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Motor replacement for HEQ5, generic options?

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9 replies to this topic

#1 Pelayo

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Posted 16 October 2021 - 06:08 AM

Hello!

 

Last night one of my motors shaft got broken. To be more precise, the DEC motor. It was a surprise, the mount was not heavily loaded, quite the opposite, and the gear mesh of the worm was just fine. I have been using the mount in low temperatures recently (as low as -4ºC), maybe there was a fracture because of that.

 

Anyway, I need a replacement and in my current location there are no official motors or whatever spare material foir Skywatcher mounts. If I'm not wrong the stepper motors are pretty standard and I just need the specifications to procure the correct one. After some research it seams the step motor is a "Nema 14" 1.8º, but what additional family names shall I take into consideration? Amperes, torque...

 

Thank you



#2 Pelayo

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Posted 16 October 2021 - 05:10 PM

Hello again,

 

Does anybody know if it could be any of these two motors?

 

https://www.omc-step...mm-4-wires.html

 

https://www.omc-step...mm-4-wires.html

 

The first one is 12v, but the size does not match with the motors of my HEQ5. The second one, however, is 34 mm like the motors I have, but it is rated at 5.4V.

 

The fact the mount is supplied with 12V doesn't necessarily mean the motors receive that voltage, therefore my doubts. Any help is more than welcome!!


Edited by Pelayo, 16 October 2021 - 05:11 PM.


#3 Pelayo

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Posted 17 October 2021 - 11:54 AM

I'm really sorry to keep re-floating this topic, but I cannot get official spares by skywtacher and I'm really desperate. 

 

I have attached some pictures of the motors, just in case someone with knowledge can determine which model they are. Sadly, there are no serial number or references, just nothing.

 

Dimensions: 35x35x34 mm

 

Rotor. The broken shaft is missing at the left.

 

1.JPG

 

Stator and housing:

 

2.JPG

 

3.JPG


Edited by Pelayo, 17 October 2021 - 11:56 AM.


#4 Tapio

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Posted 17 October 2021 - 12:19 PM

Have you done Google search - 'heq5 motor'

This?
https://tavcso.hu/en/product/MotorHEQ5

#5 Pelayo

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Posted 17 October 2021 - 12:45 PM

Have you done Google search - 'heq5 motor'

This?
https://tavcso.hu/en/product/MotorHEQ5

Yes, I have, thank you. Unfortunately, because of my current location I cannot get those or other "official" spare parts. At least neither easily nor in a reasonable delivery time.

 

I have to procure generic stepper motors locally. In the end there is nothing special about the heq5 motors, but I need the characteristics.



#6 Tapio

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Posted 17 October 2021 - 01:33 PM

https://stargazerslo...w-easy-is-this/
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#7 ThatsMyCoffee

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Posted 19 October 2021 - 01:49 AM

Do you live in North Korea?  :)

 

 

I'd try E-Bay.  Or put an ad for 'wanted' gear in the classifieds here.  Somebody may have a mount that is damaged in other ways, but still has good motors.


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#8 Pelayo

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Posted 19 October 2021 - 06:55 AM

Do you live in North Korea?  smile.gif

 

 

I'd try E-Bay.  Or put an ad for 'wanted' gear in the classifieds here.  Somebody may have a mount that is damaged in other ways, but still has good motors.

More or less lol.gif

 

I'm in a remote area in Chile for working reasons. I could get spares by skywatcher, but they probably would arrive when I'm already packing back to Spain. However, standard stepper motors are easier to get in electronic stores and that's what skywatcher is actually selling as a spares, but more pricey. I finally got these two. They arrive next week, fingers crossed:

 

https://www.omc-step...35x26mm 4 Wires

 

https://www.omc-step...35x34mm 4 wires



#9 ThatsMyCoffee

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Posted 19 October 2021 - 11:52 AM

Please tell us if it works. Might just pick up a few spares myself.


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#10 Pelayo

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Posted 24 November 2021 - 05:59 PM

Please tell us if it works. Might just pick up a few spares myself.

For your info, and anyone interested, this motor is working perfectly so far:

https://www.omc-step...35x34mm 4 wires

 

I have used it for three nights with my 9,25 SCT for visual and one night for imaging with my 80 mm APO. Guiding performance was nice and I got round stars.

 

I measure the phase resistance of the original motors and it is 7 ohms, which is also the resistance of the motor I procured. Dimensions are almost identically, being the new one slightly larger but it fits with no problems at all within the HEQ5 casing.

 

We aware that the motor is supplied with a long cable with no connection at the mount motherboard end, so it is necessary to buy it also or cut and solder the connection of the old motor. This is the tricky part and it is advisable to open both motors (old and new) to be 100% sure we are using the same phases and pins in the connector. If you fail, the smell after powering it up will tell you (no pressure).


Edited by Pelayo, 24 November 2021 - 06:02 PM.

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