UK- heidelberg windmill three phase to single

Sorry if this is a repeat question (I’m new to the group)

I am a fine art printer with an opportunity of a Heidelberg windmill

My studio is in the UK. the Heidelberg has 3 phase electric which I do not have, my studio is only single
what are my options , can I change the motor??
I rent my studio and can not get three phase installed
any thoughts would be useful

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You should look for what is called a VFD — variable frequency drive. It can take a 3 phase motor and convert it to single phase output. Shouldn’t cost much more than £100 plus installation.

You could change the motor as well, but finding a VFD would likely be easier.

Hope this helps,

in my opinion changing the motor is asking for trouble, most people go the way Brad says and use a converter. Dick G.

Machine Mart have a single phase 1.5 hp motor for £88.
This in my opinion would be your best option; much better than using any type of converter, and you could probably use the existing starter control (consult your local electrician).

thanks for comments

I have looked for VFD but can only find the in the £400 to £500, what size motor power is needed ie. W
If I can find one for £100 my troubles are over

I try not to chime in on here when my advice goes against that of others’ but since I am a better electrician than I ever will be a printer and since I own a couple of windmills here’s my 2 cents worth. You don’t need a variable frequency control. The motor pulley on a windmill is what varies the speed of the press. Plus, you don’t have 3 phase power to begin with. The easiest and most trouble-free solution is to replace the motor. The motor mount on a windmill can be adjusted to accomodate almost any 1 to 2 horsepower motor. Three features of your replacement motor are critical: The rotation needs to match that of the press. ( see the arrow on the flywheel ) Some motors are reversible and the ones that aren’t spell out the rotation on the nameplate in reference to looking at the end of the shaft. Secondly, you need to choose a motor with the same diameter shaft as the old one so that your pulley will fit. Third, the nameplate RPM should be approximately 1750. Most windmills used a 1.5 horsepower motor. The better quality motors of this size can usually be wired to run on either 115 - 125 volts or 220 - 240 volts. Use the higher voltage if possible. Your start / stop switch will last longer and the motor will run cooler, plus your house lights won’t dim as much when you turn it on each time. Your press might have come with a motor starter or ‘contactor’ box since it was originally 3 phase. If so and re-hooking this for single phase operation is over your head, you can replace it with a standard 2 pole, 20 amp household type wall switch and it will work just fine - especially on 220 volts.

many thanks for those comments, esp. Musikwerke for details. Brian

I too need to replace my three phase motor and wondered if anyone here has replaced their motor. I just want to make sure that parts don’t go flying everywhere when I take the pully off. Is it pretty simple?

Consult an electrician or more particularly an electric motor company about having the existing motor rewound from 3-phase to single phase. It can be done, and the motor then goes straight back on.

Would starting the press with a single phase put too much pressure on the motor? Would it be a case of needing to get the flywheel moving first, then engaging the motor?

The flywheel spins freely until the clutch is engaged. The motor you need will likely have a start capacitor circuit that gives the motor an extra kick to get it off the dime, then centrifugally cuts out once the motor and flywheel are up to speed.

I’ve two Heidelberg platens (Windmills) running on 3-phase and another two on single phase. These motors only spin the flywheel, so when the motor starts it only needs to get the flywheel rotating up to speed. The flywheels are pretty heavy and pushing the handle to start the machine engages a clutch, just like getting moving in a car, and the momentum of the flywheel then starts the motion of the press and keeps it going. 3-phase motors draw less current and here in the UK work at 415 volts. One of my single phase platens simply plugs into an ordinary wall socket like you’d have in a house - it’s just the same as plugging in a lamp or a TV!!
I know a printer who had a 3-phase motor rewound to single phase and that motor now sports a capacitor on top.
Like Dick says just to give it a quick kick in the pants to get it going, then the flywheel momentum does the rest.

So at $4500 to have a house rewired to 3-phase I investigated the new motor option but hit a brick wall with the electric motor guy saying that because the engine was imperial and we are now metric that it would require a lot of work, namely a new shaft, maybe a new pulley etc. He quoted the install of a convertor but at $2400 it’s still quite costly. I can see engines like this are available but being not mechanically minded they may very well be useless anyway. Does anyone have a suggestion as to how I should proceed? I gave the motor guy this thread but he wasn’t to interested.
David, can you please explain the ‘rewinding’ idea, as he doesn’t seem to understand and I am interested in finding any option to keep this well under $1000 is possible.

We replaced a three phase motor with a single phase that cost a few hundred dollars - never had a problem and my husband was able to do the swap over with his electrical knowledge. Was all quite easy and cheap to do!

Thanks Bespoke, that gives me hope. Unfortunately my hubbie has zero electrical knowledge. Maybe that’s why we are getting these costly quotes since they think we don’t know any better.
If you don’t mind my asking, what were the details of the motor you swapped over? I have a lovely electrician and if he can’t help I’m sure I can chase someone up who might if I just had the right hardware to start with. And the knowledge that it has been done successfully by someone else.

Hello, have had my husband suss it out for you. We are in Australia so swapped our 3 phase motor to a single phase 1.5 kw/2 HP motor - the important thing is that it needs to be 1400rpm. We bought it new off ebay for Au$210.

Hope that helps!

I’m also in Australia and recently picked up a Heidelberg platen with a 3 phase motor and ran into the same problem.

I investigated the route of replacing the motor, but soon ran into trouble with trying to get the specifications of the new motor right to fit the machine. The old motor was made to imperial sizes (they no longer make them like this) but any new one that I would pick up would be metric. This posed a problem because the frame of the motor would not be exactly right to sit on the platform behind the press, and modifications would need to be made by an engineer to fit the existing pulley drive to the shaft. It may have even required a spacer to sit under the motor to prop it up to the right height. All in all, it would’ve been an expensive and painful exercise.

Instead of messing around with fitting a new motor, my motor mechanic installed an inverter and new power cords to my existing motor - this effectively would take single phase power from the mains, convert and spit out 3 phase power to run the motor. It works a treat and I can even vary the speed of the motor by pressing a few buttons.

Including installation, it was about $650AUD - slightly expensive, but I believe it was well worth it.

Good luck!

Arrgghh. This is so frustrating. I got the same long story as Yundalay about a new engine might not fit with the metric/imperial conversion and the shaft issue, blah blah. I’m in Australia as well but I don’t know anyone mechanically minded (who’s not 1000km away). I found the same engine you mentioned on eBay Bespoke, and it was from some guys in Adelaide that I happen to have found yesterday. Will call them back soon. They also sell the convertors but it was price on app so I may still get a shock. But Yundalay’s $650 is still preferable to $2500.

Sorry to bug you again Bespoke, but I assume from your description that your husband didn’t run into the shaft/pully issues that both myself and Yundalay were warned about? It seemed from Musikwerke’s description above that imperial to metric shouldn’t be an issue either.

My head is going to pop over this soon I’m sure.

I’ve just emailed you quidditycreative


Like musikwerke said, get rid of the 3 phase motor.

I have done this on all my equipment. Most motor mounts are adjustable, or you can make up an adapter out of wood or aluminum.

A good motor shop, machinist and electrician are always worth their weight in gold.


Thanks Dan,
I have to admit, from a cost perspective, that a new motor is the winner. However, two electric motor people (non-letterpress people of course) have suggested that my problem with this is that the shaft ‘may’ not be the same length and/or diameter of the current motor. Which will then leave me with a useless motor or more costs in adapting it.
Bespoke hasn’t mentioned that this was a problem she encountered, nor has anybody else. But living in a country with only metric motors needing to replace an imperial motor, seems to make everyone pessimistic.
The quote for sending the current motor across the country and getting an invertor and stop/start switch installed is around $800. A lot better than my previous quotes I admit, but if I could just figure out if there is any strength to their new motor argument about the shaft I’d be in a more educated position.

Although i went through all this six months ago - i referred constantly to this site to find out what other people’s experiences were so i’m going to add mine in case it’s of any help somewhere down the line!

I am in Australia - Way out west and purchased a very old windmill from SA.

It was originally wired for 3 phase - hardwired into the building it came from which meant that all the wires had been more or less severed from the building and the press had cables and all sorts of things running all over the place.

The motor was old but working, and imperical dimensions - like the pulley - and everything about my 70,000 serial no machine.

Australia is all metric these days.

I couldn’t find any local solutions and ended up:

- purchasing a new 3 phase motor from SA (500$)
- purchasing also a new electricity transformer thing (800$)
- having a sleeve machined for the shaft on the motor so it would fit the original pulley. (lots more $)

Then the sparky came over ($300) to install the variable transformer, new motor and switches.

Basically one of these:[ProductCodeID]=VFNC1S

Now, i switch heidi on at the transformer on the wall and vary the speed from the enclosure its safely inside of on the wall of my press room.

It was expensive. Heidi runs suepr smooth and super quiet now!

My windmill runs a Dayton 6K393R in single phase 220V. I have not measured the shaft size but someone prior to me got it to work.

Just thought I’d add my two-pennorth to this, from the UK. I’m on 240VAC and the press had a motor made for 415V 3-phase (with no rating plate but a scary 32A plug))

Long story short, I took the pulley off the original 3-phase motor and found the shaft is 80mm. That’s 30mm longer than a standard 90S frame motor Otherwise all the 90S dimensions are fine. Diameter is 24mm as standard, keyway is the same etc.

So to avoid paying silly money for an extended shaft motor I tried Machine Mart’s phase converter.

Dunno if the one I bought was defective (the man did say it had been returned once already) but it wouldn’t start my motor. The contactor in the converter chattered and eventually the overload tripped out.

MM were good enough to swap the unit for a 2HP (1.5kW) motor. (and some other bits). I believe the correct size for the press is actally 1.5HP (1.1kW) but I figured a little more oomph wouldn’t hurt, especially as running up the heidelberg’s flywheel is effectively starting “under load”. The shaft is of course just a standard 50mm long. But I don’t really see how there could be any serious problem in using a shorter shaft. The pulley hub is certainly strong enough on its own.

I found out that 1-phase motors are really just 3-phase motors with a capacitor fitted to add a third phase. You can buy single phase motors with 1 capacitor which are intended to run up to speed off load. Or you can get “cap-cap” machines which use a starting capacitor of one size, then switch over to the other for running.

Despite the details on MM’s website, the one I bought has two capacitors and seems to “change gear” shortly after switch-on, so I think it is actually a cap-cap version.

The upshot is that this motor: Starts and runs the press just fine. I had to fettle the nominal 24mm diameter shaft with fine emery to get a smooth fit and similarly adjust the key. Other than that it all fits perfectly.

The startup is very fast and all is smooth and strong once running.

So I’d recommend to convert a 10x15 Windmill to single phase, just buy a standard 1.5kW 90S 4-pole motor with B3 foot mount and cap-cap start.

Swapping the pulley is interesting but pretty straightforward. Top tip - tie up the spring with cable ties before unscrewing the big nut.

Oh and despite successfully rewiring the 3 phase starter to switch the single phase, it proved unreliable so I swapped the guts of it out in favour of a 1-phase pushbutton switch, like the ones you’d find on a pillar drill, band saw etc. The motor draws 4-5 A when running with an inrush on startup up to about 10A. It’s perfectly happy plugged into a standard UK 13A mains socket.