Unless you know something that I don't, rutex is still very much in business. There is of course two totally different rutex companies: Rutex AU who manufactuers the drives and Rutex US who sells them. I have always dealt with Tom from Rutex US and he explained there has been a lot of problems getting the drives from australia but has has a big order with them and has been assured they will be on their way to him soon.

Also because of all the delays and problems he has had, Tom is also working on his own brand of drives which will be similar to the rutex in size, shape and specification and will work as a direct replacement for existing rutex boards.

Your retrofits look good, do you do it professionally? Also do you have any experience using the CNC4PC breakout boards ?

Dom,

The Rutex AU have stopped producing Rutex drives and are not responding to any emails from customers. Tom's redesigned Rutex boards aren't ready for market yet.

I did my first professional retrofit last year. Before that it was just a hobby and experiment with my toolroom machines. I am a mechanical engineer and my knowledge of electronic is much limited compared to you. My electronics technician has designed his own breakout boards for connection with bridgeport switches and the Pixie drives.

Zafar

Dom,

Just a quick message to wish you well with this project. I can't imagine how you are managing to do this and find time to study for you finals.

Your detailed project diary, photos, and schematics are an invaluable record for the rest of us and help to give us courage to undertake similar retrofit projects. In particular, I am grateful for your discussion regarding the power supply to the servo drives and spindle, as this is often overlooked in other projects.

Its great to find there are other CNC enthusiasts in the UK, and discover useful contacts for parts and supplies.

Kind regards,

fringe

Hi Fringe, welcome to the boards.

I'm not managing is the honest answer . In the holidays I get the oppertunity to spend some time on the thing but now its back into term time i've just got to put it all to one side and come back to it at easter

I have also done looooads more to it over christmas but have not yet had a chance to post the updates.

So hows it doing?

I am thinking of a matsuura VMC that is said to be working but if it dies will probably need a new controller, I was told about a £1200 charge to send a blolk out to check a controller fault, blokes opinion was it needed a new controller!
So I am looking at your interact with some interest, I was actually looking for a 2 mk4..

I've very nearly finished. Havent had time to update the site for a while, nor have I looked at the machine for some time.

I have now finished all my exams so expect some updates soon.

Hello, I got my interact 1MK2 machine 4 to 5 weeks ago now and have just managed to get everything working of my single phase supply. i had to make a large DC power supply for the axis motors and totally replace the Spindle drive.

I got the blower motor working with a capacitor, but i have to make some electronics to help with my spindle control.

My main spindle motor takes about 1.7A in the feild and up to 400Volts in the armature.... this gives me about 1600 rpm... so to get the spindle upto its 4,000 rpm i will have to weaken the field current but keep the 400Volts on the armature... so am thinking of using a PIC microprocessor to do the job.

At the moment i just have a simple voltage halving circuit powering the motor field... but i am limited in top RPM.

Apart from this everything is working fine...

I am feeding the machine with a 400v line from my transformer and a 240v line and also the neutral, this allows me to power everything from my single phase supply.... i am going to be measuring the current pull when am using the machine soon with a clip on amp meter, just to make sure am not kicking hell out of my supply... aslong as the accelerations are kept low for the motors am sure it will be fine....

Dom :- if you have just set your variable transformer voltage to give you top speed...by weekening your field current are you losing your 'torque' low down in the rev range..

as i think the motor will produce constant torque upto a RPM then after that it is constant Power (so the torque falls off).

Am going to make a box of tricks that the voltage demand from the heidenhain comes into then this box sorts my spindle drive out and weakens the field current to get the top speed.

Oh just another thing..... what value of backlash compensation have you put into your control software for each axis??

Anyway am glad to hear you will be updating everyone soon.
all the best from Derbyshire!

Wess

Hi Wess,

I would be interested to hear more about your spindle setup, what are you using for your spindle drive ? Also what are the specs of your motor ? Is it one of the big square yellow ones ?

I have recently run into some major problems with mine. A few months back I got my spindle running nicely for the first time but then when I tried to fire it up again more recently I kept tripping the RCD in the main breaker for the building. I thought this was more to do with dodgy wiring leading up to the machine causing earth leakage but upon further investigation it seems that the problem resides with the motor.

I dont think earth "leakage" is the right word, its more like a broken dam. Unless i'm just being stupid here , I'm assuming that continuity between both + and - of the armature and earth is a bad thing!

I have no idea what has caused this. I'm really hoping it is something simple like a wire that has come loose rather than a whole rewind job. Considering I recently spent near enough a grand having that motor refurbished i'm fearing the worst!

I have set my field votlage to around the 200v range and havent really experimented with varying it yet. You are right that there is a trade off between speed and torque though the machine hasnt been close enough to finished for me to find out yet.

Same for the backlash compensation. Havent got that far yet!

Well as I have a smaller machine than you my spindle motor is also smaller in power.. it is made by :-

http://www.sicmemotori.com/index.php?lng=2

What I did was measure the resistance of the field (with a cold motor…. No point doing this if you have been running the motor for an hour)

If memory serves I got around 66 ohms field resitance and the motor name plate said 1.7A so abit of ohms law give me 112volts or approximately half the domestic main voltage of 230V so I used two diodes to form a half wave rectifier. This puts 1.7A through my field…… I’ve always had the blower running aswell…so I didn’t fry my field.

Obviously I have to weaken my field voltage down to about 43volts to get full speedbut this is another days work… and I need to get it make me some £$£ before I have a another big spend to sort the automatic field weakening out...

I have a eurotherm 512C drive that I supply with 400Volts and this seams to work fine. At the moment the TNC2500 control sort out the demand. So I just need to think of a nice reliable way of getting it all working.

As for your earth leakage problem:- are you using filters any where ?? or does any of your equipment have filters built in that have been activated, some inverters I’ve used have a tab that activates the filter and this has legged me up in the past..

Can you isolate parts of your wiring with breakers? ie does everything else come ON ? its just when your drive is activated.. have you taken the armature leads of the motor and started the circuit ? (To prove its not a drive fault.. and possible a motor fault?)

I will get you my motor details… but there’s not that much to go off and with a 200v field voltage yours sounds completely different to mine !

Am in Germany currenty until Friday (working on my new milling machine design that’s being built) but I do have internet access for some of the time. So I will reply if I can

I disconnected everything so it was just the motor. If i remember rightly the short was confined to the armature and earth only. The field was not effected.

I think my only option to make any progress is to remove the motor from the machine once again and take it to somone who can open it up and diagnoise/solve the problem.

However this time I will be seeking advice from a different company as I feel that the company I have been dealing with so far has been very economical with the truth on more than one occasion and have been exagruating the work that needs to be done in order to get more money out of me.

Dom, the motor I believe you have is a Contraves GF112M10BF9. The motor is fitted with a compensation winding. This winding is in the field and wired in series with the armature. This could have gone to earth, or pssibly not correctly wired up after the rebuild. Contraves are no longer with us, but EDMR in Northampton are motor experts, and also know Contraves equipment well, so may advise you.

What have you done with the original drive? Was this definitely the original problem?

PS I belive that motor was a 400v armature and a 270v field. I will try and find the current ratings for the motor if you need them.

Thanks for the info, current ratings would be handy if you dont mind.

What is a compensation winding exactly ?

I figured EDMR might know about this stuff but they are a long way from here so it would make things difficult. A friend/machine shop owner has reccomended a local motor repair shop who he assures me are trustworthy. I have arranged for a friend with a forklift to remove the motor from the bridgeport this weekend and will take it to this newly reccomended motor repairer early next week.

To start with I will ask them to take a look inside and diagnose what is wrong + an estimate of how much it will cost to fix.

Armed with that information i'll be better placed to make a decision on how to proceed.

To try and keep it simple. Like on your car engine the ignition advances as the rpm rises. on a dc motor as the current increases in the armature, the compensation winding advances the field. This reduces the arcing on the motor brushes.
Any decent motor rewinder could easily check the motor and tell you exactly what is wrong before they do any real work. Obviously they also need some sort of dc drive system to run the motor.


As yet apart from EDMR I have not found a good rewinder in the last 25 years, so I wish you good luck.

Dom, Assuming I am correct in that the motor you have is a GF112M10BF9.
the rating are:

Power 8.2 KW continuous
Field 270V @ 1.15A
Armature 400V @ 28A
Field weakening occurs at 1140 rpm and motor will run to 6000rpm
Tacho is a GT9.06 which gives 20V/1000rpm

and as you probably have realised weighs about 80Kg

Thanks for the advice.

I still havent been able to get the motor out the machine. It just so happens that these last few days have been the best in months so my friend with the tractor has been too busy driving combines to have time to pull the motor out my machine.

Hopefully some time this week/weekend he will have a spare moment.

It's time to get serious about this retrofit project now. It's been going on for waaay too long and now i've finished uni and have a lot of free time, its really a case of now or never.

So in the last couple of weeks i've been back to the machine, cleaned up the workshop and swept up all the dust/mud/leaves that blew in from outside, I've checked the machine over and pleased to see very little in the way of rust and i've drowned every exposed unpainted metal surface in way oil.

I had actually managed to make more proggress with the machine previously than I remembered so that was a nice find. I'm now abandoning the old DC spindle motor in favour of a new 4hp 3 phase inverter driven solution. About £300 total cost for an almost turnkey solution - cant complain at that.

Yesterday wired up the low voltage lights which shine onto the table. Also fired up the 4kw axis PSU, gently taking the capacitors up to full voltage with a variac in case they had become weakend through lack of use.

Spend the rest of the afternooon doing PID tuning on the X axis motor. To do this I mechanically disconnected it from the table by removing the belt drive and then I wired up the encoders which I had previously fitted to the motors but just needed the electrical connection making to the rutex board.

The PID tuning was done at 24v from a nicad drill battery for safety reasons. Today I will hook it up to the main PSU and tune again at 140v. If that goes well then I will reconnect the belt and attempt to move the axis through mach3.

With the x-axis tuned will it should be possible to copy the PID settings to the other axes and not have to tweak them too much to get into the right sort of ballpark. It's possible that by the end of the day I could have x,yand z under mach3 control!.

This afternoon/evening I will order the new spindle motor and inverter drive so progress is being made there. Still to do on the machine is to wire up all the things like lube/suds pumps, powered drawbar, associated sensors and bits like that. I also need to look at my wiring diagram and re-draw some of it as a lot has changed since the last revision.


The current draw on the 12/5/24v powersupplies is a bit on the high side so this might need to be addressed sooner rather than later; other than that I dont anticipate any huge problems.

The plan now to 'finish' the machine is to first get it into an operating state, then use the machine to manufacture some new sealed encoder mounts which will keep out oil and grime and then the final touch will be to manufacture a freestanding control unit which will house a touch screen LCD, keyboard and mouse/trackpad.


With all this done, the covers can go back on and I will consider the machine finished. That said there is always room for improvement. A 4th axis was considered from the start and space is available inside the electronics cabinet (As well as a 4th psu) to run a 4th axis motor should I want to add one at a later date. In fact all i'd need is a rotary table, rutex axis card and encoder to get a 4th axis running.

There is also a possibility of building my own ATC using a PLC which interfaces to mach3, howevever I could see this being such I big project I might just buy a VMC with ATC when I need that sort of functionality.


For my own reference: The position marked A axis on the rutex motherboard is my X axis, their x is my y and their y is my Z.

Didnt get quite so much done today but on the same token I didnt set fire to anything (or myself!) so I'm not going to complain.

Arrived at the workshop, booted up the pc and the CMOS battery had died and of course lost the settings to ignore the lack of PS/2 keyboard. After driving back home and returning with a ps2 keyboard I was able to get into windows and carry on where I left off.

First did a quick test to ensure machine was still working the same as yesterday. That was good so I set about replacing the 24v drill battery with a 140vdc PSU. It was about this time I figured an E-stop would be a really good idea and I ended up spending most of the afternoon feeding wires from the control cabinet to an e-stop switch mounted above the quill.

Satisfied that the e-stop was working reliably I powered everything up and everything worked nicely, however the PID tuning for 24v was totally different for 140v so I had to start tuning again from scratch. It was taking me a while to make any progress and then the computer crashed. Decided to call it a day as it was getting late.

I'm hoping once i've done the PID tuning for one motor the others will be virtually the same and I can save time by copying the various values.

what sort of inverter are you going for?

One of these:

http://cgi.ebay.co.uk/VARIABLE-FREQUENC ... 240%3A1318

Today got a price on some slideway oil and suds, per litre it wasnt bad but the place i called only sold in 25l drums. Spoke nicely to a friend who owns a local precision engineering firm ( http://www.msengineering.org.uk ) and was able to buy a few litres rather than a few gallons.

Also spoke to Tom over at Rutex US, he assured me that while there were still problems with supply of the drives, they are still being made and Rutex is still in business, so should I blow one up replacements will be available in the not too distant future. He also talked me through the PID tuning and gave me some tips which should help with setting up my drives/motors.

Yesterday I ordered both my 3 phase inverter and 3 phase spindle motor. I expect to have the motor tomorrow and the drive by early next week.