What are the negatives of an SKR board over a “proper” CNC controller?
I was planning on using an SKR pro but still wondering if it’s the best route to go down?
I’m not sure what you define as “proper.” If you are talking about the firmware, Marlin, which grew out of 3D printing, is the dominant firmware for the MPCNC. A small fraction of the MPCNC users use GRBL. My take from the few posts comparing features of GRBL and Marlin is that Marlin is a worthy competitor with both firmware versions having positives. Personally I like to run headless (without a computer) to keep my laptop out of the workshop. Marlin allows this. As far as I know, GRBL does not.
As for the boards themselves, with the exception of the CNC Shield (which is Arduino UNO based and only runs GRBL), all the control boards I see were designed for 3D printing.
Note that the Arduino Mega based boards like the Ramps add-on board and the Rambo board can run GRBL. I’m not sure how much work it would take to get it up and running. For the boards that V1 sells, V1 maintains pre-configured Marlin firmware. This is the easiest path to getting a machine up and running.
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The downsides is that it is pretty complicated under the hood, and we are starting to get a good handle on the issues, but there are still some odd issues that have been creeping up occasionally that we haven’t really gotten to the bottom of.
But that is a minority. There are a lot of them out there and most of them work great.
This might be a superficial input from my side, but I have to chime in. I have the Rambo 1.4, and I really appreciate that I can move the gantry around, without risking frying something on the board. There are countless times where I need to move the gantry, and it would be a hassle to boot up to jog it around. I don’t know if other boards are very vulnerable to current buildup, but I seem to remember some warnings about it.
The motors can generate voltage and as long as the voltage stays below the supply, there isn’t any risk. My rule of thumb is, is you see the lcd turn on, you need to slow down.
Thanks guys, I’m happy with marlin configuration as my 3D printer is marlin so I’ll carry on with this path and get the skr pro
Funny you mention that. A number of times I have moved the router by hand and saw the LCD turn on. Then I thought to myself “I should ask on the forum if that’s a bad thing” by the time I’m out of the garage I forget about it. I’ve done it lots and have had no issues…yet
You only need a place to store your gcode file to run a job headless, the software you use has nothing to do with it. Historically GRBL was usually run on an uno or nano based solution which does not have any sort of sd card storage whereas historically Marlin was run on boards designed for 3D printers, which did have sd card storage. There are now more options about. The addition of a tft display to an uno or nano based board gives you that sd card storage and allows headless operation, as do the esp32 based solutions.
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I was going to note that I just did my first crown on Sunday and ran it headless on my grbl based machine. Having done 3d printing and now using grbl I do like how setting are done on grbl better than marlin but I thinks it’s more about what your comfterble with and personal preference.
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Just to be clear here, does GRBL have native display support? For example, can I use a Rambo board with an LCD display? From what I’ve read on the forum, TFT displays have their own firmware, and reading between the lines, that firmware just communicates with the control board over a serial connection…at least I think this is how it is done with Marlin using g-code. So I assume for these TFT displays there is GRBL-specific firmware? If so what displays does it support and where is it released? Does anyone have GRBL on a Rambo board with a TFT display?
In short yes, you can use a mks tft.
@robertbu For displays see this thread GRBL and TFT screens (and some WiFi too)
I run mine using the esp32 web ui. So my tft is my phone or tablet. I could use my pc but I currently have the wifi card pulled out so I can’t connect to the esp32 in its current configuration.
Interesting thread. Thanks. I view LCD and TFT as different things. An LCD is (typically?) dumb. In the case of Marlin, the display is driven directly from the Marlin firmware. There was no mention of native display support in GRBL in the thread. As I expected, the TFT runs it own firmware and communicates over a serial connection. When I knew what to search for (from the thread) it was relatively easy to find the source for the firmware.
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I understand I see them as different as well, just in a different way than you. To me an LCD is a simple dumb screen. While a TFT is an LCD with a digitizer. The digitizer usually requires some level of on board processing to make it easy to connect to other devices.
So my answer came from the concempt that to me all TFTs are LCDs (I guess I am leaving out fancy led screens but who can afford those?)
I’m not sure about built in screen support(like marlin has)
Edit: I guess a quick Google search clarifies things. TFT stands for thin-film transistor and is a type of LCD technology. The TFT increases resolutions and image quality. So all TFTs are LCDs however neither have anything to do with touch sensitivity or level of intelligence.
I learn somthing new everyday!
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The main difference is that Marlin decides what to draw on the LCD, and any menu options or menu clicks are interpreted by Marlin (for better or worse). The TFT acts more like repetier host, or UGS.
One example where that matters is that the TFT on my printer changes when I start a print from Octoprint. Once it’s running, the controls simplify and I can do things like change the feedrate, or adjust the Z baby stepping right away, without finding those settings in the menus. The TFT is completely unaware that I am printing, unless I actually run the file from the TFT screen itself.
The Marlin LCD is also a lot more mature, in my mind. But that can change. I think the TFT screens have a lot of potential. And making all that control happen in another box is awesome for grbl. But the trouble comes in the software for the TFT. You don’t have to trust the manufacturer of the LCD. They just need to draw pixels. But trusting BTT to get the TFT software right (or even me) is not as easy.
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