Sabalias

Thanks Andrew. I’m currently using Astroberry but about to start experimenting with a PC solution and NINA. 

Stu

Hi All,

I've been trying to search various sources for some information to help me with a small problem but without much success. My scope is not balanced correctly in the off-axis direction due to the auto-focuser and bulk of a filter wheel hanging off the same side. I want to avoid adding additional weight to the rig so I am trialling mounting the camera upside down (which means the weight of the filter wheel is now counterbalancing the weight of the auto-focuser). Could someone confirm that the main OTA camera orientation will not cause a problem for plate solving etc if I set the CCD FOV rotation to 180 in my software please?

Many thanks,

Stu

1 hour ago, michael8554 said:

Yep, for once us amateurs came to the same conclusion as the PHD2 guys, a cable snag.

They suggested setting up at the same Alt and Az, to see what may be catching.

Michael

Indeed. I saw the answer in the PHD2 forum and was, at least, relieved to hear that it was something I could probably fix. I've checked and rechecked the backlash adjustments in case it's binding and I'll have a look at the scope in situ during daylight hours to see if there is a snagging issue. Will post back here in case it's something someone might find useful.

Stu

5 minutes ago, vlaiv said:

Looks to me like some sort of cable snag.

You have the same issue in both RA and DEC - which is unusual because DEC should really "stay put" without too much corrections, however you graph is almost the same in both axis:

 

I'm guessing that cable is pulling on OTA in such way that it moves both axis and when you do RA correction - it actually manages to make cable give a little and it takes more for DEC to recover - then cable tightens up again, RA correction manages to get a bit more slack of the cable and DEC slowly follows.

Binding would produce similar RA behavior but I'm not sure it would have the same impact on DEC though.

Thanks Vlaiv, that was what I wondered last night but I couldn't find anything obvious. I'll try again tonight to see if I can spot any external interference. I've reworked my backlash adjustments in case there is binding.

Stu

15 minutes ago, michael8554 said:

As you've already posted this on the PHD2 help site, you should try their suggestions before contacting us "amateurs".

Michael

I posted here first as I didn't have a google account but then realised that I might benefit from the input there so I sucked it up and 'went google'. You never know though - someone here might have seen the same results specifically....

Stu

Hi All,

I was wondering if a kind soul could lend me their wisdom regarding the attached PHD2 guidelog. First time out since April for me and something is very, very wrong. It's an HEQ5 Pro with Rowan belt mod; I've tuned out the backlash as much as I am able (but it looks ridiculously high in the log). I may have mucked up the PHD2 calibration (easy fix of course) or perhaps there is something else going on. Any ideas would be gratefully received.

PHD2_GuideLog_2023-09-04_153511.txt

PHD2_DebugLog_2023-09-04_153511.txt

Many thanks,

Stu🤯

Not exactly proud of this one:

Guess who managed to strip the thread on one of the backlash adjustment holes……

Stu

Really interesting thread, thank you for starting it OP.

I'm still in full time (day) work and like to get a full night's sleep whatever the day of the week. As a result my rig gets put to bed in May and doesn't come out again until late August; also, my imaging times are short but get longer as the year progresses (automated but no observatory here so I'm not willing to leave all that expensive kit outside). I'm knocking on the door of early retirement and an aspiration is to move to a quieter part of the country (eventually) where I hope to build a secure set up so that I can leave my sessions running overnight.

Stu

In my experience you are quite right, £500 won't get much of a set up. I would suggest looking at second hand, you can get more for your money (though astro kit tends to hold its value quite well).

Does your friend have a DLSR with a long lens? If so then a Star Adventurer GTi and tripod comes in at £559 on FLO and that might be a good place to start; you can get some lovely images of DSOs with that sort of kit. Alternatively there's the Star Adventurer 2i and tripod for £415.

Stu

12 hours ago, newbie alert said:

Hi Stu, depends if you're pulse guiding or ST4, if ST4 you calibrate on every target and after the flip, if pulse guiding then you calibrate on the equator/ meridian

Polar scope pa is deemed a rough alignment

And to drift you need to point south, but as you say your house is there

Have you tried sharpcap?

Thanks for the helpful info. I'm using pulse guiding through Astroberry so I will try the PA module in EKOS (as Sharpcap isn't available for my setup as far as I'm aware).

Stu

4 minutes ago, malc-c said:

Stu, PHD2 states that you should calibrate within 30 degrees of Dec 0. The ideal spot is the intersection of the meridian and the Celestial Equator, where you will have the most movement of a target star.

With regards to the belts.  Ideally you don't want any stretching or slack in the tension, otherwise you are not going to have any of the benefits a belt conversion offers over the geared system.   When I was developing a belt conversion 12 years ago (my doesn't time fly !)  I didn't use an idler wheel like the Rowan kit, but went direct between motor and worm pulleys, using the adjustment slots built into the mount for the motor fixings. You'll never get perfection as you'll still have backlash in the worm gear, which, given the pricing point of the mount is going to me manufactured to a certain level of tolerance.

Thanks Malc,

So, to clear up my understanding, I would need to be calibrating with my scope pointing towards the south at a Dec angle of 0 degrees (+/- 30 degrees)? Shame my house is in the way 😂

Stu

1 hour ago, newbie alert said:

Why are you calibrating on Dec 56.7?...

you could also tighten up your PA

A Error= 2.7 arc-min

What level of error are you looking to achieve as these are really budget mounts and always going to have machining inaccuracies

What does your calibration data look like, and have you a screenshot of your guiding?

I’m not sure what you mean by calibrating on Dec 56.7. I’m just asking PHD2 to do it’s thing.  Edit - I see you are referring to the Dec angle at calibration; this is because I start guiding after slewing to the target. Presumably I need to get the calibration done before I start slewing?

For tightening up PA I probably need to start drift aligning or something because I think I’m as good as I can get using the polar scope. 

I’m happier with the guiding I got last night; previous attempts were really bad (hence the initial post). 

Stu

Finally a clear night last night!  Attached is the latest guide log.

I'm a little surprised at the backlash remaining in the mount (clearly I have some more work to do on that) but I'm feeling better about the guiding (session 4). Having said that there were some drastic deviations in the first 15 mins of the main session; I guess these could have been shifting cables or slipping in the axes? Or could they have been caused by a passing vehicle (the third spike happened at the same time I went out to check on the mount so maybe there is a bit of vibration being detected)? Anyway, I might see if I can tighten the belts a tiny bit more and also revisit the worm meshing so make sure I have eliminated (as much as possible) the backlash.

Stu

PHD2_GuideLog_2023-02-13_184443.txt

1 hour ago, jfrijhoff said:

Interested to hear the result, as I’m also in the market for such a modded HEQ5 Pro.

I'll let you know how it goes. The tune and belt mod installation went pretty well by following various guides, so I recommend it if you are looking to enhance your mount (assuming my latest tweaking has worked and my mount is now performing well 😁).

Stu

2 hours ago, vlaiv said:

I had issues with belt mod on my HEQ5 until I really tightened belts, then problems went away.

Quite possible that issue was due to belt tension.

Thanks Vlaiv, I was hoping you might be able to chime in 😉. The slack in the belts has all but disappeared but the flex seems to be a little less than the recommended 2mm; I could go a little tighter if necessary but I'll see how it goes on a trial run first..

Stu

Small update - I've had an email back from Rowan and I've made some adjustments to the belt tension and the 'slop' in the belt seems to have disappeared (I hope this will result in less backlash on PHD2). Is this all it could be?

Thanks,

Stu

Hi All,

A couple of months ago I replaced all the bearings in my HEQ5 and installed a belt mod. Maybe I was expecting too much but I'm getting a bit frustrated with the quality of guiding; it's better than before I stripped it down but not nearly as good as I was hoping for. Would some kind soul be able to take a look at the log below and let me know what might be wrong please? For reference this is what I have tried so far (using various sources including Astrobaby's):

• I've re-stripped the mount and checked everything is put together correctly. The axes both turn freely when not locked
• I've checked and re-checked the worm-gear meshing for backlash
• I've adjusted the worm-drive float (maybe it's wrongly adjusted?)
• I've tidied up (as much as possible) the cabling but I still have 4 power cables running to mains and one is very rigid)
• I regularly check the mount for cable drag etc but nothing obvious shows
• My kit weight is within tolerance
• The balance is as good as I can get it
• The mount is as level as I can get it

I have noticed that the belts on the drive slacken slightly when commanded to move in the opposite direction, which surprised me, and PHD2 tells me I have about 4000ms backlash. I have not yet got a dew heater on my guidescope (next purchase). Once I have figured out what's going on I'm planning on getting a power hub to reduce the dangling cables. Finally, there was no wind last night

Anyway, has anyone got any ideas? Is the mount operating as expected; in other words, am I expecting too much? Is it simply a duff mount (I found swarf in amongst the worm gears when I stripped it down to replace the bearings)?

Many thanks in advance,

Stu

PHD2_GuideLog_2023-02-07_182344.txt

On 29/01/2023 at 13:11, newbie alert said:

If you took your car in for a super tune and the mechanic replaced a few components and a re-grease is that just a service??

There's a whole host of other things you can do to a mount that wasn't paid enough attention to , even at the factory... 

And yes a gritty bearing should be replaced

I did find that there was a badly cast area within the mount (I don't think it was impinging on anything but I sanded it down anyway). Not sure what else I could have done without some dedicated machinery 😂

On 27/01/2023 at 18:53, pipnina said:

I believe the HEQ5 uses a lithium grease normally, I'm sure other greases will work as a substitute but I would probably choose to go with the manufacturer's choice myself, unless there's an obviously better alternative.

Lithium grease is quite thick but of course that can be quite good for the slow, high torque and high load gearing being lubricated.

Hi Pipnina

I did put some lithium grease on it about a year ago but I don't think it helped; when I opened the mount up to install the belt mod I found that the lithium grease was pretty solid which is why I went with the grease that was recommended by various sources. Seems to have done the trick

Stu

On 05/01/2023 at 14:50, Sabalias said:

I'd love to be able to upload a photo of my lovely new Skywatcher EvoGuide 50 but, even though FLO dispatched it yesterday and DPD gave me a delivery slot today, it has not materialised. Instead it's been taken back to the depot with no reason given 🙄. Perhaps I'd be a little more forgiving but its the second time it's happened with DPD delivering from FLO; so I'll request carrier pigeon delivery next time.

Note - not FLO's fault; DPD is about as effective as a chocolate fireguard.

Pleased to say that my guide scope arrived safe and sound later that day. No idea if the fuss I made persuaded DPD to re-dispatch it but I’m grateful either way. 
 

Stu

I'd love to be able to upload a photo of my lovely new Skywatcher EvoGuide 50 but, even though FLO dispatched it yesterday and DPD gave me a delivery slot today, it has not materialised. Instead it's been taken back to the depot with no reason given 🙄. Perhaps I'd be a little more forgiving but its the second time it's happened with DPD delivering from FLO; so I'll request carrier pigeon delivery next time.

Note - not FLO's fault; DPD is about as effective as a chocolate fireguard.

Hi Gus,

I used Loctite Superlube. 

Stu

What a fantastic Christmas it's been - I was given a Rowan Belt Mod Kit for Christmas and also ordered a complete set of replacement bearings (because both axes of the mount had become stiff and the guiding was appalling). So for the last few days I've stripped down my (from new and never opened) HEQ5 Pro; de-greased and cleaned everything (there were even some worrying flakes of metal and paint in the worm gears); replaced all the bearings and re-greased; and finally installed the belt mod. Most fun I've had in a long time (what does that say about me? 😂).

Anyway, the mount is all back together and seems to be operating as smooth as silk (I hope to try to test it this evening).  Some of the things to take away from the exercise:

1. Don't necessarily trust the stock hardware (one bearing on each axis felt as though it had sand it it)
2. Lakes of grease don't necessarily mean a smoothly operating mount (it felt like I spent longer cleaning all the old grease off than reconstructing each axis)
3. If the mount's tracking and guiding has gone awry then it might not be an evening set up error

Happy to share more detail if anyone's interested (tempted to try it themselves).

Stu

4 hours ago, fwm891 said:

Clear Outside is showing clear Thurs/Friday this week (Full Moon!) Although showing as 90% low cloud for now but skies are very clear? C.O. can be quite hit-n-miss...

Unfortunately, my experience of CO for my location has tended towards miss and miss by a mile 😂. To be fair though I don't think any other apps are any more accurate.

Stu

Iris Nebula

Skywatcher Evostar ED80

ASI 1600MM-Pro

4hrs 18min of LRGB over 3 sessions starting on 4th November

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