Are you building a model first???

I would think the side-by side would make a huge difference, as it introduces a HUGE cone error (optical axis not in line with the mechanical axis).? ? If I'm thinking of the wrong 'side by side' or there is a way to correct the cone error mechanically (I can't visualize how that would work) then ignore me.?

-Brian

This week I updated to L6, and tonight was my first night out. Immediately I encounter an odd error that I previously had when I first got my mount. This was best emphasized in N.I.N.A. when I attempted to slew to M81 through the framing tool. First I start getting this error "DEC coordinate is invalid or inaccessible". To be honest I was messing around so much I do not know what I changed that got rid of this error.? But what came next has me perplexed, and this is what I was experiencing when I first got my mount:

So M81 is RA 09 & DEC +69 (per Cartes du Ciel). In Framing tool NINA reports the same. But what NINA slews to is this: Cartes is showing the cursor right over M81, yet plate solving is way off. Better yet it does slew to correct and I get this: And it goes right back to where it started and? I restarted Gemini multiple times, even did "Reset SRAM to Factory Defaults". I went to Gemini site and double checked my address to get the coordinates
Latitude & Longitude:
45:03:52 ? -94:02:40
From the mount:
Longitude ? ?-94°02'40
Latitude ? ?+45°03'52

I even tried messing with the time zone offset changing from -5 to -6. This was the problem I had when I first got the mount. I would slew to a target and I would be off as if my time was off my 3-4 hours. Stranger still when I slewed to M101 up around Meridian at this time, my telescope was pointing south when, as if my location was off. Another strange sign was when I slewed to Alp Lyr which was about 35 degrees yet the telescope started to slew as if it was something odd like 5 degrees altitude. I do have a NTP server, and it does appear to sync. The mount currently reports accurately the time from the web UI.?

One thing to note that I do not believe would have been a factor. I did get the side by side but I don't see how that would have affected anything except if some weird bug in new L6 firmware when rotating DEC.??

On Sat, May 18, 2024 at 01:53 PM, DaleN wrote:

Adjusting worm and backlash removal seem the easiest and least intrusive for the moment. I'll check the clutch disc while I'm at it.

Dale

Dale,

The clutch discs are easy to get at - no wrenches required. Just spin the clutch knob at the way off and pull the shaft up and out. Just remember the order of the thrust washers and bearings under the knob for reassembly.?

John
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

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Thanks John.

I always diligently remove Dec backlash; hadn't really considered doing same for RA.

Adjusting worm and backlash removal seem the easiest and least intrusive for the moment. I'll check the clutch disc while I'm at it.

Dale

Dale,

After going to the calibration zone in the south, try doing a mini-slew to the west first off. This may take up any backlash in the RA worm and ring gear. You may want to tighten up the worm tension if this is a large problem.

You RA clutch disc could be slipping. This part can get oily over time or worn. You can get some extra life if you clean and then scuff the pad with a light sanding, but it may need to be replaced. I switched to the non-Losmandy high-friction type quite a while ago to avoid slippage.

Good luck.

John
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

OK, thank you Paul.? I am now a member of Gemini-II, yay!? Apparently I did not switch over to this group when I traded in my Gemini for a Gemini-II way back when.

Paul, are the links on your February post #82039 still the entry points to follow??

--
Edward

Been struggling with RA movement recently (a few nights).?

PHD2 calibration settings are calibration expert defaults. 12 steps for both RA and Dec.

Using PHD2 Calibration Wizard tool to slew and calibrate, the first calibration of the night can take 25-50 steps for RA, then 12 for Dec. I have re-calibrated with the wizard, and the step count for RA remains very high. Last night it started at about 15, then 14, then 13, which I finally accepted. The subsequent GA run showed about a 20” PA error. I’m usually 1-5” off at worst.

other nights 30-50 steps, and after tightening clutch, checking snags, etc etc, takes >10 calibration runs to get acceptable RA.

I’m looking for “most obvious thing that is going wrong”?

Oil on clutch surface
“Newer” wavy washer on RA axis
PEMPro 2 cycle analysis performed, and PEM on while calibrating. Should it be off?
Clutch too tight
Clutch too loose
Guidescope 210mm FL, with ASI290 camera, binned 2, giving ~5.4”/px (I think)
Guide scope flexure? Is rigidly bolted.
Guidescope/camera frame orientation probably well off RA/Dec alignment (don’t think this is ever a problem though, is it?)
Guidescope focus? Gain?
Other?


Thanks much,
Dale

On Thu, May 16, 2024 at 06:53 PM, Edward Plumer wrote:

I am trying to find DIY instructions for upgrading to Level 6.? I saw that Paul posted some links to this group on Feb 6, but all of those seem to reference the home page of Gemini 2 now.?

Edward, you need to join the Gemini-II group to be able to see the files section there. Otherwise, you'll see the home page, instead.

Edward,??

I just did my upgrade today. First you can find docs in the Gemini II group here: /g/Gemini-II. In the files section is /g/Gemini-II/files/+++%20Gemini%202%20Level%206%20Upgrade%20+++

I ended up doing the servos with my PIC, but then ran into problems with the SD card. I could not get to my hand controllers card, no worries as I did replace the SD card in the main control unit. The instructions for doing the servos is good, rest of the documentation is lacking some. I ended up downloading zip files from Losmandy's site, then taking the file from gemhc161.zip. ?and placing that on the SD card. Loading up, it updated the hand controller as well.?

I did get someone to reply about enabling the 4X encoders through the web UI, still waiting for someone to tell me where exactly as I did not find that.?

I finally have a Pic3 programmer in hand (and the eclipse is over so less worry about bricking my mount) ...? I do not have the official Losmandy kit which appears to be backordered now, anyway.?

I am trying to find DIY instructions for upgrading to Level 6.? I saw that Paul posted some links to this group on Feb 6, but all of those seem to reference the home page of Gemini 2 now.?

Is there a standard spot where instructions are posted or can anyone who already went the DIY route direct me to instructions and firmware downloads?

Thank you!

--
Edward

Thanks, folks. I wasted money on a new gearbox and RA cable all because of your suggestions.

I couldn't be happier. : )?

If nothing else, it confirmed an upgrade to a Titan RA axis would be money well spent for my C11 Edge. A community of folks helping out with issues, including user error, is pretty spectacular.?

My mount behaves absolutely normally when the star brightness values are under control. I used values between 5,000, and 15,000 here.?

Wasted money joke aside, thanks to all of you.?

George

On Wed, May 8, 2024 at 03:33 PM, Russ wrote:

With regards to the RA extension for the G11G, there are 2 adjustment/lock bolts on each side of it. I assume these are the only items that need to be tight???? I do see 4 other bolts on the RA extension and I have checked those and they are extremely tight. Just trying to narrow down this whole wobble thing.

Yes. There are 4 Allen head screws under each part of the RA EXT sides. These don't need to be crushingly tight - 2 to 3 ft-pounds should suffice. In many cases you are tightening a stainless screw into a threaded aluminum hole which you don't want to strip. The RA EXT halves fit together like a glove, so I would doubt there's any play there.

John?
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

Just a gentle reminder (trying to help, not annoy…) that ‘the screw is tight’ doesn’t necessarily mean ‘the parts are tight’. A too-long screw can bottom-out in a threaded hole and be tight without bringing the two parts together to make them tight. Thus the screw can be tight and allow the parts to rock back and forth.
Good luck.
-KW

With regards to the RA extension for the G11G, there are 2 adjustment/lock bolts on each side of it. I assume these are the only items that need to be tight???? I do see 4 other bolts on the RA extension and I have checked those and they are extremely tight. Just trying to narrow down this whole wobble thing.

Dan,

After doing the upgrade, absolutely you need to rerun PEMPro and recalibrate PHD2. You are monitoring the number of steps differently and more than likely are out of sync with your previously PEMPro curve.? You should be able to simply update PEMPro to the latest version in the Help menu if you have the paid version. After I slew to the south and do a PEC curve, I do a second data acquisition run to see if the peak-to-peak distance has been reduced (or doubled if the curve is not inverted correctly). Since you're in that part of the sky anyway, running a PHD2 calibration curve, is just one more small step.

Best of luck!

John
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

OK... so I believe I have upgraded everything required for the L6.2 upgrade.? I installed the L6.2 firmware on the circuit board, updated the HC to latest, updated Gemini driver to latest, update ASCOM to latest, and flashed my servo chips with the PIC kit with the latest .hex file.

I'm running an Edge 14 on a Losmandy Titan mount, using an ONAG, so with the 0.7X reducer, my guiding F/L is 2737mm.?

After the firmware upgrades, I tried getting away with not having to re-calibrate PHD2..... no way.? So, I started re-calibrating, and the first few attempts wound up in failure.? But, I wasn't seeing movement of the star for each calibration step.? So.... I increased the number of pixels per step, saw movement, and got a pretty good calibration.? The number of steps per axis were both in the teens, expected rates for both RA and DEC were extremely close, and orthogonality was OK.... previously with L5 I had a calibration of 1.0 or less, this time I got 2.9.... the axes looked perpendicular to the naked eye, but the value was a little high.? I can probably try again and do better for orthogonality.

But, my comment is that for each time I ran a calibration, and it was probably more than 5 times, the plots of the steps were exactly on the axes.... no deviation.? Makes me kind of wonder if that relates to the encoder resolution improvement.

My real question is this:? I recently ran PEMPro with L5, and uploaded a nice PEC curve to the mount.? My thinking was that the gears have not changed with the L 6.2 upgrade..... so would the improvement in encoder resolution necessitate my re-running PEMPro, or it would not make a difference??

I do have the newest version of PEMPro that handles L 6.2.

Thanks so much.

Dan??

On Sun, May 5, 2024 at 07:41 PM, Frank wrote:

Their cup like design and spring steel material may not fully compress to give maximum surface contact/friction.? Their sharp edges coupled with joint movement may carve out adjacent surfaces.

This is not the case, Frank. I've been using Belleville washers for years. They compress at 6–7 pounds of load and don't go any further. They do not have sharp edges and don't cut into any surfaces, especially the surrounding steel flat washers I suggested. Once the knobs snug up, you have all the torque you need to keep the mount in place. There is no need to tighten any further to gain mount stability and lock ALT/AZ into position.

John
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

I assume the 4x means 4 bolts? I have not heard of a 4x Hex Bolt? ? :-)

Thank you gents for the advice. I just ordered nylon washers from Amazon and will place them with all the screws on the G11G various tubes (RA extension...etc). With regards to the 4x Hex Head Grade 8 Bolts; anyone know the length? Only asking because it is pouring rain here and when it stops, I'll take a trip out to the observatory and measure the bolts, but just curious if anyone knew. Really appreciate all the help with this whole thread!!

I added?Belleville Washers to all 6 adjustment bolts on the AZ/ALT adjustment knobs on the G11G.? These belleville washers were sandwiched in between stainless steel washers so hopefully that will provide some additional help.