Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: nitecreate on February 17, 2011, 07:42:52 PM

Title: Bad BOB???
Post by: nitecreate on February 17, 2011, 07:42:52 PM
 ???   First of all I'm a real beginner in building a CNC.  I built a Router, which was a real blast.  Problem being that I think I purchased a real inexpensive break out board.  Toshiba  board.
I'm having a fit trying to figure out the problem with my Y axis. The other 2 axis cooperate rather well.   At any motor setting or speed, the Y wants to stall out for only a millisecond now and then?  Which pretty much messes up my projects.  I've checked all the wiring, changed stepper motors, and no change.  I've even switched axis.  And in doing so my problem is with the axis that I've changed to. So to me this pretty much tells me the problem is with the board???  In looking into purchasing a new board, I'm really confused as to what to look at or look for?  I don't mind spending money on a quality product, on the other hand I don't want to break the bank (I'm retired) and this is suppose to be a hobby.  Anyway, any suggestions on a new board or possibly might be the problem if not the board.  I would be really appreciate input. Please keep it simple. 
Title: Re: Bad BOB???
Post by: Peter Homann on February 17, 2011, 08:08:24 PM
Hi,

You haven't provided information about what stepper drivers and other components you are using.  A bit more info whould be helpful.

I sell, a robust and simple to use breakout board.
http://homanndesigns.com/store/index.php?main_page=product_info&cPath=22&products_id=59

Cheers,

Peter.

Title: Re: Bad BOB???
Post by: nitecreate on February 17, 2011, 08:34:24 PM
Ok, I'm using (3) KL23H2100-30-4B   382 oz-in Stepper motors, TB6560 Driver Board (4 axis) but only use 3.  Ball and screws acme drive.  And of coarse Mach3
Title: Re: Bad BOB???
Post by: ostie01 on February 17, 2011, 08:52:07 PM
You could try to rotate the screw by hand on the Y axis, seems like a mechanical problem.

Verify if it is easy to rotate the screw all the way from one side to the other



Jeff
Title: Re: Bad BOB???
Post by: nitecreate on February 17, 2011, 10:03:30 PM
I've done that, in fact when I power jog the Y axis it works really good, it's only noticeable when I run a X Y combined move?   The Y axis stops and the X continues and then the Y starts moving again, and that happens anyplace on the table, so I doubt that it's mechanical. 
Title: Re: Bad BOB???
Post by: Overloaded on February 17, 2011, 10:55:02 PM
You might monitor the power supply output voltage while making combined axis moves. A significant drop due to an undersized PS can produce symptoms similar to what you are seeing.
Title: Re: Bad BOB???
Post by: larryc on February 18, 2011, 09:04:43 AM
have you got a capacitor on each driver as well as a main one in the power supply. If not maybe there isnt enough power to run both motors at the same time
Title: Re: Bad BOB???
Post by: nitecreate on February 18, 2011, 01:36:47 PM
Each one has it's own capacitor, my power supply is a HS 300-4  24 volt 12.5 amps.  Not quite sure what the voltage at each motor is suppose to be (4 wire stepper motors)?    In playing around a lot more, I've found out that the machine seems to run X Y combination moves without hesitation, but when you run arcs, is when it appears that the Y Stalls???? Frustrated, but retired and have lots of time.  I have no doubt that it's electronics and not mechanical. 
Title: Re: Bad BOB???
Post by: larryc on February 18, 2011, 09:59:09 PM
the voltage should be around 10 to 20  times the motor voltage if the voltage per coil is 2.5 volts at 1 amp for example you could use any thing from 24 volts to 50 volts dont forget when you take for example 20 volts ac and convert it to DC with your compacitor in line the voltage will increase 1.5 per cent so now you have 21.5 volts this is all aproxamite but all within  a volt. look on a forum called   mechmate.com    they have all the formulas and infermation that you need to check machine build problems . They were out of south africa now it it run out of the U.S.
Title: Re: Bad BOB???
Post by: Hood on February 19, 2011, 06:17:02 AM
Larry,
the DC voltage will be 1.4 times approx the AC volatge so 20vAC would be approx 28vDC.

nitecreate
It seems you are using an all in one 4 axis driver with inbuilt bob? You mentioned swapping motors around and the problem stayed with the actual outputs I think? Have you tried putting the motor on the spare drive outputs?

Hood
Title: Re: Bad BOB???
Post by: larryc on February 19, 2011, 08:56:47 AM
Sorry hood you are right my math isnt my best thing. thst is why I said aprox.
Title: Re: Bad BOB???
Post by: Hood on February 19, 2011, 09:11:49 AM
No probs Larry, I know enough about electricity to be dangerous so I try to be careful with it :)

Hood
Title: Re: Bad BOB???
Post by: nitecreate on February 20, 2011, 03:13:41 AM
Larry, I tried using the extra drive output, seems that even though I felt it worked better, it still played stalled on arcs.  I really think that this Toshiba board isn't doing the job???  I'm seriously thinking of purchasing a Geckodrive 540 to replace it with. 
Title: Re: Bad BOB???
Post by: larryc on February 20, 2011, 05:36:26 PM
why are you going to use a 540 geko drive I use a 201  or 210 gecko drive with a  c10 interface  and I have no trouble I think the gecko no. is 210 look at there web site It works well for me . I use 450 stepper motors  Cheaper than the othe bigger driver.
Title: Re: Bad BOB???
Post by: Peter Homann on February 20, 2011, 05:48:27 PM
Larry, I tried using the extra drive output, seems that even though I felt it worked better, it still played stalled on arcs.  I really think that this Toshiba board isn't doing the job???  I'm seriously thinking of purchasing a Geckodrive 540 to replace it with. 

As a replacement for the Toshiba board. the G540 would be a great choice. Coupled with a 48V 7A power supply it makes a neat self contained 4 axis stepper drive system.

I currently have the G540 on sale for US$249.00
http://homanndesigns.com/store/index.php?main_page=product_info&products_id=80

Cheers,

Peter.
Title: Re: Bad BOB???
Post by: larryc on February 20, 2011, 06:31:54 PM
Okay I was just wondering I just used 3 geckos 210s and a c10 board found at( cnc 4pc)  it works well and I never had any problems. I was going to use a 4 axiz board when I started to design the mache 4 years ago but quickl changed my mind for the  same reason you are changing boards now If one axiz goes you chang everything . with a interface board and three or 4 geckos just unhook and change the part you need.  I was wondering are you sure you dont have a problem with mach a adjustment or somthing. one of the other forum members in this section on the same page was having trouble with his motor stoping for a second then starting again. somthing to do with his setting I think . Check his site and see if he is having the same problem.
Title: Re: Bad BOB???
Post by: Hood on February 20, 2011, 06:36:17 PM
Larry, the G540 is actually 4 seperate drives that plug into a motherboard which acts as a breakout so you have the best of both worlds. Its lower volt and current than Geckos other stepper drives but its aimed at the smaller stepper market
Hood
Title: Re: Bad BOB???
Post by: larryc on February 20, 2011, 06:57:30 PM
Ha that is a good idea. So you can take the board apart and chang just one drive . I will have to check that out . Does it also have a icealated breakout board built in also.
Title: Re: Bad BOB???
Post by: Hood on February 20, 2011, 07:00:47 PM
Yes you can do that and they are relatively cheap compared to the bigger Geckos. The BOB I believe has opto isolation but best check that out in the docs as I have never read them properly as its not really the type of thing I would use as all my machines are bigger and I tend to use servos.
Hood
Title: Re: Bad BOB???
Post by: Hood on February 20, 2011, 07:03:51 PM
Larry, heres the specs from Peters site

  G540 Specifications:
      - Four 10-Microstep motor drives
      - 0 to 3.5A rated phase current
      - 18VDC to 50VDC supply voltage
      - Mid-band resonance compensation
      - Auto standby current (70% current)
      - Short-circuit protected
      - Optoisolation on all LPT signal pins
      - Two 1A at 0 to 50VDC rated outputs
      - Four SPST to GND inputs
      - FAULT indicator LED,signal to PC
      - POWER indicator LED
      - I-SET resistor on motor connector
      - TRIM adjust for motor smoothness
      - Panel mount (5.7” by2.4” hole dim.)
      - Anodized aluminum package
      - No heatsink needed below 40C ambient
      - Easy to service, removable drives
      - Modular PCB design with no internal wires           
           - 10kHz watchdog timer (charge pump)
           - Optoisolated analog output for a VFD drive
      - Conservative ratings, premium components
           - Comes with four backshells and four DB9 solder cup connectors
Title: Re: Bad BOB???
Post by: larryc on February 20, 2011, 07:12:41 PM
Not bad  I think I will check them out some more as I will be building a couple more machines smaller than my big one.  these may just do what I want. Thanks
Title: Re: Bad BOB???
Post by: Hood on February 20, 2011, 07:14:27 PM
Gecko make nice stepper drives, so if building a small machine it would be what I would look at for sure.
Hood
Title: Re: Bad BOB???
Post by: Peter Homann on February 20, 2011, 08:12:40 PM
Thanks Hood,


Just to add a bit. For any machine being driven by Size 23 motors, the G540 is arguably the best value for money.  Coupled with a 48Vdc  7A switch mode power supply, you have a complete 4 axis setup.

The G540 contains 4 separate G250 stepper drives that are user replaceable. If one blows it is easily changed. I've been using a G540 since they were first released, some 2 years ago without any issues.

Cheers,

Peter.
Title: Re: Bad BOB???
Post by: larryc on February 20, 2011, 09:02:32 PM
Technoligy changes so fast 3 years ago I designed and built my machine. Now I am ready to start building a few more machines differnt type and smaller The other machine used 680 and 450 oz. inch motors. The head was a 100 pounds moving gantry. Now the new machines will use much smaller motors and use a moving pallet on a sprocket, roller arangment  Much smaller foot print and for a differnt use. But it will use use gekos. I was going to use the same arangment as before but this controller looks better and would be a couple of hundred cheaper. I was also looking at puting a computer board into the control panel. leave the main computer to run more than one machine.