hall effect home switches
21 Oct 2018 23:47 #119183
by andypugh
Depending on what you are machining, magnets can be a poor choice. Certainly if you intend to machine steel I would avoid them. (it seems fair to assume that you are unlikely to be machining Nickel or Cobalt)
Inductive proximity switches work well.
Replied by andypugh on topic hall effect home switches
While trying to conceive of an appropriate cam mechanism to effect this, I realized that the easiest and most reliable mechanism for achieving this would be a hall-effect switch and a magnet. !
Depending on what you are machining, magnets can be a poor choice. Certainly if you intend to machine steel I would avoid them. (it seems fair to assume that you are unlikely to be machining Nickel or Cobalt)
Inductive proximity switches work well.
Please Log in or Create an account to join the conversation.
22 Oct 2018 14:38 #119205
by OT-CNC
What repeatability are you guys getting with these switches when used for precision homing? I have mainly used optical switches for home switches and sealed roller micro switches for limits.
Replied by OT-CNC on topic hall effect home switches
Inductive proximity switches work well.
What repeatability are you guys getting with these switches when used for precision homing? I have mainly used optical switches for home switches and sealed roller micro switches for limits.
Please Log in or Create an account to join the conversation.
22 Oct 2018 15:00 #119206
by yamaplos
Replied by yamaplos on topic the thing about...
"when it works, it works really well. But getting it to work is maddeningly difficult. Oh well."
I should make my sig out of that line![:-) :-)](/media/kunena/emoticons/smile.png)
I built my CNC totally from scratch, of my own design, getting a few ideas from a handful of Youtube videos, parts from my garage, and what I didn't have from China. Zero previous experience with Gcode or CNCs.
From placing my order for parts, it was 11 days to carving the example code (had to wait for parts, etc.). Yes, that first test came out also inverted, but in my case I remembered that there was a setting... then, all of 29 more days before the thing was RELIABLE, that is, put some material, load a file, and voila.
Those 29 days were a lot of pain![:p :p](/media/kunena/emoticons/tongue.png)
As we say in the Marines, I'm the better for it!
Thank you, and good CNCing, to noobs and experts!
I should make my sig out of that line
![:-) :-)](/media/kunena/emoticons/smile.png)
I built my CNC totally from scratch, of my own design, getting a few ideas from a handful of Youtube videos, parts from my garage, and what I didn't have from China. Zero previous experience with Gcode or CNCs.
From placing my order for parts, it was 11 days to carving the example code (had to wait for parts, etc.). Yes, that first test came out also inverted, but in my case I remembered that there was a setting... then, all of 29 more days before the thing was RELIABLE, that is, put some material, load a file, and voila.
Those 29 days were a lot of pain
![:p :p](/media/kunena/emoticons/tongue.png)
As we say in the Marines, I'm the better for it!
Thank you, and good CNCing, to noobs and experts!
Please Log in or Create an account to join the conversation.
22 Oct 2018 15:21 #119207
by andypugh
Ah, well, I should probably have said that my machines all have encoders or resolvers, so I can home to index and the home is exactly as accurate as the feedback is capable of measuring.
Adding a second prox that senses the motor-shaft flat (or whatever) for an emulated index would be possible for open-loop machines.
Replied by andypugh on topic hall effect home switches
What repeatability are you guys getting with these switches when used for precision homing? I have mainly used optical switches for home switches and sealed roller micro switches for limits.Inductive proximity switches work well.
Ah, well, I should probably have said that my machines all have encoders or resolvers, so I can home to index and the home is exactly as accurate as the feedback is capable of measuring.
Adding a second prox that senses the motor-shaft flat (or whatever) for an emulated index would be possible for open-loop machines.
Please Log in or Create an account to join the conversation.
22 Oct 2018 16:01 #119208
by OT-CNC
Replied by OT-CNC on topic hall effect home switches
I need to revisit the homing to encoder index on one of my machines with ac servo, stepper input and encoder feedback. Is that working reliably now in 2.8?
Please Log in or Create an account to join the conversation.
22 Oct 2018 16:11 #119209
by mozmck
There is always interest in improving the documentation!
One of the problems with making "noobie" friendly documentation is that every noobie is different and has different experience and knowledge. It's not merely a problem of developers not understanding the needs of users - it's a problem of users not understanding the needs of other users. Your approach will undoubtedly help some noobies, but might hopelessly confuse others
In the current case - I have seen quite a few machines which have home switches - and have never seen one that operates as you mention in this thread - they all work using one of the methods supported by linuxcnc. I think a truly noobie friendly documentation would be several thousand pages and would probably need to start with a tutorial on the English language!
Don't let that dissuade you in any way however from contributing better documentation!
Replied by mozmck on topic hall effect home switches
Thanks guys for your help. It's clear to me now.
The thing that you might want to keep in mind is that some of us are approaching their CNC project without previous CNC experience, but with experience from other areas. So, when we ask a noobie question like this one, it might be with complete naivete relative to you guys. Hence the question in this forum.
...
The problem is in the documentation. For those of us who are just starting out, it's hard to find what you need, and the information is often presented in a way that is from an insider's view rather than an outsider's view. It's a natural problem. Developers often don't understand the needs of users, especially those who come from a different background.
I've thought of trying to help by generating some noobie friendly documentation (which I'm doing for myself so, if necessary, I can accomplish the same thing again without the same pain). I've yet to complete a document for my small configuration, so contemplating trying to complete one that might be applicable to all of the different configurations that LinuxCNC is capable of supporting is a bit overwhelming at the moment. But, maybe when I'm further along, and if there is interest from you guys...
There is always interest in improving the documentation!
One of the problems with making "noobie" friendly documentation is that every noobie is different and has different experience and knowledge. It's not merely a problem of developers not understanding the needs of users - it's a problem of users not understanding the needs of other users. Your approach will undoubtedly help some noobies, but might hopelessly confuse others
![:-) :-)](/media/kunena/emoticons/smile.png)
Don't let that dissuade you in any way however from contributing better documentation!
The following user(s) said Thank You: tommylight
Please Log in or Create an account to join the conversation.
- tommylight
-
- Away
- Moderator
-
Less
More
- Posts: 18564
- Thank you received: 6220
22 Oct 2018 16:31 #119210
by tommylight
Replied by tommylight on topic hall effect home switches
Holly Moses !!!
![:) :)](/media/kunena/emoticons/smile.png)
Please Log in or Create an account to join the conversation.
Time to create page: 0.092 seconds