Ultimate accuracy of HEQ5 (EQMod) GoTo?

[chrisshillito]

Aside: I'm really starting to *like* EQMOD, though, in fairness, it (realistically) takes up all the resources (USB sockets, notably) of my humble NCxx Netbook. I now need another one to run any (Video) capturing! Also, remote, ELECTRIC focussing seems almost an essential for this idea... Never blimmin' ends, does it?

Stick your gamepad and mount serial link on a USB hub - Plug your camera directly into the netbook (things will work better that way!). If you get yourself a focuser with an ASCOM driver then you can control that via the gamepad as well using ASCOMPAD (another bit of EQMOD Project software).

Chris.

[ashworthacca]

Once I have perfect polar alignment I'll spend 10 minutes or so creating triangles in the areas I'll be imaging. What I found was first time you generate a star list is the first star will be off and what I did was slacken the clutches and centre the star then tighten up, all GOTOS after that were pretty much bang on.

This was proberbly down to cone error.

That's exactly what I do. I think the trick is to slacken the clutches and centre the first star manually and don't use eqmod to move the mount.

[Macavity]

Stick your gamepad and mount serial link on a USB hub...

Never say die, Eh? Like it!

But again, thanks for helping here. EQMOD certainly works well via USB hub. My (rather dodgy) Wireless gamepad [dongle] seems a bit reluctant tho'. Looks like there might be Bluetooth Gamepads? Who knows - Bluetooth never does much for ME, except interfere with detection of USB ports? Indeed, a focuser controlled by the Gamepad too? How cool would THAT be.

But we digress! Some good, and useful, info here, thoughbut.

[RogerTheDodger]

I tried a wireless gamepad but kept losing connection. I've gone to a wired one as I have a mini usb hub on the mount anyway, and all works fine now.

BTW Chris, keep up the good work, it really is appreciated

[MikeWilson]

Yes, you can do that - you can even filter on local quadrant if you like as well (but then your going to need 12 alignment points, three in each quadrant, which is getting to be a bit of a chore unless your mount is permanently sited.

Yes I'm the guy boring everyone to death with EQMOD videos - I also write the majority of the software nowadays. The video that mentions the points filter is here YouTube - ‪EQASCOM Alignment Part 4: Proximity Range & Point Filter‬‏

Chris.

Thanks Chris,

I think I'll stick with one side of the meridian for now although it would be nice to know that I can do filtering on each side of the meridian for longer term use. I'm a tripod-user, so always temporary setups.

While I'm here - do you know what might cause EQMOD to stop tracking after I manually slew using a gamepad? If not, no worries - but I thought I'd pick your brains quickly on a little bug that's been driving me nuts for weeks!

All the best,

Mike

[Macavity]

I tried a wireless gamepad but kept losing connection. I've gone to a wired one as I have a mini usb hub on the mount anyway, and all works fine now.

Heh. I might return to that idea too - I have a mini hub. I sense I always use the gamepad in the vicinity of the scope. This wireless one has a permanently stuck (ergo disabled) "North" button, keeps entering it's sleep state etc.

Not to mention I keep trying to use it behind a steel pillar, and wondering why nothing is happening.

[RogerTheDodger]

Funnily enough, with good levelling and polar alignment last night, my first goto for alignment was almost spot on - just needed a quick tweak before sync.... normally I have to loosen the clutches and center manually.

[chrisshillito]

While I'm here - do you know what might cause EQMOD to stop tracking after I manually slew using a gamepad?

Do you have mount limits enabled? If so, could you have slewed into the limited zone?

Chris.

[Revs]

A meridian flip might be in order.

[MikeWilson]

Do you have mount limits enabled? If so, could you have slewed into the limited zone?

Chris.

Nope and nope. It's possible that a meridian flip might be required but I'm not so sure... I'll see if I can reproduce it and make some notes on when it happens.

Clear skies,

Mike

[SJC03]

How do you measure the accuracy ? ..the handset Identify ?

I ask because I have been setting my HEQ5 Pro up again after many years where the polar scope had been removed.

Having used many guides from the web I did the uncomfortable way kneeling while in view of Polaris an hour at a time making adjustments:

I got 0.7 to start from..then 0.265 then 0.2 and last 0.01 which is the reading from the handset Identify at a star other than Polaris which gives 0.00

I do have doubts though

[Macavity]

Just re. a minor personal intrigue (in your own time, Chris?):

EQMod - Are RAOffset, DECOffset (points list) values, Degrees?

I think mine were all (unsurprisingly?) bigger than the doc. figs.

But magnitudes, signs etc. MIGHT suggest areas to look at?

[chrisshillito]

The RAOffset and DECOffset values are in stepper motor microsteps. For the HEQ5 and EQ6 Pro each microstep represents 0.144 arcsecs of movement. If you right click the map display you can see how gotos across the entire sky will be transformed based upon the offsets of the points already measured (if it all looks a bit cluttered - resize/maximize the window.

Chris.

[teleskopjo]

Once I have perfect polar alignment I'll spend 10 minutes or so creating triangles in the areas I'll be imaging. What I found was first time you generate a star list is the first star will be off and what I did was slacken the clutches and centre the star then tighten up, all GOTOS after that were pretty much bang on.

This was proberbly down to cone error.

Any tips for triangle star selection when doing the 12 point model (one triangle per sky quadrant).? 

I assume the basic requirement is to create equilateral triangles in each quadrant and between each triangle, iykwim.

[Zakalwe]

That's exactly what I do. I think the trick is to slacken the clutches and centre the first star manually and don't use eqmod to move the mount.

As long as your mount doesn't have encoders. Try that with the AZ EQ6 or the EQ8 and the encoders will just tell EQMOD that you've moved the mount.

[beamer3.6m]

What about using software to plate solve.

I understand that it takes a pic, works out what it is looking at and then moves the mount relative to that picture to the desired object.

I coukd be wrong.

[perfrej]

It was a while since I eqmodded my NEQ6, but as has been stated, centering the first point by means of loosening the clutches solves most pointing errors. That is if the mount is reasonably polar aligned and free of significant cone error.

You would love using a modeled and encoded mount. When I power up my babies frim completely off and do the first slew I end up less than 15" off every time, and usually within 5".

With Eqmod, the EQ5-6 is capable of very good pointing too, given a good, preserved home position.

/p