But in my case, more weight (within reason) = better damping. You aint going to cool the water much more :-)Quote:
Originally Posted by Desertboy
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But in my case, more weight (within reason) = better damping. You aint going to cool the water much more :-)Quote:
Originally Posted by Desertboy
Something like this maybe
http://www.ebay.co.uk/itm/Industrial...UAAOSwjL5ZFuNL
I have a water chiller unit that you are welcome to f.o.c. if you collect. It's rather chunky (maybe about 450 mm cube from memory) but then this is rather a chunky build :)
ThanksQuote:
Originally Posted by Davek0974
Many thanks, much appreciated, happy to pay for it if needed. Where are you based?Quote:
Originally Posted by AndrewMawson
Actually, looked at your profile.
Correct place?
https://www.google.co.uk/maps/place/...91!4d0.5339843
I'm in Uxbridge, so perhaps not too bad to do over an early weekend morning (if that suits you).
That's fine - I'm up early feeding the animals :)
Give me a call on 07740-308623 to sort out
I got it a couple of years ago to use with a big (and I mean big !) TIG welder but never used either of them ,and now I'm having a clear out - the TIG is going as well !
Thanks.Quote:
Originally Posted by AndrewMawson
Ill give you a call. Might Sunday work? We are out tomorrow.
Yes Sunday would be fine up to mid afternoon
I said it was chunky - it's a bit bigger than I thought :)
I presume it will fit into a saloon car boot?Quote:
Originally Posted by AndrewMawson
What else will I need with it for it to work?
Water pump, hose in, hose out if it's normal chiller (I have an expub chiller which is for another project which draws 4.2kw) but if it's chunky it might be drawing a lot of power at once won't cost you more to run as it will be on less proportionally but there might be wiring considerations.Quote:
Originally Posted by Chaz
I don't think you'll need anything other than a bit of wiring. I got it, then circumstances changed and it got put in storage - I have literally never investigated it other than to note it was a relatively simple unit - coils, fan, pump etc.
It's a bit buried where it is but accessible to pull out for you on Sunday.
Thanks will call and arrange
Hi, sent you a text earlier, did you receive it?Quote:
Originally Posted by AndrewMawson
No nothing received !
Will PM you.Quote:
Originally Posted by AndrewMawson
Ok, I missed a digit in the number. That's why you didnt get it.
Two questions.
1. Inverters / VFDs.
I was sent two in error for the 4KW Chinese spindle. One is a 220V input, the other 380V. My logic says that I can use either with a 220V input (single phase) and that the 380V could later be used if I had a 3 phase 380V supply (different motor).
The supplier indicates that the 380V one (with a 220V input) will damage the 220V spindle.
Thoughts?
2. I am looking to use NPN proximity switches for home locations. Easy.
The CS Labs IPA unit document shows an example where normal switches are used where home and -- (limit) is the same switch and then ++ (limit) is a different switch.
Is this commonly done? I was under the impression that there are only very limited inputs that Mach 3 will accept as limits (from 9 to 13 from memory).
Thanks
1 will depend on if the 380V inverter can be set to work with 220V. It'll need the DC bus voltage limits changed to stop it faulting due to too low a voltage.
The output will be configurable for the motor. IIRC you need to set the point at which the voltage gets limited, rather than the current, otherwise you will risk cooking the motor at higher RPM.
2. Have not got a clue, as it's that long since I've configured anything in Mach.
Thanks, probably not worth the effort / concern then. Ill just return the 380V one.Quote:
Originally Posted by m_c
Ill play around with the proxy switches this week / weekend. I wasnt aware home / limit could be the same switch. I cant afford a run away going past my limits - the damage with these motors / big components is difficult / expensive to fix.
Morning hows things today? Just been to vote ;)Quote:
Originally Posted by Chaz
I hear you there I'd imagine a crash would be a very bad thing.
What I would worry with an inductive probe is a stray chip triggering a max limit, I'm going to use high quality microswitches wired so if the connection drops off it will fault. (I think NC but too early for my brain this morning.)
I found the best quality microswitches I've come across cheap are proper arcade microswitches.
I agreed, Im not sure if they are the best but I got 6 of them for a reasonable cost. I might just do homing with them.Quote:
Originally Posted by Desertboy
Can you link the switches you are using please?
I agree with comments re inverter - without studying the manual and doing some parameter reconfiguration (and if the manual is in the same Chinglish as the HY manuals, that's not easy) it probably won't work out of the box.
IP/A - assuming that the digital I/o is the same as my IP/M, which seems likely - Mach3 can handle all the inputs, no problem. If you add one of the I/o extenders, it can handle those as well, so number of ports is not an issue. So, you could use separate limit+/limit-/home switches on each axis. On my own machine, I use a single switch for home/limit at one end plus another switch for upper limit on X and Y. For X and Y, I wire both switches in series (it's slightly more complicated than that but effectively that's what happens) so I only need three IP/M inputs. Wiring proximity switches in series works fine using the 24V supply you need for the IP/M. That's with NPN n/c proximity switches so I get the fail-safe effect of series switch wiring - any wiring fault and the limit switch appears to have tripped. You can use n/o switches in parallel but of course you lose the fail-safe feature. Keeping X, Y, and Z switches on separate inputs means that you can home two or three axes at the same time (I home Z to get it to safe height then X and Y together)
I have to google the ones I've got because I recovered them from this thing (I have an almost identical one with no surface rust and a mint ballscrew to cannibalise for my Z axis.)Quote:
Originally Posted by Chaz
Attachment 21859
But you cannot go wrong with Cherry or Happ microswitches, high repeat-ability and guaranteed for 10 million clicks which should be good for a few weeks lol. Should cost ~£1 to £1.50 a switch which for cnc is refreshing lol.
Thanks. IPA is teh same, many inputs. Ill find a screenshot of why I believe Mach 3 is the problem with inputs. Ill do it this evening.Quote:
Originally Posted by Neale
IP/whatever only works with Mach3/4, so Mach3 must be able to handle all the I/O. However, it's certainly not obvious first time round exactly how you refer to the connections. Took me a while to figure it out from the manuals. Post the screen shot and I'm sure someone can talk you through it. Is one of those things that's obvious, but only after you've done it the first time!
Thanks Neale, I understand how the inputs / mapping work. Ive setup a few machines on CS Labs kit. Ill find the image / reference to why I believe Mach 3 is the problem here with limit inputs specifically.Quote:
Originally Posted by Neale
My only experience with microswitches and CNC style controllers are Arduino based but I do know the Arduino has internal pullup resistors so that microswitchs work from 2 wires (Unpowered) but when you use inductive sensors they need to be powered so you have to turn the internal pullup resistors off in the firmware (You also need to wire some resistors to drop the voltage from 12v to 5v so it doesn't fry the Arduino.) and make sure you have the correct firmware setting for NO/NC. I wonder if this could be related?Quote:
Originally Posted by Chaz
I have an inductive sensor for auto levelling my 3d printer bed and an aluminium print bed and fried 1 Arduino before I found this out.
This is the limitation (for limit switches).
Attachment 21860
'Only 5 of these inputs blah blah' ....
Ive actually crashed Mach 3 before by trying to use other inputs than those (for limit switches, I must stress). No problem using them for ATC switches etc.
Getting them to work as single NC switches is fairly easy on the CS Labs / Mach 3 setup.Quote:
Originally Posted by Desertboy
Im trying to work out how to wire them in series and how to mix between limit / home options.
Another way is to wire something via the E Stop circuit for limit switches and not actually use the 'limit switch' pins available to Mach 3.
You should be aware that mechanical switches often have a minimum switching current needed for those kind of expected lifespans. If switch contacts don't switch enough current, they oxidise and fail to conduct, as they rely on a certain amount of arcing to keep the contacts conducting.Quote:
Originally Posted by Desertboy
The same also applies to relay contacts.
So many options.
http://uk.rs-online.com/web/c/automa...sort-order=asc
Id probably consider the ones like this (http://uk.rs-online.com/web/p/limit-switches/0199046/) or similar.
Panasonic, so not cheap crap. NC, Easy to mount, should work for me but I dont really want to buy 6 if I can avoid it.
You should be fine to wire them in series no problems but only if you use them as Normally Closed, if you use them Normally open they won't trigger! Normally closed the circuits is flowing and your detecting a break it doesn't matter which one triggers. Normally open the circuit is closed and unless you trigger both microswitches at the same time (Which can never happen in real world use) the circuit can't complete.Quote:
Originally Posted by Chaz
There's no real power going through them so wire from one to the other so should be no need for anything else.
If I were you I would wire a 2nd set of limits to the Estop regardless as it seems more reliable than relying on the software and you really can't afford a crash.
You're paying for the IP rating mostly if you're not running liquid coolant I would be happy with Cherry or Happ microswitches simply because arcades have used them since the 80's pretty much unchanged design and they have proven themselves to be ultra reliable over a long time and arcade machines were abused! They are certainly not suitable if your cutting under running liquid but they are so cheap 6 would cost the same as 1 panasonic and although the panasonic might be better the happ's or cherry's have certainly had a lot lot more real world testing as almost every arcade machine, including gamblers in the 80's, 90's, 00's and even today had/have either happ or cherry switchesQuote:
Originally Posted by Chaz
True. At the moment I'm not sure if Ill be using coolants. Ive been thinking to get some form of metal / material bellows system in place, id be more comfortable to have them IP Rated, just in case. Suppose in the overall costs of the machine, paying £50 for switches is not really an issue.Quote:
Originally Posted by Desertboy
Ok, fundamental question.
Is it normal or acceptable to use the same switch (mechanical or proxy) for both home and limit? I dont understand how the machine would know if it was simply sent home or it actually needs to stop as its a limit. Is there logic that says 'ref all' and it goes home but if its hits the home limit during any other movement (manual or programmed) that the machine will then stop?
That I didn't know I built an arcade cabinet to Jamma specifications including the correct jamma wiring loom, sanwa joysticks & cherry microswitchs and a pirate 200 in 1 cart but I cannot remember how I wired it up now lol it was over 10 years ago, the cabinet still works fine after a hell of a lot of abuse, sits on a campsite my mate owns in Luxembourg on free play.Quote:
Originally Posted by m_c
Arcades could take a hell of a lot of abuse but there was 1 type of game that killed the microswitchs in an insanely short time, Daley Thompson's Decathalon type games lol.
I would think that if you got even 1% of the performance out the microswitches (100,000 presses) unpowered it would last any cnc machine well over 10 years as you don't really trigger the limits much a day even if you're using the machine 24/7.
I know how it works on grbl (Arduino cnc solution) when it's doing a home it ignores the limit so doesn't go into shutdown mode. If it's not homing then it treats it as a limit switch and shuts everything down until reset G code is sent.Quote:
Originally Posted by Chaz
I'm sure Mach 3 treats it the same way (I think LinuxCNC does)
If I were you though I would fit another set of limit switch further back that trigger an E stop as well as extra protection! I can maybe help you source high quality IP64 rated microswitches I have a friend who services and repairs 4 poster lifting ramps for steam cleaning bays I'll give him a bell see how much he would charge for new ones if they're cheap enough I'll use them lol.
Chas I have not used the IP/A but doesn't the controller use its own plugin with Mach and it states on the website 24 inputs at 24V I don't think it uses the Mach screen to set them up. I could be wrong.Quote:
Originally Posted by Chaz
Clive, yes, I need to check. All I recall is 'killing' Mach 3 when I inadvertently used the inputs outside of Mach 3's range. Maybe coincident but its all I could relate to making Mach 3 crash.Quote:
Originally Posted by Clive S