[ACETRENB]

Hey guys, i am having some trouble on missing steps with my cnc machine,it have 3 axes, 23nema stepper motor, tb6560 driver board and mach3 to run, so i have been reading that this driver board is very problematic, poor engineered, so i am getting missing steps when using a feed of 1000mm/min+ (40ipm+), i am using the 1/16 microstep setting, 50% decay mode and 75% of current, one guy i know recommended to me to use a power grid stabilizer of 2kVA that it would up the feed a good amount, but i am not very confident to it, so i am thinkin to buy a gecko driver board because i have seen some video and threads saying its a good board to get speed and use a usb-to-parallel cable to connect to a laptop that have a lot more processing power than the cpu that its currently running, what you guys think ? i am not an expertice in eletronics so all that capacitor thing its out of my league

[rbraeking]

Missed steps is normally caused by overpowering the stepper motor. Microstepping is to be avoided if at all possible. It is a torque robber. It could be that you just have too much mass to move with too small a motor. How big is the machine? What kind of linear bearings? What system for converting rotary motion of stepper to linear? Normally it is not the computer but it could be noise in the conductors. You say that you are running a laptop. That is specifically warned against in Mach3 documentation. Are you using a USB smooth stepper? Home If you are using a usb to parallel converter for printers that could be a problem as they usually are not buffered.

[ACETRENB]

no, currently i am using a desktop cpu, i was thinking to get a usb to parallel because the laptop could get a pulse rate much greater than the desktop that only gets 23khz~, so, i am using couplings and the machine is about to 1,5m x 85cm and about to 25 cm in Z, and the linear guide is that one on the photo and my machine is that one in the other photo, ok so without a microstepping setting the precision is 0,015 mm with gives about a 0.000590551181 inch precision, i think that its ok to wood work right ? but what if taking out the micro step out and it still continue to miss steps, it could be the computer ? in the future i am thinking in get a bigger machine, so would be the gecko drivers be the right driver with a new computer ?

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[ACETRENB]

hey guys, sorry for reviving, just want to give some feedback, so, today i can go almost 3000mm/min ( ~118 IPM ), i think its pretty good for a TB6560 axis drivers, but i want to sell this machine and build another one with a better structure, but i have to change the drivers, thinking about getting a BOB with separate axis drivers and 15A power sup to at least run at 118IPM with a good torque

[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]

I am not familiar with your driver board but from the chatter on the web your problem appears to be congenital with that board. I was never convinced that a single board could do everything including driving the motors. I prefer an optoisolated BOB and separate motor drivers.

[rbraeking]

IMHO, if you really want a powerful machine you need to upgrade your electronics package. I would recommend a Ethenet Smooth Stepper, C32 BOB, separate drivers for each motor, 20 amp 60 or 72 v power supply. Motors and drivers would depend on size of machine but this setup is sufficient for a large format high speed router. 120 ipm is nothing to write home about. Routing requires cutting speeds upwards of 200 ipm and rapids up to 1000 ipm. Anything less would burn bits and waste time. Unless you really want the experience in building the cost will begin approaching the cost of a Chinese import. Good luck on your sale and new build.

Bob

[ACETRENB]

thanks man, but for know i dont wanna invest in so much velocity because if i do i will have to change the leadscrew to a ball screw or ratchet (rack), just want to go 5m/min in rapid moves and 2,5m/m or 2m/min in cuting move

[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 ?

[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]

could u give me a hand and tell me what is that BOB and where i can read about this ? would be a good help, thanks a lot man

[rbraeking]

I apologize for using acronyms. A break out board (BOB) is the interface between the computer and the motor controllers/limit switches/etc. It protects your computer from being fried by the high voltages o stepper motors (high for a computer). Some contain relays for starting routers/power supplies/ what have you. If you are running motors at 72V DC and are using 24v DC power to control spindle speed then the computer is just waiting for a release of smoke if you do not protect it.

[rowbare]

Are you running from a laptop? Mach doesn't like that much.

Another thing that will cause missed steps is mid-band resonance. In this case you are in a range where the motor still has sufficient torque but unexpicalbly stalls out. It is fine if you go faster or if you go slower. On a machine without a lot of reserve power, it will lose steps or stall otherwise will be noisy and vibrate some. Well designed drives will compensate for it..

I have no experience with the board you have but from what I have read here it is problematic. A Gecko G540 with a suitable power supply might be a better choice. Do you have the specs for your motors? Whatis the current rating and what is the inductance? There are plenty of threads here that talk about matching motors and drives. Search for and read a few of them before spending your hard-earned money.

bob

[ACETRENB]

i have noticed something annoying now, the x and y motors have almost zero torque, if i use my hands to try to stop the motors its stalls, but the z axis have a bigger torque, than i noticed that the cnc is losing steps (stalling because of the lack of torque), could that be a problem in the configuration pins of TB6560 that its not setting the 100% current on those axis ?

[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

[ACETRENB]

hi, i am using a desktop cpu at the momment, i am thinking in get that bob with 3 stepper motor drivers 3 axis Stepper Motor Driver 0.2-5A controller & Breakout board for CNC Router, this bob has a better price than the gecko board and have about the same specs, and buy a new psu with a 2kVA power grid stabilizer, and does the wattage power of psu matters in this problem ?this bob need a 5v dc power supply, does the psu i use in tb6560 works in that bob ? i have no experience with eletronics, i am currently studying mechanic technician, and just entered in eletric machines subject in school

[rbraeking]

There are a number of causes of low torque unrelated to motor size.
1. are the motor drivers set to the proper amp rating?
2. are you micro-stepping? Microstepping seriously reduces torque.
3. Is there sufficient current? Volts * Amps = Watts. Watts is power. Motor drivers limit the amps so putting more voltage to your motors will increase the power.
4. Mechanical friction. There is a fine line between tight enough and too tight.

Bob

[rbraeking]

You may be jumping ahead of the game. Windows® steals a lot of power that is need to run the parallel cable. Before spending any money make absolutely certain that no other programs are running when you are running your router. Turn off any routers, modems, anti virus software, etc. DO NOT try to open another program while running the router. The problem may be in your computer and the way that it is running.

That said, if you are going to build a bigger machine in the future a bigger amp rating on motor drivers might be money well spent. Otherwise 2.5A should be sufficient for your situation. I have never been a fan of those 3-axis all-in-one units. It is like those old Christmas lights. If one goes out they all go out.

Bob

[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

[ger21]

i am thinking in get that bob with 3 stepper motor drivers 3 axis Stepper Motor Driver 0.2-5A controller & Breakout board for CNC Router, this bob has a better price than the gecko board and have about the same specs,

You get exactly what you pay for.