Looking for help for vfd for Boxford

Moper361

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Hello
Looking for help on basic ideas for suitable vfd to fit to my new second hand boxford aud.Currently its 3 phase were it is but plan to move it in the future to were i only have 240volt single phase .The lathe still has original wiring and switches in it .
The safety switches for backgear lockout .cabinate door. gear train cover and estop run of 110volt through a magnetic contactor .

I would like to still keep all these switches and safety devices in use when i change to VFD i would also like to utalise original forward off reverse switch .
What VFD would allow me to utalise all these and suit my electric motor .
I would also like to fit a foot pedal that you could depress when threading at very low speed obviuosly due to scew on chuck that would stop the motor and also brake at the same time .
I am far from being an electricial but would appreciate if i could get advice on a vfd that would cover this and ideas on how to wire it all up to work have attached best picture of motor plate and a basic wiring diagram that originally came with lathe with manual .it only shows basic motor wiring .20190721_141832.jpg20190721_141915.jpgPART_1562897426681.jpegPART_1562897816653.jpeg20190721_141824.jpg
 
nearly all VFDs should meet your needs. As you are outside USA, could you pick out a few possible selections and we can make sure they will work for you. I used this vendor recently

What size is your spindle motor? get a VFD a bit oversize.

its going to take a few pictures and a bit of back and forth with questions and answers to help with the wiring.
 
nearly all VFDs should meet your needs. As you are outside USA, could you pick out a few possible selections and we can make sure they will work for you. I used this vendor recently

What size if your spindle motor? get a VFD a bit oversize.
The motor is 750 watt so guess thats 3/4 hp
I live in thailand and was planning on buying vfd and just take it back to australia when i travel there again .
I can lay my hand on mitsubishi Fr-d740s 1.5 kw pretty easily .but will take more of a look when im back there next week and see what else is available
 
I see you got pics up. they were not there when I first responded. doesn't look hard at all to install a VFD. 750 watt is one hp.

That Mitsubishi would be a real good choice. Not sure the HY I showed supports a VFD brake resistor. The mit surely would. You might want that upgrade on a lathe
 
OK been looking it all over a bit.

My approach would be to first re wire your Estop circuit to just bring in that contactor. remove the forward reverse stuff and disconnect your forward reverse switches.

install the VFD and get it to run with the VFD control panel. confirm estop drops it out and reset brings it back in.

Then install the forward reverse switches to the VFD.

You will almost certainly want to install a potentiometer to control speed.

I'd suggest placing the VFD inside your existing enclosure if it will fit. A remote wire to move the VFD control panel to visible spot is a real nice option.

Just an outline here for your comment.
let others chime in here.
 
I see you got pics up. they were not there when I first responded. doesn't look hard at all to install a VFD. 750 watt is one hp.

That Mitsubishi would be a real good choice. Not sure the HY I showed supports a VFD brake resistor. The mit surely would. You might want that upgrade on a lathe
Yes got the pics up .after looking at the pics of the vfd you sent the link for i have a basic understanding from the diagram .

First question i would ask is if i wanted to fit a foot switch for braking were would this be wired in ? Or would it be wired in in series with the resistor ?i would like the brake to only be used when threading at low speeds not for general turning at higher rpm example if bedal depressed lathe stops and brakes


Second question would the estop and power on off with light be wired in on the single phase lines supplying the vfd ?

Forward reverse common is straight foward

The safety switches for guards etc would they be wired in series and go common to ?

Yes a foot brake just for threading would be a great upgrade
 
OK been looking it all over a bit.

My approach would be to first re wire your Estop circuit to just bring in that contactor. remove the forward reverse stuff and disconnect your forward reverse switches.

install the VFD and get it to run with the VFD control panel. confirm estop drops it out and reset brings it back in.

Then install the forward reverse switches to the VFD.

You will almost certainly want to install a potentiometer to control speed.

I'd suggest placing the VFD inside your existing enclosure if it will fit. A remote wire to move the VFD control panel to visible spot is a real nice option.

Just an outline here for your comment.
let others chime in here.
Just got this message after sending my questions lol
Yes i was planning to fit vfd in original enclosure if i can after some other unused items are removed as from what i understand is magnetic contactor would be redundant .
 
We will use one contactor to go through your estop and all your safety switches. Anything here opens, it drops the contactor.

contactor then goes to the VFD.

Foot switch, no problem. just describe exactly how it should work for the operator. Also does the operator turn the spindle forward/stop reverse with the panel pic above?

lets make sure the VFD you select support moving the control panel/pad and a brake resistor.
 
Re read yet again.

I think you want a foot switch to quick stop the lathe?

That means forward/stop/reverse push buttons would work better. Not all VFDs support this, but many do. lets looks for that ability before your purchase.
 
We will use one contactor to go through your estop and all your safety switches. Anything here opens, it drops the contactor.

contactor then goes to the VFD.

Foot switch, no problem. just describe exactly how it should work for the operator. Also does the operator turn the spindle forward/stop reverse with the panel pic above?

lets make sure the VFD you select support moving the control panel/pad and a brake resistor.
Okay I understand yes the estop on off switch and safety switches can be wired through magnetic contractor to supply single phase to VFD .

The foot switch i only want to use it to Brake the motor when threading or in an absolute emergency IE if I got caught up in work piece or chuck .It is a threaded chuckand can come undone if break is applied at higher rpm .
Basically during threading operations you would press the pedal to stop and brake the motor .for normal machining or turning I would not Italian the pedal .i would just turn the forward reverse switch to off position .

Normal operation the forward reverse switch would be switched to either forward or reverse then the green button would be pushed to start the motor in direction of selected rotation .Then the forward reverse switch would be switched to off when you want spindle
Re read yet again.

I think you want a foot switch to quick stop the lathe?

That means forward/stop/reverse push buttons would work better. Not all VFDs support this, but many do. lets looks for that ability before your purchase.
Yes i only want foot stop to quick stop lathe when threading

For normal use i would use forward reverse switch without brake to stop lathe
 
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