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Messages - geoffby

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1
General Mach Discussion / Setting tool height
« on: December 04, 2017, 07:41:45 AM »
Hi,
I've been using Mach3 for a number of years with very little problem. I have now encountered a problem with setting tool heights.
I have a quick change tool holder and have 9 tools available.
My method of setting my tool heights (which may sound odd to some, but has worked for all the time I have been using Mach) is as follows:-
First, I position the table to somewhere easily accessible for setting tool heights from the table and zero the X and Y position on the DROs.
I then open the tool table and zero all tool heights and enter tool diameters and tool type (for my reference) that I am about to reset, clicking apply and closing the table.
I have one tool (in this case No2 tool, that I very rarely ever change) and using a roller gauge (one that I made) with tool "0" selected, jog to touch the gauge on the TOOL HOLDER and set this at zero.
I then jog up to touch the tool tip I want to set (in this case, tool No 2), change the tool number to the appropriate tool - in this case, No 2 - in the Tool Information, noting that the Z DRO now reads the tool length and then click the "Set Tool Offset" button to set the height. This resets the "Z" DRO to zero. So far, so good.
I then jog the Z axis up for say 20mm or so and then click "Go To Zeros" button and the Z axis moves down to the zero point, which I then check with the roller gauge. If it is out, then I adjust the tool height by jogging in increments (say 0.0254mm) up or down to re-position the tip, set the Z DRO to zero, change the jog mode to continuous and repeat the jog up and Go to Zeros and recheck. If OK, I then click the "Set Tool Offset" button to reset the tool height/length.
I would then continue to all the other tools - using their respective tool numbers.
This, in the past, reset the tool offset to the new length, but now, for some reason, the tool offset reading does not change to the new length, in relation to the Zero set in tool 0.
I have even tried opening the tool table again and removing the offset/tool length (resetting it to 0.0000) and then trying the set tool offset again to no avail.
What has happened?
I did press the "Remember" button on the tool "0", which I haven't in the past. Will this actin have changed things?

To finish, when I come to carry out the machining operations, I set the tool X & Y positions to my start (zero) point and reset the X & Y to zero clicking the set Zero buttons for each. The "Z" height is then set with tool "0" selected with the roller gauge against the No 2 tool holder, press the Z DRO set to zero, then change the DRO to read the roller Gauge thickness. This sets the work height for all tool+offsets.

Where am I going wrong - I don't want to change to a new tool setting regime as I'm comfortable with my usual method, but can anyone tell me what has changed?

Regards,

GeoffB

2
Hi Breastfed,
Now all working fine (well it was at the last use!!) Frequencies fine and all the problems seem to be the acceleration rates that were originally set in Mach3 software by others - I have now reduced them from 125mm/sec/sec to 85mm/sec/sec and still at 2000mm/min top jog speed and all is working fine. Just t aken a long route to get t o the answer.
GB

3
General Mach Discussion / Re: mach appears to send odd signals
« on: March 18, 2014, 01:00:50 PM »
Hi Hood,

Wow, wow, wow and WOW!!!! ;D Just done 2 days of milling with some complicated programmes - some taking a couple of hours to go through - and many fast jogs and not a beat missed! Looks like this is (dare I say it?) the final answer. Been looking at why the motor stalled onn the X axis and not the Y and thinking (and measuring) the saddle and gib lengths and the X one is about 15% longer than the Y, so the drag on the X would be marginally greater, so the motor was probably right on the edge of the acceleration and that one got it! Whatever, looks like I now enjoy going in the machine shop to do jobs (that have been mounting up!) instead of not daring to look at the miller, never mind working on it, in case it played up!

Anyway, many, many thanks for all your help. :)

GeoffB

4
General Mach Discussion / Re: mach appears to send odd signals
« on: March 14, 2014, 04:27:21 PM »
Hi Hood,

Yes - it is on the one axis and not necessarily in the same place, although it is a similar move on different programmes - and not in the same direction. Have checked and double checked everything mechanically and changed everything that can be changed electrically.

Now your last comments about stepper speeds/acceleration started me thinking - I related back to my mechanical days in motor racing and looked at what made engines stall -worked fine and accelerated good but with wheel spin on a quick take off - fitted fatter tyres and the clutch slipped - fitted heavier clutch - and the engine stalled. Ease on the quick take up on the clutch and cure the problem.
Acceleration! That must be the answer.
So I turned down the motors even further to 1200mm/min and the problem became rarer - only every so often. So acceleration it must be - turned the acc down to 85mm/sec/sec and the problem has dissappeared - then if it's just acceleration then the jog speed is not so critical - turned the jog speed up in increments and am back to 2000mm/min but with longer acceleration time and - wow! I just completed 6 jobs in the last hour!!!

Well done Hood - you've (it seems - so far!??) hit the nail on the head. I have a load of work to get on with on monday so I'll see what transpires. I'll let you know. And all the other bits I fitted or software setting that have been altered have all been to the good, so that's fine.

Many thanks for sticking with me on this one.
Regards,
GeoffB

5
General Mach Discussion / Re: mach appears to send odd signals
« on: March 14, 2014, 11:12:11 AM »
Hi Again,
Just turned the motors down by 25% from original speed - were orig 2000mm/min - 5mm pitch screw - now at 1500mm/sec - Acceleration was 125mm/sec/sec now down to 105mm/sec/sec but still no different still stalls the motor momentarilly - looses almost 3mm on  and 8-9mm fast jog at one place only. Went through fine on one run then on second run the dreaded stall!!!! Is there a test I can do on the motors or some way of monitoring what is happening?
GB

6
General Mach Discussion / Re: mach appears to send odd signals
« on: March 14, 2014, 07:50:04 AM »
Hi Hood,

Yep - I did that earlier - I reduced it by 10% and the accel by 20% - that was the question I was going to ask about the motor's capabilities at the top end. I know that steppers have good torque at low speed but really drop off at the top end. I ran the machine yesterday and had the same problems again on one certain move. Hair out time!! So, I'll go in the workshop now and turn the motors down by 25% and see if that cures the problem. I'll report back. Thanks for your continuing help!! :)

GB

7
General Mach Discussion / Re: mach appears to send odd signals
« on: March 13, 2014, 08:23:49 AM »
Thanks Hood. Just checked and it is already set at that.
GB

8
General Mach Discussion / Re: mach appears to send odd signals
« on: March 12, 2014, 02:44:09 PM »
Thanks Hood - does it need anything else altering or do you just apply this mode. BTW, the stop gap of changing sequence on the programme for pockets 7 - 8 has worked on this one and the job is now finished - bated breath time though. But I still need to get to the bottom of why it;s happening. I'll give this mode a try.
GeoffB

9
General Mach Discussion / Re: mach appears to send odd signals
« on: March 12, 2014, 06:14:02 AM »
Ah! You got me again - what is Sherline mode? And where can I find it? And what does it do?

GB

10
Hi BF
Nope - still got issues - the machine will jog along all day long but at a particular place in the programme it goes for a G0 and stalls the stepper for a brief sec - usually around 5-7mm of travel. Checked out the G-code have fitted new steppers and drivers and shielded cabling, checked out everything going and still it happens - as a quick fix it appears swapping the two pocket sequences around has cured it on this programme but it has happened on others to - and on this prog it went through the prog 3 or 4 times OK then suddenly it happened again - hair pulling out time!
The drivertest shows steady frequency as does the diagnostics - only varying by the odd 00001 - 2 and a straqight line on the graph with just a small (tiny) spike here and there.
GeoffB

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