CPC 800 and wedge Query

[Kerrp30]

Bought a heavy duty wedge and upgrade kit from ebay a while back just built it up today and assembled it all today.

I think I have done this correctly, reading the instructions in how to align seems a whole new world, which I will explore at another date.

Please tell me I have attached the scope/wedge to the tripod correctly.

Is it much more difficult than the normal sky align? Do I need to point one leg to polaris or does it not matter on this type of setup.

I have attached some images of the scope and mount.

Any feedback welcome

Paul

[brantuk]

It all looks fine to me - the main thing is to get the weight over a leg (not between two legs) otherwise it will fall over when the legs aren't extended.

The lock nuts look fine at the top of the latitude adjustment screw - keep each pair tight together but with a little play between to allow the angle plate bar to move up and down when turning the latitude screw. If too loose either the the whole assembly will lock up - or loosen off and drive the screw into the underside of the plate.

The side bolts need to be tight enough to hold everything in place but loose enough to allow up/down movement of the plate.

And the bolts that attach the botom plate to the tripod need to be just loose enough to allow small azimuth adjustments when polar aligning - but again tight enough to keep it all in place.

Underneath the bottom plate - finely adjust the azimuth screw so the block moves eaqualy in both directions - bit fiddly but just possible. I found the grub screw a bit poor for locking the ring in place on a wedge of this price.

Otherwise - you look as if you've cracked it - but I can't tell how tight/loose everything is from the pictures.

Well done with a fiddly job

[brantuk]

Oh one other answer - you'll be pointing the telescope at polaris - this will usually mean two legs will be pointing north - and the one with the weight over it pointing south (northern hemisphere).

Do come back to me with alignment questions once you've double checked the assembly - it's easy but the manual is sadly lacking in it's explanation. If you're at Kelling in April I'll gladly come round and demo for you.

Hope I've helped

[Kerrp30]

Thanks for this Brantuk, I find celestron could improve on the documentation side as it is badly lacking in clear concise information.

That is why people like yourself and forums like this are invaluable.

I may and try and give this type of alignment a go over the next week.

I have one or two questions.

1. The altitude (arm) drive I lock this to the two pointers on the arm and the scope. This then does not move is that correct? Or does this also move but once you have the object in sight it is only the azimuth drive that moves to compensate for the rotation of the earth.

2. What does the wedge actually do for me at 55 Deg N. That is my location.

3. Do i move the scope tube using the cursor keys or do i adjust the tripod to align the scope?

4. How do you find the meridian? on a globe you can have lots of points that go through both poles.

Cheers

Paul

[brantuk]

You're very welcome Paul - this is a great little scope that's let down by the documentation on key points - I remember fretting with exactly the same questions when I got my wedge.

OK: First thing - when it's on the wedge - ignore the two pointers on the alt arm totally - they're only any use in alt/az mode.

Second (and obvious) get the mount (with wedge on) level and pointing due North - I use a compass and angle a length of string between two tent pegs to acheive this (remember you're pointing the wedge so when you mount the scope the base is looking north). At the moment everything is approximate

Next - mount the scope, level the arms horizontally, and set the latitude using the adjustment screw. Now the arms will be pointing north (as if you were holding your own arms up at polaris).

Then - raise the tube (motors or manual) so it too is pointing in the same direction as the arms - the more accurate the better but you may have to make your own reference mark on the arm and tube so you can repeat again later.

Now we have an equatorial scope and it works the same as any other - so only lock both axis clutches as if it were an eq mount (both need to move).

If you're incredibly lucky you'll see polaris somewhere in the finder scope. If not then you'll have to center it using the motors - make sure you have the finder and ota pre aligned with each other - then center polaris in the ota and adjust the finder - this is where you may need to do fine adjustments in altitude and azimuth using the wedge screws.

Now you have your reference position for the motors - switch off totally for a good 30 seconds (key step) - then switch back on again. Give it up to 20 mins to find satellites for the gps.

Now - when you use the arrow keys to swing the base through 180 degrees and the tube through 90 degrees (downward) you'll find everything ponting south at the meridian exactly as per the picture in the manual (fig 4-3 on page 18).

Sounds horrendous but once you've done it a few times it all becomes very natural

Now everything in the instructions for alignment make sense and you can do the electronic wedge alignment and star alignment with no problems. Whew

[brantuk]

Oh - I didn't cover question two - that's easy - the wedge will make the scope track in one plane (RA) only at any latitude (with only very minor tracking adjustments in Dec - depending on polar alignment accuracy). Makes taking long exposure dso pics a lot easier.

[Kerrp30]

Brantuk, thanks for your input, will probably read this along with the book lots of times, hope it is not too cold when i try it!!

Paul

[brantuk]

You're welcome - once you've done it a coupla times it all suddenly becomes very obvious what's going on and you'll be a dab hand at it - anything else - don't hesitate to ask

[Space Bat]

Please feel free to send me your wedge for a 6 month evaluation, as it looks like its faulty

Chris

[Psychobilly]

The latest firmware updates for the CPC allow you to perform the wedge align routines on any star not just Polaris handy if you have restricted Northely views...

[Kerrp30]

Please feel free to send me your wedge for a 6 month evaluation, as it looks like its faulty

Chris

I have seen your pics with no wedge, you need no help from a wedge:D

[TrickySpot]

Hi everyone,

I'm roughly at this stage as well now, but having some problems. Hope somebody has some bright idea?

1. I do a 2 star EQ north align

2. Slew to Deneb

3. Start the polar alignment routine

4. My thinking is that if I now do a 2nd polar alignment procedure, debeb should be pretty much centred in the eyepiece already when it asks me to adjust in alt-az, i.e. indicating a good polar alignment. But no matter how many times I do it, Deneb never seems to get closer to being centred. In fact after 3 or 4 itterations, my polar alignment is so off, I have to start from scratch.

Any ideas whats happening here?

Thanks,

Martin

[riklaunim]

Try maybe EQAlign or WebCamScheinern. They will analise the drift of a star and allow easily way to improve mount alignment.

[Psychobilly]

I guess your running the latest HC software that supports the All Star wedge align and following the procedure on P30 of the manual?

After completing each itteration of the All Star Wedge Align routine I would cycle the power to the scope ... and go through the 2 star alignment process again.

I find this "easier" than the re-syncing after you have "mechanically" moved the wedge during the alignment routine...

Peter...

[continuum]

Grrr - so you are the one who outbid me in the last few seconds!!

Good luck anyway.

RonJ

[Psychobilly]

looks like i need to update my HC firmware again the latest version 4.18 doent need the re-align after the All Star Wedge align ...

Peter...