EQ6R-Pro 7.5 min periodic hiccup

[blair.r...@gmail.com]

Hi Everyone!

Finally got out last night to setup my new mount and give it a test run. While I ran into some setup issues, once I had guiding running I was super happy with the performance. Today after reviewing the data I noticed an odd hiccup of sorts that would occur ever 7.5-ish minutes. 

I suspect this has something to do with the worm gears since it's periodic, but I was wondering if anyone else has seen behavior like this with the EQ6R-Pro mount. I've attached a screenshot from the logs to mark the behavior I observed.

Log data is available here: https://openphdguiding.org/logs/dl/PHD2_logs_39Mf.zip

Thanks for any help!

Best regards,

Blair

[Brian Valente]

Hi Blair

i agree, it looks like something is going on with your mount, unrelated to guiding

you might be better served by posting this to a user group specific to your mount?

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Brian Valente

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[David Woods]

This looks external to the drivetrain. The worm gear and gear ring are the same as the NEQ6 and AZEQ6GT. Likely culprit is something like an electric focuser, or even a laptop on the same power supply, which matches the spike profile. Any major current draw can show up in guiding if it shares the same power source and it’s less than a 12v 5Amp supply. Especially if the mount is competing for power, with a heavy payload, for example.

Actual faults on any Sky-watcher worm and gear ring are very, very rare due to the fact, they are lapped at the factory, as matched pairs, and numbered as such. This operation is performed for the HEQ5, AZEQ5GT, EQ6, EQ6R and AZEQ6GT. Other manufacturers also use this process. However, the periodic worm values do vary from mount to mount, because of the way they are manufactured to a price point.

A simple guide test, would better serve identifying the source and confirming a mount problem, by removing any imaging ‘aid’ be it hardware or software, and just using PHD2.

Regards,

Dave

[steve]

Hi

Yeah, every worm revolution. Best to dismantle RA, then clean and inspect the worm with a lens.

At the very minimum, replace the bearings. They're these ones. Any skate-board/bike shop will have them. Even if you don't see anything on the worm spiral, rotate it in steel wool a few times before re-greasing.

Cheers and HTH,

Steve

[Chuck Koos]

I had someone provide me with this information about EQ6R periods when I was having issues. I don't see anything at 7 1/2 minutes (450s). The closest is about 8 minutes for the worm gear. 

Spur Gears.

Gears Mesh 10.2 sec (Belt teeth?)

Stepper motor gear 122.2.sec

Transfer gear 366.6.sec

Worm gear 478.7 sec (The classic source of PE! )

Worm crown gear 23hrs 56min and a bit

 

Bearings

Worm Bearings

Defect on internal band 108 sec

Defect on external band 187 sec

Defect on one ball 139 sec

 

Axis bearings

Defect on internal band 3hr 29 min

Defect on external band 4hr 40min

Defect on one ball 3hr 3min

 

Taper Bearings

Defect on internal band 2hr 25min

Defect on external band 3hr 21min

Defect on one ball 2hr 31min

[wave...@talktalk.net]

Hi Guys,

To my untrained eye, the worm period of 478.7seconds seems to tally pretty well with the major peak on the frequency analysis curve at 475.6 seconds. This is from the longer Run 28 in the GuideLog.

It contributes around an arcsecond peak to peak. Apart from that one, all the other frequencies are tiny in comparison.

- Jack