When I was deciding what path to my build, I spend a lot of time sorting through options. It was a bit daunting with the different boards offered in the shop. I chose the Archim 2 so I would need the least tweaking for setting up end stops and also to get the quieter drivers of the board. Perhaps the Archim board made end stops easy for me. It seems that using some of the other boards requires a little more understanding of the layout of the boards and where to plug in all the steppers since pins are being repurposed.
I understand that the forum discussion and the documentation reflects the process of getting dual end stops to work reliably, so that gives it a sense of difficulty.
I also know that setting up hard, physical end stops to act as reference points for squaring the machine is pretty easy, so in one sense the digital end stop solution isn’t all that much of a gain.
So, then @Bstforge’s recommendation that dual end stops is still for intermediate or advanced users, i.e. folks who have an understanding of the wiring, boards, and firmware requirements is still the company line?
I just can say that mine have worked great, once I fixed a wiring issue on the end stop itself and got my axes in the right direction which weren’t really issues with the end stops. I can understand that different boards can complicate this.
Just thought I would ask this question in general to get a state of the issue from veterans and also from new builders who have might have experience in this.
The reason I stated that is because even the concept of auto squaring and dual endstops may be a bit much for the beginner. I’m sure it’s relatively easy to configure, but if someone just wants to get up and running, with no experience in cnc or the like, it would be easier without some of the advanced features, dual endstops and auto squaring being the the easiest to eliminate.
I keep forgetting that there a lot of folks who purchase even the 3D printed parts so haven’t had experience with end stops in 3D printers. I have two 3D printers and a laser and have been monkeying around with steppers for some time.
Yes, you are right. It does add some complexity to a complex process. To someone completely new to the CNC world it is just one more thing to try to understand.
I have been into 3d printing for 6 years, almost 7 come Feb, with four printers over that time span and I can tell you endstops, at all, is not something I am used to for a CNC where you tell the controller (Mach 3 usually) where your position is at and it zeros there.
Oh, I just found out about this (and this makes perfect sense) but the dual endstop has a reason to be and that is for grabbing a controller made for a 3d printer (could be any of them) and using X, and Y drivers for X and Y BUT E0, and E1 (normally for a 3d printer dual extruder system) will now become X2, and Y2 respectively. The reason this is considered more advanced is because you have to go into Marlin (the controller driving firmware) and tell it stuff (trying not to be too technical) so it will know that E0 and E1 are now X2 and Y2 instead. This requires you to know how to code and while not a problem for a lot of us for others it could be a nightmare which is why it is Intermediate to Advanced users’ playground.
The single Endstop (or no endstop) method means you will have to make (or buy it) Y adapter for X and Y and the motors will share the same driver so it suddenly becomes weaker since 1 driver is now being forced to handle two motors. What could be two 1.5A motors will suddenly be driven by 750 miliamps for each motor (1.5A max shared) so the torque will not be nearly as good. For me I now know I will be doing the dual endstop method since it is already crazy for a CNC router to be using 5 motors we might as well be able to drive each to the max the drivers will allow for the extra torque (which I will need for the Aluminum I plan to be using this on).
I’ll raise the flags for @jeffeb3 and @vicious1, but having all five motors on separate drivers is really only useful for having an automated squaring function using the endstops. You’re not losing enough torque to make any difference within the operating envelope of the rest of the design. Even if you’re milling aluminium (or even steel, I think Ryan was running series steppers for that extreme stunt). Stepper torque isn’t the limiting factor, and you’re likely chasing theoretical gains that will never really materialize.
Could be possible but the main point is the shared amps is a bad idea for our already limited 1.5A max (some controllers can do 2A) per motor.
Oh, let me add that I had a Prusa I3 Rework back in 2013 and the dual motor (Z) for one driver made it constantly lose steps over time until you had to center it again (tram) so now Prusa does the single motor per single driver so E1 is Z2 and two endstops to make it level (tram).
OK, you win. Do your thing. If that’s what rustles your Jimmies, go for it. Just know that there’s been a lot of time and brain cells thrown at this design, and for the stated design goals and working envelope, running steppers in series is perfectly fine, and imperial buttloads of folks don’t have issues with it. You’re not doing it for major gains or (r)evolutionary improvement. You’re doing it for self-satisfaction and academic rigor.
Non-dual endstops wires the motors in series, not parallel, so they both get the full current. If anything they are “sharing” voltage but at our relatively low speeds and 12V supply voltage there is plenty of voltage to go around. The advantage of separate drivers is only to get independent control, not for more power.
Every setup I have ever seen where one motor shares has been a parallel setup. Y like that for the wiring harness and not one video have I watched showed them to be wired in a series configuration. Hmmm, I am not even sure that would work or how it would work. Now I am intrigued.
Hang on. I was being overly snarky and feeling punchy. It’s been a particularly unproductive day at work, and that makes me a bit crabby and crotchety. I’m sorry. I also get grumpy when I don’t have the facts at my fingertips that I know (like the sharing voltage instead of current in series).
I really don’t want you to go away with a bad feeling about the community. I was having a bad afternoon, and you got a blast of it for no good reason.
I can see that there are different perspectives about the wiring and implementation of dual end stops, so plus one for taking it out of beginner experience level. I haven’t come across a post that says the current implementations are detrimental though.
I was just relaying my knowledge of how the Prusa machines did it and now do it. That I am 100% sure how they worked/work because I had them now if this works differently (iow in series rather than in parallel) I am honestly intrigued.
Yes, I walked away from this thread as I actually muted it because I felt attacked and it was 100% unprovoked but it is alright and I understand as we all have those types of days so it is cool.
As I said in the Prusa machines (since before Prusa even) you would take the Ramps 1.4 (or Sangra or w/e) and you used the same Z channel that shared the amps. On the Ramps it was made like that with them connected on the board but for other boards you had to make a Y connector where two wires went into each slot so it was 100% shared. I have a board like that on one of my machines but I can’t remember which board it was as I replaced a lot of mine with 32 bit boards now.
So I hope its ok to ask some questions on this topic. I bought the Rambo board from Ryan with the dual end stop kit as an add-on. When building my mpcnc I used the normal wiring kit because I was nervous about setting up the dual end stops. I would like to add the end stops soon and re-wire the machine, but I can’t find a definitive wiring schematic on this site. Is that the downside to the dual end stop kit? That there is very little documentation and therefore you really need to have a background in electronics to do it without frying your board? Also, I’m assuming that Ryan flashed the dual end stop configuration to the mainboard since I bought the kit. Is that a safe assumption?
Because really, who is advanced? Am I advanced? I have mountains of experiance compared to anyone else that I know in person. Compared to this board, I’m a total noob. So I generally play it safe. There were a few other posts in the forums that seemed to confirm that it really isn’t a big deal, and I do intend to make some complicated things when I get going so I went with it.
I think the company line is that they are currently recommended unless you really don’t see the need for them.
Ryan (or some others here) found this series method a few years ago and it works great. It is a bit trickier to wire up and you need both motors wired well or you get trouble, which is why is isn’t used in printers.
So yes, series wiring is just as good in terms of torque as dual motors, with some caveats.
WOW, nice and I am amazed this never made it to the RepRap world (China made machines I can understand). I suspect this would have the same issue where each motor never turns precisely the same amount and over time gets out of sync with each other like the old Mendels, Prusa, et. al. did, right?
Regarding the original topic. I think a lot of it in my mind is still due to the fact that we didn’t have it available for the first couple years I was here. I still haven’t set up a dual endstop system myself.
Ryan does a great job hiding most of the complication from the user. The one part they do need to worry about though, is the coordinate system. You don’t want to smash your endstops, so you set the firmware up to never go negative. So that means you always have to put your work in the positive coordinates. This can’t be fixed by Ryan, you have to know it yourself. So that makes it intermediate.
Then, if you are going under the hood, there are some good tricks Ryan has made to get it to work. So that means there will be confusion from DIYers.
You also need (IMO) a computer to fine tune it, which many beginners don’t otherwise need.
With all that said, considering the new board availability, and the new firmware changes coming from Marlin, I wouldn’t be surprised if dual motors or dual endstops aren’t the standard at some point.
