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Alignmaster + GPS dongle

malc-c

By malc-c
in Discussions - Software

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pritc

pritc

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Received and installed my USB GPS dongle.

First impressions are very positive.

The main display is clear to follow.Found com port and Long/lat co-ordinates were instant.

Actually, I was pretty bang on with my location settings already.But my elevation was 4.5 mtrs out.

Now to check alignmaster, when clear skies allow:mad:

I have a feeling my polar alignment will be way out. :D

Wayne

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malc-c

malc-c

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Received and installed my USB GPS dongle.

First impressions are very positive.

The main display is clear to follow.Found com port and Long/lat co-ordinates were instant.

Actually, I was pretty bang on with my location settings already.But my elevation was 4.5 mtrs out.

Now to check alignmaster, when clear skies allow:mad:

I have a feeling my polar alignment will be way out. :D

Wayne

Fingers crossed, we won't have to wait too long.....

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MikeP

MikeP

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Going back to Alignmaster .....

I seem to recall chrisshillito (author of EQMOD) suggesting that whilst using Alignmaster, you turn off the "append on sync" option in EQMOD so that Alignmaster does not interfere with the storage of alignment points.

It is possible I have mis-remembered, hopefully Chris will spot this thread and clarify.

Mike

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pritc

pritc

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Mike thanks for the tip. I plan on clearing all the data in EQMod prior to running Alignmaster... sorta starting from fresh so to speak

Same here:)

I plan to delete EQmod data files and start over.If I have to adjust alt/az bolts to much to get near perfect alignment.Then all my saved points would be out anyway.

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chrisshillito

chrisshillito

Posted
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Going back to Alignmaster .....

I seem to recall chrisshillito (author of EQMOD) suggesting that whilst using Alignmaster, you turn off the "append on sync" option in EQMOD so that Alignmaster does not interfere with the storage of alignment points.

It is possible I have mis-remembered, hopefully Chris will spot this thread and clarify.

Mike

Yes. you need to make sure there is no pointing model in EQMOD and that it is temporarilly put into "dialog mode" for alignments. If you don't do this then when Alignmaster syncs on the first star it will add a new point to the EQMOD model which will in turn correct the slew to the second star - clearly any correction will affect Alignmaster's measurement of the true error.

Also note that that Alignmaster accuracy is vulnerable to cone error (which it can't distinguish from polar alignment error) so you really need to take steps to remove that first.

Chris.

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malc-c

malc-c

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Doesn't this quest for a near perfect alignment get complicated :D

So lets see if I have this right. Having run the polar alignment utility in EQmod to get a visual polar alignment through the polar finder, then do a cone error correction process (presumably on Polaris), then disable the pointing model in EQMOD, then run Alignmaster and make any small tweaks to alt / azimuth using the bolts over a few successive runs, then enable the alignment model again in EQmod and start syncing targets.... phew !

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MG1

MG1

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Chris, just a thought, but if the polaris drift is a known quantity wouldn't it be possible to put an overlay in the EQmod polar align tool to show a jnow position or Polaris. Or is this likely not to be accurate enough for imaging?

Currently I guess those of us who use the EQmod tool put Polaris in the centre of the small bubble after it has been rotated to the correct position, if we had a scale we could at least approximate to within half of a small bubble width.

(apologies for the technical language...this constant cloud is turning me cuckoo!)

Off for a doze....alarm optimistically set for 2:30!

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MG1

MG1

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Doesn't this quest for a near perfect alignment get complicated :D

So lets see if I have this right. Having run the polar alignment utility in EQmod to get a visual polar alignment through the polar finder, then do a cone error correction process (presumably on Polaris), then disable the pointing model in EQMOD, then run Alignmaster and make any small tweaks to alt / azimuth using the bolts over a few successive runs, then enable the alignment model again in EQmod and start syncing targets.... phew !

But won't u need a new alignment model if you've subsequently corrected for cone error and refined your polar alignment?

:eek:

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chrisshillito

chrisshillito

Posted
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Doesn't this quest for a near perfect alignment get complicated :D

So lets see if I have this right. Having run the polar alignment utility in EQmod to get a visual polar alignment through the polar finder, then do a cone error correction process (presumably on Polaris), then disable the pointing model in EQMOD, then run Alignmaster and make any small tweaks to alt / azimuth using the bolts over a few successive runs, then enable the alignment model again in EQmod and start syncing targets.... phew !

That's the problem with trying to be perfect :eek:.

Not sure I'd bother with EQMOD's polar alignment process if using Alignmaster. I would have thought just sticking Polaris on the central cross hair would be good enough.

Chris.

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chrisshillito

chrisshillito

Posted
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Chris, just a thought, but if the polaris drift is a known quantity wouldn't it be possible to put an overlay in the EQmod polar align tool to show a jnow position or Polaris. Or is this likely not to be accurate enough for imaging?

Currently I guess those of us who use the EQmod tool put Polaris in the centre of the small bubble after it has been rotated to the correct position, if we had a scale we could at least approximate to within half of a small bubble width.

(apologies for the technical language...this constant cloud is turning me cuckoo!)

Off for a doze....alarm optimistically set for 2:30!

Not sure I follow. Are you referring to the increasing inaccuracy of the reticule over time. In terms of hour angle the polaris position is precessed to JNOW by EQMOD (which is why it differs from that shown in the synscan).

Chris

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MG1

MG1

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Sorry Chris it was late and I wasn't being particularly articulate....I'll try again.

My thoughts are based upon the (quite possibly incorrect) assumption that since the EQalign tool starts by positioning Polaris and the reticule at the 6 o'clock position, whilst we might be getting an accurate position of the polar clock angle, the position doesn't correct for the fact that the small circle in the reticule should now be closer to the centre of the large circle (due to procession)

I was simply suggesting that maybe a diagram could be overlaid to show how much closer we should position Polaris. Ie, is it on the edge of the little circle or even closer in?

Of course I may have completely got my bits tangled and in fact EQalign accounts for this. In which case sorry for being a bit of a numpty...!

Cheers

Michael

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MG1

MG1

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PS EQAlign is something altogether different and not part of EQMOD.

ooops....so it is! :D

I was of course refering to the excellent EQASCOM Polarscope Alignment tool

Thanks Chris, I'm assuming most current 'synta' mounts are based upon 2000 Epoch, but I'm not sure how to verify that?!?

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pritc

pritc

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Also note that that Alignmaster accuracy is vulnerable to cone error (which it can't distinguish from polar alignment error) so you really need to take steps to remove that first.

Chris.

It has taken me 3hrs tonight to get my cone error sorted. :eek:

I have never checked it before,it was way out!!

Very fiddley and time consuming.All sorted now though.:)

Polaris sits perfectly in recticle crosshairs on both sides now.:D

Started Alignmaster synced to one star (Algol).Went to slew to second star (Dubhe).Clouds rolled in........:p

Polar alignment will have to wait.........

Wayne

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malc-c

malc-c

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It has taken me 3hrs tonight to get my cone error sorted. :eek:

I have never checked it before,it was way out!!

Very fiddley and time consuming.All sorted now though.:)

Polaris sits perfectly in recticle crosshairs on both sides now.:D

Started Alignmaster synced to one star (Algol).Went to slew to second star (Dubhe).Clouds rolled in........:p

Polar alignment will have to wait.........

Wayne

Nooo.. 3hrs :)

At least you managed to see stars tonight !

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MG1

MG1

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It has taken me 3hrs tonight to get my cone error sorted. :)

I have never checked it before,it was way out!!

Very fiddley and time consuming.All sorted now though.:)

Polaris sits perfectly in recticle crosshairs on both sides now.:p

Started Alignmaster synced to one star (Algol).Went to slew to second star (Dubhe).Clouds rolled in........:)

Polar alignment will have to wait.........

Wayne

LOL...that made me chuckle...'coz i've done just the same! :eek:

What did you use to tweak your cone error? I went for kitchen foil temporarily, but slowly building up in thin layers. It's very thing as 14 layers is only 6 thou'

Didn't manage to get started with alignmaster, but did get a few hours of PHD log for PECPrep whilst waiting for key.

So although it may have been pretty rubbish sky hope I've managed to get something useful out of it! :D

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pritc

pritc

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LOL...that made me chuckle...'coz i've done just the same! :eek:

What did you use to tweak your cone error? I went for kitchen foil temporarily, but slowly building up in thin layers. It's very thing as 14 layers is only 6 thou'

No foil used in my cone error adjustment.

I followed Dion's cone error tutorial video from AstronomyShed.

His tutorial collection is great.:D

I could not believe how sensitive adjusting the scope's dovetail bar was!! :p:eek:

Wayne

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LongJohn54

LongJohn54

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I followed Dion's cone error tutorial video from AstronomyShed.

Wayne

Can you provide a link please. I've searched AstronomyShed's video's and not found it. Also searching for cone error on You Tube got no results.

Google is not my friend :D

John

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