How to config one Switch for limit and reference
13 Jun 2016 13:48 - 13 Jun 2016 14:06 #75915
by Thomas
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13 Jun 2016 15:30 #75926
by Thomas
Replied by Thomas on topic How to config one Switch for limit and reference
Hi Todd,
that're terrible news
because I don't know how the get the matching pins out 
First I wanted to use screws, but the matching pins looking better, but now I have the problem to pull one of them out again 
However, thank you for your fast reply.
that're terrible news
because I don't know how the get the matching pins out First I wanted to use screws, but the matching pins looking better, but now I have the problem to pull one of them out again However, thank you for your fast reply.
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13 Jun 2016 17:09 #75930
by Thomas
Replied by Thomas on topic How to config one Switch for limit and reference
the pins are made of steal and are hardened, used in mechanical engineering for example. I know 2 kinds of pins, one with thread inside and one without. I've the one without 
They are held in by press them in. The diameter of the pins is 6m6 mm. The hole in the plate is 5.8 or 5.9 mm.
They are held in by press them in. The diameter of the pins is 6m6 mm. The hole in the plate is 5.8 or 5.9 mm. Please Log in or Create an account to join the conversation.
14 Jun 2016 09:16 - 14 Jun 2016 09:17 #75969
by andypugh
The underlying problem is that with only one sensor, no matter how you wire it, the system has no way to know if the sensor is sensing a limit pin or the home pin.
Even if you had two sensors and the pins were on different axes, having a single pin mid-travel as a home pin is a problem because the machine does not know which direction to move to search for the home pin. The only way to get a reliable mid-travel home is to have a long target that covers half the travel.
So, given that there is basically no way that the mid-travel pin can ever be useful you do need to find a way to remove it.
I think I would try drilling a hole at a shallow angle underneath the table to insert a punch from the back to push the pin out.
If it makes you feel better, I recently had a very similar problem myself. I drilled a hole in the bed of a lathe to work as a limit switch target, then hammered in an aluminium disc to make it look neat and stop swarf building up in it. What I hadn't realised is that the aluminium disc makes the hole invisible to the proximity sensor. (plastic is fine). In my position I could drill and tap the plug to insert a screw to pull it out.
I would have suggested this to you, but you said that the pin was hardened, so that won't work.
If the hole is deeper than the length of the pin you could try pushing it further in so that it no longer trips the sensor. But that is a bit of a gamble and might not work, but will make the pin even harder to extract.
I am guessing you don't have a welder?
Replied by andypugh on topic How to config one Switch for limit and reference
that're terrible news
The underlying problem is that with only one sensor, no matter how you wire it, the system has no way to know if the sensor is sensing a limit pin or the home pin.
Even if you had two sensors and the pins were on different axes, having a single pin mid-travel as a home pin is a problem because the machine does not know which direction to move to search for the home pin. The only way to get a reliable mid-travel home is to have a long target that covers half the travel.
So, given that there is basically no way that the mid-travel pin can ever be useful you do need to find a way to remove it.
I think I would try drilling a hole at a shallow angle underneath the table to insert a punch from the back to push the pin out.
If it makes you feel better, I recently had a very similar problem myself. I drilled a hole in the bed of a lathe to work as a limit switch target, then hammered in an aluminium disc to make it look neat and stop swarf building up in it. What I hadn't realised is that the aluminium disc makes the hole invisible to the proximity sensor. (plastic is fine). In my position I could drill and tap the plug to insert a screw to pull it out.
I would have suggested this to you, but you said that the pin was hardened, so that won't work.
If the hole is deeper than the length of the pin you could try pushing it further in so that it no longer trips the sensor. But that is a bit of a gamble and might not work, but will make the pin even harder to extract.
I am guessing you don't have a welder?
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14 Jun 2016 20:07 - 14 Jun 2016 20:16 #76023
by Thomas
Replied by Thomas on topic How to config one Switch for limit and reference
the pin ist out 
MDF is very soft and so I decided to drill 2 small holes (3mm) next to the pin on both sides, then I used 2 small screwdrivers and pulled the pin out. All is good
Now I have to mount the limit switches again and I use the promixy switches only for reference again.
@andypugh:
what? Do you want that i burn my router? But anyway, good luck with your challenge.
thank you all for your tips and help.
MDF is very soft and so I decided to drill 2 small holes (3mm) next to the pin on both sides, then I used 2 small screwdrivers and pulled the pin out. All is good Now I have to mount the limit switches again and I use the promixy switches only for reference again.
@andypugh:
I am guessing you don't have a welder?
what? Do you want that i burn my router? But anyway, good luck with your challenge.thank you all for your tips and help.
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