eq6 stepper motor

[alacant]

Hi everyone

Can anyone confirm these as the correct motor?

TIA

Edited October 29, 2021 by alacant

[newbie alert]

Nema 17... be interesting if they are

[malc-c]

NEMA 17 refers to the face plate size, which is 1.7" x 1.7".  It doesn't relate to the actual specs of the windings, torque etc.  For example the holding torque can range form 0.85kg / CM up to 3.7kg / CM and they all look the same physical size with a 5mm diameter shaft.  Also the operating voltages can vary between 3v and 30v  (Seeing that the switch mode power supply on HEQ5 / EQ6 mounts generate 34v to the driver chips, it may well be that the  NEMA 17 sized motors in the EQ6 that have the designated part number HM6GT-F00-1 are custom / hybrid design, and you may burn out an off the shelf Stepper motor and or damage the motorcontrol board.

I would do more investigation before committing to an order

[malc-c]

If you have one, measure the face plate of the existing motor... you may find that they are NEMA 14

[malc-c]

Trawling through posts on this forum and cloudy nights, seems one suggestion was this  - $54 per motor, which might explain why SW replacements are averaging £75 with new mounting plates included

[newbie alert]

6 hours ago, malc-c said:

NEMA 17 refers to the face plate size, which is 1.7" x 1.7".  It doesn't relate to the actual specs of the windings, torque etc.  For example the holding torque can range form 0.85kg / CM up to 3.7kg / CM and they all look the same physical size with a 5mm diameter shaft.  Also the operating voltages can vary between 3v and 30v  (Seeing that the switch mode power supply on HEQ5 / EQ6 mounts generate 34v to the driver chips, it may well be that the  NEMA 17 sized motors in the EQ6 that have the designated part number HM6GT-F00-1 are custom / hybrid design, and you may burn out an off the shelf Stepper motor and or damage the motorcontrol board.

I would do more investigation before committing to an order

I'm not so sure that's correct.. the motors themselves look far different.. as the image shows

[malc-c]

As mentioned NEMA XX standard is simply the measurement across the face plate.  NEMA 17 is 1.7" x 1.7", NEMA 14 is 1.4" x 1.4".    The depth of the motor, the internal resistance, the method of control (bipolar or unipolar), and other electrical characteristics all vary depending on their specification. 

All these are NEMA 17

But available in 8 different specifications - see here

Unless the internal resistance and voltage ratings for the coils of the original motor is known,  it's not a straight forward case to just replace a $55 stepper with a $6 one.

Edited October 30, 2021 by malc-c

[newbie alert]

On 31/10/2021 at 00:02, malc-c said:

As mentioned NEMA XX standard is simply the measurement across the face plate.  NEMA 17 is 1.7" x 1.7", NEMA 14 is 1.4" x 1.4".    The depth of the motor, the internal resistance, the method of control (bipolar or unipolar), and other electrical characteristics all vary depending on their specification. 

All these are NEMA 17

But available in 8 different specifications - see here

Unless the internal resistance and voltage ratings for the coils of the original motor is known,  it's not a straight forward case to just replace a $55 stepper with a $6 one.

Ok, just confuses me that you can buy a nema17 and a nema 23 and you get 2 totally different sized motors.. so I presumed that the whole thing was either a 17 or a 23..

[malc-c]

20 minutes ago, newbie alert said:

Ok, just confuses me that you can buy a nema17 and a nema 23 and you get 2 totally different sized motors.. so I presumed that the whole thing was either a 17 or a 23..

Well a NEMA 17 and NEMA 23 are different motors, the NEMA 17 being 1.7" x 1.7" and the NEMA 23 being 2.3" x 2.3", so the 23 will be half an inch square larger.

I doubt that Synta would run to the trouble of having custom NEMA 17's wound for the HEQ5 / EQ6 mounts, and would use off the shelf components, but as I mentioned, it's possible that they have used motors that operate at high voltages with large amounts of torque, given the 34v the motors are driven at.