Messages

501

General Mach Discussion / Re: Is this a suitable power supply

« on: April 21, 2014, 07:06:39 AM »

Personally I'd be thinking closer to the 36V rather than 24V. Also 15A is waaaaaaay over what you'll need for the motor specs you've posted.

502

General Mach Discussion / Re: When is a circle not a circle? When it's 4 arcs!

« on: April 21, 2014, 06:30:35 AM »

OK your steps/per of 127.3 and max vel of 15m/min for X&Y does indeed require a kernel of 35KHz. HOWEVER...

Your accel is pretty poor at just 500mm/s^2.

Max vel and accel are generally a trade off. Personally I'd lower your max vel and see whether you can improve your accel. CV and good accel make good bed-fellows.

You're getting different results between a full 360 and 4, 90 degree arcs. The ONLY difference I can see is that with the 4 arcs, CV HAS to do a blend whereas with a full 360 it doesn't. Given your accel is so low, I think this may be your problem (particularly with your high feedrate of 9.9m/min).

If you choose to try this then leave your kernel at 25KHz because it's sufficient for anything below 11m/min with your steps/per and I'd expect you to be reducing below even that quite dramatically to get usable accel.

BTW - you may want to revise your pin settings for e-stop.

503

General Mach Discussion / Re: Is this a suitable power supply

« on: April 21, 2014, 05:43:22 AM »

The page you linked to for the driver appears to give a range of 12 to 36V. The datasheet for the TB6600HG's gives an absolute max rating of 42V so the 36V seems appropriate. There are several warnings on the data sheet about the consequences of going over this absolute max of 42V - most of which seem to involve some form of mayhem  .

Ian

504

Modbus / Re: How to Address Modbus Outputs if you have more than 20

« on: April 19, 2014, 12:47:29 PM »

Hi shangJie

If I understand your requirement correctly, I *think* you may be going about this in an overly complicated way. If it were me I'd be looking at something like an Arduino mega and have Mach simply send the number of the colour you want across modbus.

505

General Mach Discussion / Re: General help wanted

« on: April 19, 2014, 03:58:58 AM »

Hi Eli - I'll move your post to the General Mach Discussion where I think you'll get more views. If no one local can help you, please post your questions here and I'm sure you'll get the help you need to get you going.

Ian

506

General Mach Discussion / Re: When is a circle not a circle? When it's 4 arcs!

« on: April 18, 2014, 09:01:23 AM »

The radio button in the general config is checked for CV. I take it that it will be on by default unless otherwise instructed by the Gcode?

Yes.

Having re-read the Mach3 install document I see that a kernel speed of 35kHz is recommended for stepper motors mine is set to 45kHz. Would that make a difference?

Got a link? The kernel should be set to the lowest frequency that supports the max speed you require/can get. Generally speaking, with steppers, this means 25KHz. Setting the kernel to higher than needed is at best pointless and at worst likely to cause problems.

507

General Mach Discussion / Re: When is a circle not a circle? When it's 4 arcs!

« on: April 18, 2014, 06:39:36 AM »

first check you actually have CV ON as you have no G64 in your code. Then maybe post your xml.

508

General Mach Discussion / Re: When is a circle not a circle? When it's 4 arcs!

« on: April 18, 2014, 05:24:56 AM »

IF CV is working "properly" AND if the 4 arc segments join correctly i.e. tangentially, then you should see no difference between 4 (90 degree) arcs and 1 (360 degree) arc because the blend between the 4 arcs should be "seamless". In that case any backlash and/or flex should produce identical results for both schemes.

If however CV is NOT working properly OR the segments do not join "properly" then you will get an "interruption" in the blend at each join which itself could cause issues but also the effects of any backlash/flex will be made more obvious.

In your gcode, the 4 arcs do appear to "join" correctly" which when added to your statement:

I have also noticed that during engraving the machine is very jerky which is causing it to vibrate.

strongly suggests to me at least that you DO have a CV problem.

509

General Mach Discussion / Re: THC Codes upset corners???

« on: April 14, 2014, 04:05:39 AM »

I'll give it some thinks and get back - gotta go.

510

General Mach Discussion / Re: System with only X and C axis and fixed tool point

« on: April 14, 2014, 04:04:24 AM »

I had it in mind that you might be able to do this using axis formulas (Function Cfgs). I tried it but it just produced a nonsense toolpath. A bit more diddling and either I'm doing it wrong or formulas don't work properly. Really simple ones seem to work but anything slightly complicated seems to throw it. The example on the formulas dialog implies it CAN handle more complex formulas but not here anyway. (3.43.22).