Ahhh...ok I get it now:stupid:....said I was being thick!! I know v little about plasma cutters....and it shows!!
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Ahhh...ok I get it now:stupid:....said I was being thick!! I know v little about plasma cutters....and it shows!!
Little bit slower now, onto the small fiddly bits....
Got the Axis hard-stops and beam end-covers designed, cut and fitted..
http://www.plasmaspider.com/download...p?id=37020&t=1
Fitted the floating head, torch mount and probe/limit switches...
http://www.plasmaspider.com/download...p?id=37017&t=1
The front Y & A axis limit/home switches...
http://www.plasmaspider.com/download...p?id=37018&t=1
And the Y far-end limit switch...
http://www.plasmaspider.com/download...p?id=37019&t=1
Started work on fitting the cable chain to the X axis now. http://www.plasmaspider.com/images/s..._e_biggrin.gif
Looking good, it's the little bits that seem to take the most time....
Looking sweet Dave, nice bit of metal work there!
Thanks,
another slow day today, had a few orders to make then fitted the cable tracks and trunking and started planning out the bed support frame.
had a couple of hours today, fitted the last of the limit switches and started on the slat support frame.
I thought a seperate frame would be best to avoid putting any heat into the side frames and make replacement easy.
50 40 x 5mm angle fitted into bed opening and a strip fitted to its bottom edge to support the slats vertically.
http://www.plasmaspider.com/download...p?id=37140&t=1
Quite disappointingly when i did the heavy tacks to secure the bottom return strips, the angle warped and is now 4mm high in the middle http://www.plasmaspider.com/images/s...on_redface.gif
Not good, not sure what to do about it - ignore it and let the THC tackle it, maybe slit the angles vertically in two or three places, press it flat and weld up or something else.
I didn't think angle that heavy would warp!
Apart from that it s all going to plan http://www.plasmaspider.com/images/s..._e_biggrin.gif
Slat bed fitted at last, total PITA http://www.plasmaspider.com/images/s..._e_biggrin.gif
http://www.plasmaspider.com/download...p?id=37169&t=1
Not 100% happy with it as the 50x3mm strip i ordered is a range of anything between 48x3 and 52x3 !
Will be changing it some time soon i think.
I also fixed the warped slat rails very nicely -
http://www.plasmaspider.com/download...p?id=37170&t=1
A quick slice with a 2mm disc and weld-up, now it sits perfectly flat on the side beams http://www.plasmaspider.com/images/s..._e_biggrin.gifhttp://www.plasmaspider.com/images/s..._e_biggrin.gifhttp://www.plasmaspider.com/images/s..._e_biggrin.gif
The vertical weld was also my first vertical-up weld as i'm normally a bench top welder, didn't come out too bad i thought http://www.plasmaspider.com/images/s...on_e_smile.gif
Stripped it all for paint now, hopefully the weather will be good tomorrow.
Feeling a bit blue today...
Gantry...
http://www.plasmaspider.com/download...p?id=37188&t=1
Main frame...
http://www.plasmaspider.com/download...p?id=37189&t=1
Had to repaint the side beams as i forgot to fit the dust shields for the HiWin rails, probably not too important as the blocks have hard scrapers and extra seals fitted on all ends http://www.plasmaspider.com/images/s..._e_biggrin.gif
Now to start rebuilding and final fitting.
Extract tray / chamber arrived today...
http://www.plasmaspider.com/download...p?id=37206&t=1
Quality is excellent, glad i outsourced this part http://www.plasmaspider.com/images/s..._e_biggrin.gif
Looking good Dave, coming together nicely!
Z axis wiring...
http://www.plasmaspider.com/download...p?id=37320&t=1
Table wired up...
http://www.plasmaspider.com/download...p?id=37321&t=1
The timer on the bottom rail is an off-delay of about 20 seconds for my downdraught fan, every cut start and stop triggers the Aux BOB relay and the delay holds the fan on between positioning cycles etc. At the end of the last cut it runs on for the full delay to clear any remaining fumes.
Preliminary panel wiring...
http://www.plasmaspider.com/download...p?id=37322&t=1
I've got an old BOB laying around and spare PC which i've installed a basic Mach3 setup on, hopefully be able to get the lot tied together this week for motion testing.
IT Lives http://www.plasmaspider.com/images/s...on_e_smile.gif
Achieved first motion today, got it lashed up to an old BOB and very poor PC (way below Mach3 specs) and it seems happy, a short video...
https://youtu.be/n34DDnw8org
It was running this file...
http://www.plasmaspider.com/download...p?id=37396&t=1
Which was the simplest file my mediocre G-Code skills could manually type http://www.plasmaspider.com/images/s..._e_biggrin.gif
Have played with motor tuning and it will go way beyond requirements so pegged it back at my 9000/mm/min target. Acceleration seemed very willing to perform but I'm not sure if the PC is hampering it there or not, its only a 500mhz CPU and Mach is supposed to need 1Ghz or more.
Still, it runs and runs VERY well indeed, smooth, fast and gives me the impression it will work nicely with the torch on.
I have tried to make it lose steps - pushing the Mach "Stop" button when running at 9000mm/min give a very abrupt stop indeed but no lost steps, can't get much more severe than that i think.
Next i need to do some book-speed tests with real cut files and verify the home position after each cut, not even sure its worth doing a pen test - it just seems happy and gives me confidence.
The final step is the tricky one - I need to strip the BOB, THC and plasma from my running table, dismantle that to move it out of the way, move the new machine into position, level it and fit the last parts to it. Then install the extract system, bed frame and slats and start test-cutting. Sounds easy but I know for a fact that as soon as i decommission the running table, jobs will come in!!! The only safe way I think is to put up the "closed" sign for a few days and get it done - we are away in a weeks time for a week so i might just extend the holiday closure period a bit to give me some slack.
Good day today http://www.plasmaspider.com/images/s..._e_biggrin.gifhttp://www.plasmaspider.com/images/s..._e_biggrin.gifhttp://www.plasmaspider.com/images/s..._e_biggrin.gif
Looking good...good to see your machine come to life!!! I'm itching to get back on mine and finish it now I've seen yours working...
It certainly was a relief, especially when i managed to get Mach3 to auto-square the gantry for me when its homed :)
Made the replacement wall panel today, fitted the extract fan to it...
http://www.plasmaspider.com/download...p?id=37476&t=1
This should replace one of the slabs in the garage wall directly, hopefully be able to undo the two bolts, pull the slab inwards and replace with this one.
The fan is connected to the table via a short length of 12" flexi ducting. Its controlled from my G-code, have altered the post processor to put the on/off codes where i want them.
I'm off for a weeks holiday now, plan is to move the table into position as soon as i return http://www.plasmaspider.com/images/s..._e_biggrin.gifhttp://www.plasmaspider.com/images/s..._e_biggrin.gif
Looks great Dave well done so far :).
.Me
Is the fan for dust removal or heat removal?Quote:
Originally Posted by Davek0974
If you try venting electronics outside you will end up killing your electronics with condensation, which would be bad. :(
You can mount a closed loop radiator externally for heat removal, but air is a no-no.
Nah that fan is the table bed downdraught fan - needs to vent outside, intake air will be through the open door. Will be cold in winter but no other way to vent that much air.
Back from a way too short holiday http://www.plasmaspider.com/images/s...icon_e_sad.gif Stripped the workshop out and moved the new table into final position...
http://www.plasmaspider.com/download...p?id=37627&t=1
http://www.plasmaspider.com/download...p?id=37628&t=1
The extract fan panel fitted perfectly, but shifting that volume of air turns out to be damn noisy, i can probably expect trouble from the neighbours i think, will have to be careful when i choose to do my cutting http://www.plasmaspider.com/images/smilies/icon_cry.gif
Finishing off the panel now, fitting the BOB boards and wiring them in, then i need to build something to hold the monitor and keyboard etc, some sort of workstation.
Then i have to puttee workshop back together again http://www.plasmaspider.com/images/s...icon_e_sad.gif
Panel finished...
http://www.plasmaspider.com/download...p?id=37681&t=1
Mesh below the slats...
http://www.plasmaspider.com/download...p?id=37682&t=1
Bit busy up that end of the shop http://www.plasmaspider.com/images/s...con_e_wink.gif
http://www.plasmaspider.com/download...p?id=37684&t=1
Stuck the monitor on the wall, seemed a good place, still working on the keyboard and mouse/trackball, might be a slide-out under the front of the table. I couldn't fit the PC into the main cabinet - not enough space http://www.plasmaspider.com/images/s...icon_e_sad.gif
http://www.plasmaspider.com/download...p?id=37683&t=1
One odd thing I noticed when motion testing with the proper PC, the X & Z axis worked perfectly but the Y & A needed the "step active low" setting reversing in ports & pins? They sounded very rough and notchy when set the same as the other axes.
This seemed odd as all drives are the same, wired the same and connected to the same BOB????
Any ideas why I need to run two axes reversed signal level???
If all wired same and the drive doesn't have an active edge Dip switch then probably because setup different in the drive software. Some drives will provide a Dip and most Digital drives you can access thru software.Quote:
Originally Posted by Davek0974
If none of the above then could just have been set different at the factory,?
"Active Low" means the drivers are wired with common +5V and step pulse inputs wired to the minus terminals, right?
Quote:
Originally Posted by Dragonfly
Yes, all wired common +ve
But these were tested with a different BOB when i was building the table and all settings were the same????Quote:
Originally Posted by JAZZCNC
One difference is that the test PC was underpowered and only ran at 25khz, the work PC runs at 45khz, step and dir pulse length is 2us on both PC's
Don't know then. Maybe the new BOB does some filtering and signal boosting depending on the PP voltage.? If your on the edge with say 3V PP then the BOB could be boosting and inverting the signal just on that line.??? . . . .Strange beasts these CNC machines.!!!!Quote:
Originally Posted by Davek0974
Hmm, interesting
Just thought of another difference, the CandCNC MP3000 DTHC uses three parallel cables - one from the pc to the controller and then one to the motor drive BOB and another to the I/O BOB, these last two are new, shorter cables.
Might be worth swapping the old long cables back in???
Don't think cable length is the cause. Anyway I see only one BOB on the photo and presumed you use Mach3.
Actually did you test all drivers set to "active low"? As far as I understand you have Y and A coupled as master and slave. Wrong polarity might make them "rough" as they need to move in sync while the others may also need low trigger but do not show rough movement because they are single. ??Hmm.
The mp3000 has two BOB's one for motor control and one for inputs and outputs, yes i am running mach3
All drives were running active low on the test pc, Y and A are slaved in mach and each on their own output.
CandCNC advised me to up the pulse width to 5us and that seems to have sorted it out, all drives now running the same way.
So you were just on the wrong side of the pulse edge then. Could only really be this or the BOB inverting signals really.! Changing the pulse width doesn't always work thou unfortunately so you've been fortunate.!Quote:
Originally Posted by Davek0974
Yes its an oddity i think,
A Mach guru has just pointed out that the BOB has opto isolated outputs and the drives have opto isolated inputs so i am driving an opto with an opto, he seemed to feel that was not a good idea generally.
Nah not at all it's common as muck with Just about every BOB worth it's salt having opto's has will any decent drives and there'll be few machines that don't run with both.!Quote:
Originally Posted by Davek0974
Unfortuantlly it's more a sign of poor drive or BOB with slow opto's.!!
If every bit and bob and driver has opto isolation why not cut out the middle man and have a fibre optic connection ? I'll bet there are some machines with bespoke electronics that do it.
Probably purely a cost issue, this stuff is not really found on the high-end machines, I have no doubt those ones would have fibre where needed.Quote:
Originally Posted by cropwell
:)
Ok, we have action http://www.plasmaspider.com/images/s..._e_biggrin.gif
Mixed bag of results, sort of exciting and disappointing all at the same time.
The good parts...
It works, speed is no issue,
The ripple effect in my cuts has disappeared,
It does not shake and wobble all over the place,
The bad parts...
The voltage is still way off of book specs, no change,
Can't get a clean cut on aluminium yet,
Need to work on divots,
Here we go...
Pierce & Cut heights are all as per book and this was checked several times by stopping mid cut and measuring the gap.
35mm washer, 45A 107v, 4000mm/min. Nasty divot as no cut rules yet just perpendicular lead in and no lead out.
http://www.plasmaspider.com/download...p?id=37708&t=1
Add a 2mm overburn and turn torch off 2mm before end - divots now pretty good.
http://www.plasmaspider.com/download...p?id=37709&t=1
Same speed, acceleration as listed, small shape again - 35mm sq. Same 2mm overburn etc but divot is terrible again????? There is a marked improvement between the 1st and 2nd cuts but little change between 2nd and 3rd so i set the acceleration at 1500mm/s/s. I can improve the internal corners a bit by setting Mach to stop CV on angles > 89 degrees but don't know if that is a good idea or not??/
http://www.plasmaspider.com/download...p?id=37710&t=1
3mm aluminium - 6400mm/min 45A 106v, lots of top dross, tried slower but made little difference. Had better cuts on old machine http://www.plasmaspider.com/images/s...icon_e_sad.gif
http://www.plasmaspider.com/download...p?id=37711&t=1
1.2mm stainless is not too bad, 7900mm/min 45A or 4800mm/min 30A 109v
10mm steel, 0.9s delay, 117v, 500mm/min 45A.
Had one nozzle blow out completely, was getting poor cuts and found the orifice practically missing, no idea how that happened at all, as i'm testing I have been very careful of wrong pierce heights etc.
So, as i said, a mixed bag really. The divots are concerning, I need to get that bit nailed as well as the aluminium.
If anyone wants to chime in with some useful settings, please do. Is there a group test file that those with some spare minutes could cut for comparison???
Swing-out keyboard, seems to work ok...
http://www.plasmaspider.com/download...p?id=37745&t=1
http://www.plasmaspider.com/download...p?id=37744&t=1
Big success, thanks to a member on another forum for his settings on the 3mmAluminium...
http://www.plasmaspider.com/download...p?id=37749&t=1
Pretty clean I think.
http://www.plasmaspider.com/download...p?id=37750&t=1
1.2mm Stainless, not too impressed yet, might have to get some 30A consumables and try that out, not sure I can cut my stuff unless I can get this better.
http://www.plasmaspider.com/download...p?id=37747&t=1
http://www.plasmaspider.com/download...p?id=37748&t=1
Now, the last major issue - that damn unequal bevel, here is a bit of 3mm steel with a 3mm slot, these parts need to slot together. You can see one side is good the other is bad, this aligns with the Y axis.
http://www.plasmaspider.com/download...p?id=37751&t=1
Heres some more, 3mm again, placed on table as in picture. I have marked the angled edges.
http://www.plasmaspider.com/download...p?id=37746&t=1
Now, I could fudge this by leaning the torch over to compensate but that is a bodge and will only ever get me two bevelled edges. So, what can do this, the consumables are new and today I have checked the condition of them between every cut after yesterdays blow-out. Overall the cut quality is impressive - the new machine is smooth and this is reflected in the cuts but this problem migrated from the old machine so must be torch related?????
Also, I can improve internal corners by switching "Stop CV on Angles >89" on in mach3 settings BUT this then gives me a jerk at the start of every arc and radius cut, I think this can be seen in one of the pictures above. So I can't run that setting as a default and as very few jobs are fully square, its practically pointless. Can Exact-Stop be triggered from Sheetcam??? Is it really this difficult?? What do you guys do for sharp internals???
SO many settings and tweaks, doing my head in. I think I can crack the divot problem, a lead-out plus torch off before end of cut seems to be reasonable but I can tune this over time.
This bevel issue is bad though I think.
Yesterdays little fun test... http://www.plasmaspider.com/images/smilies/icon_lol.gif
http://www.plasmaspider.com/download...p?id=37786&t=1
3mm Stainless, 108v, 45A, 3800mm/min, pretty clean...
The bottom 4 lines are on the new table, the top mess is the result i had on the old table which made me build the new one!!!
http://www.plasmaspider.com/download...p?id=37787&t=1
Test shape, old m/c vs new m/c...
I know the slot is buggered - this was because i used the test file for mild steel and forgot to tweak the settings on the slot part first http://www.plasmaspider.com/images/s...on_redface.gif
http://www.plasmaspider.com/download...p?id=37788&t=1
You can at least see the waste in the slot, that a 3mm slot and the waste is about 1mm.
http://www.plasmaspider.com/download...p?id=37790&t=1
So, not too bad today, also been messing with divots, internal holes. Tried a 5mm overburn with the torch off 1mm before the end, so the end of the cut is 6mm from torch off and you can still see a mark. Will keep messing with that one but at least she's up and running again. http://www.plasmaspider.com/images/s..._e_biggrin.gif
I have twisted the torch mount to correct the odd bevel or at least balance it out, I'm leaving the torch at the current angle - it's working so until i find a reason, i'll live with itI
30A consumables arrived today, gave them a spin on 1.2mm 304 stainless and got excellent results http://www.plasmaspider.com/images/s..._e_biggrin.gifhttp://www.plasmaspider.com/images/s..._e_biggrin.gif As good as the finecuts on the 30XP were at least.
Both pics as they came off the table...
Top...
http://www.plasmaspider.com/download...p?id=37883&t=1
Bottom...
http://www.plasmaspider.com/download...p?id=37884&t=1
Voltage was low as normal it seems, 76v instead of book 98v but speed was bang on at 4000mm/min, pierce height 2.5mm, cut height 0.5mm. Still need to dial the THC in as its a bit unstable on thin stuff but at least it works and the table is now producing paying work.