It's begun....

[JAZZCNC]

No, you want to increase the acceleration if anything. I run my machine at around 1m/s^2, so twice what you've set.

Be very careful here because while Jon's right acceleration is useful it's also the biggest cause of missed steps.!! . . . .6mtr/min and 500m/s/s on 5mm pitch screws is not unreasonable speed for first use and unless your doing lots of 3D work or lots of short moves then it will be fine for most work.

Like Jon's says it a compromise of velocity or Accel so if your happy 6mtr/min then wind the acceleration up until motors stall and then back off 10-20% and you should be fine.

[Jonathan]

Yes, clearly if you set the acceleration higher you want to test the system thoroughly to make sure the motors wont stall. After doing what Jazz suggests, I suggest running some code from here:

http://www.mycncuk.com/forums/gcode/...or-tuning.html

Then you can change from 'should be fine' to almost certainly fine.

[JAZZCNC]

Yes, clearly if you set the acceleration higher you want to test the system thoroughly to make sure the motors wont stall. After doing what Jazz suggests, I suggest running some code from here:

http://www.mycncuk.com/forums/gcode/...or-tuning.html

Then you can change from 'should be fine' to almost certainly fine.

That's handy Jon not seen that before and with G61 exact stop mode at G0 speeds with high acceleration it will double to test of how anchored the machine is.!! . . . . . Again careful has with high settings the Bloody thing will try to walk off. . Lol

[Washout]

Some progress tonight, whilst I had some "workshop time".

I decided to do a complete re-wire of the VFD a. to give me some more space with the machine and b. to ensure that the old stuff was not at fault. I also replaced the RCD in the workshop and now rely on the RCD at the consumer unit which feeds the barn/workshop where its split off from the main house supply.

The VFD fired up first time and still had my old settings in it, which was nice. So I then ran a quick 2D job on some 6082 aluminium, which was very light work i.e. one central 3mm drill mark at 0.1mm deep and then 4 surrounding 6mm "dowel hole" marks at 2mm deep using ramping. Used a 3mm 2flute carbide bit at 16800rpm and 800mm/min. The job itself ran a treat apart from 3 spurious e-stops (tried a debounce setting in MACH3 of 1000 and 3000, but still had a phantom e-stop). I'll have to check earthing continuity on all the CY going back to the control box, as I know my spindle is earthed back to the VFD and the CY carrying the spindle cables is also earthed at the VFD end only i.e. no loop.

Interestingly I checked continuity/resistance from the spindle to various parts of my machine and I'm getting negligible readings from the spindle, through the gantry and all the way to the main frame.

Still some progress and light possibly at the end of the tunnel - at least the job I did complete showed very little grumbling from the tool and ripped through what it did have to do, with nice chips, which gives me some hope that I can start doing something other than work on the machine and make the machine do some work for a change ;-)

More as I get time....


Chris

[Washout]

Another quick update:


I still have spurious e-stops, which I thought I might get rid of by running the VFD off of a circuit in the workshop which does not go through the dado trunking next to the control box supply, but to no avail. Also checked all my earthing for the control cables and that is OK i.e. CY shielding going back to the control box star point, with good continuity. Also tried Mach3 de-bounce settings up to 3000. Only thing I have left I think is I replaced a big chunky, but very long (3mtr) parallel cable with a shorter one, so will switch that back to see if there's an improvement.


On the bright side, to do the testing for the spurious e-stops I ran a job in beech block just to try and the following pic resulted, which despite the e-stops probably losing steps when incurred, is at least something and came out nice and clean apart from where the wood won't hold the very thin details. The 3mm end mill went through the wood like it was not even there (ran at 18600 rpm at 800mm/min on a 3flute), so aluminium next :-)

[Washout]

Even quicker update: looks like all parallel cables are not equal, as I have just replaced that for the old one and all is now well - test job ran without any e-stops :-)

Now for some cutting.......

[JAZZCNC]

Even quicker update: looks like all parallel cables are not equal, as I have just replaced that for the old one and all is now well - test job ran without any e-stops :-)

Now for some cutting.......

When having any problems with signals first place I always go is the Parallel Cable and swap it for a known good one.

Pleased your sorted.!