conor1n
Member
- Messages
- 567
- Location
- London/Ireland
Hello there,
A friend of mine is a machinist and does various jobs for people. One such job on the mill was cutting keyways into shafts, and he had a few to do. With his machines being manual, he was caught up winding his bed over and back quite a number of times.. I gather it was a major PITA!
So.. he has asked me (very novice) to help him setup a motor he acquired a while back to motorise the bed.
Unfortunately I don't have any pictures of the machine in question but I will get some the next day I am out.
The motor is as follows:
24VDC Brushed, 350W, 18.7A, 2750RPM
My plan for a controller is as follows. There is actually a control box on it with empty slots and loose wires so there was obviously something there before, i'm not sure what. The idea is to make up this panel to fit that housing, and include the various gubbins behind it in some kind of enclosure.
SAFETY FIRST - not included in picture. I will include an emergency stop (big red button) somewhere on the mill where an operator standing in front could easily hit with their hand. I reckon i'll just have it switch off the entire controller... but not sure how bad that is for harsh stop of a motor.
The plan is to get a motor controller (cheap Amazon job) as the centre piece of the project. And along with that, I will add the following functions:
Note, Power and Speed will be direct controls to the controller.
* FWD/REV will be done with a two step rotary knob SPST, and I will wire it to two SPDT relays to allow me to reverse the polarity of the motors so that the bed can navigate forward and back.
* STOP WARN will be an audible buzzer that will be triggered by two limit switches, to stop the bed when it reaches a preset point (there is a track on the mill bed). It will be implemented as follows:
- The limit switch will be normally open
- When the limit switch closes it will trigger a buzzer and flick a relay to stop the motor from driving.
Serves two purposes
1. Can alert the operator when stop is reached i.e. job is finished.
2. When operator is trying to do something or they just turn on unit, it will inform them of a STOP condition and be the reason the bed isn't moving.
One problem I see with this is that in the current design there would be no way to reverse the bed through electronics. You would need to turn off the controller and then manually wind the bed back away from limit switch, before turning on the controller to continue it. I think we might be able to live with that, but one solution is to have some kind of momentary switch "override" meaning when you press it, it will power the motor regardless of limit switch/stop condition.
I am using regular switches, and opting to pass the main current through a relay instead of switch etc.
How does this look to all, functionality wise? Personally I think the functionality is at the limit of discreet components. I think for anything more I would want to introduce a microcontroller/plc which is not something I want to do tbh.
Here are some of the parts I am thinking of using.
(Open to recommendations on all)
- Motor controller (awaits chinesium onslaught) https://www.amazon.co.uk/Controller-Adjustable-Stepless-Governor-Regulator/dp/B078TC3DTX/
- E stop (undecided) https://www.amazon.co.uk/IDEC-Emergency-Switch-Stop-YW1B-V4E02R/dp/B0CRS5N4BJ
- PSU (First item in Amazon) https://www.amazon.co.uk/MOGOULUA-480W-Universal-Transformer-Regulated/dp/B0B3T6NBZM
I'm usually not a fan of Chinese stuff. But honestly, the more and more I give them a go, and hear from other people they are often a lot more hit than miss. And they are so cheap they are worth a shot first off, as you might be surprised. But then again, I would be slow to leave them powered on and unattended overnight etc..
Curious what you all think. This is my first foray into any kind of industrial control so keen to hear from others.
Thank you so much.
A friend of mine is a machinist and does various jobs for people. One such job on the mill was cutting keyways into shafts, and he had a few to do. With his machines being manual, he was caught up winding his bed over and back quite a number of times.. I gather it was a major PITA!
So.. he has asked me (very novice) to help him setup a motor he acquired a while back to motorise the bed.
Unfortunately I don't have any pictures of the machine in question but I will get some the next day I am out.
The motor is as follows:
24VDC Brushed, 350W, 18.7A, 2750RPM
My plan for a controller is as follows. There is actually a control box on it with empty slots and loose wires so there was obviously something there before, i'm not sure what. The idea is to make up this panel to fit that housing, and include the various gubbins behind it in some kind of enclosure.
SAFETY FIRST - not included in picture. I will include an emergency stop (big red button) somewhere on the mill where an operator standing in front could easily hit with their hand. I reckon i'll just have it switch off the entire controller... but not sure how bad that is for harsh stop of a motor.
The plan is to get a motor controller (cheap Amazon job) as the centre piece of the project. And along with that, I will add the following functions:
Note, Power and Speed will be direct controls to the controller.
* FWD/REV will be done with a two step rotary knob SPST, and I will wire it to two SPDT relays to allow me to reverse the polarity of the motors so that the bed can navigate forward and back.
* STOP WARN will be an audible buzzer that will be triggered by two limit switches, to stop the bed when it reaches a preset point (there is a track on the mill bed). It will be implemented as follows:
- The limit switch will be normally open
- When the limit switch closes it will trigger a buzzer and flick a relay to stop the motor from driving.
Serves two purposes
1. Can alert the operator when stop is reached i.e. job is finished.
2. When operator is trying to do something or they just turn on unit, it will inform them of a STOP condition and be the reason the bed isn't moving.
One problem I see with this is that in the current design there would be no way to reverse the bed through electronics. You would need to turn off the controller and then manually wind the bed back away from limit switch, before turning on the controller to continue it. I think we might be able to live with that, but one solution is to have some kind of momentary switch "override" meaning when you press it, it will power the motor regardless of limit switch/stop condition.
I am using regular switches, and opting to pass the main current through a relay instead of switch etc.
How does this look to all, functionality wise? Personally I think the functionality is at the limit of discreet components. I think for anything more I would want to introduce a microcontroller/plc which is not something I want to do tbh.
Here are some of the parts I am thinking of using.
(Open to recommendations on all)
- Motor controller (awaits chinesium onslaught) https://www.amazon.co.uk/Controller-Adjustable-Stepless-Governor-Regulator/dp/B078TC3DTX/
- E stop (undecided) https://www.amazon.co.uk/IDEC-Emergency-Switch-Stop-YW1B-V4E02R/dp/B0CRS5N4BJ
- PSU (First item in Amazon) https://www.amazon.co.uk/MOGOULUA-480W-Universal-Transformer-Regulated/dp/B0B3T6NBZM
I'm usually not a fan of Chinese stuff. But honestly, the more and more I give them a go, and hear from other people they are often a lot more hit than miss. And they are so cheap they are worth a shot first off, as you might be surprised. But then again, I would be slow to leave them powered on and unattended overnight etc..
Curious what you all think. This is my first foray into any kind of industrial control so keen to hear from others.
Thank you so much.