Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: stirling on May 04, 2014, 05:48:26 AM
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I've been working on and off for a while on a hardware gizmo for protecting ANY probe from getting crunched. It's currently bread-boarded and under test/development. Once OK - I'll go ahead and vero one but if there's sufficient interest I may have a batch of pro boards made up once it's completely tested.
Basically it's hardware that's added into the control box and then any move that is going to crunch the probe if not stopped will throw a limit (or e-stop).
It'll protect the probe during ANY and ALL types of move, jog, rapid, feed and EVEN (but of course) G31.
I'm aware there are some software attempts at this out there but IMHO they STILL depend on the control software (Mach/LinuxCNC, whatever) not doing anything bizarre. Because this is a hardware solution entirely independent of the control software it *should* be foolproof (that's where the work is at the moment - checking, checking and triple checking).
So - over to you - any interest?
Cheers
Ian
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Offcourse! Are you going to disable motor movement at breakout board ?
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Sounds great, though not sure how a g31 can trigger a disable output whenever used.
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Offcourse! Are you going to disable motor movement at breakout board ?
It provides a TTL logic output which you can connect to whatever you like. e.g. you could connect it into Mach e-stop or limit or you could connect it direct into your e-stop hardware - up to you really.
Sounds great, though not sure how a g31 can trigger a disable output whenever used.
Neat isn't it ;)
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Then sign me up to help in anyway. That is other than going to the airport and getting on a plane. ;)
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HIYA Ian , I like it.
Do you have a flow chart of the signal monitoring and control.??I worked on a software solution as a plugin and here it works well. BUT we all know that can change from PC to PC.
I tried to explain the IMPORTANCE of such things for MACH4 BUT you know how that went (;-)
IF I can help let me know, Us probers have to stick together or else we will all be running routers in Mach4.
(;-) TP
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OK I am confused HOW is it to know wether it is a GOOD trip or a BAD trip. Do you turn it ON/OFF when needed like protected movemode on commercial controllers or ???
(;-) TP
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OK I am confused HOW is it to know wether it is a GOOD trip or a BAD trip. Do you turn it ON/OFF when needed like protected movemode on commercial controllers or ???
(;-) TP
It just knows ;) - no you don't need to do anything - you connect it and forget it - it just sits there and takes care of you.
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(;-) You do not sell used cars in your spare time do ya ??
(;-) TP
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So - over to you - any interest?
Oh, I'm interested al right. Anti-crunch on a probe is always going to be good. But I (we?) would need a few more details to see how to fit it into my interface. My eStop interface is custom you see: possibilities and benefits of course.
For reference: my old 3rd-party electronics kit started to die and was not repairable. obsolete. So I have rebuilt everything between the transformer output to the moter/encoder cables. Works fine - at last.
Cheers
Roger
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Hi Roger - at the moment I'm just wanting to gauge interest before I commit to spending more time (and money) developing it. Hardware and software solutions are how I earn my crust so it has to be worth my while. I doubt I'll be able to retire to Florida on it but hey... it's what I do.
At the moment it simply activates a TTL signal - and TBH I'm not sure what else it could do but if you have suggestions please feel free. I currently have that signal as a limit into Mach - simple as that. This of course allows you to TREAT it as a limit and jog back off it. You could of course add it into the E-Stop into Mach but I'm not sure how you'd get off it (without disabling it - and I'd like not to have to do that). Depending on your hardware you could also wire it into your hardware E-Stop - but again - getting off it might be an issue I suppose. Like I say - still under development.
Ian
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Hi Ian
This of course allows you to TREAT it as a limit and jog back off it. You could of course add it into the E-Stop into Mach but I'm not sure how you'd get off it (without disabling it - and I'd like not to have to do that). Depending on your hardware you could also wire it into your hardware E-Stop - but again - getting off it might be an issue I suppose.
Ah, OK.
First point: I definitely do not want to trigger an eStop with the probe. That causes the servo drivers to lose control of the motors and the whole system has then to be completely re-zeroed. Not on!
Treating it as a Limit switch - yeah, with a LOT of macro programming. Can do, but I have higher priorities right now.
My own opinion, fwiiw: the whole concept of G31 needs to be rewritten back at the Standards level. Or maybe there should be a new G-code created. A new one might be better. To explain: I would love to be able to have (say) a light beam above my ZTO so I can come down fast to (say) 5 mm above the touch plate, then switch to a gentle crawl. That way I don't break things!
What to do about a full 3-axis probe - not sure. At the moment I have to program long slow movements to avoid breaking the probe tip (or the suspension). Maybe I can improve the optics on a video probe to sufficient resolution - maybe. Not cheap.
I remain very interested.
Cheers
Roger
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Hi Roger - I think perhaps you mis-understand me or I'm mis-understanding you perhaps. I'm not asking for proposals on how this could be done - I have a fully working prototype device sat here on my bench being tested as we speak. There's nothing for you to do - no macro programming involved. From your perspective if I produce it as a finished product and you bought one - then you'd just plug it in and go.
BTW - in case I haven't made it clear it works in full 1, 2 or 3 axis moves. However you move your axis(s) with a probe attached - it protects it from crunching.
Ian
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Hi Ian
Photos?
Videos?
Techie details?
Enquiring minds want to understand. :-)
Cheers
Roger
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Ian,
I'm interested, but my probe crunching issues went away when I quit using the probing routine that comes with Mach3 and started using your 2.5D edge and 3D probing routine and the probing options in MachStdMill Professional Edition. I remember you were working on a new Deluxe version, so did you ever finish it? I sure would be interested in trying that also.
http://www.machsupport.com/forum/index.php/topic,4352.160.html
Thanks. Jeff
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Photos?
Videos?
Techie details?
Enquiring minds want to understand. :-)
Hi Roger
Videos will come later. At the moment I'm testing it with a simulator.
Tech details: I use two microprocessors running in parallel (one wasn't up to handling all three axes at once) to run a 3D math model representation of a probe. It models in real-time what happens AFTER a trip. By modelling WHERE the probe tip is I can compare it with the user defined mechanical limits of the ACTUAL probe and cause a limit to be thrown if necessary. This is why it can do G31 as well as all other moves. As I say - It does this in real-time for each and every step pulse in all 3 dimensions. i.e. it needs to be sh1t hot fast ;D.
Ian,
I'm interested, but my probe crunching issues went away when I quit using the probing routine that comes with Mach3 and started using your 2.5D edge and 3D probing routine and the probing options in MachStdMill Professional Edition. I remember you were working on a new Deluxe version, so did you ever finish it? I sure would be interested in trying that also.
http://www.machsupport.com/forum/index.php/topic,4352.160.html
Thanks. Jeff
Hi Jeff
Thanks again for the kind words about my probing software and the interest here. I kinda lost the faith with the probing routines because of some Mach3 issues that were never going to be addressed because of the dev of Mach4 (understandably). Maybe I'll dig it all out at some point and re-visit it - just don't know really because they'd have to be re-done to some extent for Mach4 and at the moment I don't readilly see the info I'd need and there's only so many hours etc....
Ian
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Thanks Ian,
I don't know what issues everyone is talking about with Mach3. My system is simple and very reliable using XP with a Lava dual PP and I don't seem to have any issues. I, myself, will never upgrade to Mach4. If it's not broke, don't........
Jeff
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Projected cost?
expected beta date?
Size?
will it be packaged, need a enclosure or mounted in the Control Box?
What is needed on our end to hook up and implement?
Number of Mach3 (Mach4) Inputs used?
Probe or solid pin?
Calibration?
Plugin or vb macro?
Size of tip calculated?
Can it be used/adapted for Tool presets?
5 volt 24 volt?
Seed money (would that show you true interest)?
BETTING there is interest, just dont put any money down on that Florida condo yet.
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Don't hold me to any of these - it'll never stand up in court... ;D
Projected cost? don't know at the moment - but FAR FAR less than any decent probe - otherwise what's the point?
expected beta date? no idea.
Size? smaller than a pack of smokes?
will it be packaged, need a enclosure or mounted in the Control Box? In the control box.
What is needed on our end to hook up and implement? a small screwdriver?
Number of Mach3 (Mach4) Inputs used? 1. (not counting your probe - which you have already).
Probe or solid pin? anything you like that generates a probe signal that you don't want benterated.
Calibration? of?
Plugin or vb macro? neither.
Size of tip calculated? don't need it.
Can it be used/adapted for Tool presets? how do you mean? - it's there to stop your probe being crunched - nothing else - if you never do anything that is about to crunch your probe - it'll sit there doing absolutely nothing. you just do with your probe whatever you now do with your probe - however you do it.
5 volt 24 volt? TBD.
Seed money (would that show you true interest)? Unmarked - non-sequential - GBP - large bag of - how kind.
BETTING there is interest, just dont put any money down on that Florida condo yet. Yeah well - you know what they say about the neighbours.
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Thanks for the details,
I'm sure Terry has a room in the back you can use for your Florida getaway, he has his neighbors trained to be tolerant of his antics. Not sure they are used to SmartA__ Brits, but Hell... sounds like fun. I might just drive down and drink a few.
Looking forward to putting your efforts to work, sign me up. Just dont look for the Brinks truck to be dropping off that bag. But Ya-Nvr-No
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HIYA Ian , Come on over I have a spare room here. The neighbors are already used to a smartA## redneck so you will fit in nicely. You will probably have to get a decent tan thought (;-)
So far the Protected move mode is working here. Probably NOT going to see it in Mach4 either. They looked at me like a crazy man when I asked for it so YOUR Solution could be a blessing to probers.
I had also asked for a solution for missed hits to create an error and signalling the OP to a problem. This would be a BIG help as I see it. MOST problems in probing is missed trips creating BAD data. A lot of the people I have helped with 3d probing could use it. It is HARD on them when I point out the proble with their point cloud is all the MISSED trips in the point cloud. After LONG 12hr probing runs they tend to get pissed that the cloud is trash and unusable for the most part and have to start over.
ANY solutions for a missed trip notification ??? AND a error trapping code in the Program does not help as MOST of my/our routines are GCODE based (very dependable) and there is no IF in that code and no access to Systems #vars to compare to.
Just a thought,(;-) TP
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HIYA Ian , Come on over I have a spare room here. The neighbors are already used to a smartA## redneck so you will fit in nicely. You will probably have to get a decent tan thought (;-)
Tan I can do - just as long as I don't have to wear your gimp suit is all...
Moving on - trying to get that out of my head...
Could a few of you guys give me an idea of your steps per (please state imperial or metric) ... ta.
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6 mm pitch ball screw (actually 1/4")
512 line encoder (so 2048 edges)
so ~328 edges per mm
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50,000 per .200" Yaskawa AC Servo at worst case
You should see his bowling shirt collection.
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Sorry - should've been clearer - steps per from motor tuning for each axis X,Y and Z.
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160 steps per mm for all axes (20mm lead, 200 steps per turn, 16 micro-steps per step), I was running it at 4 and 8 micro-steps before.
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40,000 per INCH ( is there really anything else) AC servos
(;-) TP
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10,000 steps per inch x and y, 60,000 steps per inch on the Z. :-[ Like a few other tools I have.............. it isn't much but it makes me happy! ;D
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Like a few other tools I have.............. it isn't much but it makes me happy! ;D
But then to a modern man like yourself - it's not supposed to be just about you Brett ;D
Any road up... Probe info... trip angle and max deflection angle. I know linear movement depends on length of stylii in use - but just to keep it simpler for the moment - what sort of linear measurements are we talking about between a good trip and crunch point? Just trying to get an idea of the range of your different probes.
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Based on my touch-probes, which I made myself:
ZTO: can handle ~1 mm overshoot in Z axis for clean reset.
3D touch-probe, with 20 mm tip: sphere of overshoot about 1 mm, for clean reset.
Further overtravel to 2 mm is possible in each one, but would need to check that they had reseated properly.
Cheers
Roger
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Just an update. Testing of the prototype shows 100% reliability so far on rapids, feeds, jogs and of course G31 - which is nice.
ToDo:
Currently has to be hard coded for a given machine - need to make it user configurable.
Currently can handle a max step pulse rate of 100KHz - need to get this much higher for those with V high step counts. (Ya-Nvr-No - 250,000 steps per inch? really? - at (say) 400 in/min rapid - that's 1.6MHz - is this correct?).
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Ya Ya Ya you got me, lol
just 50,000 per inch
been so busy f___ing with mach4/Lua that I forgot to get back to you, sorry
I bad
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Cheers Craig.
Made more progress this afternoon. It's now completely configurable via USB. I think maybe I'll leave it at the 100KHz limit for now unless there's any interest to have it cope with higher step frequencies.
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A question: The USB hardware I'm planning on using for the machine config interface requires SP3 for those using XP. Do any of you see this as a problem? i.e. for those using XP, are you using SP3?
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Am running SP3, though I'm sure that win 7 would be next if hardware failure and I had to get back online.
Id heard no support for XP from microsoft any longer, so not even sure updates are available.
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A question: The USB hardware I'm planning on using for the machine config interface requires SP3 for those using XP. Do any of you see this as a problem? i.e. for those using XP, are you using SP3?
I am running XP SP3 on all our machines -desktop and CNC. I fail totally to see why I should change (except maybe to Linux when Mach4 is released).
Cheers
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nobody says you have to change versions, mach3 works great for the most part, if it works, live with it and be content. As I've heard many times "If it ain't broke don't fix it." Hell at times I still play with CNCPro, (DOS Based cnc) works fine for a lot of things.