wadkin lathe motor

[wallace]

hello all, I have recently aquired a big old wadkin RS lathe. I'd like some advice on how best to tackle the motor. It is 3 phase 380/420 volt. And I wish to use it on a domestic supply. So what do I need? The spec plate is
Type- KZ3514
Volts- 380/420
Cyc- 50
Ph- 3
hp- 1.5
Amps 2.4
Speed- 960
No.- 4385204
Any advise would be much appreciated
thanks
Mark

 

[flh801978]

If you want to make it variable spped you need an inverter to run it
one that steps up the 240v input to 415v output required for your motor
those are more expensive than the ones that output at 240v
or you could take the motor to bits and remove the star point and bring the wires out so you make it dual voltage
Or buy a new 3 phase motor that already dual voltage
Or buy a single phase motor if you not bothered about variable speed
or a simple 3 phase converter for your existing motor ( expensive)

Ian

 

[NetBlindPaul]

That sounds like an imperial motor, so some tweaks will be needed if you decide to replace it with a modern metric version.
You'll want a foot mount B05 or B35 depending on the room you have.
1.5HP = 1.1kW approx. 960 rpm will be a 6 pole motor in either 80 or 90 frame size probably.
You will need to change the starter also for a 1ph device, a motor of this size will require an overload of around 9A rating.
These can be found here (other suppliers are available) & you would have to satisfy yourself that the IP rating of this unit was suitable for your use, & meets your other requirements, should you choose to use it.:
http://www.tlc-direct.co.uk/Main_Index/Distribution_and_Switchgear_Index/DOL_Starters/index.html
Toy will probably have to run this on a C or d 10 or 16A breaker, it "may" run off a 13A plug & socket, but it "may" not this will depend on mechanical drag on start.
Will check on the availability & spec of motor as soon as I can.

 

[NetBlindPaul]

wallace,
A 1ph 6 pole is available, however, the cost is not nice!
You are looking at the other side of £300 probably plus VAT!
Then you would need to look at whatever mechanical mods are required to fit the motor, possibly mounts, pulley bore/keyway, it may be cheaper to get a new pulley bored & keyed than modify yours.
Keep asking and I'll help as much as I can.

 

[wallace]

Thanks paul, Ian I think I may have to keep the existing motor because the pulley shaft is about 12" long and fits into a bearing on the other side of the lathe.

 

[NetBlindPaul]

wallace,
Is the shaft not coupled to the motor?
If it is then a mod could be done to link the new motor to the old shaft.
Other option is as has been suggested a 1ph to 3ph conversion of some sort.
I'm not familiar with static converters, I know rotary converters, and inverters, as i used to work for an inverter manufacturer on applications & service.
Just be careful with the lecktrickery.
It may pay to swap the control to 240V anyway and then use this to control the inverter if you go down that route.
Check 9fingers paper linked to in this post:
https://www.ukworkshop.co.uk/forums...in-the-home-workshop-updated-iss2-t35143.html

 

[Darren D Breeze]

Hi Wallace, i went through the same thing last year when i bought an RS8 myself, in the end i took the motor to a "motor rewinder" who checked it out and then cut the coil wires which made the additional seperate windings needed , cant remember exactly what he done tbh, he then supplied me with a second hand inverter and wired up a seperate control box with forward/stop/reverse switch, rotary speed control and an emergency stop button. Whole thing was then ready to bolt back onto lathe and plug in and go. Cost was £2-300. Totally happy with my decision to stick with the original motor and just upgrade the controls, I've also removed the leather belt and got a new rubber impregnated one from Tony at http://www.lathes.co.uk its quieter and doesn't suffer from beltslip. Any more info just ask, regards Darren

 

[wallace]

Hello Darren, I would prefer to keep the original motor even if I have to pay a few quid more to use it. I have one of those 1.5hp clarke motors kicking around somewhere, I cant imagine that will have the nuts to do aswell as the old original motor. Darren, does the weight of the motor maintain the tension of the belt?
thanks Mark

 

[Darren D Breeze]

Hello Darren, I would prefer to keep the original motor even if I have to pay a few quid more to use it. I have one of those 1.5hp clarke motors kicking around somewhere, I cant imagine that will have the nuts to do aswell as the old original motor. Darren, does the weight of the motor maintain the tension of the belt?
thanks Mark

Hi Mark, yes the motor and pulley shaft bearing assembly are all on a hinged plate and basically the weight of the plate and motor etc create the tension, there is also a big bolt on the front corner of the hinged plate which can be adjusted to ease the tension by partly supporting the plate, I have mine set up so the bolt is half a turn tightened, approximately! this just eases the tension and works for me, i also use the motor lift pedal to raise the motor and chock under the plate to release the tension completely when im not using the lathe. Just read on another forum about your fun and games shifting the 'Monster/Beast' the motor alone is a 2 -man lift, I agree that your Clarke motor wont match the original, stick with it and get it altered, thats a simple job, basically just chopping into the wiring to form 6-ends from the original 3-ends, star to delta enabling. If i remember i'll take a pic or two of my set up, inside motor wiring box, inverter and remote box, and post on here tomoz evening, it may be of use to you, i was on a tight budget, and dont think i'd change any of my decisions if i had to do it again.
Regards Darren

 

[NetBlindPaul]

As long as your machine is hobby / home use you are probably OK.

The belt tension relying on the motor mass will give you issues with changing the motor end drive design in any significant way.

It is possible to change anything given enough thought & time though!

The rubber type belt is a very good suggestion.

Clarke do not do a 6 pole motor as far as I can tell, so if you fit a 4 pole your drive speeds will be all to pot.

As long as your motor guy can get at the winding ends then it is possible to convert the motor to an inverter drive, this will then give you infinitely variable speed.

See 9fingers sticky on motors for a little more info.

Just remember that if you are using the machine as part of a business undertaking then you have statutory legislation to contend with!

 

[OldWood]

Hi Wallace
You don't say where you are, but I would back up the motor rewire suggestion. Certainly if you can get a package for £200-300 that is a good deal. One particular asset of induction motors is that they are mechanically so simple that they are a dawdle to take apart - apart from possible the weight factor that is !!

It is pretty easy to whip off the back bearing plate and get access to the wiring so that it can be changed from 415vac star connection, where all the coils have one common junction point and the other ends of the coils are connected to the 3 phases, to 240vac delta connection where the coils are connected like the sides of an equilateral triangle with the phases connected to the three corners. It shouldn't be more than a 2 hour job for an experienced guy.

You'll be looking for a 2hp or 1.5kw inverter plus a control box to give you start stop, reverse and variable speed - allow ~£250. You will also require some intelligence to work out how the instruction manual works and how to set the electronics up to give remote control, emergency off, run and run down times, etc.

Rob

 

[wallace]

Hi Rob, I'm in Durham. I found a guy local who says he can provide me with an inverter which will work with my motor as it is 415v and not dual voltage. When I asked about variable speed and being able to alter the ramp up speed. He said it will do all of this for the princely sum of £200. Does this seem a bit cheap or have I just got a decent deal?
thanks
Mark

 

[OldWood]

With all due respect I think that sounds a bit on the cheap side if it is a new unit - see if you can get the manufacturer and part number from him and I'll have a look at the spec.

For price guidance go to Ebay and dial this in "inverter phase 415v -(rotary)", and you will see why I'm a bit suspicious about how cheap that is.

You are in a trade off area between how much motor modification costs and the additional cost of a 415v inverter.

Rob

 

[wallace]

Hi all, I spoke to the chap this morning and he said it will be an inverter and not a converter and has a display with buttons to programme, and wont need to be hooked upto a laptop or control unit. He said it will change 240 in supply to 415 without haveing a dual voltage motor. Also the make would be Hitachi or Omron but did not have the spec details.

 

[OldWood]

Hi Wallace - sounds a good deal, go for it. The one thing you will now want to look for is a wired remote control pad for the lathe working position - you really do not want to have to control the speed etc by pressing the buttons on the inverter, nor do you want to have to switch it on and off there. The inverter should be on the wall away from all the dust from the turning. Try Ebay if your source doesn't do such a thing

The other factor is that digital (ie push button) adjustment of the speed is a pain (is slow and irritating) - it wants to be done with a knob like a radio volume control so you get instant response. If you are concerned about the actual revs you either have to look for a suitable tachometer, or set up a chart on the wall that relates the revs to the frequency the inverter is putting out (the inverter will not show revs as it doesn't know what sort of motor it is driving, but it will show frequency). But then turning speed is a matter of feel and although I have such a chart, I rarely use it.

The other thing you will need to consider is an emergency off button, which again can be wired into the inverter box. The box can be programmed to ramp the motor down more quickly for emergency off.

I hope you are not to much of a technophobe as setting these inverters up is a bit of a learning curve. In all likelihood the manual will be downloadable so if you need it I, or someone, should be able to help.

Rob

 

[CHJ]

Hi all, I spoke to the chap this morning and he said it will be an inverter and not a converter and has a display with buttons to programme, and wont need to be hooked upto a laptop or control unit. He said it will change 240 in supply to 415 without haveing a dual voltage motor. Also the make would be Hitachi or Omron but did not have the spec details.

Ask the guy if it would still be guarantied by the manufacturer, and does the unit meet the specifications for connection to local domestic mains supplies. I.E. how well are any harmonics it generates back into the supplies controlled. The actual Part No. of the device can be checked against the manufactures site to confirm specification.

There were some units around (240volt Pt. no's.) with what one might call after market mods, not approved by the original manufacturer and can cause harmonics problems on local supplies, something your local energy supplier might not be too happy about if it receives complaints.

 

[CHJ]

......I hope you are not to much of a technophobe as setting these inverters up is a bit of a learning curve. In all likelihood the manual will be downloadable so if you need it I, or someone, should be able to help.

Rob

I would think many of the current generation work fine out of the box, the default settings and the units 'intelegent' response to the motor it finds itself connect to will be fine for wood lathe purposes, digging into increased braking responce and adding any required load resistors to absorb the power generated or speed change ramps is fine if you really must but most folks need never bother.

 

[kirkpoore1]

Here is a thread on the OWWM site about restoring a similar lathe:
http://owwm.org/viewtopic.php?f=1&t=70658

The author is Ottawa, and is signed up here (userid is tool613, I think) though doesn't visit very often.

The standard answer on the OWWM site would be to buy a transformer to boost your voltage from 240V to 415V, then get a VFD (variable frequency device) to create the 3ph power from the single phase input. The VFD would also give you the ability to use a remote pushbutton start (in fact, you could re-use the existing buttons if you wanted), plus speed changes in addition to changing speed via moving the belt. (Note that the VFD and the inverter that Rob is talking about may be the same thing under a different name--this is one area of the local lingo that I haven't translated yet.) I also realize that you have different electrical regulations which may preclude this approach.

If a motor shop can convert the motor to dual voltage with a few wiring changes, I think that would be a good approach. Otherwise, I wouldn't mess with the motor wiring itself. Better to rig up a system to feed the motor what it needs.

Kirk

 

[OldWood]

......I hope you are not to much of a technophobe as setting these inverters up is a bit of a learning curve. In all likelihood the manual will be downloadable so if you need it I, or someone, should be able to help.

Rob

I would think many of the current generation work fine out of the box, the default settings and the units 'intelegent' response to the motor it finds itself connect to will be fine for wood lathe purposes, digging into increased braking responce and adding any required load resistors to absorb the power generated or speed change ramps is fine if you really must but most folks need never bother.

Not my experience Chas, and I've set up 4 within the last 2 years. Straight out of box, yes, if you are not using remote control, but the moment you do that it's a different game and really control on the lathe is essential in my opinion, plus you really do have to have an emergency stop facility, even an amateur !!

Rob

 

[CHJ]

Not my experience Chas, and I've set up 4 within the last 2 years. Straight out of box, yes, if you are not using remote control, but the moment you do that it's a different game and really control on the lathe is essential in my opinion, plus you really do have to have an emergency stop facility, even an amateur !!

Rob

Yes but on the ones i've used it's external wiring not needing to re-program the microcode in the device, which is the point I was trying to make, obviously not clearly enough.
Anyone seeing a manufacturers manual for such a device for the first time could easily baulk at all the technical information it contained.

Speed control is usually achieved by wiring a potentiometer between three terminals.

Likewise direction of rotation is at most a two way switch between three terminals.

An emergency stop switch is just required to break the connection in the mains feed to the NVR switch feeding the invertor, assuming that the NVR switch itself is not the type already fitted with a large 'Hit' switch.