Author Topic: Project: Converting a milling machine to a CNC machine.  (Read 25098 times)

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Offline Pat Pending

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #25 on: April 08, 2013, 07:16:07 pm »
Fake TB6560 chips + Inductive load + poor gnd management = loud musical motor tones + erratic steps + smoke + frustration + time and money wasted

I've tried with that exact same board, blew it up and almost abandoned my CNC build.

 

Offline Spawn

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #26 on: April 12, 2013, 04:51:56 pm »
Some update:
The steppers are on their way, Franky (iloveelectronics) got me the stepper motors, and I really appreciate his effort and like to thank him.

I went for 57BYGH56-401A steppers, bipolar NEMA 23 Stepper Motors 175Oz-in 1.8Degre 4Leads 56mm

Meanwhile I stripped down a old backup UPS from APC, I am going to use the case for the power supply and controller board. Ordered some connectors for the axis wiring and a e-stop. Also ordered a 12V 3A PSU for the fans in the case I am going to build and for the fan on the controller board, I don’t want to stress the 12 regulator because it’s known to fail.

I was planning to do some youtube video but I don’t have anything here yet so that will come later on, meanwhile some photo’s below.

The case and the CNC dedicated XP machine in the background:



The actual steppers Franky got for me:


The connectors, e-stop and 12V PS:


Meanwhile I am trying to learn CamBam to create g-codes and this is probably first thing I am going to mill when it works, its own control front panel, holes for connectors and LED’s, the bigger hole is for the e-stop:


Offline kinsa

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #27 on: May 13, 2013, 03:07:59 am »
Hi,

You don't really need a NEMA23 for this little machine. A NEMA17 motor will do.

Here's a pic of my conversion using pololu drivers and a RaspberryPi running linuxcnc as the controller.



All the aluminum motor mounts were milled using the MF70. The initial mounts were hand made from 10mm acrylic sheets.

Cheers!
42
 

Offline iloveelectronics

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #28 on: May 13, 2013, 10:06:15 am »
Some update:
The steppers are on their way, Franky (iloveelectronics) got me the stepper motors, and I really appreciate his effort and like to thank him.

I went for 57BYGH56-401A steppers, bipolar NEMA 23 Stepper Motors 175Oz-in 1.8Degre 4Leads 56mm


Hi Spawn,

Didn't see this thread until just now. I didn't know you were ordering these stepper motors for making a CNC machine. Coincidentally I have actually bought one of those mini Chinese 3020 CNC machines because they look like a lot of fun (but am too lazy/busy to build my own) :D If you don't mind I might post in this thread some pics once I have it set up and running.
My email address: franky @ 99centHobbies . com
My eBay store: http://stores.ebay.com/99centhobbies
 

Offline Spawn

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #29 on: May 13, 2013, 09:41:46 pm »
Franky, I would love to see your pictures :)

Unfortunately I don’t have time at this time of the year like always, working on an airport at high vacation session times don’t help much with the hobbies, probably I won’t have time to finish things till September. But if I find some free time I will start to build this up, I got everything to finish the project.


Kinsa, that is nice setup, about nema23 I know 17 was enough but if I like this CNC stuff I want to build something else that’s why I got bigger ones so I can use it later.

Offline Iano

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #30 on: June 29, 2013, 03:45:00 pm »
Just my humble two cents worth, since I stumbled over this conversation and thought I could add my personal experiences with this board. 

I've now bought two of these blue Chinese TB6560 boards in the past couple of years for separate home build CNC projects.  The first 3 axis board I bought separately and then Ebay'ed 3xNema 17 motors from the US.  The second was for a heavier duty build with the 4 axis board package with 4xNema 23 all from China.   The boards work and have served me well, but are not "ideal".  My experience is occasional lost motor steps at higher speeds and the motors are pretty noisy, but nothing that is totally destroying my CNC experience as an enthusiast cutting parts and shapes only for home use.  It has been fun and the Chinese boards were a WAY cheaper option to start things out with.  The problems really are a non-event for me most of the time.

There was little information on the net about them before, but there is more and more each day so setup (without suitable instructions in English at the time!) would probably be easier for the beginner than in the earlier days of this board design. 

Like others, I've spent days on the net in the past reading about all sorts of driver boards and hacks and have seen all the horror stories about Chinese boards.  So far, perhaps I have just been lucky, or too accepting of the occasional missed step at higher speeds.  I can almost say I have enjoyed learning so much by having these slightly flawed boards and being FORCED to research more about them.

One of my TB6560 chips (of all 7 on two boards) had the stray solder problem on Pin 25 of the TB6560.  I was able to scrap it away with a Dremel disc relatively easily.  I am not sure if it was causing problems in operation or not.  Nothing I noticed at the time.

DIP switches all tested out ok.

I have both boards set up on 25V and have a separate relay for the cutter start/stop on the larger 4 axis machine.

I have run one of the boards pretty hard on (non-essential only) jobs during the last year and during Summer.  I use a separate control box fan off the 25V supply to help cool the 4 axis board just in case of risk of overheating ... knowing the stories!  The fan turns on separately with the main on/off switch when the entire system is switched on.  I am not sure if this addition has saved any frying of chips or not.

After all my reading and research to this point, I agree with others.  The Toshiba TB6560 seems to be a good chip by all accounts.  The motor controller board is  "moderately good" (from my experience) to being a lost cause, considering the low cost and generally ok function that allows a CNC machine to work and for CNC builders to get off the ground to start in general. 

I very much doubt the Toshiba TB6560 chips on my boards are fakes at all as some have suggested.   Its just the board design around them that seems a little flawed in places.

I am wondering about the relay protection diode.  I have to admit, I have heard the occasional strange jolt out of the motor.  Its not dead jet though ... lol ;-)

I am now at the point where I am also considering doing board hacks in the close future on one board soon to see if I can make any improvement to motor noise and to refine the lost steps problem for even greater precision.    Approximately 0.5 mm on my large machine is no problem at this stage with the controller as is.
 
I think I have a handle on what is required for the fix, but I am not sure if I will implement all hacks people talk of.  Or use necessarily use the same approach.  When I go ahead, I will let you know what I did and how things turn out.


So in my overall experience, the board is worthwhile for what if achieves with its low cost.  But perhaps only if you are not too serious about total reliability or absolute precision on every project, every time.  The hack fixes should be fun.  they don't seem too hard once you get your head around what's required.
 

Offline Iano

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #31 on: June 30, 2013, 05:02:36 pm »
Wow…
I just read 100+ pages on different forums and there is so many mixed information about this TB6560 most don’t recommend and some like it. The thing is most are using this board for higher voltage and have problems and around 24V there is not much complains, but there is also some easy fixes for smoother runs:  http://www.homediystuff.com/fixing-a-chinese-made-cnc-stepper-motor-driver-board-tb6560-chips/


Wow! I spent a lot of time today on that http://www.homediystuff.com/fixing-a-chinese-made-cnc-stepper-motor-driver-board-tb6560-chips/ site you linked to.  It's the first time I've seen it, despite the huge amount of time I've spent researching what's needed for the mods on the net in the past.
The site's worth a look for anyone considering the TB6560 board.  Everything is put in understandable terms with good big pics and explanations of what to do.

Good pics and diagrams that show closeups, so mod changes should be easy enough to follow.  I was a little worried about destroying my board so was hesitating to do the fix before, but I think it should be ok now if this guide does the job???

Doesn't seem to touch on the relay diode addition at all???  My board(s) have been running for ages and haven't really noticed the relay problem too much anyway.  I guess the diode it is not a difficult addition anyway.
 

Offline jnissen

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Re: Project: Converting a milling machine to a CNC machine.
« Reply #32 on: July 02, 2013, 01:48:52 am »
Nice project. I have a complete Sherline setup and have not gone over the CNC cliff just yet. Just a lot of potential options on the software side and with that little machine your really going to be limited in feed rates and project size. Have you done much manual work with the machine? I find it's terrific for enclosures and all but I also build custom pieces for my hobby stuff. I'll be following along to see what you settle on.
 


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