Hi, I just did the test with the 2 stickers X and Y on both steppers and the code on the youtube video......and all was o.k so fingers crossed....
So my only advise so far is check your Earth terminal as per my picture.....I also checked the silver sockets on the back and they have the same issue....the black paint on the case is causing them not to make contact with the box(the outer part which screws up).... glad I checked it with my meter...
The software workaround: 1) make sure that the Mach3 signal level is such that when there is no step, pin 5 of the TB6560 (named CLK in the datasheet) is low. 2) Use 1/2 step Sherline mode, with kernel running at 25 or 35 kHz. The effect of Sherline mode is that the pulse will stay high for the entire duration of the kernel cycle, and reset on the next cycle. 3) Set the Direction pulse timing to the maximum (15 us - note the GUI indicates 1 to 5 but it will accept up to 15). The net effect is a long pulse (40 us for 25 kHz kernel, 28.5 us for 35 kHz), with the limitation that the maximum pulse rate is reduced to one half of the kernel frequency. This is not a problem given the fact that in any case the TB6560 maximum allowable step frequency is only 15 kHz.
The hardware workaround: replace R4 to R9 with lower value (470 or 1k). This will make the rising edge sharper and gain some pulse width margin. You can't go too low with the value, otherwise the falling edge will become too slow, reducing the margin. You still need to make sure the Mach3 signal level is as in point 1 above. You can then either use Sherline mode as above, or normal mode. In the latter case, just make sure both step and direction timings are set to their maximum (15 us) and don't exceed 35 kHz.
Can someone tell me how to accomplish step one of the above comments in Mach3? Rakounet maybe you can tell me how? Max hasn't been on in some time so he's out on that one.... Shot in the dark Rakounet but thanks anyway...
This has been a very helpful thread. I purchased a 3040t-dj, and have been experiencing the same lost steps in the x axis in reverse.
So my takeaway from reading the entire thread is that I need to install three 470nf ceramic capcitors from pin #15 of each TB6560 to a power supply trace which runs under the resistors as seen in post #12 ( thanks for this Rakounet).
Here is a picture of my control box card. Are my indications correct?
is it difficult to scratch off the green lacquer on the trace? what tool would work best for this, and Xacto knife perhaps? When I solder to the trace and the chip pin do I need to use a clip on heat sink?
Once these three capacitors are installed, do you think I am good to go, or is there more I should do?
I used a small phillips screw driver to scrape them here but just about anything works that is pointed and small. The hard part is in this doing the swap of the six surface mounted resistors as mentioned further back in this thread and then setting the parallel port data line low. I am working on it at the moment since some one pointed me in the right direction on how to keep pin 5 low in the following statements made by Max further back in the post. If you have any information on how to set the data line low to the control chip of the controller feel free to jump right in and let me know. Pretty sure after starting to research it that it will take me some time to get to the bottom on how it is accomplished it in my computers parallel port setup. The reason I did the further hardware modifications is that the capacitors alone didn't fix mine to the point it is reliable. Mine still skips and if I can't figure out how to adjust my parallel port outputs/controller inputs, a new controller will be the only solution in it. A reprint of Max768's comments on it from page four of this thread are as follows:
The software workaround: 1) make sure that the Mach3 signal level is such that when there is no step, pin 5 of the TB6560 (named CLK in the datasheet) is low. 2) Use 1/2 step Sherline mode, with kernel running at 25 or 35 kHz. The effect of Sherline mode is that the pulse will stay high for the entire duration of the kernel cycle, and reset on the next cycle. 3) Set the Direction pulse timing to the maximum (15 us - note the GUI indicates 1 to 5 but it will accept up to 15). The net effect is a long pulse (40 us for 25 kHz kernel, 28.5 us for 35 kHz), with the limitation that the maximum pulse rate is reduced to one half of the kernel frequency. This is not a problem given the fact that in any case the TB6560 maximum allowable step frequency is only 15 kHz.
The hardware workaround: replace R4 to R9 with lower value (470 or 1k). This will make the rising edge sharper and gain some pulse width margin. You can't go too low with the value, otherwise the falling edge will become too slow, reducing the margin. You still need to make sure the Mach3 signal level is as in point 1 above. You can then either use Sherline mode as above, or normal mode. In the latter case, just make sure both step and direction timings are set to their maximum (15 us) and don't exceed 35 kHz (there is no point and all it will do is reduce your pulse times, this eating the margin).
There are many more subtle and less subtle problems with the board design. It really sucks, but with either workaround it can be made to at least operate without losing steps.
Unfortunately Max didn't mention how to accomplish the step one in the above comments on this controller. He also hasn't been on the forum since last year as far as I can tell. I really would like to ask an expert how to keep the data to pin 5 low but can't find one to ask. So I guess it is up to me to find the solution in it for myself. Wish me luck I thinks I am going to need it. If I make any head way in it I will be sure and post a how to on it if I manage to make it happen here. Hope this helps................
Another thing I found was a very similar power supply diagram only it has noise chokes in it. So I am adding some from an old satellite receiver. If nothing else mine is very quiet compared to what it was. Hasn't hurt anything so I plan to add the full Monty of them into my power supply. The diagram I saw had two but I intend to put four of them in mine. On both the 34 V supply and the 12 V supply. One each to both ground and output side of it. I am cutting the trace and adding them where I can with epoxy, long leads, and heat shrink tubing. It is very quiet compared to what it was so I can't see that it hurt a thing here. Might not have have helped but can't hurt at this point to reduce as much noise in it as possible even in the power supply.
The low input thing I still have not figured out but I intend to find an answer in it as well. One other thing that has been helpful to me is adding a registration mark with my cutter so that if jumps track I can restart it on line in the same job. It has helped. Also I figured out how to only cut what I want in my projects by adding by adding a bounding line in my 3D jobs. Very helpful in keeping the run time lower and reducing the chance it will jump ship before I finish.
The capacitors should be ok, also the indications on your picture. However, be careful of the VIA under C33 (don't scratch the varnish at this area).
A Xacto knife is perfect for that.
I don't understand why you want to "use a clip on heat sink"?
If your lost of steps in the x axis come from the noisy power supply, it should solve the issue.
Do you think adding these three caps is the first thing I should try to correct the lost steps? It seems pretty easy, and looks to be the best first step to try, do you agree?
Regarding the heat sink, I was asking whether I should clip a soldering heatsink on the processor pin while soldering, I am worried about heating the chip too much and damaging it. I am not a proficient solderer, and feel a bit out of my element.
Beauman58:
Thanks for your two responses. I am hoping just adding the caps will fix the problem, fingers crossed. If it does not I will move to other fixes, such as adding other caps, swapping resistors, and altering Mach3 settings.
If just adding the caps works, then I am considering adding limit switches.
The capacitors arrived today and I soldered them on. I ran a 90 minute "air cut" and the zero at the end matched the zero at the beginning. Right now I am running a test piece and so far I see no evidence of lost steps!
I have to say that this thread has been a source of very valuable information for me. I'm planing to buy the YOOCNC 3020Z-D52 from Amazon in order to use it for produce PCBs in a minor scale. I would like to know if you think that this machine is suitable for that work? I mean, do you think I could keep it milling/routing for 8 hours a day and seven days a week? How much lifetime do you think this machine could have under this duty cycle?
In my opinion the answer is NO. Not 8 hours a day and seven days a week.
Why ?
All the mechanical parts are not "high end" parts and the spindle is not good enough to run 8 hours per day.
It is a good machine for hobbyist, not for professional.
Of course, it is only my opinion.
Regards,
Rak
I have this same board in my CNC controller.
I just got my scope in and was measuring the frequency of the 555 being used as a PWM, it is at 18.25KHz. Duty cycle approx 5 - 95 %
My breakout and 3-axis driver board has the Spindle PWM output connected through a Schmitt Trigger inverter from pin 17 of the DB-25.
Activating it in MAch 3 and varying the frequeny in the spindle setup I can get approx a 5KHz PWM. Duty cycle 0 to approx 99%.
I was wondering if you had used Mach 3 to control the Spindle speed and what your settings are?
Hi!
I am writing from Hungary in Google translate.
Sorry to bother you with my letter, but I saw that you YOOCNC 4-axis driver. Can you help me in sending parameters to the recommended setting? Specifically, I had the spindle configuration parameters needed. Thanks for your help too..
Hi,
i have four axis cnc machine similar to RAK where it has the same board YOOCNC-NT65-3X
i try to find ceramic capacitor but i found MKT with name +47J63 i connect it as most of other.
but the result not change they are missing step only work with very low feed rate which same as past,
can you help me?
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Re: YOOCNC 3020Z-D52 losing steps
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