Keighley Lifts (Denham Junior) lathe

[Frans LateganParticipant @franslategan]

Hello everybody,

I just found this old Keighley lifts lathe and I need to clean it up and get it working.

My first problem: I only have an off-grid solar power system on the farm with (SMILE5) 5kW inverter (220V, single phase, 20A output) and 11.4kWh Li-ion batteries. When I start the lathe it kicks my power off, so either the motor is too big, or it is faulty.

Do you guys think that I can replace the motor with a single phase motor, or should I rather look at a 3-phase with a VSD inverter. I have a 2.2kW, 3-phase inverter, but I will need to find a motor.

I also have a couple of single phase motors: a 750W and a 1.1kW.

Does anybody know where I can download a manual for this lathe?

Thank you

[Frans LateganParticipant @franslategan]

[not done it yetParticipant @notdoneityet]

What does the motor plate say? Start there.

Is the motor running free?

Is the lathe turning easily?

[Frans LateganParticipant @franslategan]

The motor does not have a plate anymore.

The motor runs when I plug it into the generator, but I do not want to start the generator every time I want to work on the lathe.

Than you

[egaParticipant @ega]

Tony at lathes.co.uk has "literature".

[Michael GilliganParticipant @michaelgilligan61133]

Frans

Not a manual, but it looks like there is a lot of good information here: **LINK**

http://www.modeng.johnbaguley.info/equipment/Denham%20Lathe/Denham%20Lathe.htm

MichaelG.

[Roger ClarkParticipant @rogerclark]

Frans,

Look in your inbox, I've sent you a pm re the manual.

Regards

Roger

[OldironParticipant @oldiron]

Mmmm Just came from your 1st post. The 1.1Kw single phase motor might be a good starting point.

regards

[Frans LateganParticipant @franslategan]

Thank you all for your help.

Thanks Roger. I sent you an email.

I will first try the 1.1kW motor.

[not done it yetParticipant @notdoneityet]

What size is the generator? Its output and motor starting capacity may well depend on the type of generator (Armature wound with rolled steel magnet frame or AVR controlled stator wound machine).

If it is only a 3/4 HP motor, it would be drawing about a kW at full power (assuming 67% efficiency). That might well be exceeded by 3 or 4 times at initial start up ,even on no load (inrush current at zero revs), so I would have thought it should start on your inverter supply.

Possibly your inverter shuts down as the initial surge exceeds its rating (some inverters are rated at surge, not continuous power) or your battery voltage drops too low, for a moment, and shuts down the system?

I can run my one horse power lathe from my chinese 2kW inverter with a 5kWh LiPo battery and I expect my 1.2HP motor will also start with no problem. But my motors are three phase and run through inverters, so they are programmed for soft starts.

220V @ 20A is only 4.4kW.

My guess is that it should work OK if you install a three phase motor with VFD. A 2.2kW inverter would work but the operating safety limits may not be programmable for such an over-sized inverter.

[Dave HalfordParticipant @davehalford22513]

Try the 1.1Kw motor before you bother to bolt it on the lathe. The solar inverter might be a bit touchy on the start up draw.

[Clive FosterParticipant @clivefoster55965]

Yep, start up draw with the standard motor is a likely issue.

Inverters / VFDs are good a at controlling the start up surges inevitable when simply switching a motor on.

Indeed one of the selling points of my favourite, for simple installations, Eaton DE series inverter / vfd boxes its that they essentially eliminate start up surge current draw. I suspect that the inverter itself has a restricted input current as there is a definite pause between switch on and the motor starting to move. But the DE series is intended as a modern, intelligent, replacement for the old style contactor. Basically switch'n go. The manual gives connections for one, two or three speeds in forwards and reverse as heavy hints to its intended market. Potentiometer connections are there too if you want to twiddle a knob as there is a full blown VFD inside the plain grey case, no spiffy display or buttons, but getting at all the functions needs the programming widget.

If you do go inverter and three phase talk to Inverter Drive Supermarket, or similar well respected supplier, as there are considerable details involved in getting the best one for your situation.

Clive

[Frans LateganParticipant @franslategan]

Thank you for all the replies, I appreciate your help.

So, I removed the drive belt to test the motor alone- it still kicks my power off without any load.

I tested my 1.1kW motor and it starts and runs from my solar system. I just hope it will still start with a load. I guess I will have to find another pulley for it. The plate on the 1.1kW motor says 1360 RPM, 7.4A and it has a 125mm pulley on.

The pulley on the headstock is 160mm and 60mm on the old motor. On the headstock pulley cover there is a brass plate that says 550 RPM. So with the 125mm pulley the headstock pulley will run 1062 RPM instead of 550. So I will need a 65mm pulley on the motor.

[Frans LateganParticipant @franslategan]

OK gentlemen, I have good news:

I put the 750w single phase motor on the lathe and it runs without kicking my power off. Now I must just learn how to operate the lathe.

Thank you for all you inputs and advice, I appreciate it.

[Frans LateganParticipant @franslategan]

I want to remove the saddle, apron and gearbox to clean everything. Is there anybody who has stripped one of these lathes who can tell me where to start and in what sequence I should remove the parts?

Thank you

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