Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Well without further due, I'm finally able to post my build thread. Although it will not be as neat and tidy as some of the other build threats here (more a collection of photos I managed to snap along the way) I will post it and share what I've learned along the way. Perhaps I've made some mistakes and will look for input from others as I already have a few in mind. I will edit this post to accommodate for photos.
Thanks to those who have already answered many of my "newb" questions in another thread.
Leon
Original bench design.
https://uploads.tapatalk-cdn.com/201...384868a661.jpg
Insulating the garage.
https://uploads.tapatalk-cdn.com/201...1651dda8a1.jpg
Testing dust collector.
https://uploads.tapatalk-cdn.com/201...d624c39922.jpg
Component layout.
https://uploads.tapatalk-cdn.com/201...8952a102f7.jpg
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
The tedious task of wiring...https://uploads.tapatalk-cdn.com/201...b5a8d3ff6b.jpg
So this last pic shows two of my early problems which I was able to find solutions for. Firstly, the 14mm to 1/2" couplers that I bought were WAY too big to fit in there. I believe they were 65mm in length and that was something I'd never considered. So I took the 1/2" one that came with the machine and had it bored out to 14mm by a friend who has a machine shop. Worked great. Problem #2, the stepper shaft was a bit too long. Solution: use my smaller CNC router to make a spacer from some scrap hardboard. Looks great, right? lol
https://uploads.tapatalk-cdn.com/201...4471aaaf6f.jpg
Sent from my SM-G950W using Tapatalk
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Ok so now for a few valuable lessons learned:
1) Stepper polarity DOES very much matter when dealing with encoders. I was sent the wrong wiring diagram from the seller (probably from language barriers) and did not initially wire them up properly. From building 3d printers and another cnc, I couldnt figure the problem out at first because my thinking was "if you find the coil pairs and its spinning the wrong way, just reverse them. Not so! The encoder senses direction and will put the driver in an error state. When I finally got the correct order, 3 of the 4 worked fine. Unfortunately I believe the one on the Z axis to be faulty. I have contacted the seller and am working to a solution.
2) Non-Leaded solder is a PITA to work with! I had a lot of trouble soldering the stepper wires to the aviation connectors. Explained the problem to a friend of mine and he handed me some 60/40 Rosin core. Problem solved. He just told me not to breath the fumes and wash hands when done.
So now here's where I'm at that I need advice on. Before the motor install, the gantry moved relatively smooth, considering that it's a couple hundred pounds. I have the motors installed and wired on the X, Y and A axis and have movement. The X axis moves great, however when I move the Y axis over the length of the machine, it seems to get tight about 2/3rds of the way through and then a "SNAP" from the R&P skipping a tooth. When I traverse the opposite direction, same thing but it's the other side that skips the tooth. Where should I start looking?
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Fist off. Wow. Great build.
As for the Y axis the only time I've seen that behavior is:
1 - Motors are fighting each other or one is carrying the weight. Drop each RnP and make sure the motors turn on their own power. Or otherwise convince yourself they are both powered and one is slaved to the other. Only one motor should be commanded and the other does the same as the first, only in reverse. (Setting in controller software)
Edit: I think you said you have servos. Don't know about those. They might be independently controlled. In any case, same effect if not working as a team.
2 - The rack is seriously out of square. Or it is square and one RnP was torqued when it was meshed with the gears. In other words it wants to be square and the gears wont let it.
Good luck and let us know how it goes.
Jack
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Quote:
Originally Posted by
wackocrash5150
Ok so now for a few valuable lessons learned:
1) Stepper polarity DOES very much matter when dealing with encoders. I was sent the wrong wiring diagram from the seller (probably from language barriers) and did not initially wire them up properly. From building 3d printers and another cnc, I couldnt figure the problem out at first because my thinking was "if you find the coil pairs and its spinning the wrong way, just reverse them. Not so! The encoder senses direction and will put the driver in an error state. When I finally got the correct order, 3 of the 4 worked fine. Unfortunately I believe the one on the Z axis to be faulty. I have contacted the seller and am working to a solution.
2) Non-Leaded solder is a PITA to work with! I had a lot of trouble soldering the stepper wires to the aviation connectors. Explained the problem to a friend of mine and he handed me some 60/40 Rosin core. Problem solved. He just told me not to breath the fumes and wash hands when done.
So now here's where I'm at that I need advice on. Before the motor install, the gantry moved relatively smooth, considering that it's a couple hundred pounds. I have the motors installed and wired on the X, Y and A axis and have movement. The X axis moves great, however when I move the Y axis over the length of the machine, it seems to get tight about 2/3rds of the way through and then a "SNAP" from the R&P skipping a tooth. When I traverse the opposite direction, same thing but it's the other side that skips the tooth. Where should I start looking?
Looks like a strong base for your machine. Thoughtfully built. Very nice. The extra caution with the hoists was a good idea. Since you lifted the machine with the gantry intact, I assume you have not removed it. I removed mine (I had no choice), and I'm glad I did. A whole story unfolded.
Yeah, rosin core solder is the only way to go. And yes, keep the nose out of the fumes.
Checking out the machine before driving away with it was a great idea. However, what did checking it out consist of? Unless you were taking actual measurements, some of the potential problems (and I am talking potential big problems) wouldn't necessarily be obvious. Don't get me wrong. I'm not being critical. If I went to Lebanon without knowing what I now know, I would have missed most of it. Lucky for you, it doesn't appear that Nate shimmed the gantry where it meets the interface plate. However, that isn't the whole ballgame. Mine was only shimmed on one side, yet the other side was way out of spec as well. Boils down to you can only force a thing so far, and when you reach the limit, you have to try something else (like shims).
Here's a link to my build: https://www.cnczone.com/forums/finel...cnc-posts.html. You can see some measurements I took and how far out of wack some things are. My Y rails were over 50X the allowable error for parallel deviation of the rails. That can certainly cause stiffness, may cause bearing failure, and will definitely cause premature wear. I also found that my Y axis frame rails were welded such that the rails were rotated inward. If your gantry is firmly bolted down to the interface plate, and your frame tops aren't level, you are binding your bearings. I also found that because the frame tubes weren't square, the gear racks were not positioned correctly relative to the drive assembly. Unless or until you figure out what was done right and what was done wrong in both the frame construction and the parts assembly processes, you are going to experience a lot of guesswork and difficulty in finding reliable answers. When I started checking my 4x4 for build quality, including taking measurements, the source of problems became more obvious.
Oh, and as for jumping out of the racks, it may just be that you don't have enough tension on the drive tension springs. I seem to recall someone else having that issue, and tightening the screws a little tighter took care of it. On the other hand, if the gear rack alignment is off, that could be a source of the problem. The gear rack to drive alignment is important. If there are problems with it, you can expect premature wear of the drive gears and racks.
Just curious, but did Nate go over your machine with you, and did he make any representations about it? Did you get to see how Nate goes about mounting the linear rails? Does he drill the linear rail mounting holes, or do they come predrilled and tapped. I'm also curious if he let you in on where the machines are manufactured? Some of us assumed China. One thought at one time it was here in the States, but later concluded China as well. Anyway, there is a question of a practice Chinese manufacturers sometimes employ where they build a product to strict standards for awhile, but later drop any pretext of quality and start turning out a substandard product. If you are a big purchaser, you have some clout. If you're a very small fish, like Fineline, not so much. Just trying to find an explanation for why my machine was so poorly put together.
Gary
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Hello everyone. Sorry for being scarce but it's a busy time of year. Over the past couple of days I've finally had some time to dedicate to machine assembly. So here's what's been going on: Got all the controls rough wired only to find out that one of the stepper encoders was faulty. Finally got a replacement from china a little over a week ago. Got the cable ends all soldered and seems good. Tracked down some MDF and attempted to fasten to the frame. PLJack was not kidding when he said that the holes were all over the place. This caused MUCH frustration and a whole bunch of 4 letter words. I'm ending up having to use the same technique of referencing each individual hole for CAD. A pain, but will come in handy when it's time to replace the spoilboard. I did learn from his video and checked the squareness before proceeding. :)
Having said that, I am having a frustrating issue. It seems that my X axis randomly reverses orientation from time to time. I've done a light check on the wiring, I've tried remapping the X axis pins to 16 and 17 on the BoB (and made changes in Mach3), I've tried swapping the BoBs with one another (I run 2 for more inputs), I've tried running Mach3 in administrator mode in windows and probably a few other things.
It's odd; everything will work fine for a bit then it will just reverse. No error. If i go into Mach3 ports and pins, reverse the direction, hit apply and save settings, all works well for about 5 to 15 min. I'm not inclined to think that it's the wiring from the driver to the motor, as if that were the case, the encoder would freak out and throw an error. I am noticing a fair bit of electrical noise on this setup, despite having the motor and vfd cable shields grounded, so I have the noise numbers up to 100 in the ESS control plugin. The most recent thing that I am trying but not tested yet, Is ditching Windows 10 on the PC and installing Windows 7. I figured that the more recent updates of Win10 messed up Mach3 that it might be worth a try. I'm really hoping it's not a Stepper Driver issue.
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Measure the voltage on the direction pin at the drive, in both directions.
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Quote:
Originally Posted by
ger21
Measure the voltage on the direction pin at the drive, in both directions.
I shall do that when I get home provided I get time. Wife says I have to blow out candles on a cake and silly stuff like that ... lol
What are you thinking Gerry? Bad ground on the BoB to Driver cable?
Here's a video of me goofing around, but it shows the direction change at the end. Linke nothing happened, just goes the opposite way.
https://youtu.be/4EUxNBfHocA
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Try it without the spindle or VFD powered. My guess your could be getting some sort of feedback into the control circuit.
On the Windows 10 did you disable the wireless so it can not update, disable power saving, disable sleep mode for the USB or whatever port your using for control? My noise filtering is at 200.
Once its set up and running the correct way, you should never need to make any changes to that part.
If its running to fast it may tend to skip steps and stall for a second, mine is set at 500 with NEMA 34 steppers.
I think my holes where more or less in a pattern. My random thought of the day.... I would next time, (never) take a drill smaller than the predrilled holes and then drill all the way down and through the bottom. Then use deck screws or like the screws we using to hang kitchen cabinets, up from the bottom.
EDITED: Finding the hole pattern. Parchment paper the kind you use to line a baking pan. I think it comes in 20 or 24 inch wide rolls. Lay on top of the crossbars and secure the ends with good masking tape and same with subsequent passes. Hold the passes or runs together with masking tape. Take a small ball peen hammer and tap each hole you can feel though the thin paper.
Remove your marked paper and transfer over to the MDF. I have used this to make gaskets and it worked slick.
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Quote:
Originally Posted by
wackocrash5150
I did learn from his video and checked the squareness before proceeding. :)
As long as you learned something from the video I'm happy. ;) That's why I made them. Seemed there should be more info about this model on youtube.
Spindle interference was my first thought as well. Although it seems the interference would not stick around long enough for you to change the configuration.
What you're describing sounds like a floating pin. If it's hanging out at 3 volts or so it's a crap shoot as to whether it will be considered low or high.
A pull up / pull down resistor would solve that but you really should not need it. I would think there is one in the controller circuit.
As Ger21 said, monitor that voltage while operating the machine.
Also make sure the controllers and ESS have a common ground. If not the pin might be floating in respect to the ESS.
Jack.
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Well.... Unfortunately it was as I'd feared. Had a few minutes when I got home. Fired up Mach3 on the Windows 7 machine now, system moved fine for 5 min then reversed. <Frustrated>
So at this point I'm about to whip out the multimeter and follow suggestions and then think to myself "What if I swap drivers? That would help isolate the problem."
Swapped with the Z axis. All was good until a few minutes after running some air code, the Z was reversing this time.
<More frustration!!>
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Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
As mentioned, start by testing with the spindle OFF.
If it's still changing direction, then check that voltage, as it's probably not correct.
What breakout board are you using?
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
If the problem followed the driver switch then the driver board is bad.
Did you try it with the VFD and spindle off by any chance?
BTW I used a oscilloscope in the USAF eons ago then later when taking a electronics class. Surprised at the size and price drop . I purchased a small SANSMART DSO Note II LED scope and with an additional 1x - 10X probe. All for less than $115. Surprised at the quality, I have yet to use it but it can capture and hold signals. Thought it would be handy to have when checking out the waveform from the VFD and noise on the input signal lines.
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Quote:
Originally Posted by
wmgeorge
If the problem followed the driver switch then the driver board is bad.
Did you try it with the VFD and spindle off by any chance?
That was my thought about the problem following. It did this with both the VFD powered on and off.
So I got a chance to fire up the machine and throw a multimeter on the drive DIR pins, and wouldn't ya know it, it wouldn't give me a problem! The only two things different from this time to the last was the pigtails on the driver pins and the fact that it was much cooler in the garage this time. I would say about 10 degrees Celsius cooler. I ran various bits of code and jogged the gantry a fair bit, left powered up for a couple hours and repeated. I could not recreate the problem this time. Go figure!
The voltage readings seemed normal. Jogged the Z up and it was 4.75V; jog the Z down and it dropped to 5.7mV. Correct me if I'm wrong but this sounds about right.
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Quote:
Correct me if I'm wrong but this sounds about right.
Yep. That's why it's working. :)
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
So basically I'm thinking I should just leave the multi-meter leads hooked up and just wait for it to happen again so I can take a voltage reading. Tough road though as I'm not sure if I trust it to do much until I get this sorted out. I've put in a message to the seller for the drivers and am waiting to hear back. I am leaning that way as the problem followed the drive but I should troubleshoot as much as I can as to support my claim with the seller.
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Ok, so .... I got the axis/driver to function and malfunction as I'd described and have video of both (which I will edit this post and add links to the videos when they're finished uploading. Regardless if the driver is function or malfunctioning at whatever particular time, When I press up, the BoB puts out around 4.7 volts and when I press down, it drops to around 5.7 mV, regardless of which direction it's actually travelling. So I know that everything up to and including the BoB is doing it's job properly. This leaves the driver and beyond. Given that I've swapped drivers and the problem follows the driver, I believe that it's safe to say that I have a faulty driver board. Fun times with more waiting ..... grrr
Driver functioning normally
https://youtu.be/KTMp0NNNGII
Driver functioning improperly
https://youtu.be/NZbkZFhrpeA
Re: Saturn 2 4x4 w/ Nema34 closed-loop - In Canada
Dumb question but here goes, does it have the problem when using the keyboard? Just wondering if it is the hand held unit. I'm sure you already thought of that, but I figured I'd ask.
Dan
