Who Knows?
Often commercial links are embedded in the post.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
They appear to be burglar alarm type? If so these are non-electronic and consist of reed switches operated by a P.M.
They MAY not have the repeatable accuracy of the hall effect.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
I think he plans to just use the magnets to trip the sensors
Sent from my HTC VLE_U using Tapatalk 4
If your plan works... please post a picture of your end results; I am very curious if they would make the job harder or easier.
My Problem is that I don't know how to change the files into G-Code just yet, and I am wait and watching this thread as this is an awesome thread I have read all of it and I have learned a lot.. but I am not sure how to put it all together. As my bob only has for terminals for switches and I don't know how I can get a CLOSED circuit for my EStop, and Three circuits for X,Y, and Z... Plus a Touch off Block for Z
I am assuming that I have to wired Z as an Open circuit or something.. anyway, I am confusted and hoping someday this will make sense as now it seems like common knowledge to everyone but me.
I also have a pile of 10-30 VOLT sensors with red lights that switch depending on if a reflector is near, but my BOB is FIVE VOLTS...
Did I get the wrong BOB Break-Out-Board or am I missing something obvious... it is all a mistery to me and I just wait till I get some help.
In the mean time I am using G-Wizard to practice G-Code enough to make G-Code for the switch mounts.
One last thing, everyone just has 3/4 or 5/8 plastic that they just had lying around... well it isn't lying around here... where would one get a chunk for the cheapest price?
Does anybody know how to set the retract after the switch has been activated. About half the time mine just stop and the switch remains activated. When it does this it stops and will not home the next axis.
Are you seeing an error message?
And are the axis displaying as being homed?
There is no retract distance. Mach3 retracts until the switch opens, then it stops.
You might be seeing some "bouncing", where the switch is toggling back and forth a bit when retracting?
Gerry
UCCNC 2017 Screenset
http://www.thecncwoodworker.com/2017.html
Mach3 2010 Screenset
http://www.thecncwoodworker.com/2010.html
JointCAM - CNC Dovetails & Box Joints
http://www.g-forcecnc.com/jointcam.html
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
Thanks Gerry
I have shielded cable with the shield grounded in the control box.
I have one of those choke coils at the switch.
I have a Y5U 104M capacitor from the 5v to ground. Without this it stops a lot on the way to home.
I made the following measurements with auto zero off and jog set to 1.
LED on = switch closed.
DRO readings. 1.0222 led turns on. 1.0431 led turns off. This is very repeatable.
I am homing at 20 speed.
jog to led on then zero DRO. Somewhere around 1.0209 is switch off.
DRO readings while homing from 2 inches. switch never opens after close led stays on.
-1.209 -1.0052 -1.0130 -1.0156 +1.0104 -1.0235 -1.0026
There are no error messages. Pressing "home" again gives the "fix the limit switch" error.
If i change the homing speed to 1 then DRO value is more repeatable but the switch remains on. Any thing over 40 goes thru the switch and hits the rail.
There is no bouncing usually it just stops dead.
The axis is marked as homed, the "X" has the green halo around it.
I have disconnected all but the X axis from the control panel and their switches.
Thanks
Jack
I finally got it to work perfectly I will post a update after I get back from dinner
Is the switch also set up as a Limit switch, or a Home only?
Does each axis' switch have it's own pin, or are they all sharing one pin?
My guess is that the switch is opening enough for Mach3 to see it, but staying closed. Probably noise related, as you have so many things already trying to minimize the noise.
Gerry
UCCNC 2017 Screenset
http://www.thecncwoodworker.com/2017.html
Mach3 2010 Screenset
http://www.thecncwoodworker.com/2010.html
JointCAM - CNC Dovetails & Box Joints
http://www.g-forcecnc.com/jointcam.html
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
Thanks Gerry
It was electrical noise.
Long story version follows
when I attached the Hall first switch I connected it directly to the bob. Worked great. I was also looking at wiring solutions, in another thread. Attached is a mini din block I found and I thought using it would simplify the wiring of the other switches. Seemed straight forward.
NEW CONCEPT INTRODUCTION SEEMED SMALL, NOT SO.
The neat green and yellow terminal blocks are ground, we need ground, but they are grounded to the chassis(box,earth). So better check a little more. Ohm meter says case and 5v ground are common. OK then I rewire everything adding the two other homing switches. Seems to work but is unreliable as documented below,this thread.
GIVE UP SEEK ADVICE, see below, this thread
IT SHOULD WORK, even though I have received expert advice
I DOCUMENT ALL THE THINGS THAT SHOULD MAKE IT WORK, see below,this thread
REALLY GIVE UP, carefully read the expert advice for nugget of truth, you usually only need one to start with.
ABSOLUTE STATEMENT FROM EXPERT, after the switch closes the motion will reverse until the switch opens. I am getting no or little reverse movement even though the switch is closed.
Process of elimination.
I disconnect the wire leading from the board to the terminal block, and to the switch so it is free. I click on home X, wait a moment, press the wire to the case. The motion stops no retrace. Since this is not according to the expert, but should work, I do this with variations for 30 minutes. Does not seem to work, well does not work.
I disconnect the 5v gnd wire from the terminal block. I click on the home X, I touch the two wires, the ground and the home wire, together. Seems to be the same but I try again. After a few tries I can get the reverse motion to continue until the wires are separated.
I rewire the terminal blocks using blocks isolated from the case(high voltage, earth).
Works every time.
Noise on the ground when the motor reverses direction, probably.
Thanks Gerry(the expert)
PS Yes I do have a college degree and yes it is in electrical engineering, solid state physics, doesn't help much when you are sure you are right
Attachment 197426
One of the biggest problems IMO, is that Hobby machines have more or less settled on 5v I/O out on the machine, instead of going with what is pretty much the industry standard of 24vdc control.
I follow this and and over the years have never had any problems that I see here almost every week!
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
If you are looking for plastic, try Laird plastics Laird Plastics that's where I get mine min order is $40 but best prices and many different thickness and types
http://youtu.be/9dTS1A2F4j8
In Canada there is also Johnston Plastics, I managed to get offcuts also.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Al
Do you have some examples or suggestions about how to use 24 V input and output signals.
It would seem that powering electronic switches with 24 V would be possible. If the inputs are just short to ground and held up by pull-up resistors Isn't the open circuit voltage still 5 V subject to the same noise problems.
Outputs would seem to be more of a problem since they short when activated. Currently they short five bolts to ground to activate the device such as a switch. If you use 24 V that seems like that would be a problem.
Thanks jack
Over the years I have used many custom built I/O boards, for Inputs, if something like the opto IC 4N25 is used close to the 5v port with 24v on the input side.
For non-isolated outputs I have use 2n7000 for a small # or just a couple of outputs.
If more is needed then I use the ULN2803 but these require some board level building with strip board.
If you don't want to get into that, then I have used Opto22 products, these are boards that are made for mix and match I/O modules that translate from 5v-24v one side to 60VDC - 240AC, either way, in or out.
If you search on Ebay for Opto22 you can see lots of it, you would need the 5v logic variety for PC port use.
I have used common ground (mainly) and also Isolated commons with no problem with noise.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Thank you, I will call them.
I searched ULN2803
http://www.digikey.ca/product-search...2803&x=16&y=15
I was thinking that I would see Opto 5volt to 60volt... but it turns out that one requires more than a
soldering gun and a oscilloscope to figure this stuff out.
Thanks again... I don't quite understand,,, but I do appreciate a point in the right direction, I'll google for 5-60 Opto HACK or DIY later. As I have over $5000.00 worth of these sensors it will be worth it for me to find a solution.
Many thanks, Edoctoor (backwords is Root Code)
I follow this and and over the years have never had any problems that I see here almost every week!