Messages

7001

General Mach Discussion / advice please

« on: December 28, 2009, 03:21:22 AM »

It all depends on the rest of your circuit - The 2803 is just a driver and is limited to 500mA per phase which is marginal.
A better choice, from the Alegro range, would be the A3979 which can provide up to 2.5A per phase also taking care of stationary current limiting, microstepping etc. etc. and requires few additional components to make a complete driver and is, of course, fully Mach3 compatible.

Tweakie.

7002

General Mach Discussion / Re: How can a CNC machine save time?

« on: December 27, 2009, 05:58:48 AM »

Ahh - My Grandad told me about the Good Old Days when all the machines were shaft and belt operated from a central steam engine. Some poor s** had to stoke the boiler and get steam up before he started work at 6am. I think he did actually operate a CNC machine (Coal Not Coke). 

Tweakie.

7003

Tangent Corner / Re: medication

« on: December 27, 2009, 05:42:14 AM »

    I Think I need some of them Sam   

Tweakie.

7004

General Mach Discussion / Re: mouse replacement

« on: December 24, 2009, 03:22:47 AM »

Thanks for posting the link - most interesting.

Tweakie.

7005

General Mach Discussion / Re: I truely believe it's a bug with many versions:

« on: December 22, 2009, 01:26:54 PM »

Hi Omri

Don't know if this is any help but I just ran your code without issue other than it scared the pants off me because I don't usually use feedrates that high.
I only cut air, with the spindle motor switched off, but there were no unusual stepper noises and as far as I could tell no missed steps.

My PC is running Pentium4 at 2.4 Gig with WinXP Sp1(I had mega problems with Sp2 onwards) and Mach R3.042.032.

Just out of curiosity - Can you set your motors (vel. and accel.) to a high rate which works OK in the motor tuning page but then they stall when jogging in the main Mach window ?.

Tweakie.

7006

General Mach Discussion / Re: New system set-up help

« on: December 22, 2009, 12:35:54 PM »

Jchal,

Just for a reference point what are the planned dimensions for your new build machine ?.

Tweakie.

7007

Show"N"Tell ( Your Machines) / Re: Dixie Duke - A machine in the making.

« on: December 22, 2009, 12:05:50 PM »

That's a good start Sam - looking forward to seeing further pics of your progress.

Tweakie.

btw. My wife sends her regards - she still remembers the Cheese Board incident. 

7008

General Mach Discussion / Re: New system set-up help

« on: December 22, 2009, 11:47:28 AM »

As has already been said - This board is no good for 7.9 Amp motors.

Incidentally they sound a bit mighty for a router - they would drive Hood's Beaver. 

Tweakie.

7009

General Mach Discussion / Re: New system set-up help

« on: December 22, 2009, 09:26:25 AM »

 The PC parallel port is not capable (without additional circuitry) of providing a -5 Volt signal it is just +5 Volts or 0 Volts (within a certain tolerance).
 The board you have shown in the picture will replace your drivers and will be easy to hook up. Additionally it has the spindle relay and I think, would be ideal for a router.

Hope this helps,

Tweakie.

7010

General Mach Discussion / Re: Need Help with Stepper Motor Driver - New User

« on: December 22, 2009, 04:24:08 AM »

You could do a forum search to find out what others are using for their BOB’s - the C10 seems to be popular and this can be found here http://www.cnc4pc.com/Store/osc/index.php?cPath=33&osCsid=2d1fd3d8ffdeb2cc6078c4da7037fc55

This is the basics of what I would do ( I don’t offer any warranty on this !!).

Q3HB220M Driver:-  Pin 6 switches alternate steps per revolution which is not required. Pin 10 is an index output which is not required at this stage. Pin 12 is a driver ready output which is not required. (This assumes that you will not be using encoders with the motors).
Set the steps per (SK1) to a realistic setting, perhaps position 9 (2000). Set motor run current (runIM) and motor hold current (stopIM) to match your motors.


LPT output pins / BOB pins and Mach setup:-

PIN      DESIGNATION   MACH ports & pins
                    Input / Output signals.

1      C0/output
2      D0/output      x step   step low active
3      D1/output      x dir   active high / low will determine motor direction.
4      D2/output      y step   step low active
5      D3/output      y dir   active high / low will determine motor direction.
6      D4/output      z step   step low active
7      D5/output      z dir   active high / low will determine motor direction.
8      D6/output      a step
9      D7/output      a dir
10      S6/input      e-stop
11      S7/input      x home/limit
12      S5/input      y home/limit
13      S4/input      z home/limit
14      C1/output
15      S3/input
16      C2/output   
17      C3/output
18      gnd      )
19      gnd      )
20      gnd      )   
21      gnd      )   GND
22      gnd      )
23      gnd      )
24      gnd      )
25      gnd      )

Under motor tuning set the steps per to 2000, acceleration and velocity low (to start with) and the step and direction pulse widths to 2 uS.

Initial test:- Connect up one drive first (X axis) as diagram. At switch on the motor should lock – If the motor rotates, switch off and change DP4 to ON. Switch on again – if the motor does not lock, switch off and connect pin 8 (motor free signal) to GND  and pin7 to +5V and try again.
Always switch off before changing any settings or connecting / disconnecting wires. Observe caution and safety when dealing with the 220 Vac and motor connections.


Tweakie.