Unknown Swiss milling machine

[Michael GilliganParticipant @michaelgilligan61133]

I spent a couple of hours, yesterday, cleaning and admiring this machine … Major reorganisation of the workshop will be required before I can use it; but so far, it looks superb.

Now … The Motor for the high-speed head:

… feels mechanically perfect, and I would really prefer not to start digging-around inside it.

Can anyone suggest a suitable VFD

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Some interesting notes here, from 'Inverter Drive Supermarket'

Is that the best [or indeed the only] way to do it ?

Grateful for any thoughts.

MichaelG.

Edited By Michael Gilligan on 20/07/2016 16:02:59

[Neil WyattModerator @neilwyatt]

Posted by Michael Gilligan on 20/07/2016 12:21:05:

Some interesting notes here, from 'Inverter Drive Supermarket'

Is that the best [or indeed the only] way to do it ?

Grateful for any thoughts.

MichaelG.

Edited By Michael Gilligan on 20/07/2016 12:21:55

Seems perfectly reasonable.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 20/07/2016 12:51:23:

Posted by Michael Gilligan on 20/07/2016 12:21:05:

Some interesting notes here, from 'Inverter Drive Supermarket'

Seems perfectly reasonable.

.

Thanks, Neil

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Another clue to the machine's parentage:

This plate is on the engraving pantograph [currently lurking in a big plastic box]

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

I started cleaning-up the slides today

For those who questioned the robustness of this little engraving machine; here's the 5mm pitch feedcrews.

 

MichaelG.

Edited By Michael Gilligan on 22/07/2016 18:45:51

[Mike PooleParticipant @mikepoole82104]

I would check that the motor can be wired for delta which will give you a good choice of inverters to choose from, if delta connection is not possible with out digging the star point out of the windings then you are limited to one of the inverters that claim to give a 400v output from a single phase input. I would be interested to know how they do that.

Mike

I see from the link what they are up to, a similar fiddle to the 87hz trick.

Edited By Michael Poole on 22/07/2016 19:22:51

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Poole on 22/07/2016 19:18:44:

I would check that the motor can be wired for delta …

.

Thanks for your thoughts, Mike

This rather poor photo [it was just coming on to rain] shows the very neat self-contained motor & switch assembly, which I am somewhat reluctant to dismantle.

Hopefully … Someone might come along to tell me just how easy it is !!

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Poole on 22/07/2016 19:18:44:

I see from the link what they are up to, a similar fiddle to the 87hz trick.

.

I've just found a paper by Siemens, about this ^^^

https://cache.industry.siemens.com/dl/files/130/25338130/att_7156/v1/25338130_betrieb_von_motoren_mit_hoeheren_frequenzen_v2_1_en.pdf

[learning has been seen to take place]

MichaelG.

[Nick_GParticipant @nick_g]

Posted by Michael Gilligan on 22/07/2016 21:04:45:

Posted by Michael Poole on 22/07/2016 19:18:44:

I would check that the motor can be wired for delta …

.

shows the very neat self-contained motor & switch assembly, which I am somewhat reluctant to dismantle.

 

MichaelG.

.

Michael I think you are going to have to dismantle it.

Others will need to see how the connections are arranged so a photo of the inside will really be required. This will help to see if the star / delta connection points are easily accessible.

If they are not then all is not lost. – Easy way if not 100% sure of your ability to rectify the issue would be to jump in your car and drive to Warrington. (not too far from you) and take it to **LINK**

They are a very helpful and knowledgeable bunch and will supply, connect up and programme for you the required equipment to the motor if needed. They will even dive inside a motors windings to retrieve the required connections if not easily accessible.

I have 2 Mitsubushi drives from them from this range http://www.newton-tesla.co.uk/product-category/inverters/mitsubishi-d700-series/mitsubishi-d720s-220v-single-to-three-phase/  that have been faultless.

Nick

Edited By Nick_G on 23/07/2016 10:26:11

[Howard LewisParticipant @howardlewis46836]

With regard to wiring, although mainly about single phase motors, you may find a useful diagram on page 19 in an article in the latest issue of Model Engineers Workshop, ( No 244)

Howard

[MuzzerParticipant @muzzer]

Higher power 3-phase industrial VFDs require an active power factor corrector (PFC) front end to meet the legislation limiting the harmonic currents imposed by the VFD on the mains network. These are "boost" converters that generate a high DC bus voltage (700Vdc or more) from the input voltage. This in turn is enough to generate a "proper" 415V output. So modifying one of these to accept a single phase 230Vac input (which is effectively a 2-phase input from the VFD's point of view), allows generation of 415V 3-phase from a 230V single phase input.

It seems that Drives Direct have managed to modify some of the Teco VFDs to work this way, presumably by changing the software or setup parameters. I've no idea if this is an "approved" (by Teco) mod but I guess you would be buying from DD, not Teco. There is generally no need for industrial drives to operate from single phase in this way, nor is there much call for PFC front ends on lower power and single phase VFDs, so this is a bit of a niche market. I've no idea how successful, safe or robust the conversion is but on the face of it, it would allow your machine to operate without having to go in and modify the motor.

Murray

[Michael GilliganParticipant @michaelgilligan61133]

Nick / Howard / Murray

Thanks for your posts … There is no real urgency to this, so please keep the ideas coming.

I have a few strategic and tactical decisions to make, before we get to running motors.

The Brown Boveri motor is for the high-speed drilling and milling head [which appears to be the genuine Aciera F3 unit]; but there is also another 3-phase motor [small, but as yet unspecified], buried in the base of the machine, to drive the pantograph spindle.

I need to check the pantograph for completeness, and for function, before I decide whether or not to keep it … and of course, if I do keep the pantograph; the machine will need occupy a bigger space and need more access.

The machine is currently just inside the doorway of my workshop; almost blocking the exit route for all the "stuff" I need to lose before installing it. … Ho-Hum … We'll get there eventually.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Yesterday, I had a preliminary look at the pantograph assembly:

It seems to be complete [except for collets and the tracer point], and the bearings are all good … but it will need a good clean.

It's an awkward contraption to man-handle, so [to avoid personal injury and/or damage to the machinery] I will need to install some sort of overhead lifting gear. … Design or product suggestions would be appreciated.

For reference: see photos of the similar machine in this advert:

http://www.petitesannonces.ch/a/2155352

The copy table detaches easily, but the remainder of the pantograph [perhaps 40kg] needs to be lifted and 'docked' on the tee-slotted top of the pedestal.

The High Speed milling/drilling head, pictured on page 1 of this thread, is interchangeable with the pantograph.

MichaelG.

.

 

Edited By Michael Gilligan on 26/07/2016 10:12:16

[frank brownParticipant @frankbrown22225]

I used a winch sliding along a heavy sliding door track mounted on a roof joist of my shed. This was for my Deckel clone hispeed head/shaper head and vertical head. There are photographs of the set up in the albums area, I can't seem to link to them, its titled " frank brown backyard mechanic".

Frank

[Michael GilliganParticipant @michaelgilligan61133]

Posted by frank brown on 26/07/2016 19:04:52:

I used a winch sliding along a heavy sliding door track mounted on a roof joist of my shed. This was for my Deckel clone hispeed head/shaper head and vertical head. There are photographs of the set up in the albums area, I can't seem to link to them, its titled " frank brown backyard mechanic".

Frank

.

Thanks, Frank … Much appreciated

Fortunately, I used 'Universal Steel Beams' [the new-fangled substitute for RSJ] to support the roof of the workshop, so I'm off to a good start.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

A couple of small steps made today:

1. Ordered a hoist … Now pondering how best to adapt it to the overhead beams, to get the manoeuvrability I will need, without working the job to death.
2. Removed the motor that drives the pantograph spindle, from the base of the machine … This one is dual voltage and the nameplate might [just possibly] explain the origin of the 'TN' branding.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

A little more cleaning and general familiarisation today The build-quality of this machine is absolutely stupendous.

I removed the gib strip from the 'Y' slide, just to clean the old oil 'varnish' from it … The strip is beautifully ground on all six faces, and has a hole for a location pin; the adjusting screws all bear on little brass slugs, shaped to the dovetail angle.

MichaelG.

[AjohnwParticipant @ajohnw51620]

It's still possible to buy the Transwave units Michael. I used one for ages and providing you do follow the instructions they are fine.

**LINK**

It can be tempting to play with the settings and all sounds ok but after a while these electrical Frankenstein noises crop up. No harm done though. They crop up on Ebay used at times. They were popular because 3phase machines were so cheap – before inverters arrived. Lots bought the 3HP one. I thought i had decided to buy a lower powered one but on getting it out it's 3HP. I was going to sell it but have decided to keep it. I used it on a Raglan without any problems at all.

You shouldn't need to worry about buying used. The internals are all passive so nothing to go wrong really. It's possible to use your own design of the same sort of thing but I wouldn't advise it. The transwaves are rock solid. From memory they don't work well with 2 speed motors.

I'd guess this unit uses watch / clock sized collets?

I would retain the motors as well. They probably runs as smooth as a gyro.

John

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Edited By Ajohnw on 13/08/2016 11:16:48

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for your thoughts, John

I have just taken delivery of an ABB inverter, and will try the '29Hz trick' on the Aciera head [see earliet posts]; the pantograph motor is dual voltage, so should be no problem. … I will report back in due course.

As for the collets: The Aciera head uses W20 [of which I have a good set], but I have not yet identified the, smaller, type required for the pantograph.

MichaelG.

[AjohnwParticipant @ajohnw51620]

I'm getting a bit fed up of the inverter noise even at high switching frequencies and random switching. It also isn't good for the motors – circulating currents through the bearings. Not that we generally use gear for the length of time that probably needs to cause serious problems.

Very decent capacity collets. Have you looked at the bearing arrangement in the head ? Just curious and wondering about max speed and range.

John

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[Michael GilliganParticipant @michaelgilligan61133]

Posted by Ajohnw on 13/08/2016 12:15:52:

Very decent capacity collets. Have you looked at the bearing arrangement in the head ? Just curious and wondering about max speed and range.

.

Nominal speeds on the Aciera head are 2000, 4000, 6000 rpm

Using the 29Hz trick, I should get less than nominal power at the upper end of the speed range, but I don't envisage that being a problem.

MichaelG.

[AjohnwParticipant @ajohnw51620]

I don't think you need to do this really Michael. The field weakening will occur above the normal frequency because inverters currently can't provide the extra volts needed to provide the motor's rated current.

In fact I think you are handicapping yourself if you use it to reduce speed because the actual power available = ability to do work / hp / kw is reduced proportionally with speed as the motor isn't rated for higher currents to enable it to produce the same power output that it has at normal speed.

There is another factor as well. Are the motors less powerful in the USA? They are not, they just run 20% faster. An interesting aspect in some ways even at higher frequencies where the current will have dropped as the paper suggests. However if the load on the motor is increased the slip will increase and that would normally increase the current even to a point where it would overheat and burn out if left like this for long enough. In this region inverters tend to stop that from happening so they just leave the problem of reduced speed = less cooling on normal motors so they can overheat even at their rated current.

Where you might want the constant torque set up suggested in the paper was if you were feeding super fine rice paper in some oriental marshal arts temple at various rates for trainees to walk on running machine style leaving no foot prints. Sorry about the example but I suspect some watched this

**LINK**

Maybe they have less space these days so need a sort of running machine.

None of this is needed on a machine tool. As the current is reduced it might help control heating effects at slower speeds. It would be possible to get some idea of the degree via the ratio of normal torque to the level it's reduced to but fan speed will drop off so that simple approach goes out of the window.

I did get Brooks to say verbally via the person I was talking to that he thought none of their motors would have a problem at 2,800 rpm. From the conversation I assume this is based on armature bursting concerns. I doubt if they would put this in specs. I settled on a safety margin of 80Hz. Maybe Siemens think it can be higher.

John

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[Michael GilliganParticipant @michaelgilligan61133]

John,

Thanks again for your opinion … But on this occasion I am happy to work on the advice given by InverterDriveSupermarket, and endorsed by Quantum Controls

MichaelG.

[AjohnwParticipant @ajohnw51620]

I do have a bit of a miss understanding Michael. I was assuming you had taken the switch cover off and found that it could be wired in delta and were following the Siemens pdf.

The constant speed versus constant torque aspect on machine tools has cropped up on here before. I'm not too keen on some UK inverter and motor suppliers as I have come across people who have been seriously mislead but can see your reasoning for doing it the way you intend to.

John

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