Thread: Hercus Motor

My 260ATM has a 0.55kW (3/4HP) 3 phase motor.

Thanks Jack620 wanted to know so I can get the wright VFD to suit
Thanks
Steve.

Hi,

The Hercus's came in various hp sizes.

Can't help you with your VFD question.

I purchased a 1 HP single phase motor from AMWH for a good price and had a mate wire it up. ELECTRIC MOTORS

Cheers Ben

Steve, there must be a stamped nameplate on your motor. Look carefully, maybe someone painted over it. This lathe can be fitted from factory with 5 different motors. On my 1988 Hercus 260 price list the 1/2HP 3-phase motor is listed as standard, with 3/4HP and 1HP 3-pase motors listed at extra cost, and also 1/2HP or 3/4HP single phase motors listed at extra cost. If you cannot find a nameplate on the motor, you may be best off getting a 1HP VFD. Because a VFD one or two sizes larger is absolutely no problem (even beneficial for braking), but a VFD one size smaller than the motor is not a good idea.

My 260 of 1988 came with a 3/4HP Electrokovina (former Yugoslavia) 3-phase motor. The nameplate was spray painted over. Came off with acetone.

Yes you can reuse the existing switches if you really want to, but you have to rewire them as low voltage control inputs. I personally did re-use the switches only to switch the mains power to the machine on and off. I made a box to mount on top of the headstock for all the VFD controls. There are somewhere pics, look for older posts.

Chris

check to see if the motor can be configured delta wound ( usually under the lid of the connection box( looks like a triangle) should be 6 connections with bridging links
usual beware if you dont know what your doing it will kill you

Thank you for the information I can get a 3hp VFD for a good price so I may go with that.
Steve.

The motor on my lathe only has 3 conection points in it on the back of the motor only a small oval shaped cover nothing else.

Originally Posted by Zenoah

The motor on my lathe only has 3 conection points in it on the back of the motor only a small oval shaped cover nothing else.

3 connections can either be a single phase motor (start winding, run winding and neutral) or a 3 phase motor wired in delta only.

In any doubt, just buy a brand new motor. 3 phase motors are the simplest electric motors there are, making them the cheapest to buy too. Look on eBay, you will find brand new motors of 1HP or 3/4HP for under $100. If you want it to be a drop-in replacement, make sure you choose the right frame (motor housing) - there are metric ISO frames and Imperial frames.

If you plan using a 3HP VFD anyway, why not go for a larger motor too? Everytime you double the motor horsepower, you halve the number of times that you will have to change belt settings during the life of your lathe. The downside is that a larger motor costs a little more, and you may have to modify the mount and bore out the pulley and maybe a longer belt. I would in any case recommend you buy a link belt to replace the original V belt. Link belts run MUCH quiter, last longer, can easily adjusted for length by inserting or removing link sections, and can be removed/reinstalled as often as you like without having to remove the main lathe spindle to do so. I upgraded my waddown drill press and the bandsaw to link belts and noticed in both cases quiter smoother running - when I got the 260ATM it was a no-brainer to upgrade it too, and I am glad I did. Chris

Thanks chris, I will run a VFD and also take your advice and get a bigger motor I can get a 1.5 hp 3phase for a cheap price around $100 I think if I am changing this would be the best way to go.
Thanks Again
Steve.

Be careful how you wire up the VFD, I have used a few different types, most indicate that a disconnection between the VFD and the motor will result in the VFD blowing up. ie. you can't use the VFD as the supply to the machines original wiring because of the switches. The original switches could however be used as the control inputs to the VFD depending on the type of VFD you get.

steve before you part with your $$$$$ s make sure the motor will fit in theres not much room and you may have to cut some of the casting away, also pulley will probably have to be rebored and yes go for power twist belts
john
experience is what you get just after you need it

G'day all

I have just got my hands on a Hercus ATLM and have the same problems as some others here.
I only have a 240v single phase supply available and the motor on the Hercus is exactly as described by Steve (Zenoah)

has 3 conection points in it on the back of the motor only a small oval shaped cover

As I'm only going to be a casual user, I don't think I need the luxury of VFD and was considering the 240v motor conversion as Ben (bwal74) describes.
So Ben and any others that have gone down this road - would you do it again? How much surgery is required? What potential problems are there in your experience?

Thanks

John

Hi,

I'm happy using a single phase motor. I did have to do some modification to the cast iron housing of the lathe with a hacksaw (took several hours) to make the larger motor fit neatly. Also, I had to enlarge the pulley bore some (can't remember how much, a couple of mm) and cut a new keyway. Apart from that wasn't easy enough (I had a mate wire it up).

I'm not a expert in electric motors but 3 ph motors are supposed to be easier on the machine and use less power. But I'm happy with the single phase. I will hopefully be buying a Hercus O Mill sooner or later, they generally all have 3 ph motors, I may go the VFD route as I now have some new mates who would be capable of wiring up such things.

Hope it helps.

Ben.

Thanks Ben

Sounds like stuff I'm capable of. I have a brother in law who's a sparkie so I'm OK there.
I don't suppose you would have any pics of the new power plant in place.

Cheers

John