[ACETRENB]

well, i am using a power supply with 14,4~A, but i need to buy a voltimeter to measure the voltage, related to the dip setting of TB6560 the x and y is set to 100% current and z to 50% and still Z axis is almost impossible to stop with hand, maybe the dip pins could have problem, like they are not changing, relating to the micro-stepping in first days of my CNC i was using 1/16, now i am using 1/2, which increase a lot the maximum speed allowed, so am i seeing the situation myself i think that could be the TB6560 or things is just too tight, my grandpa was a toolmaker and he setup the machine without knowing what he was doing and he like things just too tight but it have a small chance that could be Voltage because i am using the power supply connected to a power grid stabilizer which could reduce the performance of the power supply

[rbraeking]

It sounds like bearing pre load is set too tight or the drivers are just not doing the J O B. You can't expect much from a 20 dollar driver.

Bob

[ACETRENB]

yeah man, i was already thinking about that, i am going to purchase an bob with separated drivers to get configs right, later on i will buy an gecko g540

[Dennis Bohlke]

Attachment 260054

I wonder if this is the board you are using. Kind of sounds like it from your description.

I have found the optical Isolation circuit won't pass step signals reliably beyond 8000 steps per second.

I also found it does not work reliably, on some tool paths it is ok and on others it looses it's position.

It looks like it works but when I test it for loosing position on complex moves it does and the movement files work on other controllers.

For the price it was too good to be true.

Dennis
Super Tech & Associates Main Web Home Page

[Larken]

I found the Chinese DM542 drives will also loose steps on some curves, but the DM860 drive doesn't loose steps.

( Hey, Dennis, remember talking to me back in the 90's ? You gave me some fast integer pascal code for knowing if a mouse was over a vector line, that you used in your SuperCam program. )

Larry k.

[Dennis Bohlke]

I made three little g-code programs to test with.

The stepper motors I have have flats on them so I positioned it at zero with flats up.

The first I moved the Z axis back and forth a quarter turn. It was set up for 1600 steps per revolution and 4mm per revolution so this in code was from 0 to 1 and back. I did a copy and paste about a hundred times. Looks like it runs consistent and good. Stops at zero with flats up.

Then I made a test where all three axis move 0 to 1 and then back. Made it run about 150 times and it seems to work perfectly.

Then I made a test where Z moves to 1 then X and Y move to 1 then X and Y moves to 0 then Z moves to 0 and repeat a couple hundred times. It fails with a random aspect to the results each time the program the flats end up someplace different.

Next step is to hardwire the Select line to enabled on the TB6560's and test again. But I hadn't thought of that then.

BTW Larry - Great seeing your response pop up. The journey has been a joy, SuperCam works great after a couple of decades writing it. silly me

Dennis
Super Tech & Associates Main Web Home Page

[ACETRENB]

i was thinking to get this one CNC Kit 4 Axis CNC Breakout Board 4 TB6600HG Stepper Driver Controller 5A | eBay ,that will be good ? i choose 4 axis, but i will use 3 axis, and if one of those drivers burn or something i wil have one more to replace

[rbraeking]

Actually, you will need 4 axes if you are going to use 2 steppers for your x axis. That breakout board is a minimalist board. If you want to add 3d print or laser cutting in the future it doesn't have enough i/o's. If all you want to do is run a router it looks like it will do the job. It may work just fine for your application and it is cheap enough for a hobby machine. You are limited to 45 volts by the drivers. That will limit your power as ohm's law cannot be violated. I would not run over 36 volts on this unit as switching power supplies are available in 24, 36, 48 volt and 48 is a bit much for these drivers. I prefer industrial quality myself because what I spend on hardware will be offset by the lack of frustration and cost of wasted material. I am a bells/whistles/blinky lights kind of guy.

Bob

[ACETRENB]

my machine is actually 1 motor per axis, and it will be only router, i dont plan on doing plasma cutter or laser, i choose this one because have a extra driver, if one of the 3 drivers in use shows a problem i will have an extra one to replace the problematic one and i dont plan on ultrapasing 24 volts, maybe 36, because my motors are nema23, one doubt i have about eletronics is, my power supply have 14~A, if i set the drivers to run on full current there will be a problem with an driver pushing more current than another one ? is it better that i set 3,3A for each driver to limit what it can use so one doesnt use more current than other and therefore not destabilize the system ?

[kreutz]

If you are using a drive based on the TB6560 you must be aware of the chip limitations. Maximum step frequency is 15 Khz, minimum step pulse duration is 30 uSec. Mach3 step pulses are a lot less than 30 uSec duration and that is a source for missing steps. Maybe if you use the Sherline 1/2 mode, on the Mach3 configuration, you would be able to get them to behave.

Here is a link to the chip's data sheet: https://www.toshiba.com/taec/compone...E_EN_27885.pdf


kreutz

[ACETRENB]

but TB6600 is a separated drivers, its not based on TB6560 which have 3 axis control in the same board, separated drivers have a much more reliable source of power, the datasheet for these separated drivers https://www.toshiba.com/taec/compone...E_EN_31288.pdf ,i dont understand very well but this chip look much more powerful than TB6560

[kreutz]

The TB6600 seems to have better specs for CNC, just make sure the step pulses are 2.2 uSec or longer. But the rest of the drive design will also influence the performance.

[ACETRENB]

do you think i can get up to 4m/min (157,5~ IPM) in rapid move and 2m/min (78,75~ IPM) in cutting move with those drivers if configurated right and 1/2 microstepping?

[kreutz]

It is not only the stepper drives what determine machine performance . It is the PC, Operating System (real time or not), CNC software, step generator (dedicated board or PC generated), drive, motor power supply, motor, rotational to translational mechanical movement conversion, load mass, including also the spindle power and tools. The weakest link in the chain determine performance limit, that is why so many people tell you that you get what you pay for. 1/2 micro stepping will let you get higher motor RPMs with a low step frequency, but will increase the susceptibility to resonances at certain speed ranges and the consequent loss of steps.

kreutz

[rbraeking]

What you are attempting to achieve for rapid speed is what you need for cutting speed. My g-wizard calculator calls for 150ipm cut speed in MDF 1/8 depth @ 24,000 rpm using a 3/16 cutter. If you want your cutters to last at 89ipm you will need to slow your spindle way down. I'm just saying that if you want this dog to hunt you will need to get a bigger gun.

[ACETRENB]

RPM is not a problem, my spindle have a rpm range of 10k-30k because i bought it just to cut wood