Dual motor idea!

[JAZZCNC]

Downside means that rapids are only 2500mm/min which seems a bit slow.

You say this is for small mill so probably 300mm max travel so at 2500mm/min thats 41.6mm in 1sec so 7.2s to cover full travel.!! Seems like you'll be going to lot of trouble and expensive with using servos when machine will probably spend 90% of time cutting at 75mm/min.?

Personally I'd go for 2.5mm or 3mm pitch 1:1 for the torque and resolution and use Lead shine closed loop steppers.! This will make a nice and very accurate machine plenty fast enough for SS.

[m.marino]

You say this is for small mill so probably 300mm max travel so at 2500mm/min thats 41.6mm in 1sec so 7.2s to cover full travel.!! Seems like you'll be going to lot of trouble and expensive with using servos when machine will probably spend 90% of time cutting at 75mm/min.?

Personally I'd go for 2.5mm or 3mm pitch 1:1 for the torque and resolution and use Lead shine closed loop steppers.! This will make a nice and very accurate machine plenty fast enough for SS.

+1

Michael

[Ross77]

You say this is for small mill so probably 300mm max travel

450 ish from memory (too cold to go out and measure :0D) I see your point thought. I was looking on U tube to get a feel for what speeds people were using and 5m/min looked about right but 2.5m/min seems abit slow. Im not aiming for 30m/min like some of the routers but I remember back to when I got the other x-y table up and running (4mm pitch and 3:1, so 1.3m/min) it was painfully slow waiting for it home.

The other minor problem is that in the interrim I need this to make the parts (in Al) for the other machines, hence a changeable resolution

Personally I'd go for 2.5mm or 3mm pitch 1:1 for the torque and resolution and use Lead shine closed loop steppers.! This will make a nice and very accurate machine plenty fast enough for SS.

do you mean the encoder based systems or the digital hybrid ones? the encoder ones look as pricey as servos! the hydbid are much cheaper and some seem to be able to reach 3000rpm! if thats correct then problem solved.

With so many on the net could you point in the right direction

2.5 or 3mm pitch? is that belt tooth pitch or ball screw?


Thanks for your input, most appreciated.

[m_c]

1234567891

[JAZZCNC]

Jazz means the leadshine closed loop encoder system - Hybrid closed loop Stepper system - Zapp Automation Ltd.

Servos can be had for not much more (DMM-tech are pretty well priced, but you need to allow for import tax/vat), or you might luck out and get something suitable on ebay for less however that requires you knowing what you're looking for. Also servos can be a bit of minefield to set-up, which is where the Leadshine closed loop steppers have a major advantage.

Yes I do mean those but they are considerably less than the DMM servo system and can be bought off Ebay for not much more than Good digital drives and decent motor setup.
New Leadshine 300W 3-phase Hybrid Servo Drives Set HBS57 Drive + 573S20EC Motor | eBay

They are fantastic for the money and very accurate. The 2Nm 1.2deg 3phase motors give finer resolution than the common stepper motors, the combination of these motors and the very good Hybrid Digital drives are a perfect match for a small machine that doesn't require high speeds servo's offer. They easily match cheap servo's for accuracy and repeatability.