The black insulation tape was used to fasten the 2nd magnet on sorry my post is misleading the one I lost had nothing holding it on other than its own magnitisumWould self-amalgamating tape prove more secure? Just a thought......
- Thread starter Carl Wilson
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Carl Wilson
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Did some more wiring this evening. Got all the conductors in for the vfd control side of things.
Just the interlocks left to do now and the machine will be ready for a test run. Aiming for middle of next week for the functional.
Just the interlocks left to do now and the machine will be ready for a test run. Aiming for middle of next week for the functional.
Carl Wilson
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There are three sets of cables here. These are for the chuck guard, changewheel cover and foot e-stop microswitches. They need to be connected in series with each other and the panel e-stop. The whole will then be connected between the emergency stop function on the vfd.
As I took this photograph I noticed I'd made a wiring error in the conductors for the vfd controls. Easily rectified but just shows ypu what a moments lapse in concentration can do.
As I took this photograph I noticed I'd made a wiring error in the conductors for the vfd controls. Easily rectified but just shows ypu what a moments lapse in concentration can do.
Carl Wilson
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I had to make a slight adjustment to the relay module, the inputs to operate each relay had to be grounded to switch them as opposed to bring taken to the 12 volts. Just moved the switch inputs to the common and swapped the diode around.
Here is a really unprofessional clip of the main functions being tested.
Next thing is to tidy up all the wiring and fit the panel with a new gasket.
Carl Wilson
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The panel is fitted now, complete with a new gasket. The RPM indication system has also been wired, and I will have to make a bracket to position the sensor correctly.
The vfd unit is boxed up now. I will also need to secure the cable conduits running from the vfd enclosure to the panel.
The vfd unit is boxed up now. I will also need to secure the cable conduits running from the vfd enclosure to the panel.
Carl Wilson
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Current plan for the sensor is to mount it on the inside of the change wheel cover and have an in line connector to allow the cover to be removed when required.
The photos below show the position on the cover where the bracket will be, i.e. below the cut out for the spindle and the position it is hoped the sensor will take up.
The photos below show the position on the cover where the bracket will be, i.e. below the cut out for the spindle and the position it is hoped the sensor will take up.
Carl Wilson
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The sensor has been fitted. I used a stauff type pipe clamp bored out to 12 mm for the sensor. This was then fitted inside the changewheel cover to allow the sensor to face the magnet on the spindle.
The stauff type clamp is spaced 16 mm from the cover using aluminium tube. The lathe has now been tested and the RPM indicator works exactly as advertised.
The stauff type clamp is spaced 16 mm from the cover using aluminium tube. The lathe has now been tested and the RPM indicator works exactly as advertised.
Carl Wilson
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Here is the RPM indicator working. It operates quite well. At lower speeds it is somewhat slow to react, but this is only to be expected given the one pulse per revolution generated by the sensor and magnet combination.
The RPM display also does not follow the shaft RPM very closely if the speed is ramped up and down quickly. I suspect this is also due to the above reason. When the shaft is stopped, the display also has a tendency to freeze, but after a few seconds with no rotation detected the display will show 0 RPM.
These shortcomings are relatively minor and are easily explained by the simplicity of the system. That aside, it was an inexpensive little unit and is more than adequate for the job in hand.
The lathe was taking a 3 mm cut from the brass hex bar.
eLuSiVeMiTe
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My Magnets turned up this week so il be fitting one to the lathe and mill tomorrow too.
Gonna have a good read through of this thread and finally start my control box build too.
Gonna have a good read through of this thread and finally start my control box build too.
Carl Wilson
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Here is the magnet for the RPM sensor. It is secured on the spindle using heat shrink tubing, the method I said I was going to use up thread.
Elusive, if you need any help with your project please let me know.
I'm toying with the idea of giving a list here of all the parameters I have set and their values for the Teco E510 vfd on my lathe. I'm not sure if it just wouldn't be rather boring and not especially helpful to others who may have a completely different unit.
I didn't give much information on the wiring of the RPM indicator, as it was fairly straightforward. It was just a case of connecting the 12 volt power to the sensor and the display unit. The output from the sensor was also connected to the display unit. You will recall that the 12 volt supply is taken into the lathe panel enclosure from the vfd unit. On the vfd it is derived from the unit's 24 volt supply by connecting a 7812 three terminal regulator between the 24 volts and ground.
Elusive, if you need any help with your project please let me know.
I'm toying with the idea of giving a list here of all the parameters I have set and their values for the Teco E510 vfd on my lathe. I'm not sure if it just wouldn't be rather boring and not especially helpful to others who may have a completely different unit.
I didn't give much information on the wiring of the RPM indicator, as it was fairly straightforward. It was just a case of connecting the 12 volt power to the sensor and the display unit. The output from the sensor was also connected to the display unit. You will recall that the 12 volt supply is taken into the lathe panel enclosure from the vfd unit. On the vfd it is derived from the unit's 24 volt supply by connecting a 7812 three terminal regulator between the 24 volts and ground.
I like your Control Panel a lot, nice work. I was thinking last night about my own panel weather to modify it or create a new one for VFD control I think I will make a new one like you.
For the main Isolator switch it looks like your switching power to VFD, Lamp and Suds Pump direct on the switch, is that the case? The plan I had drawn up so far was to use a contractor to switch everything in bulk back in the VFD enclosure so I just need a single control wire to the Isolator switch at the panel but I'm wondering if this is overkill now looking at yours its simpler and has less components.
Re the Tacho I'm also going to copy this too, nice simple design that should be very useful.
For the main Isolator switch it looks like your switching power to VFD, Lamp and Suds Pump direct on the switch, is that the case? The plan I had drawn up so far was to use a contractor to switch everything in bulk back in the VFD enclosure so I just need a single control wire to the Isolator switch at the panel but I'm wondering if this is overkill now looking at yours its simpler and has less components.
Re the Tacho I'm also going to copy this too, nice simple design that should be very useful.
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Hopefuldave
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're the tacho, I used a frequency meter, same sort of price as the 1 pulse-per-rev tacho modules, and put a gear tooth sensor on one of the spindle gears - if it had been a 60-tooth that would be it, but it's a 70, so I swapped the crystal from 20MHz to 23.3 (7/6 the frequency) to compensate, it's within a few % and reads a lot faster than the tacho modules.
Very nice job on the panel and VFD conversion
Dave H. (the other one)
Very nice job on the panel and VFD conversion
Dave H. (the other one)
Carl Wilson
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Thank you for all the kind comments.
RDR - I seriously considered using the old panel to operate the vfd functions, as I wanted the lathe to remain as original as I could. This would have meant having a separate pendant for the speed pot though.
So in the end I opted to build a new panel but tried to keep it as faithful to the design of the Harrison one as I could. The idea was to have the versatility of the vfd with the same "feel" as the original controls. The Harrison panel didn't have an e-stop button on it so I added one to mine.
When you look at M250's it becomes apparent that Harrison used a variety of different styles of switchgear over the years that the machine was in production. So I didn't feel too bad about building a new one.
The main isolator is exactly the same component as on the original panel, just a brand new one. All the single phase electrics and the vfd are wired through it. The old panel did this so I just kept my version the same.
Dave - I wish I'd thought of that for the tachometer. I like changing the crystal to compensate for the exciter signal being of a different frequency because of the gear teeth. The one I've got works well enough for my purposes so I think I'll just keep it. I want to use the lathe now, it's been idle for what seems a very long time!
There are a few niggly things to put right. One of these is the speed pot - it goes the wrong way! Anti clockwise to increase as it is at the moment. It's simply a case of swapping two wires over. Pedantic? Perhaps, but it makes sense to me.
So far I'm really happy with how it has turned out. I like the forwards and reverse with centre off and the rapid stop I programmed this to have. The idea behind this was to use it for screwcutting up to a shoulder or other feature. Keep the half nut engaged, ease up to the feature, stop on a sixpence and reverse back out. The idea was to have the functionality of a clutch that the 140 has for this type of operation, but do it electronically. I'm going to cut a test screw soon to see if this really can work!
RDR - I seriously considered using the old panel to operate the vfd functions, as I wanted the lathe to remain as original as I could. This would have meant having a separate pendant for the speed pot though.
So in the end I opted to build a new panel but tried to keep it as faithful to the design of the Harrison one as I could. The idea was to have the versatility of the vfd with the same "feel" as the original controls. The Harrison panel didn't have an e-stop button on it so I added one to mine.
When you look at M250's it becomes apparent that Harrison used a variety of different styles of switchgear over the years that the machine was in production. So I didn't feel too bad about building a new one.
The main isolator is exactly the same component as on the original panel, just a brand new one. All the single phase electrics and the vfd are wired through it. The old panel did this so I just kept my version the same.
Dave - I wish I'd thought of that for the tachometer. I like changing the crystal to compensate for the exciter signal being of a different frequency because of the gear teeth. The one I've got works well enough for my purposes so I think I'll just keep it. I want to use the lathe now, it's been idle for what seems a very long time!
There are a few niggly things to put right. One of these is the speed pot - it goes the wrong way! Anti clockwise to increase as it is at the moment. It's simply a case of swapping two wires over. Pedantic? Perhaps, but it makes sense to me.
So far I'm really happy with how it has turned out. I like the forwards and reverse with centre off and the rapid stop I programmed this to have. The idea behind this was to use it for screwcutting up to a shoulder or other feature. Keep the half nut engaged, ease up to the feature, stop on a sixpence and reverse back out. The idea was to have the functionality of a clutch that the 140 has for this type of operation, but do it electronically. I'm going to cut a test screw soon to see if this really can work!
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Thanks Carl for the added colour, I haven't looked at the components on the back of mine in detail its on the todo pile. You made the new panel for the same reason I was thinking I would like to use the original but want the additional items and don't want to hack it about. I cant see any nice spot to add another set of controls, I did think of an arm above the Gearbox where people mount a DRO display but its just more clutter.
Carl Wilson
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That spot is where I thought to have a box with jog buttons and speed control. That or a pendant.
Speaking of a DRO, that is the next thing to be fitted to my lathe!
I have an EMS International one to go on.
Speaking of a DRO, that is the next thing to be fitted to my lathe!
I have an EMS International one to go on.
Carl Wilson
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RDG tools are doing chucks in various sizes with a D1-3 camlock mounting.
slim_boy_fat
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eLuSiVeMiTe
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Lol. Its my challenge.
About time I cut a thread.
