Eq5/6 motor advice

[Robindonne]

Im not familiar with the ins and outs of stepper motors, but while needing a repair on my cnc spindle (complete different category, 16KW) i discussed some things with the repairguy.   We talked about the small nema 14 motors from the skywatcher mounts, also the plenty of room inside the housing of the mount.  The high torque versions are just a bit longer and deliver maybe only max 10% more torque. Did any of you swapped the original steppermotor for a high torque version? Or does it fry the circuitboard? 

Edited January 29, 2021 by Robindonne

[Dr_Ju_ju]

Yes, to high torque Nema 17's on my EQ5, but driven by an AstroEQ board using TMC driver modules....

[Robindonne]

42 minutes ago, Dr_Ju_ju said:

Yes, to high torque Nema 17's on my EQ5, but driven by an AstroEQ board using TMC driver modules....

Thats a very helpful answer.  I just forgot the eq5 has its motors on the outside.  Maybe i should have asked for heq5 and all the 6 series.   But did you go to this AstroEQ because the mount didn’t have synscan goto?   Because my planned experiment is swap the motors from an Azeq6.  New mount but wondering if that spare space inside the housing can be used to mount stronger and longer motors on the same synscan system.  

[Lonestar70]

Longer and stronger stepper motors will draw considerably more current and may well overload the drivers on your control board.

I would be very cautious about such a change on any Sky Watcher mount... they tend to be unforgiving of such things and just blow the control board... EXPENSIVE to replace.

[Robindonne]

Thats indeed what i expect to happen.  If its confirmed that it will happen, of course ill skip the whole experiment.  Although that astroEQ might be usefull for some other rainy day experiments.  If i was aware of that system i would have bought that outdated celestron g11 for a couple of hundreds, that was for sale some months ago.  I was afraid there were no options to make it a proper guiding mount.  
 

Im still curious what can be done to eliminate the boardfrying of a synscan mount with upgraded motors

[malc-c]

As far as I know NEMA 17s are used in HEQ5 and EQ6 mounts as standard.

The governing factor in with these mount is the MIC2171U which produces the 33v the steppers are run at, and is rated at 2.5A.  When slewing the mount draws around 1.8 -2.0A when both motors are running (assuming the scope is balanced correctly)

Edited January 30, 2021 by malc-c
addition info