Changing the motor in Drill press

[Ian PParticipant @ianp]

There have been a few mentions in this thread regarding the unsuitability of a drilling machine for milling purposes.

The OP made no mention of wanting to use the drill for milling purposes, he just asked a straightforward question about changing a motor. I think that all that is happening now is that the OP will get more and more confused.

Ian P

[SillyOldDufferModerator @sillyoldduffer]

Posted by Andrew David on 10/01/2023 07:23:03:

This is what i am thinking about VFD wiring . Any thoughts most welcome. Thanks

I vote for Plan A. The problem with the relay is it's unnecessary (I think), and adds a potential source of trouble. Either the relay fails, stopping the VFD, or the contacts stick, failing to stop the VFD in an emergency. I see relays as useful for providing isolation, not needed here, and/or, allowing small switches to operate a big switch that has to manage a lot of power. VFD control switching is electronic, typically 12 or 5V at a few milliamperes, making relays superfluous.

A point about jargon may help. Folk with a background in signal switching mostly call these devices "relays". Those with a background in power switching usually call them "contactors".

The hard part of setting up a VFD is usually configuring it, rather than the wiring. Inside the box is a mass of sophisticated functionality, which the user can use to adjust dozens of factors like logic sense and voltages, whether or not a pendant is used. They can also be parametrised to adjust soft-start characteristics, optimised to suit a particular motor, or support advance motor control features. Manuals can run to hundreds of pages of gobbledygook. Most are configured with a plug-in calculator like device, others with a computer interface.

When VFDs first appeared, they were high-end devices sold to industry, who either had them pre-programmed to a specification, or sent someone on a training course. The manuals at this stage were for expert reference, not simple How To Guides. The full manual of a VFD is still intimidating, but the good news is that most ordinary VFDs now work out of the box. They come sensibly pre-configured, and are likely to 'just work'. And if tweaks are necessary, they're likely to be straightforward, and explained in a much simplified get you started guide.

There's a high chance of success, only risk being forced into the deep manual because the defaults are unsuitable. One fairly common problem is the chap who accidentally changes an important setting due to inexperience, and can only fix it by understanding a difficult manual! Another is buying second-hand and finding nothing works because the previous owner specially configured it, and there's no manual. Last case is buying a sooper-dooper high-end VFD, and discovering it assumes installers are fully trained, must be configured from scratch, and the manual is an inch thick…

Dave

[Dave HalfordParticipant @davehalford22513]

Posted by Ian P on 10/01/2023 10:13:22:

There have been a few mentions in this thread regarding the unsuitability of a drilling machine for milling purposes.

The OP made no mention of wanting to use the drill for milling purposes, he just asked a straightforward question about changing a motor. I think that all that is happening now is that the OP will get more and more confused.

Ian P

Indeed The op states WOOD. Admittedly it's not often we get someone from the dark side posting, but even I know that a basic milling machine for wood is called a router and commonly spins a lot faster than our milling cutters.

Andrew,

On picking your belt speed try to keep the motor speed fairly close to the plated 50hz speed as the motor fan is not very effective at significantly lower speeds. You may also need more power for large forstner type bits or hole saws if you.

[john fletcher 1Participant @johnfletcher1]

Ay up Dave, in my day relays frequently controlled contactors and a timers was a small lead screw slowly pulled down by an energised coil, but retarded via a paddle in container to give the timing. No of that electron stuff. John

[Mike HurleyParticipant @mikehurley60381]

To be fair to many who have responded, they tried to be helpful to someone admitting to be a bit of an engineering novice. Perhaps the wording originally was confusing as I quite clearly read the drift to be ' I'm into woodworking and have kit, but am interested in getting into engineering and I want to modify my drill….. ' so understandably some confusion might have occured, if so, apologies.

[Andrew DavidParticipant @andrewdavid60356]

Posted by Ian P on 10/01/2023 10:13:22:

There have been a few mentions in this thread regarding the unsuitability of a drilling machine for milling purposes.

The OP made no mention of wanting to use the drill for milling purposes, he just asked a straightforward question about changing a motor. I think that all that is happening now is that the OP will get more and more confused.

Ian P

Correct. Thanks Ian

I never wanted to convert my drill press to a milling machine. If I was not clear about that, sorry for that.

All I wanted a variable speed control for ease of use. Period!

Andrew

[Andrew DavidParticipant @andrewdavid60356]

I appreciate all your inputs and learning a lot as I prod along.

Andrew.

[Andrew DavidParticipant @andrewdavid60356]

Posted by SillyOldDuffer on 10/01/2023 10:37:53:

Posted by Andrew David on 10/01/2023 07:23:03:

This is what i am thinking about VFD wiring . Any thoughts most welcome. Thanks

I vote for Plan A. The problem with the relay is it's unnecessary (I think), and adds a potential source of trouble. Either the relay fails, stopping the VFD, or the contacts stick, failing to stop the VFD in an emergency. I see relays as useful for providing isolation, not needed here, and/or, allowing small switches to operate a big switch that has to manage a lot of power. VFD control switching is electronic, typically 12 or 5V at a few milliamperes, making relays superfluous.

A point about jargon may help. Folk with a background in signal switching mostly call these devices "relays". Those with a background in power switching usually call them "contactors".

The hard part of setting up a VFD is usually configuring it, rather than the wiring. Inside the box is a mass of sophisticated functionality, which the user can use to adjust dozens of factors like logic sense and voltages, whether or not a pendant is used. They can also be parametrised to adjust soft-start characteristics, optimised to suit a particular motor, or support advance motor control features. Manuals can run to hundreds of pages of gobbledygook. Most are configured with a plug-in calculator like device, others with a computer interface.

When VFDs first appeared, they were high-end devices sold to industry, who either had them pre-programmed to a specification, or sent someone on a training course. The manuals at this stage were for expert reference, not simple How To Guides. The full manual of a VFD is still intimidating, but the good news is that most ordinary VFDs now work out of the box. They come sensibly pre-configured, and are likely to 'just work'. And if tweaks are necessary, they're likely to be straightforward, and explained in a much simplified get you started guide.

There's a high chance of success, only risk being forced into the deep manual because the defaults are unsuitable. One fairly common problem is the chap who accidentally changes an important setting due to inexperience, and can only fix it by understanding a difficult manual! Another is buying second-hand and finding nothing works because the previous owner specially configured it, and there's no manual. Last case is buying a sooper-dooper high-end VFD, and discovering it assumes installers are fully trained, must be configured from scratch, and the manual is an inch thick…

Dave

Hi Dave, one question , what happens in case of power failure during operation. When the power comes back, will the VFD power the motor from the pre power failure setup. Or, should VFD be switched on again to run the motor?

Thanks

Andrew

[Andrew DavidParticipant @andrewdavid60356]

Posted by Andrew David on 10/01/2023 14:40:20:

Posted by SillyOldDuffer on 10/01/2023 10:37:53:

Posted by Andrew David on 10/01/2023 07:23:03:

This is what i am thinking about VFD wiring . Any thoughts most welcome. Thanks

I vote for Plan A. The problem with the relay is it's unnecessary (I think), and adds a potential source of trouble. Either the relay fails, stopping the VFD, or the contacts stick, failing to stop the VFD in an emergency. I see relays as useful for providing isolation, not needed here, and/or, allowing small switches to operate a big switch that has to manage a lot of power. VFD control switching is electronic, typically 12 or 5V at a few milliamperes, making relays superfluous.

A point about jargon may help. Folk with a background in signal switching mostly call these devices "relays". Those with a background in power switching usually call them "contactors".

The hard part of setting up a VFD is usually configuring it, rather than the wiring. Inside the box is a mass of sophisticated functionality, which the user can use to adjust dozens of factors like logic sense and voltages, whether or not a pendant is used. They can also be parametrised to adjust soft-start characteristics, optimised to suit a particular motor, or support advance motor control features. Manuals can run to hundreds of pages of gobbledygook. Most are configured with a plug-in calculator like device, others with a computer interface.

When VFDs first appeared, they were high-end devices sold to industry, who either had them pre-programmed to a specification, or sent someone on a training course. The manuals at this stage were for expert reference, not simple How To Guides. The full manual of a VFD is still intimidating, but the good news is that most ordinary VFDs now work out of the box. They come sensibly pre-configured, and are likely to 'just work'. And if tweaks are necessary, they're likely to be straightforward, and explained in a much simplified get you started guide.

There's a high chance of success, only risk being forced into the deep manual because the defaults are unsuitable. One fairly common problem is the chap who accidentally changes an important setting due to inexperience, and can only fix it by understanding a difficult manual! Another is buying second-hand and finding nothing works because the previous owner specially configured it, and there's no manual. Last case is buying a sooper-dooper high-end VFD, and discovering it assumes installers are fully trained, must be configured from scratch, and the manual is an inch thick…

Dave

Hi Dave, one question , what happens in case of power failure during operation. When the power comes back, will the VFD power the motor from the pre power failure setup. Or, should VFD be switched on again to run the motor?

Thanks

Andrew

If i chose Plan A that is!

[Ian PParticipant @ianp]

My VFD's are mostly as your plan A but instead of a (two position) F/R switch, I have a toggle switch with a centre off position (so no need for stop/start buttons) On the drilling machine I can reach easily the switch with the same hand holding the downfeed lever.

I use the drill for tapping threads (M2 to M14) and the ability to reverse is a godsend.

I can also reach the speed control potentiometer (to which I have fitted a very extended pointer (just a long grubscrew actually) which means I can change speed by fingertip without having to grip the knob.

I strongly suggest that you fit a remote potentiometer rather than using the up/down buttons on the VFD itself which in my experience carry out their intended purpose but are nowhere near as ergonomic as a potentiometer.

Ian P

P.S. I'm sure Dave will answer, but VFD's are usually set up so that the motor will not restart after cutting the mains power .

Edited By Ian P on 10/01/2023 15:13:23

[Andrew DavidParticipant @andrewdavid60356]

Posted by Ian P on 10/01/2023 15:10:39:

My VFD's are mostly as your plan A but instead of a (two position) F/R switch, I have a toggle switch with a centre off position (so no need for stop/start buttons) On the drilling machine I can reach easily the switch with the same hand holding the downfeed lever.

I use the drill for tapping threads (M2 to M14) and the ability to reverse is a godsend.

I can also reach the speed control potentiometer (to which I have fitted a very extended pointer (just a long grubscrew actually) which means I can change speed by fingertip without having to grip the knob.

I strongly suggest that you fit a remote potentiometer rather than using the up/down buttons on the VFD itself which in my experience carry out their intended purpose but are nowhere near as ergonomic as a potentiometer.

Ian P

P.S. I'm sure Dave will answer, but VFD's are usually set up so that the motor will not restart after cutting the mains power .

Edited By Ian P on 10/01/2023 15:13:23

Hi Ian,

Have you ever tried to turn the main power off while your drill press is running and turning it back on? This will answer if the VFD comes back on and run the motor or not?

Logically thinking, if the VFD power is interrupted and your toggle switch is in the on position and you left it that way, when the power comes back, the VFD will get the power and the toggle switch will keep the connection on , and the motor should power up. Unless there is a contactor upstream to VFD, in that case we will need a power on off button for the contactor. Hmmm!

I hope someone will be able to clarify this conundrum.

Cheers.

[Ian PParticipant @ianp]

Andrew, its not really a conundrum. I cannot say all, but most VFDs act in a No-Volt method.

Some can be programmed to restart the motor after power fail but by default most do not 'read' the switch positions at power up so even if the RUN switch is closed tha motor will not start. (until the switch is cycled off first)

Ian P

 

Edited By Ian P on 10/01/2023 16:02:03

[Andrew DavidParticipant @andrewdavid60356]

Posted by Ian P on 10/01/2023 16:00:29:

Andrew, its not really a conundrum. I cannot say all, but most VFDs act in a No-Volt method.

Some can be programmed to restart the motor after power fail but by default most do not 'read' the switch positions at power up so even if the RUN switch is closed tha motor will not start. (until the switch is cycled off first)

Ian P

Edited By Ian P on 10/01/2023 16:02:03

Makes sense. Thanks.

[old martParticipant @oldmart]

Posted by Ian P on 09/01/2023 22:03:26:

Hopper, how can a grubscrew bearing on the bottom of a keyway recess damage the shaft?

Ian P

This is my solution to grubscrews and keyways. The key was milled down to me just below the shaft OD and the grubscrews were screwed in tight when the pulley was aligned. Then the key was removed, using thesmall threaded hole to jack it out of the keyway and holes made for the tips of the grubscrewsin line with the witness marks. No damage to the shaft and plenty of security.

[Author]

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