Rover Mini SPi and MPi Stepper Motors
Turbo Mini Forums

I need to re update this at some point, after I recovered from throwing my toys out of the pram

Edited by Sprocket on 16th Dec, 2007.

OOO thats not good news, i hope you sort it mate.

Manchester Minis

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Edited by Sprocket on 13th May, 2007.

Im not worried... honest.... im trying to find a cheap spi unit to take apart ha ha to get a general understandings of how it works.

Manchester Minis

I threw my stepper in the bin and just made a v small bypass hose. Idles at 1200 but then any slower and it would be a bit lumpy!

never did look into the stepper as i jstu opened it right up and ran a bosch 2 wire IACV. however there was a circuit posted that may be able to controll that type of stepper that translated the PWM signal to a stepper putput.(was designed so that us msns-e'ers could use a stepper) be worth a search on the megasquirt forums

Edited by evolotion on 29th Aug, 2006.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

seen this thread and thought of you :)

http://www.msefi.com/viewtopic.php?t=18971...control&start=0

the driver IC http://www.st.com/stonline/products/literature/ds/1377.pdf is a bipolar driver, but if a unipolar equivalent is avaliable this shoudl sort your problem

edit again, soem info on driving unipolar motors with bipolar drivers..



http://www.st.com/stonline/products/literature/an/1675.pdf

Edited by evolotion on 3rd Sep, 2006.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

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Edited by Sprocket on 13th May, 2007.

no probs. iv got my head burrie din other work right now, but i'd also liek my rover unipolar stepper to be controlled by my megasquirt, as the bosch IACV im useing makes a noise like a foghorn when its active :(

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

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Edited by Sprocket on 13th May, 2007.

May be worth having a nose around on CNCzone.com

It's a site for those interested in building their own CNC mills, routers etc. and there are a lot of knowledgeable people on there regarding driving stepper motors.

Andy

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

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Edited by Sprocket on 13th May, 2007.

I've just measured the resistance between the common centre tapping and the other four windings and it is consistantly 9-10 ohms.

Winding to winding is about 19 ohms as you would expect.

Megasquirt info suggests resistance of 35-50 ohms.

So, do we need to add in additional resistance to lower the voltage at the windings?

I can't see why we can't use the SPi/MPi IACV but will it need modification?

Do we need to split the centre tappings, otherwise we will be energising both windings. Or will the fact that the other coils are open circuit mean this doesnt matter?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

So, do we need to add in additional resistance to lower the voltage at the windings?

-- you may do, you may not, see the datasheets for the megasquirt driver IC. if you cannot drive them directly and the added resistance drops the torque output to much its not too much hast le to knock up a few TIP122's and ods and ends to drive the coils properly.

I can't see why we can't use the SPi/MPi IACV but will it need modification?

--The valve can be used, the windings need disconected from each other. see Mini Sprockerts post "Its mearly a matter of disconnecting the windings from the center tap and each other, to be able to use these motors with MSII. The only thing I have not checked as of yet i the winding resistances and whether they are within the limits of the MSII stepper driver. "

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Well the MSII IAC controller can output 750mA continuously.

So 12v and 19 Ohms gives me 630mA - should be OK as long as the motor can take the current. MS site suggests to check if it gets hot if left on!

As long as I break one of the black wires in the picture above it should work as bipolar.

Sprox - how did you get the unit apart, looks like three pins, did you drill them?

Edited by Paul S on 3rd Dec, 2006.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

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Edited by Sprocket on 13th May, 2007.

iv got a spare motor jsut for this.., jsut not the time, allthough i plan on implementing the PWM to stepper convertoer or mayb even MSII when i rebuild the car over the winter.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

motor is DEFINATELY 12v. the signle big commmon terminal is connected to a switched +12v alogn wiht the injectors and ignition coil in the standard loom.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

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Edited by Sprocket on 13th May, 2007.

My MSII arrived yesterday and I'm now waiting for some parts to get the EDIS fitted and working.

I'm going to bring in the sensors one by one, and then fit the MPi inlet. But I then need the siamesed code to actually run it. Let's hope Jean is getting on OK with it.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Axel,

I'm sorry it's taking so long but I haven't been able to put the time I thought I could on the siamese code. I probably still won't be able to put much time on it in the next 2 weeks but should have plenty of time during the holidays.

My current plan is to have a first version of the code go public for the start of 2007 at the latest.

Regards,
Jean

http://www.jbperf.com/

Jean,

Did you ever get the air-temp sensor I posted (and the other stuff in the package)? I'm guessing not as you never mentioned it???

Dave,

No, I never received it. How long ago did you send it?

http://www.jbperf.com/

months... :(

Send me your address again and I'll send another. Maybe some greedy customs / mail man spotted the 'jelly belly' sweeties and decided to make the parcel disappear...

I'll put tracking on it this time LOL!