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Messages - Davek0974

2421
General Mach Discussion / Re: Controlling THC?
« on: April 27, 2014, 03:40:40 AM »
Point taken, I need to stop over complicating matters, my fault entirely but valuable lessons learnt.

Many thanks for putting up with me :)

I really feel a full and proper instruction manual would benefit many users setting out, but I am fully aware that creating one would be a mammoth task. I know there are a few on the 'net but none fully explain stuff like CV, THC, side effects of low acceleration settings etc.


BTW, if I need a small hole in thick material, it needs to slow down, I have found 70% seems to work but as that is programmed in sheetcam! how does anti-dive deal with that?

As far as I know there are no hidden auto-slowdown features in Mach, it just does what it's told.
Just wondering.

2422
General Mach Discussion / Re: Odd glitch in movement?
« on: April 27, 2014, 03:33:29 AM »
Many thanks for that help, you see this is where lack of knowledge really bites me.

As I know not what is right or wrong, I can only follow stuff given to me here and there on the 'net. So far this advice has been to cut at silly fast speed with full-on acceleration and as much power as I have. That is what I was testing when I spotted this effect. Obviously I had pushed my parameters too far and not realised.

My previous cuts were exactly where you just said - around 3300mm.min!

I was going faster to see if it reduced dross (easily tapped off) as I had been advised. In the end the dross got less but harder so counter productive effect. This was with standard consumables.

Even at that 236ipm rate, the little table still managed to make that cut without losing a step which I feel is a good thing, I will retune it this week and reduce the speeds again a fair bit back into the real world.

BTW the book recommends 10,000mm/min which just seems stupid fast and there is no way that could be attained on a table that is only 700mm square without some serious G force effects, it would probably tip over on each corner :)

Thanks again, it is real-world figures I am searching for, but bear in mind I only have 30A to play with.

2423
General Mach Discussion / Re: Odd glitch in movement?
« on: April 26, 2014, 02:05:43 PM »
Pasted wrong code, my apologies. It should be this one, it's the same but I killed the THC stuff in sheetcam then wound the speed up.

N0010 (Filename: Test 1.tap)
N0020 (Post processor: Mach3 THC with scriber 2.scpost)
N0030 (Date: 25/04/2014)
N0040 G21 (Units: Metric)
N0050 F1
N0060 G53 G90 G40 G64
N0070 (Part: Test 1)
N0080 (Operation: Outside Offset, 0, T2: 1.5mm Steel, 30A, Std Tip, 103v)
N0090 G00 X41.3478 Y30.1053
N0100 G28.1 Z3.00 F800.0
N0110 G92 Z0.0
N0120 G00 Z3.9000
N0130 G92 Z0.0
N0140 G00 Z3.5000
N0150 M03
N0160 G01 Z1.0000
N0170 G03 X50.9478 Y20.5053 I9.6000 J0.0000 F6000.0
N0180 G01 X72.6444 F6000.0
N0190 G02 Y9.4947 I14.3556 J-5.5053 F6000.0
N0200 G01 X29.3556 F6000.0
N0210 G02 X0.5522 Y9.7414 I-14.3556 J5.5053 F6000.0
N0220 X9.7414 Y29.4478 I14.4478 J5.2586
N0230 X29.3556 Y20.5053 I5.2586 J-14.4478
N0240 G01 X50.9478 F6000.0
N0250 X52.4478
N0260 M05
N0270 G00 Z10.0000
N0280 X0.0000 Y0.0000
N0290 M05 M30

It might be better if I retune my settings before you invest any time on this one, if it is connected with poor acceleration then it could resolve itself, thanks anyway.

2424
General Mach Discussion / Re: Odd glitch in movement?
« on: April 26, 2014, 07:09:46 AM »
I upped the speed, the 6000 marked is 6000mm/min, the other would have been at 3300mm/min.

The different entry/exit angle is still there just not so visible at the lower speed.

From what I have been told and read, this is related to CV being choked by poor acceleration and if this correct, hopefully I will be able to fix it this week when I redo my acceleration settings.

Does that sound correct?

2425
General Mach Discussion / Re: Controlling THC?
« on: April 26, 2014, 07:04:39 AM »
Dave - Before we do the group hug I'll just get this out of the way ok.

Sorry, your answer was a little contradictory, you said you could turn the THC on or off whenever you liked, but also said it would only work smoothly at certain points I.e. When not in CV.

Better to have said you can only turn it on/off at these points without upsetting motion, it's not the same as being able to do it whenever you want :)

IMHO Terry is THE plasma guru here but for whatever reason it looks like you're generally stuck with me at the moment. However, I'm not your hired help. If you're going to chip at me and even advise me on how I should phrase things I'll just call it a day here.

Now... onwards...

Yes - CV (and therefore accel and therefore rigidity) are the keys to happiness. I'm pretty sure Terry and I have said this already. I'm think I've also said that you shouldn't need to "tune" CV at all - maybe it was to someone else.

With ref. to No CV on angles > 89: NO - don't do this. You don't want to restrict CV at all.


It wasn't meant as a chip Stirling, that's why I put the smiley face on it, I was trying to explain how I misunderstood it that was all.

Re the CV angle I will certainly clear that on Monday and then retune my machine.

Thanks

2426
General Mach Discussion / Re: Odd glitch in movement?
« on: April 26, 2014, 03:41:06 AM »
It seems to get very confused between line 260 and 340?

The first arc is a lead-in mid way on the top straight

2427
General Mach Discussion / Re: Controlling THC?
« on: April 26, 2014, 03:34:13 AM »
Please believe me when I say I really am not biting anyone's hand off, I'm not moaning or criticising anyone, I am just trying to learn as much as I can, and unfortunately that means asking questions.

I really do appreciate all the help that has been offered here, it's been most helpful, really. :)

I do know now that I need to retune my acceleration parameters and will do so this week, the CV stuff I think is all bog-standard (I think), I use G64 at the start of a program and I think the no-cv angle is set at 89 degrees in config, I don't know if that should come out though?

The other cv settings are all blank.

Once again, thanks to you guys,and if I come across as hand biting then I apologise.
;)

2428
General Mach Discussion / Re: Odd glitch in movement?
« on: April 25, 2014, 01:49:39 PM »
This is the code, I know there is an issue with the odd THC on/off codes but that's not the issue here and is being dealt with elsewhere.

I have learnt that it seems to be connected with CV and acceleration settings so I'm going to retune next week and see if that makes a change.

N0010 (Filename: Test 1.tap)
N0020 (Post processor: Mach3 THC with scriber 2.scpost)
N0030 (Date: 25/04/2014)
N0040 G21 (Units: Metric)
N0050 F1
N0060 G53 G90 G40 G64
N0070 (Part: Test 1)
N0080 (Operation: Outside Offset, 0, T2: 1.5mm Steel, 30A, Std Tip, 103v)
N0090 G00 X41.3478 Y30.1053
N0100 G28.1 Z3.00 F800.0
N0110 G92 Z0.0
N0120 G00 Z3.9000
N0130 G92 Z0.0
N0140 G00 Z3.5000
N0150 M03
N0160 G01 Z1.0000
N0170 M101 (THC Off) (On arcs)
N0180 G03 X50.9478 Y20.5053 I9.6000 J0.0000 F2310.0
N0190 M102 (THC On) (On arcs)
N0200 G01 X72.6444 F3300.0
N0210 M101 (THC Off) (On arcs)
N0220 G02 Y9.4947 I14.3556 J-5.5053 F2310.0
N0230 M102 (THC On) (On arcs)
N0240 G01 X29.3556 F3300.0
N0250 M101 (THC Off) (On arcs)
N0260 G02 X0.5522 Y9.7414 I-14.3556 J5.5053 F2310.0
N0270 M102 (THC On) (On arcs)
N0280 M101 (THC Off) (On arcs)
N0290 X9.7414 Y29.4478 I14.4478 J5.2586
N0300 M102 (THC On) (On arcs)
N0310 M101 (THC Off) (On arcs)
N0320 X29.3556 Y20.5053 I5.2586 J-14.4478
N0330 M102 (THC On) (On arcs)
N0340 G01 X50.9478 F3300.0
N0350 X52.4478
N0360 M05
N0370 G00 Z10.0000
N0380 X0.0000 Y0.0000
N0390 M05 M30

2429
General Mach Discussion / Re: Controlling THC?
« on: April 25, 2014, 01:17:04 PM »
Sorry, your answer was a little contradictory, you said you could turn the THC on or off whenever you liked, but also said it would only work smoothly at certain points I.e. When not in CV.

Better to have said you can only turn it on/off at these points without upsetting motion, it's not the same as being able to do it whenever you want :)

As for the code being three arcs, it is something to do with sheetcam, les newel over there is looking into now as he was baffled too,.

I have found that my machine is less impressed with holes sub 20mm but also know now it is connected with acceleration and CV so I will be going back to the basics next week and retuning the axes from scratch to see if I can get her singing a better tune, then I can forget about flipping the THC off and on.

Anyway, my foot is intact and I've learnt a little more, as always thanks for your help, it really is appreciated.

2430
General Mach Discussion / Re: Odd glitch in movement?
« on: April 25, 2014, 10:40:12 AM »
062 made no difference.

Something I have just noticed is that on a dumbell shape cut - a bar with a circle on each end, I get a sharp entry into the arc from the straight but on exit from the arc to the straight Mach is cutting the corner and giving some sort of fillet - the two sides do not match.

Picture attached.

the drawing looks like the sharp transitions not the rounded ones.

Is this a mach issue or a settings issue?

Clearly it could not be used like this.

It is better at low speed but still the entry/exit do not match