[Thomasdj]

Hi,

I've got two siemens 1FL3042 motors I would like to use for my x/y-axes. However, I'm not sure how to control/drive these steppers.

any suggestions or diy circuit would be great

Best regards

Thomas

[irving2008]

Your going to have significant difficulties finding a driver to work with these... they are 3-phase high voltage motors (325v @ 2A per phase). The proprietary Siemens FM_Stepdrive system has a step control unit operating from 24v DC and a motor power unit operating from 115/230v AC. Some details regarding typical application/wiring to a PLC can be found here and the user manual for the overall Siemens FM_Stepdrive system here

Hope this helps (probably doesnt if you see what I mean )

[Thomasdj]

Hi irving2008, thanks for your reply

yea...I know it won't be easy to find a driver that works..I also noticed the FM-stepdrive unit and so on..

I am used to read electronic circuits/schematics but I am not educated in electronics. However, I'll try to build my own driver. 325v/2A supply is not a problem, I just need a driver schematic for a high voltage AC stepper. I've found the term 'half H-bridge' and guess that's the starting point.

Thanks

Thomas

[irving2008]

Have a look at the Sanken 7600D datasheet. This is a 3-phase stepper control IC with everything on-board except the MOSFET output stages. Given the voltages in question a discrete output stage is probably a must and some care in design and layout will be needed... transient voltages will be potentially problematic. As the 7600D includes the high-side drivers some thinking is required to handle the voltage differential between the 7600D high-side outputs and the actual high-side drivers - I think a simple resistive arrangement might work OK if the Vbb rail is the same as the Vcc logic rail but given the output voltages I'd consider implementing opto-isolation for the output stage which would also overcome the voltage differentials.

The actual MOSFETs would need to be driven by hi-voltage drivers such as irf2114 as these are one of the few devices that can handle that offset voltage.

Attached is an outline concept diagram... datasheets should give you more ideas and specifics but as I said before the layout of the output stage will be critical - there will be >500v transients floating around here...

I doubt you'll find an off-the-shelf design for this requirement and be prepared to fry a few devices getting this to work...

Also I dont need to reiterate the dangers of DIY and >100v, do I?

[Thomasdj]

Hi again, thanks very much for your help irving2008

I'm about to give up on this...I think I'll go with something more usual.

I misunderstood the 325/2A per phase. Such a power supply would kill my budget. And since 4Nm/3Nm is available in lower voltage range, I think I'll go with that instead and just sell the siemens on ebay. The drivers are also available.

However, I'm new to steppers and have tried to read the FAQ docs found on the net.

My machine is constucted of aluminium - solid 30mm x 80mm flat bar. I would like to be able to route in aluminium bar and maybe light steel plate. Can you give me a quick answer on what to look for when choosing the motors?

btw, the table is 800mm x 500mm and the x-axis has two leadscrews

Best regards

Thomas

[irving2008]

Hi again, thanks very much for your help irving2008

I'm about to give up on this...I think I'll go with something more usual.

I misunderstood the 325/2A per phase. Such a power supply would kill my budget. And since 4Nm/3Nm is available in lower voltage range, I think I'll go with that instead and just sell the siemens on ebay. The drivers are also available.

However, I'm new to steppers and have tried to read the FAQ docs found on the net.

My machine is constucted of aluminium - solid 30mm x 80mm flat bar. I would like to be able to route in aluminium bar and maybe light steel plate. Can you give me a quick answer on what to look for when choosing the motors?

btw, the table is 800mm x 500mm and the x-axis has two leadscrews

Best regards

Thomas

Thomas,

You'll need to do some calculations to tell you what torque etc. you'll need. There are several threads on this subject, however if you answer the following I could give you a clue...

type/pitch/# starts of leadscrew on X, Y, Z
type of linear bearings on each axis and travel
weight of cutting head on Z axis
weight of Z assembly on Y axis
weight of Y+Z on X axis (I'm assuming moving gantry here and not moving table)
expected rapid traverse speed on each axis
max cutting speed on each axis
max dia of cutter planned
max depth of cut planned
router spindle speed
stepper to leadscrew connection (direct, belt/geared?)


I think thats all... I'd prefer metric values (its so much easier to work out!)