Colchester Bantam and VDF, help please

[acobParticipant @acob]

Help with converting Colchester Bantam 1600 to VFD with pre wired motor

Apologies, I know this may have been asked many times before but I would be grateful if I could get support or contact someone who has experience of VFD conversion. My lathe currently has no motor but is a 3 phase. Thanks, apologies once again, but I would be grateful if anyone can help

 

[John HaineParticipant @johnhaine32865]

The simple but more expensive route would be to contact Newton Tesla and ask their advice. I bought a vfd/motor package from them for my Super 7 and it was straightforward to fit and works very well. I have also bought separate motors and VFDs and fitted them, as I’m an electrical engineer I had no qualms doing this. For me the advantage of the NT route for the myford was the knowledge that the motor would fit without problems.

https://www.lathespeedcontrol.com/

[Simon Williams 3Participant @simonwilliams3]

I have a Bantam 2000 I converted to single phase, but I reworked the internal control panel to keep the functions of the controls exactly as original. Initially I fitted a single phase  single speed motor but didn’t like it, so revised my plan to use a VFD controlled three phase motor, again single speed.  Knowing what I know now I could have kept the original three phase two speed motor but I didn’t know that at the time.

I fitted a 4 pole motor and drove it at 50 Hz for the low speed range, then doubled the frequency to 100 Hz for the high speeds.  Presently it has a 1.1 KW motor fitted which hasn’t quite got enough oomph to power the 2000 rpm gear, but I just don’t use this speed and don’t miss it.

Whereabouts are you?  If you can face a trip to West Gloucestershire you’re welcome to come and have a play, and discuss the mod’s I made to the original electrics face to face.  with (if I can find them) drawings of the revised circuit schematic.

In the meanwhile what are you planning?  You say the lathe is three phase, do you have a three phase supply from which to power it?  Or are we talking single phase supply with a vfd deriving three phase for the lathe motor?  Variable speed is kind of cute for a geared head lathe but wholly unnecessary except if you want to machine something at a lower speed than the makers imagined.  Bottom speed normally is about 40 rpm; this feels quite fast when you’ve got something big in the chuck.

[acobParticipant @acob]

Hi Simon

Thank you for your kind reply. I only have single phase. I have a 1976 Colchester Bantam 1600 with no motor. It has a 3 phase supply cable that has just been cut through. I was considering something like a Newton Tesla or something similar that was already wired, so all I had to do is get the right 3 phase motor with the correct spindle and mount the controls on the front (VFD to single phase) I would lose the cover, and foot switch micro switches, unless somehow they were wired in, otherwise I would try and fit a second mushroom stop switch for safety. Does that make any sense?

I am only in Wiltshire

Best

[Simon Williams 3Participant @simonwilliams3]

Eminently.

As you suggest, next stop is a conversation with someone (Newton Tesla seem well thought of) for a prewired and pre-configured motor + VFD + pendant controls.

Motor should be straightforward with a standard foot mount frame and shaft size with a keyway, buy a taperlock pully and bush to suit.  Can’t help with the right PCD for the pulley as mine is the higher speed version but I’m sure others will assist.  Otherwise a bit of measuring and arithmetic from the size of the gearbox pulley should reveal what size pulley to buy.  Oh, and you’ll need a drive belt (I think only one) as well.  Don’t forget that the drive ratio of the pulleys uses their PCD not OD.  PCD = OD – 15 mm is a good guess for A section belts.

You have realised there is more to incorporating the foot brake switch, the rear cover switch and the fwd/stop/rev lever rhs of the saddle, but that’s the price you pay for a minimalist installation.  I think the pendant controls will include an E Stop button, maybe that’s for discussion with the supplier.  If you want to use some or all of these fitted features (the fwd/off/rev switch is handy but a bit complicated to re-incorporate as it is a multipole cam switch) do come back to us.

Not 100 % sure but I think I’ve got a spare motor in stock if you get stuck, but NT will oblige and better for you to have a stand alone complete system you can see running under warranty and keep away from buying separate bits to cobble together.  If needs must Machine Mart do stand alone electric motors.

I’m just the other side of the old Severn Bridge from you (Ross on Wye near enough) so a visit either way is doable.

[acobParticipant @acob]

Many thanks, I have had a conversation with Newton Tesla, who were very helpful, and I asked if it would be possible to configure the controls to have an extra emergency off button which I can position (probably on the floor) the foot bar is also mechanical as well as electrical so if NT comes good then only thing I will really lose is the micro switch on the gear cover. Fingers crossed!

[Richard BParticipant @richardb44403]

I also have a Newton Tesla pre wired VFD on my Denford Viceroy.

They supplied the motor and new slim line control panel to mount on the lathe front – replacing the original.

I have retained the original emergency foot switch but not the gear cover switches. They advised how to connect it, however similar to the Emergency switch supplied on the control panel it should not be operated regularly – emergency only.

Very low motor speeds should only be used for shorter periods. I’ve made up this speed/pully chart attached.

It has transformed the lathe especially as it was previously a little underpowered and the variable speed control means often I don’t need to change pulleys.

I  can confirm they were very helpful throughout and I can highly recommend the system I bought quite a few years ago now !

I’m in North Somerset if you want to view.

[acobParticipant @acob]

Thanks Richard

What a fantastic forum, brilliant to get so much expert support. Thank you!

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