Struggling to find a decent starter guide on the control electronics and software.
For instance, is seems to me that that lowest cost option is a Ramps 1.4 and the arduino board that goes with it running Marlin. But what advantages does the Jackpot board have over this?
And how do I interact with the machine once it is built? Does Marlin have a web-ui or do I need to run software on the PC to send G-codes to the control board?
Does the RAMPs have 5 drivers? If so then it should be able to work just as well as the jackpot. But if not then you will be losing a big feature of auto squaring the machine.
Also the Jackpot is the most supported board around here, with the SKR Pro 1.2 coming in second.
We used RAMPS exclusively about 8-10 years ago. The main problems with it were:
inconsistent build quality, especially for the cheapest sourced versions
drv8825 drivers need calibration, they are noisier, they don’t give feedback to the controller.
susceptible to a few user errors that would fry it. No reverse polarity protection or backfeed protection from the motors. ESD killed a lot of clones megas.
slow processor has issues when doing variable power laser etching.
Marlin does not have builtin wifi. You would most commonly use the screen and an sd card to set up and run jobs. We also would use cnc.js or octoprint running from a pi to control it. We made Marlin versions for RAMPS for a long time at marlinbuilder releases
The jackpot fixed those problems, also has web ui, and is designed for CNC machines instead of 3D printers.
To be fair, we ran a lot of jobs through Marlin and RAMPS. But the jackpot is easier to set up, easier to use, and has better performance when cutting or etching.
Ramps does have 5 drivers and can do dual endstops.
I might try a RAMPS to get started then - I can buy it from Amazon for $25 equivalent (I am in the UK) and once I have verified that everything moves in the right direction etc. than I can order a jackpot.
We have some preconfigured marlin for the skr pro v1.2 at marlinbuilder releases. The skr pro v1.2 fixes the issues I listed above for the ramps board, but still runs Marlin. There are some other builds for other skr boards, but they haven’t been tested as much. BTT has a very confusing naming scheme, so make sure it is exactly the same. For example, skr v1.3, skr turbo v1.4, and skr pro v1.2 all came out in the same generation and are completely different boards.
It has been a while since we talked a lot about them in these forums. So I have surely forgotten most of the details. So I will be limited when answering specific questions.
Jeff has done a great job answering the questions, so I’ll throw a bit of commentary around it.
If you wanted to run firmware like Klipper and had a pile of RAMPS or the SKR series, then it might be something to fiddle with. Similar if you had existing boards and wanted to fiddle with alternative firmware like GrblHAL.
I have to ask why you’re thinking of starting with one board and then swap boards. That doesn’t seem to make sense to me if you value your time at all. The one exception being that you just love to tinker and build. Even then, why start with one and then immediately pivot?
The SKR boards have 32 bit processors, so have no problem running modern Marlin, Klipper, or GrblHAL- but except for SKR Pro 1.2 they’re not the mainstream here. Although we’ll try to help you it will be trial and error.
The Jackpot boards are avialable on Elecrow. For the MPCNC they are a perfect match. They’re also very similar in price to what you’ve been consdiering.
My thought was to use an inexpensive board to get started with and verify the build - with the risk that I might do something silly and fry the board…I would rather fry a cheap one than the jackpot.
Most of what you could do to fry boards happens when you first hook it up (e.g. reversing power).
You do that fresh even if you swap boards.
There are two versions of the Jackpot that I’d consider “current”. The one linked above is Jackpot V1. That board uses a removable ESP-32 and removable TMC-2209 drivers. Until recently it was the only Jackpot board available. That one needs to add the ESP-32 in order to be a complete set (it’s linked on the elecrow page. Avoid the LCD, no Idea why they list that together).
Jackpt V3 is about to be available on Elecrow. The big difference is that the V3 board has a built in ESP-32 and drivers. It has small but notable quality of life improvements.
The deciding factor for me would be if you need an external antenna (because the board is going in a metal case- not normally the way we build them.). That would mandate the V1. Otherwise, either V1 or V3 would be a great place to start a build.
Unless you already have the drivers, etc, i would encourage a fluidnc board. Buy the time you are done with the arduino, the cnc board, drivers, etc. You do not save much at all. Fluidnc is a eal benefit!
I’d recommend the Jackpot as well. FluidNC is pretty awesome. Here are a few pointers to keep you from frying things:
On Jackpot v1, if you are removing/inserting the ESP32, make sure you put it in the correct way (pins lined up with the USB port at the edge of the board). If you put it in backwards, you will likely fry the ESP32 but the Jackpot would probably be ok. (Ask me how I know…)
Do not plug/unplug anything while the Jackpot is powered.
If using dust collection, make sure it is grounded.
Make sure you get the polarity correct on the power connectors.
Avoid moving the motors around while unpowered, especially quickly. They can generate power and do bad things.
(Someone please correct me if I stated anything incorrectly here. This is what I recall.)
That’s a good list, we should probably collect this type of list to guide users.
A few more that come to mind: (I think you added some while I was typing )
Don’t move your machine around by hand when it’s off at speeds that cause the controller board to light up. The back EMF from your motors can blow electronics (this was seen more commonly in SKR boards but it potentially affects all the machines)
Match up supply voltages for any accessories you use (e.g. don’t try to use a 5V fan hooked up to a 24V power supply)
If you add things like lasers or fancy spindles, pay attention again to supply voltages and also to how the power supply returns are connected. Get help if you’re not certain.
Pay attention to the type of ESP-32 you buy. If it doesn’t fill all the available pins on the Jackpot, it’s the wrong one. It won’t blow up the jackpot, it just won’t work.
Be sure any USB cable you use with the ESP-32 is not a charge-only cable. It won’t break things, but it will cause immense frustration when it doesn’t work. I’ve thrown away/cut up piles of these damned cables.
Another “quality of life” improvement I don’t see spelled out in the above discussion is that with Marlin you have to update the source, compile, and then flash the controller for lots of the configuration changes during initial setup. With fluidnc you edit the config.yaml and restart - no compiling or flashing, so the adjustment process moves along much faster, and it is easier to work on one element at a time.
With Marlin I would always try to “batch” changes together because of the time it took to compile and flash. While I haven’t gotten to implementing the 2 Jackpots I’ve purchased yet, I’m loving the config file approach with Klipper firmware and expect that the Jackpot experience will be similar.
I’ve got no idea because I don’t use any of those. 
