I’m working on building a V1 Engineering Mostly Printed CNC router, and while I understand the mechanical side of things quite well, I’m not so confident about the electronics side of things. My biggest question is regarding the differences between the Rambo and Archim1 control boards. I found threads here and here about the differences between the two boards, and it sounds like the consensus is it doesn’t make a difference. Given that the latter of the two threads was started almost a year ago I thought I’d start a new one to see if there are any updates.
Fairly obviously, this will be used to cut flat stock, primarily wood and aluminum. Mainly I want something that is a size upgrade over my existing Sherline mill without compromising surface finishes or accuracy. For that reason, I’m leaning towards the 32 bit Archim1 rather than the 16 bit Rambo for (potentially) smother motion during arc movements, however if the Rambo can match the Archim1 for accuracy then I certainly like the idea of not having to worry about flashing firmware or wondering if I’ll run into some hitherto unknown edge case that causes a board closer to the beta phase to have issues.
If anyone has used both (given his position, I suspect Ryan has) and can provide feedback or better yet examples of the performance of the two boards I’d really appreciate it.
The Rambo and other boards based on the Mega2560 have more than enough CPU to do everything we do, including arcs, so that is not an advantage of the Archim or any of the other 32-bit boards.
There have been issues with arcs in the past but it was not due to CPU and had more to do with cornering behavior.
If that is the only concern, I think the Rambo is the better option. The 32 bit boards support the TFT displays and perhaps other features (I don’t really pay attention) but for stable ordinary use the Rambo is ideal.
I think the Archim is still in beta, as it has been since we fist started to try using it a few years ago. I’d stick with the Rambo until Ryan is comfortable with the SKR Pro that is likely to replace the Archim.
Trying to remember my decision tree for choosing the Archim 2.0. Maybe it was that it was the most expensive so I figured it must be best. However, I did think of the drivers being Trinamic and the fact that it could be end stops. Not sure about the Rambo specs, but I am very happy with the Archim.
The rambo does dual endstops. It is an excellent board, and if you aren’t interested in learning about the electronics and the firmware, it is the best choice.
The archim2 uses a 32 bit processor and trinamic drivers. Trinamic is a brand of drivers, and the neat thing about them is they can communicate with the controller. The rambo uses drv drivers, which are good, but they don’t talk to the controller. The trinamic ones can adjust their stepping motion, and report skipped steps to the controller on the fly. It is neat, and useful in a 3D printer, but it’s utility in a CNC machine where you want max torque at (relatively) slow speeds is marginal. The 32 bit processor also seems good, but in reality, these machines aren’t running as fast as they can, they are running as fast as they have to. Since it is the same basic firmware between an 8 bit and a 32 bit, there are few cases where it makes any difference to have a faster processor.
There’s no tricks here, the rambo is just at good at doing what we are asking of it, but it is tried and true, and comes flashed with the right software from Ryan. That’s what you should get unless you are interested in exploring the new frontier in controllers (which the archim definitely is).
Hey there!
I ran into several issues with my last milling project and after several days of headaches my problems seemed to be solved(test is running this second). It was all up the Arduino not being able to handle the speeds with the micro stepping given. (Ramps, 5 stepperdriver grbl and a lot error 25 at high feedrates) Since the machine is runing in my room in a shared flat I reduced the micro steps instead of the speed. I have two questions:
Does the fact that I’m using GRBL instead of Marlin matter?
Would a 32bit board be able to handle this better?
What stepper driver are you using? What microstepping settings are you using? What feedrate where you using. According to the a GRBL reference, Error 25 is STATUS_GCODE_WORD_REPEATED. A quick search I found one user that fixed the problem by replacing the USB cable, so it is unclear to me this is a processor speed issue. Better boards (32-bit and/or higher frequency and/or hardware math support) can have better throughput, but typical CNC operations don’t push even 8-boards hard enough to cause problems. It is possible this is related to the specific version of GRBL you are running, but it is not a general GRBL (vs. Marlin) issue.
Hey Robert, thanks for your answer!
Well, even with micro stepping put to 1/8 (40st/mm) and 1/4 (200st/mm) (Z) and speeds under 500mm/min I’m having the same problems.
Originally my micro stepping was 1/16 with 4 steppers being 1,8° and Z 0.9°. I was pushing it with shallow cuts at 1800mm/min. My Drivers are TMC2208 V3.0 but since it’s GRBL no connection through UART. I’m using the newest version of GRBL (Mega 5X 1.2d - dowloaded a week ago).
I’m having the same problems when I connect the arduino without ramps connected and run the program through the original 20cm cable. I tried other cables, different Laptops (old Mac and new Linux), CNCjs aswell as UGS with different sender options. I also get regular Error codes 1, 2, 24, and 35.
I had similar problems with an older version of Mega 5x but not as often as I have them now. But for the sake of speed and less errors I’d switch to Marlin on a 32bit board…
Edit: I also checked the 16u2 version. The Fusion360 postprocessor(pp) is updated and I tried the pp of carbide 3D, X-Carve and another one I found on the net. They all gave me more errors then before so back to standart F360 GRBL.
There is something strange going on here. The standard V1 Marlin setup has microstepping set to 1/32 for the TMC2209 and DRV8825 drivers, and I don’t see any issues similar to your come across the forum. Some of the active members on this forum run GRBL off a CNC shield, which is just an Arduino UNO, and I don’t see similar issues to yours from them either. I know little of GRBL, but is it possible there is some settings in GRBL that need to be changed…like acceleration for example, or maybe the setup for the TM2208? I don’t know what an Error 25 really means. Some GRBL forum, or if you have any programming background, just looking at the source, might be helpful.
Since you seem comfortable with flashing firmware, you might consider trying Marlin. The V1 maintained firmware for the Ramps boards I believe is setup for the DRV8825, so there will be a bit of work there. If you have a problem with Marlin as well, that promotes the idea that hardware is the issue. If Marlin does not have issues, that promotes the idea of GRBL setup being the issue.
And you might try opening a new topic with this issue rather than appending your question to an old topic. That might attract someone from the minority of forum participants that run GRBL to give you an answer.
