Greetings people! So, I just completed my 1500x1100 OX build. And getting ready to do some calibrations and first cuts, I ran into some problems, right out of the box. Both X- and Y-axis are stuttering and not running correctly. (Chinese NEMA23) But the Z-axis has no problems at all (Chinese NEMA17) I thought that it could be the current beeing too low or too high, but after adjusting according to Sparks guide, it still stutters the same. And the board is getting too hot to my liking, without cooling that is, with the fan it is pretty cool. I made sure the PSU is running at excactly 24.0v, and the wiring is pretty much done by the book. Had some challenge getting the right wires connected from the steppers to the board, but now it is right. And again, the Z-axis has no problems. This isn´t my first build, I have built several 3D printers and a lasercutter before and never stumbled upon a problem like this before. Spent my whole day troubleshooting and reading what I could find around the interniets without getting any solutions. Made a short clip for you below:
Hey Foggin, what's your microstep and decay set to? list your $$ settings for us. are your wheels super tight? might be too tight Cheers
Does your chinese motors have datasheets? Incorrect voltage specification or wrong inductance, sounds to me looking at the video, like likely issue.
I entered the same settings as Mark´s tutorial, except for sizes etc.. Same happend with standard settings and Mark´s settings. I´ll have to check it again tomorrow, but I changed the values to match. I don´t think the wheels are too tight, both axis moved smoothly, and I could push them away without stopping too soon. Also gave the belts some slack to see if they were too tight, made no difference, I could try to free them up completely to see. I feel pretty sure that this has to be a stepper issue, not mechanical..
Well, heh, no, they had stickers on them though. I´ll have to get the seller to answer me, bought from a Norwegian webshop selling complete kits. This is all I have for now: NEMA23, 2,8A, 1,2Nm. Ø6,35mm NEMA17, 1,8A, 0,55Nm. Ø5mm And a picture of the board..
I found one that seems to have the same specs: Nema 23 Stepper Motor 1.26Nm 2.8A 4-wires 6.35mm Shaft DIY CNC Robot 3D Printer | eBay
I haven´t tried yet, but at that speed it shouldn´t stutter like that, going to look over mye settings again now.
Try the default settings 5. Troubleshooting · Spark-Concepts/xPRO Wiki · GitHub first - this doesnt sound like settings at all though, more like a mismatch between motor and driver. Betting replacing those with OB motors will solve your headache
You could be right, well, after playing with some settings and adjusting the current, I finally got it to run pretty well. Did a quick run with a marker, and it seems to work allright now. The stuttering was probably a combination of wrong current, too slow feedrate and some wrong settings. looks like I have to play a bit more with this, but now I should be able to run a job. I might take you up on that, getting some good steppers. Is it possible to run separate drivers with xPro?
what's the exact model number off the back of the stepper motors ? OB motors are Chinese as are 90% of the lower end motors not all motors are equal and specs can vary wildly Is the xpro running hot ? if you go with individual drivers you will not need the xpro at all Is this the 1500 x 1500mm Ox ? your right on the boarder of what the xpro can handle, and what the steppers at capable of as those motors are spec'd for the smaller ox machines another member is having a similar issue atm
Modelnumber on the NEMA23's: 57BYGH56-401A EC Yes, without the cooling fan in the cabinet it is, with cooling fan it is pretty cool. This is the 1100x1500mm OX, and yes both steppers and board is on the smallest size to my liking (I have been running a 2000x3000 Multicam 3000 this last year, feeling pretty spoiled and 4times the speed) The initial plan was to build a kit from what I wanted, bigger steppers, lead screws, individual drivers etc, but my budget disappeared pretty fast getting all the stuff I need for my startup, heh.. I went for the budget-version instead. Anyway, it seems that I solved this problem by fiddling a bit with settings and current. I bet there is more I can do, but the machine seems to cut fine now, the only thing left is to do some calibration-tests to see if everything is square.
I made the same mistake with my c beam - I like a bit overhead to allow for the unexpected, Its never good to run things on the edge as there just going to die quicker A lot of the figures that are about for the equipment are also peak ratings what is sort of meaningless really as it can be as much as 70% > true rms
So, I can't figure this out... At low Feed Rate, I get VERY choppy movement, both X and Y. Lets say I am running F100 (metric), things get very choppy and it does the same running a job with small cross movements, i.e a very fine angled cut along X or Y. And it shows in the material. Lets say I am cutting an A along the Y, the middle line is perfect, but both of the angled are choppy. All the mechanical components are fine, adjusting the current does not help, and trying to change my settings with no luck. Here are my settings: And a short video:
try turning your acceleration up, should be able to run around 500 to 600, you are accelerating and decelerating for each line segment, never getting up to speed smoothly (probably).
yes, I run my ox at 700 for x and y and 600 for z, but i have bigger motors and dq542ma's so it will be different.
what happens when you use the 500mm/min feed rate? sometimes slow feeds act weird with grbl. Jogging can do strange things as well.
Without any settings change, 500mm/min is the same, but faster obviously, so I´ll try the settings tomorrow. Feedrate at 2000mm/min sounds good and running smooth.
So, changing 120 and 121 to 500 did nothing at all, I ran a job as well to see if there was any change, but nada. Now I am pretty clueless. Checklist: - the machine is square - wheels moving as they should, not too tight - belt is not to tight or too loose (also tried too loosen up too much with same result) - steppers are wired correctly - adjusted current on drivers to find the sweetspot, no result - changed settings as seen above - tested 1/16 microstepping with no luck What am I missing here?
Ok, only thing that still looks strange is the $0 is 3 instead of 10 which is default I thought? Using an xPro V3 right? You did the fast decay solder jumper?
Following the build guide it said 3 and not 10, I have tried everything from 2 to 15 without any noticeable change. Back on 10 now. Yep, xPro V3, with no mods out of the box, I should solder something? Seems that I have missed that part if that is the case.
Most people are using fast decay for the solder jumpers on the back of the board. If is was mine i would use a small jumper wire first on X or Y and see if that improves the motion, it's hard to un-solder a solder bridge without a solder sucker. There is also the issue with some of the xPro's having the jumpers vs the screen print wrong on the back of the board. so it might be fast or slow that works for you. I think this one is correct..
Okay, so that was pretty difficult without soldering, but i managed to jump the X axis, both slow and fast did nothing to the motion I'm afraid. It did make a clicking sound when connected, so it made good contact. And it was the same print.. ****, this is frustrating!
Order proper motors (; and the frustration goes away. Pennies saved on parts ends up filling your life with time wasted. We test our motors to work with our controllers so its easy plug and play pretty much. That's often the investment in a little pricier component - the knowledge that the store has sold hundreds or thousands of them and know they work well with settings/companion products/machines recommended
So as shown in the video, that wouldn´t happen with the OB branded steppers? But you are right, and proper components was the initial plan. By the way, what carriers do the openbuildspartstore have? UPS/DHL/FedEx?
Well, no it shouldnt make those weird noises, there are plenty of existing users running just fine using our motors. You've already checked the mechanics, and Grbl settings really wont help with what I am seeing the video no matter how much you play with it. Specifying stepper motor / driver combinations are often boiled down to "current" only and thats not really the case. Stepper inductance, coil voltage rating, current rating, steps per rotation, all come into play. We know that our NEMA 23 Stepper Motor motors play really nice with the DRV8825 drivers on the XPRO (sometimes you may need to add a cooling fan pointed at the XPRO if you start skipping steps after couple minutes into a job). Sure, they are rated for 2.8A so the max 2.5A of the DRV8825s are not allowing them 100% max torque, but it does allow them to run with a nice tradeoff between enough power, yet still running not too hot. Our bigger NEMA 23 Stepper Motor - High Torque Series motors really need proper drivers like DQ542MA Stepper Motor Driver though, as they are rated 3.0A and the DRV8825s on the XPRO can't deliver that much (so you run them undercurrent, which means less torque). If you can hunt down a datasheet of your motors (or a proper model number like BYGH57....something something) we can see if maybe a driver upgrade will help (perhaps possible to keep your motors and run them off DQ542MAs)
Thanks, that is well explained! And you are probably right, something isn´t playing along here. Probably have to send another email to the seller again. I have the datasheet here:
Specs arent much different from our motors: http://cdn6.bigcommerce.com/s-itwgl...ts/180/1759/NEMA_23__41399.1461353746.JPG?c=2 Just slightly less resistance, less torque. But then again, do you trust that the seller actually meets the specs on the datasheet? Who says its not factory rejects? What else could be wrong, we dont know. Here's what i'd do if this was my personal machine / problem (and my thinking as to why) 1. I'd order DQ542MA drivers from DQ542MA Stepper Motor Driver - either just one as a test or two to fix your X and Y (You say Z is fine. Personally I'd order 3 so I can just make Z super as well.) 2. My thinking is, that even with OB motors, the XPRO is nearing its max current capability anyway, so spending the 80ish quid now on DQ542MAs adds a little future proofing for when inevitably I upgrade to bigger motors, or transplant my electronics onto my next CNC (yes, i know, 2005 I built the first one and thought it would be my forever machine. 20+ machines later I'm still thinking of designing and building no 21 this Christmas) 3. I've used the DQ542MAs a lot and have yet to break one. Plus they run super smooth, none of that audible screetching sound the DRV8825s make 4. I can wire up the DQ542MAs to my XPRO for now... But if in a couple months I want to try some other firmware flavour, maybe Smoothieware, I can still use my drivers with that too 5. Up to 4.2A per motor (; can you say torque? 6. Since its an Ox, consider that the Threaded Rod Plate - NEMA 23 Stepper Motor plate supports both NEMA17s and NEMA23s (; with a heavy router a NEMA23 Z axis is really nice (; for the price of the plate (if you dont have it), a NEMA23 and a 6.35mm->8mm flex coupling (; why not 7. Realistically, this may not solve your problem. If its a case of the stepper drivers on the XPRO not being able to properly run your motors, it will, but... if the motors are odd / broken / fake / rejects / who knows... You may need to get new ones anyway (but showing Paypal/ebay you even tried DQ542MAs - should help you get a refund). I still feel like you "will need bigger drivers at some point anyway" and theres a good chance they'll get you going... that if it was me personally (and dont hold me responsible if it doesnt hehe) i'd take the gamble on upgrading drivers first
