Inverter VSD for Myford Super 7 attempting auto destruct

Good Morning all, excellent start to my week! Turned on the S7 this morning to test all the new "Harrogate" goodies I bought yesterday and
instantly plunged the house into darkness. Apart that is from the small fireworks display from the back of the motor. As well as dying it was also trying to "auto cremate"; I almost let it carry on but then thought that if is this is an unknown Myford "accessory" success would come with a fairly large bill which I couldn't afford. So boringly, I pulled the plug and stopped it trying.
I don't have a spare resilient mount motor (would a normal foot mounted do?) so was thinking of going the inverter route. I have read the many informative posts here but being an electrical ass (red to red, black to black, throw the switch and stand right back is my standard) I am a bit uncertain that I have the capability to get one working. I did basic electrics as part of my training and did manage to wire the thing up in the first place and get the reversing function working with a normal 6 pole switch, so do I need a great deal more electrical knowledge to wire up a VFD?
I also noticed some excellent advice from John S in an earlier post on the then current best deal. Is this still a good option or is there something newer (cheaper, better) to search the RS catalogue for? The Newton Tesla option seems well regarded by all except my wallet which is having a bit if a fit after yesterday's exertions. So, is it very difficult and if not what should I be looking at? Or should I just crowbar the wallet open. Any advice would be much appreciated.
Thanks best regards
Keith
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On 9 May 2005 03:15:49 -0700, jontom snipped-for-privacy@hotmail.com wrote:

Keith
I am a convert to the inverter and yes, they're dead easy to wire in. Three wires in, four wires out and maybe 4 more for remote control and forward/reverse. I've just bought one for another machine from Clive Steer who advertises on the Homeworkshop pages. If it's as good as it appears (waiting for it to arrive) then for the money it's a bargain.
Regards
Charles
Visit http://www.homeworkshop.org.uk The free pages to buy and sell workshop equipment
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On 9 May 2005 03:15:49 -0700, jontom snipped-for-privacy@hotmail.com wrote:

Normal foot mount in 3 phase will do nicely as they are smoother than the original single phase. Have a look on the web site in my sig line. There are some motors and invertors on there from different people that will fit the bill very well.
The technology is getting better by the day and what used to be a specialised domain is now available to the masses.
-- Regards,
John Stevenson Nottingham, England.
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Charles, John
Thank you for your very rapid replies but as always you have prompted a couple more questions if you don't mind.
Having looked at your site as suggested, I did a "google" on Yaskawa inverters but unfortunately all the pages I found appear to be written in a strange language and I can't find the "this fits a myford" statement!
I had thought that a motor between .75 and 1hp would do nicely - will the 1.5hp inverter be OK with a smaller motor or does it need to have a load nearer the rated capacity? If so will a bigger 1.5hp motor still fit the lathe? The other one I could find on your excellent page, although much nearer to me, I felt might be a little small at .5hp? I'm sorry but you will see from my question I really don't know much about this.
John, my question was not very clear I'm afraid, the foot mounted motor I have spare is a single phase not three phase and although its an old Brooke Crompton I don't want to go to the bother of fitting it if it is likely to produce the old "white finger" vibration and that "lovely pattern" (my wife's description as I showed her what was wrong with my cheap chinese lathe) on the finish.
If I went the inverter route to get the variable speed advantage anyway are motors easy to come by and more importantly does it need to be anything particular. I gather it has to be 230v not 415v but I don't understand what is involved in matching the motor with the VFD or in diving into the motor to change the "windings" (star delta??). If I look at the motors are they easy to identify? I'm happy (I think) to pay for a new motor if necessary but will need to ensure I get the right one. I have already wasted a bit of money on a different machine when I fell for the Machine Mart "quality costs less" and bought a .75hp motor which must have been measured on a very small or very old horse. Unfortunately, I don't have your knowledge to identify bargains even if they stare me in the face, and without the necessary contacts or buying power I can't get anything other than "list" prices. So I need to buy wisely. I suspect I need to read some of your old posts a bit more deeply.
Hope you will forgive my long list of daft questions.
Thanks both for your help, best regards
Keith
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On 9 May 2005 07:05:40 -0700, jontom snipped-for-privacy@hotmail.com wrote:

Keith
Where are you based. I have a freshly rebuilt 3/4 hp 3 phase motor that keeps getting in the way if that helps?
Regards
Charles
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Charles
Thanks for your kind offer, certainly sounds as if it might have helped. Trouble is I'm located in South Wales and based on the location in your advert for your Clarkson Drill Point and Tap Lead Grinding attachment, I suspect there may be a few too many gallons of that expensive fluid between us to make it sensible. Pity as I've just spent the afternoon clearing a space for the Boxford I need to pick up tomorrow night and there seems to be an excess of floor space at the moment. I suspect it will soon escape though. However, in the longer term and if I can sort this Myford successfully there is always the new boxford to "improve". Do you frequent any of the exhibitions? At the moment I can't think of anything that I visit that is remotely close to you. Thanks again.
Best regards
Keith
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jontom snipped-for-privacy@hotmail.comsaid
Hi Keith,
I've just been down the same route and have come out the other side wiser and with so much more control over my ML7 than I ever imagined possible!

The inverter doesn't have to 'fit the Myford' - I bought a Hyundai N100 1500SF via eBay (once John Stevenson confirmed that it would be 'ideal') along with a .37Kw motor.
The issues that I had were purely to do with the physical size of the motor, the pully that I had on the shelf and the size of the belt on the Myford. The original single phase Crompton motor (1425rpm) had a 1 7/8" pully on a 5/8" spindle driving a 36" O/D belt with a base to centre height of 3.5". The new motor (1380 rpm) has a 14mm spindle with a base to centre height of 70mm, the pully is 19mm bore and 76mm O/D and I need to use the same belt - so, a bush from 14mm to 19mm and packing pieces to raise the motor to a suitable height.

That was one of my questions as well.
The Hyundai has a motor test routine which sets it's parameters to match what the motor is capable of.

I haven't had time to fully test this yet but JS tells me that 1/2 hp 3~ is more powerful that 1/2 hp 1~. Up to now I have found no problem.

Again I had no idea what Star and Delta meant in reality but once I got the motor it all became very clear via the wiring diagram on the inside of the motor connection box. As I now understand it Delta is 240V with three straps linking across the U, V & W connectors and Star is 415V with terminals U, V & W linked together.

As long as the motor is specified as Dual Voltage (240/415) then you ought to have no problem.

I had as many (if not more) - I still have some that I posted to JS last week!
Since I have already been down this route and have built a remote control unit which gives me Forward and Reverse at the touch of a button as well as three selectable fixed speeds plus fully variable, I would be happy to talk you through any issues you may have.
JG
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JG
Thanks for your reply you have clarified things greatly. With most engineering issues I always find that once you can get past the basic "daft" questions and start to talk and think the new/different language things start to make a bit more sense. The other advantage for me is obviously it is much easier to follow than lead. I really wish I had found this group earlier I might have bought more of the "right stuff" and less of the accumulated junk in the garage. Still these days I think "junk" has been redefined as "Ebay treasure" although thankfully, as you have identified, when equipped with the right shopping list the real goodies are certainly there.
One of the issues I have with the Newton Tesla option is that if I repeat the process for the bigger lathe and the mill it makes a big hole in my modest budget. From what Charles, John and yourself have described it looks as if I could improve all of my current machines and also still save the cost of another "essential" machine. Sounds good to me.
I must admit that I hadn't even thought of the mechanical differences between the motors although I should have as I can remember being told that 3 phase - more efficient - smaller motor for similar output. If you don't mind I will certainly take you up on your kind offer to talk me through the issues just as soon as I have gained enough of an insight to know what they are. I suspect some of you guys on here must be kept very busy "sharing" with us less experienced individuals.
The facilities you describe on your remote control unit seem very appealing; to build such an animal do you need any "electronic" skills or is it the more (for me) understandable switches pots etc? The other question currently in mind how long does this buying and building process take? Despite the high cost at least the Newton Tesla package is available quickly and with the Myford totally dead at the moment I'm missing all the fun! Still if I can get the Boxford I'm picking up tomorrow running perhaps the Myford can wait a while. Sorry thinking with my fingers on the keyboard again.
Anyway, JG thanks for your very helpful reply and if you don't mind I will certainly shout when I know what the (first) problems are for me. Thanks again.
Best regards
Keith
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On 9 May 2005 11:01:40 -0700, jontom snipped-for-privacy@hotmail.com wrote:

Without taking anything away from Newton Tesla they are only assemblers of off the shelf items, invertors, switches etc.
Technology has gotten to the stage where once you get past the terrible documentation sent out with these magic boxes it's really easy.
There are basically three terminals strips in an invertor. Single phase in, usually marked L&N or L1,L2 and sometimes even L3 which you ignore. If it's the L1, L2 marking it doesn't matter which way is live unless the book says. Then you have the three phase out, usually marked U,V,W, again it doesn't matter which wire go where to the motor as long as they do all go there. If the motor goes the wrong way just swap any two.
These two terminal blocks are at mains potential so normal care and safety apply.
Last is a smaller terminal strip for the start stop and speed pot. These are low voltage connections 10v to 24v at around 10 mA depending on model so very safe. These are the wires you need to bring out to the remote switches and can be on thin alarm type cabling.
The default wiring for most invertors in industry is for the invertor to be switched on with contactors and locked on until stopped. This is usually handled by relays as part of the machine package.
We can do the same but need other safety procedures to prevent it auto starting after a mains failure. The best procedure for the home shop guy is to use what is known as 3 wire operation. This used two switches a start switch that needs to be made to start the motor and a stop switch that needs to be broken to stop the motor. he idea of the broken stop switch is a series of them can be daisy chained together for things like guards and limit switches. The three wire configuration gets it's name form the three wires, one common, one start and one stop.
How these are wired in depends on the manufacturer, many have a quick connection cheat sheet if you ask.
-- Regards,
John Stevenson Nottingham, England.
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John
Many thanks for the information you have a real gift for making the complicated appear quite straightforward even logical. I believe with your and the other guys help I'm now getting a basic picture of what a VFD Inverter consists of and how it is connected. I build computers for a hobby and many people have a "blind spot" that convinces them that it is some sort of "black art", of course it isn't you just need to know what plugs into where. I suspect after your excellent description that I have the same problem with these inverters.
I'm getting the idea that at my sort of level once you have identified the individual components (inverter, filter? / keypad?) required it is just a matter of connecting them up and sorting out a suitable location/ housing and adding the various control switches/pots either in the same housing or remotely if more convenient. I had originally thought that some sort of programming interface was essential to adjust to the motor parameters but from what JG said and the RS web site am I right in believing that this function is already built in to some inverters? At least to a sufficient level to look after my basic needs for motor speed control. If this assumption is correct is it safe to accept their "default" parameters? Do I also understand correctly that a "filter" is required? I notice that some inverters claim to have these built in, is this the same thing or are additional filters always required.
Having had a quick look at the RS web site I'm guessing (top of my head stuff) that something like the Siemens 420, Telemecanique IP55 or Mitsubishi E520 is the sort of thing I would be looking for. Am I in the right "ball park" or have I got it hopelessly wrong (wouldn't be the first time). I did find an Ebay supplier that sells the Hyundai N100 that JG mentioned but can't see his specific model. If this guess is somewhere handy they all appear to be about 200 (0.75Kw) to which I need to add a few pounds for the switches/pots etc. Although both sites talked about selling suitable motors I can't see any prices listed so would guess about 100 off the shelf? With a bit of care I'm guessing that I could put a system together for under 300 using new components and my buying power of 1. I've also noticed that RS sell one under their own name for quite a bit less but I am always wary of "own brand" as I can not tell who put it together for them.
Obviously I need to learn a lot more about the various functions etc but would this get me a reasonable system that should be reliable and give me basic control of the motor without any longer term reliability issues? I have also got the feeling that this approach is rather "throwing" money at it and is not likely to produce the best bang for my pound. In comparing these inverters is there anything in the spec that I should particularly look for? It all gets a bit technical for a non electrician (as they intended of course) and I wouldn't want to miss a critical factor.
John, I really appreciate the time you spent preparing your earlier detailed advice and I certainly am not looking for hours of "free training" but could you give me a clue to confirm (or not) that my initial thoughts are at least on the "right planet". I hate it when I get all excited about a project only to be shot down in flames later because I hadn't grasped the basic concept. Particularly if it is after I have already spent some money. I'm off to pick up my "new" Boxford tomorrow so I promise I won't hit you with any more "multi-question papers", thanks again for your patience and help, very best regards
Keith
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On 9 May 2005 15:39:05 -0700, jontom snipped-for-privacy@hotmail.com wrote:

A decent modern Invertor should have all the parts included. Beware some models like the Mitsubishi where the keypad is an extra. These will only work in basic made because you need the keypad to alter any parameters. Still the best bang for the buck if you are not savvy with fitting industrial board invertors into boxes and picking you way round are The Telemechanique ones from RS. are called the Altivar ATV 11 series. 0.75Kw [ 1 hp ] part number 431-9184 is 100 less VAT This is complete.
You then need a 3 phase motor, 3/4 hp is fine. Expect to pay 70 tops for a new one. Anyone selling one more than this is ripping you off. If I told you the import price you would be amazed at the mark up. Don't buy machine Mart motors, burn the money instead under a kettle. This will improve the efficiency 200%.
Motors are calibrated in KW, roughly 750 KW = 1 HP so a motor than consumes 750Kw is rated at 1 Hp but one bar of an electric fire is also 750 KW and that doesn't revolve [ unless you are holding the hot end ] What matters on a motor are various formula that work out the efficiency. This can be expressed as a+b+c+bullshit = well know brand and you can't go far wrong. The Great Wall Tractor and Silk Flower factory is not a well known brand.
You then need two or three switches depending if you want reverse and a pot for speed. Start and reverse switches are identical and are push to make contact type. Stop switch is a push to break type. Decent 22mm Telemechanique ones from RS are about 7.00 each or raid the scrap box as anything will do, they have to switch 24volt max at 10 milli amp. The pot is determined by the invertor, the value will be listed in the book but thy are not critical. I fit 22K ones to everything I get because I'm to idle to order all different ones. Expect to pay 4-5 max.
You then need an enclosure, box or panel to mount the switches, a length of 6 core alarm cable or similar light cable, a length of 1.5mm 3 core plus earth for the motor and a length of 2.5 mm 2 core plus earth for the mains in.
That's the total expense.
-- Regards,
John Stevenson Nottingham, England.
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wrote:

John, you need to check your units; 1 HP = 750W (actually, 748W but that would be too pedantic!). I wouldn't want to be paying your electricity bill if you have any 750KW electric fires in your place. Martin
--
martin<dot here>whybrow<at here>ntlworld<dot here>com

> What matters on a motor are various formula that work out the
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At last the true cause of global warming is revealed :)
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On Wed, 11 May 2005 00:26:48 GMT, "Martin Whybrow"

OK, OK it was late and funnily enough I had spent about an hour on the phone talking to the motor importers so I had KW on the brain.
-- Regards,
John Stevenson Nottingham, England.
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John
Thanks for your detailed post which has filled in the remaining (at the moment) blanks that were stopping me actually getting on and doing something. I'm a bit slow to say thank you I'm afraid as I missed it last night (you must have been up late) as I was "playing" with my "new" old Boxford that I had just brought home from JL down in deepest Wales.
I'm struggling this morning trying to find a supplier that agrees with your fair pricing strategy for a motor. RS want 136 for an ABB and the "local" rip off merchants obviously want me to pay for their next Rolls Royce (or is it BMW these days). Strange you say that the "The Great Wall Tractor and Silk Flower factory" is not well known, down here all the traders seem to have found them and have lots in stock (funny that). Anyway the search continues but with hope more than expectation. I suppose I could always fit an old single phase motor to the Myford for the time being while I collect the bits as they appear on E-bay. Trouble is as you will know this "enthusiasm" is volatile stuff, if you don't use it straight away it evaporates.
If I take the Telemechanique option will I be missing any (important) functions that I need later when I might know a bit more about what I'm doing? I know that I've obviously been "got at" by modern advertising but it does seem very good value for money. A couple of people including yourself I think have pointed me towards your adverts page and the Yaskawa inverters being sold by Clive Steer. I know Charles is waiting for his to arrive. If he has any left would a couple of these fill the bill?
JG kindly sent me a detailed E-mail with a few pictures of his set up and when picking up the Boxford last night JL let me have a look at his arrangement on the Marlow. Both of these were quick to point out the excellent advice and support you gave them and both agreed with you that it really is more straight forward than I was suspecting.
With the excellent advice I've received from you all my confidence is very high and I'm now thinking of 3 systems to do the Myford, Boxford and a VMC mill. Possibly better to sort one out first but I 'm so fired up with enthusiasm I just need to get off my backside and chase down some motors that won't empty the wallet completely. I feel a trip "up north" coming on but how do you know where to look. Hundreds of small 3 phase motors must be "disposed of" in a month; I know that we used to throw them away because no one wanted them - how times change at least for me.
Many thanks to all of you for your help and advice, I'll stop thinking and get on with doing although, I suspect I might be back for a few more pointers on the detail.
Best regards Keith
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On 11 May 2005 06:05:12 -0700, jontom snipped-for-privacy@hotmail.com wrote:

Ironically ABB motors are now made in Rumania. The truck that delivers to my supplier has 1/2 a load of motors badged in his name and the other half are ABB's going to other distributors.

Yes nothing wrong with any of the modern invertors provided they are complete. Check with Clive that they have the panel and other bits. I did see a post where some were being offered without panels and heat sinks but these could have been old stock ones. Best to check. As regards features you will never need anything that isn't here now. In fact they have roughly from 130 to 250 different parameters to change to suit all applications. If you play with one a week you will be dead before you find out how it all works <g>

Can't help on second hand ones but if you want two or three it may pay to get them all shipped to you in one go, drop me an email with what you need.

-- Regards,
John Stevenson Nottingham, England.
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The ones Clive has do not have the programming panel, but he will set them for your requirements if you tell him what it's for. The 1kw is a modified (and suitably de-rated) 440v inverter -but at 40 including postage it's almost as cheap as a big capacitor, and a much better job. I'm just waiting for a couple to arrive (1kw & 2kw).
Regards
Kevin
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wrote:

S T M power transmissions might be worth talking to Tel 01606 301 250
sold me 10 off 0.37 kW motors at 56 each..
--
Jonathan

Barnes's theorem; for every foolproof device
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On Wed, 11 May 2005 18:14:34 +0000 (UTC), "Jonathan Barnes"

You were ripped off for 10 off. Ask me next time.
-- Regards,
John Stevenson Nottingham, England.
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Hi there
I have just fitted a Newton Tesla CL 750 to my Myford 254, dead easy to do and I can't believe the how quiet the motor runs. No wiring for you to do at all just plug it in and off you go.
Kit came with a 1hp motor (old one 3/4 hp)
And a ten year guarantee on the inverter!
George Newton is always there for any advice you might need, I asked if I could chop the 13 amp plug top off so I could wire into the main switch on my lathe, no problem and no effect on the warranty either.
Perhaps not the cheapest way to go but a class bit of kit, with the back up of a company that really knows their shit!!
Rich
On 9 May 2005 03:15:49 -0700, jontom snipped-for-privacy@hotmail.com wrote:

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