Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: gldfshrdr on February 22, 2014, 09:51:27 AM
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Yeah, I'm a nooby, My machine doesn't look like much but it's allowing me to get a feel for the software and coordinate systems. My current challenge is using the Home switches. The Y axes homes and moves off the switch. The X axes hits the switch and just stops. It does not move off the switch. I've checked Configs and home limit settings but there doesn't seem any difference there between the axes.
I've changed the X axes switch thinking maybe a bounce or momentary contact in the switch was the cause. That didn't fix it. Any suggestions would be a big help.
Thanks.....gldfshrdr
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Greetings gldfshrdr,
Firstly, set the debounce in Config to 1000 and try again. If that helps, reduce the setting until it craps out again, then increase it slightly.
Russ
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Thanks Russ. I went to "Input signal debouncing / debounce interval and set it to 1000. Didn't make a difference. Do I have to change the Index Debounce also?
Trouble shooting:
I verified connections between the LPT! and IDC connector on the controller.
Touched up the solder points on the Controller.
swapped Y motor for X motor and it behaved the same way. And verified Y motor still reacted normally when swapped back.
I checked the Config and found X and Y config is identical.
Thanks......gldfshrdr
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In 'Ports&Pins" under inputs, do you have home and limits enabled for each axis or just home? Do you have both types of switches on the machine now?
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I have had it both ways and didn't make a difference. Currently it's Home switches only.
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Are the home switches at the end of travel of the axis or is it in the middle somewhere?
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At the end pf travel.
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Using the Diagnostics screen, when the Y limit is hit, just the limit LED lights up. When the X limit switch is hit, both the Limit and the Estop light up.
I had given the Estop the pin number (10). That's the pin for the X axes limit switch.
Lesson learned: Trust the Diagnostics screen.
Thanks for help Fastest1.......gldfshrdr
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Easy to do.
Glad you got it figured out.
Good luck,
Russ
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Hi, i am new to cnc and have a problem i need some help with please. I need help with my limit switch problem?
I`m new to cnc and this forum, i have built a router and controller but can only get it to work without limit switches pluged in.
My settup,
4 steppers, one slaved to the y axis.
E stop wired NO on pin 10
limit switches, 2 each axis all 6 wired NC in series on pin 11. Active low.
The problem, the nachine will only run if the limit socket on my controller is not pluged in as soon as i plug it in even with machine idle but under mach control the reset button comes on and advises limit activated.
I have tried limits active high, no result.
i am getting very frustrated with this, the machine runs well without the limits pluged in but i do not want to run the risk of machine damage if i get a problem, i also want to use the same switches for homing but i need the limit problem solved, new to this so to solve one problen at a time.
Hope i can get some help.
Best wishes to all.
Billy
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Sounds like you either need to make the switches NC or flip the setting in pis & ports so that it is active low or the opposite of what is set now.
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Hi, i am new to cnc and have a problem i need some help with please. I need help with my limit switch problem?
I`m new to cnc and this forum, i have built a router and controller but can only get it to work without limit switches pluged in.
My settup,
4 steppers, one slaved to the y axis.
E stop wired NO on pin 10
limit switches, 2 each axis all 6 wired NC in series on pin 11. Active low.
The problem, the nachine will only run if the limit socket on my controller is not pluged in as soon as i plug it in even with machine idle but under mach control the reset button comes on and advises limit activated.
I have tried limits active high, no result.
i am getting very frustrated with this, the machine runs well without the limits pluged in but i do not want to run the risk of machine damage if i get a problem, i also want to use the same switches for homing but i need the limit problem solved, new to this so to solve one problen at a time.
Hope i can get some help.
Best wishes to all.
Billy
Have you changed the debounce setting?
Try installing a value of 1000 for starters. If it works, try 500, keep going less and less. Switches especially cheap mechanical ones are prone to bounce. Mach sees this as a trigger. If you lengthen this time (debounce) the signal must be present for the set time to be recognized. Try this first.
It could also be a ground issue but more on that later.
Do not switch to an NO set of switches. NC is the safest way and will come to a halt if ANYTHING in that circuit should fail. Better safe than sorry.
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Hi, thanks for your reply.
Limits are in series and NC config ticked for active low
E Stop now changed to NC config ticked for active low
On screen E Stop flashing on Message External E Stop Requested
Tried debounce at 1000> 500 no change
Cannot get off E Stop to run the machine.
Billybob
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These are 2 different set of problems.
First lets get the EStop sorted. Are you sure your EStop is using NC contacts (the contacts are available separately and in both configurations). If you untick the "active low" does the EStop requested error go away? If so leave it that way until you get some new contacts or EStop button. Personally I have had this issue too. I now order my EStop switches with 2 sets of NC contacts. I use 1 set for the latching feature of my contactor and the other set for the EStop within Mach and my controller. My computer is powered upstream of the contactor so it never loses power. The pressing of the EStop kills all power to the machine at that very moment AND triggers Mach into a fault/EStop condition.
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Hi Again,
My e stop has 2 x sets of contacts, one for NO (green) and one for NC (red), wiring connected to NC. IT is not making any difference if i untick active low makes no difference Estop request still on.
I am only using the e stop to stop the machine in Mach.
New machine and controller.
Regards Billybob.
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BB, First go back thru the diagnostics. It sounds like the switch might be wired correctly but not the BOB.
Which inputs are you using? pin 10 port 1?
Does 1 leg of the EStop switch go to the ground of the BOB and the other leg go to pin 10? Try a jumper for a test. If that works then suspect your switch and or wiring.
Also, you say you built your router and controller. Controller from a kit? Hobby Cnc?
If you can, post pictures with your cell phone. Some of us are much more visual.
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Hi,
Bob is wired to port 1 and pin 10.
Out from pin 10 to one side of the switch then from the other side of the switch to the ground of the bob. This ground shared with another ground.
The cable is twin core shielded.
I have tried grounding the shield to the steel enclosure through the plug, also grounded it direct to the bob and also grounded it to the earth terminal inside the case all gave same result.
I built the controller from components i picked up in a few places. I have built a controller before, a few years ago exactly the same and it was fine, but i droped out of the cnc thing due to health problems, back fighting fit now so at cnc again. I`m in the UK so its evening now, i`ll try and take a few pics tomorrow
Best wishes.
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Hi Billy,
Can you double check your pin assignments in Ports and Pins, Input Signals ?
Russ
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Let's not suspect noise just yet. Leave the shield unconnected at both ends.
Didn't you say you can't get your EStop to stop flashing? Let's put a jumper from pin 10 on the BOB to the nearest ground on that side of the board. Try active low checked and unchecked if need be. Disable all limit and home switches til step 1 is complete.
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Hi Fastest 1,
Disconnected my estop. Disabled all limits.
Connected jumper ditect from pin 1 to bob ground.
Can reset estop when active low box un ticked. (X in box)
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Hi Overloaded,
Pin assignments are
E Stop Port 1, Pin 10 Active low ticked
Limits Port1, Pin 11 Active low ticked
Thanks for everyones help.
Billy
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Did the EStop ever come out of fault? If you are trying active low checked and unchecked and it didn't come out, it is defective, wired wrong or your pin assignment is wrong.
A simple wire as a jumper from 10 to ground will let you know quickly.
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Hi, yes when i wired to test as you advised EStop came out of fault when active low unchecked. (X in box)
So in the morning, 26th, i will checkout the E Stop switch and wiring
Thanks for the help looks like we are getting somewhere.
Thanks Billy
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Sounds great, forward progress is always nice. Now just use a continuity tester on your switch circuit, should beep the whole time until the EStop button is pressed. Or it is a NO circuit/switch.
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Hi, i have tested the EStop switch circuit and it is working ok as NC with the limits switched off in Mach. Have run a test program and the router runs ok.
Activated the limits and result as below.
So i have just run a short program and it stops with a limit switch activation tried a few times same result without an actual limit actuated.
The limits are wired in series and are NC.
The limit cables are shielded and the shield grounded to the bob.
So i guess its onto another problem
Best wishes.
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It is faulting with a limit switch error though they arent enabled? (I think I misunderstood your statement, it does appear your limit switches were enabled during your run)
Back to the debounce setting (of which there are 2 but one is for the spindle ignore it) put a value of 1000 in there. Try again.
My suspicion is now noise. Typically the shields are connected to the Star ground not the BOB's ground (though they may be tied together at some place).
There is a machine side and computer side to BOB's, these must be kept isolated.
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Hi, thanks for getting back so quickly.
Following my last post i got into my workshop and checked over my wiring i found 1 x motor shield faulty and not going to ground, also found limit cable not grounded with a break in the shield, very small wires.
Made up new motor shielded cable and fitted it.
Next soldered a piece of wire to the faulty limit shield and run it to ground.
Have run a few programes to try, all worked ok so i will tidy up the wiring when i`m at it next and retry the router. Monday i should think.
Will be away at our holiday getaway in Mid Wales on the coast for a few days to check the place out following the extremely wet and windy winter in the UK, wetest on record.
Thanks for your help, very much appreciated.
Best wishes
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Enjoy!