WARCO Major Motor upgrade???

[BevelParticipant @bevel]

Hi All,

I have an old WARCO Major mill that has been absolutely brilliant from day I got it and it was well used up to that point. Your all familiar with the belt driven set-up and as you know it can be a pain to change speeds whilst performing repetitive ops. Seriously thinking about changing the motor to 3ph with VFD giving me the option of adjustable speed on a dial rather than reaching for my stool every 10 mins lol.

I would appreciate any advice and info you may have, things like best place to get the doings, what type of fitting I need is it b3, b14 etc and maybe your own experience with what I’m suggesting please.

I know there’s an absolute wealth of knowledge on this forum so I welcome your input guys and gals alike. I thank you all in advance and please don’t be offended if I take a liitle while to respond as I’m currently still working and have limited access to my PC whilst there.

Cheers All

[not done it yetParticipant @notdoneityet]

Can’t comment on specifics for your mill, but I can say that my machines, which are equipped to run on 3 phase with VFDs, are considered a much better option.  While extremes of speed range might/can be better served with the mechanical speed control, the VFD often allows mid range mechanical speed setting to be left unchanged.

[John HaineParticipant @johnhaine32865]

I changed the motor on my VMB from the original single phase induction to 3 phase, having scored a couple of 0.75HP 3ph motors on eBay.  The motor fitting was quite different (though still foot mounted) so had to do quite a lot of drilling and threading on the motor plate.  I’m not familiar with the pulley system on the Major, but if like the VMB it had an intermediate pulley and 2 belts I can imagine the pain!  What I did in the end was to ditch the centre pulley and (with a suitable bush loctited in) use that on the new motor as it was pretty well the inverse of the spindle pulley.  And I use a red link belt as I happened to have a spare metre or so of it.  I was really pleased with the result, and the macine is much more usable, right down to being able to do powered tapping at low speed.  As to choice of motor and inverter, I suggest to ask Newton Tesla for their recommendation.  Though I did the mill myself for my Super 7 I bought their package and it fitted with no problems and transformed the machine.

[DiogenesParticipant @diogenes]

I’ve dealt with this supplier and found them helpful & okay, with a decent range that may cover some of the wants of those who have an ‘arm length to pocket depth’ ratio not catered for by NT.

https://inverterdrive.com/

..as far as motor mounts go, normal fitment is usually B3 Foot Mount – however I think frame sizes (and maybe other details) differ between models / variants / years so you should measure the distance between the holes in the foot, the shaft diameter, and how far it sticks out, etc. just to be sure. Specs., frame size charts etc. should be easily found on the ‘net.

I’d also recommend retaining some mechanical reduction in the gearing..

..but there – truth is I’d probably actually recommend building a ‘hop-up’ and leaving the mill as it is..

[Speedy Builder5Participant @speedybuilder5]

I have the ECONOMY mill which is similar.

The 240volt single phase motor runs at 1440 RPM.  If your 3 phase motor uses the same pulleys as mine, then the path of the belt would be between motor and spindle on one side and motor/intermediatepulley and spindle on the other so as to miss the round column when the head is lowered. (unless you retain the 2 belt system. HOWEVER if using a single belt and existing pulleys, you would get a much reduced top speed.

You would need to replace the motor pulley with a pulley slightly greater than the spindle pulley.

To clear the head chassis etc, you would need a 6.5″ pulley on the motor driving the 6″ spindle pulley to achieve 1570 spindle revs (assuming the 3 phase motor had a top speed of 1440RPM) and with those pulley sizes, you could use a single belt as it would clear the column when the head was lowered.

Have a look on this site as to how I overcame your problem.

Bob

If you could get a 3000RPM 3 phase motor, then all sorts of things change but bear in mind the path of the belts before committing to purchase.

Bob

[Speedy Builder5Participant @speedybuilder5]

Follow this link for a low tech speed change system.

Speed change Warco Economy Mill

https://www.model-engineer.co.uk/forums/topic/speed-change-warco-economy-mill/

[John HaineParticipant @johnhaine32865]

On my VMB I don’t have the column problem but even if it did have the column rising through the drive system it wouldn’t matter as there’s only one (long) belt.  The motor is 4 pole so 1440rpm @50Hz, but the VFD is set to run up to 100Hz max – the motor hardly gets warm and the rotor hasn’t exploded yet!  I seldom run at other than the highest speed pulley setting and reduce the speed with the VFD.  Exception is for threading.

[MacolmParticipant @macolm]

I modified my similar Clark mill soon after I bought it so that the intermediate pulley carrier is free to rotate round the column. Now it is only necessary to de-tension the motor, change the belts, then retention. This means the same tension force is applied to both belts, perhaps not theoretically ideal, but this has not caused any problem whatsoever.

To avoid wear on the column, I made up Phosphor bronze shim to go right round the column as a bearing surface for the cast iron pulley carrier to run on. This was made with also two horizontal fixing lugs. Then top hat spacers were turned up to guide the carrier with running clearance, and they were tightened down using the existing bolts, also nipping the shim fixing lugs. A drop or two of oil, and the carrier/pulley can rotate freely round the column without other slack. In regular use for years, I had indeed forgotten all about making this most useful modification.

[trevor gettyParticipant @trevor-getty]

I just bought a varible speed controller for the current motor for now on a very similar mill by NuTools.

If changing the motor I would use one of the brushless stepper designs for the lathe that are rated the same around 3/4 to 1hp and allow you to change ur setup easily and you get the induction motor and little controller in a package for under 100 quid.

But my current setup works and only cast 20 quid and came next day lol.

 

Currently I just have it set at the top speed on the speed around 1400 rpm using pulley 2-8.  Of course you can use higher gear combo but I wanted low down torque still.

Then I simply have this controller that works up to 4kw motors. Note there is no rewiring or changing just plug the mill into this and keep it on the bench beside it.

https://www.ebay.co.uk/itm/155448640385?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=k9d0vxbvqfi&sssrc=4429486&ssuid=ncMfuXcJS9u&var=&widget_ver=artemis&media=COPY

Simple and cheap until you need a better solution.

[BevelParticipant @bevel]

 

Wow thanks fellas, lots to think about there with range of suggestions just what I was hoping for.

 

Much appreciated and again thx to you all

[trevor getty]

On trevor getty Said:

I just bought a varible speed controller for the current motor for now on a very similar mill by NuTools.

[…]

 

That’s VERY interesting, Trevor !

… I admit to being surprised, so I hope one of the forum’s electrical experts can advise … I was not aware that such controllers would work on an induction motor [which I am assuming that your mill uses]

Mmm …

MichaelG.

[Michael Gilligan]

On Michael Gilligan Said:

On trevor getty Said:

I just bought a varible speed controller for the current motor for now on a very similar mill by NuTools.

[…]

 

That’s VERY interesting, Trevor !

… I admit to being surprised, so I hope one of the forum’s electrical experts can advise … I was not aware that such controllers would work on an induction motor [which I am assuming that your mill uses]

Mmm …

MichaelG.

The phrase “the current motor” perhaps suggests that it is not the standard original induction motor found on RF mill/drill clones but perhaps a replacement DC motor. Used treadmills are popular donors for this sort of thing.

Scratch that. I just read the post properly and looked at the eBay item. If the motor is the usual capacitor start induction motor, no way is this working.

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