 2017 11:51AM
Does the ESP32 have enough pins to support all the motors and periferals needed in a 3D printer?
Re: RAMPSXB: An Expansion Shield for RAMPS
November 28, 2017 11:53AM
Disregard my last post I just went to your Github site and read the description. Nice idea!
Re: RAMPSXB: An Expansion Shield for RAMPS
November 28, 2017 11:54AM
Normally it doesn't, but with an I/O expander like the PCF8575 it will.
Re: RAMPSXB: An Expansion Shield for RAMPS
November 29, 2017 06:18AM
SZiv,

I've added a third extruder to RAMPS, here is a simple tutorial on howto ...

[youtu.be]

Regards,
Ed
Re: RAMPSXB: An Expansion Shield for RAMPS
November 29, 2017 08:28AM
Also, as an update to the RAMPSXB project, I've been talking with www.reprap.me, and I believe they are going to produce and sell the RAMPSXB. Boards have been made and tested, and as of now, I think they just need to make the listing.
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