milburn wedge

[hubble space telescope]

hello everyone!

i have the cpc 1100 gps xlt sct telescope from celestron. i bought the milburn wedge and just attached it to the mount!

one thing that was weird is how the setup looks...

that's how the setup need to look? this is not reverse or in the other side? because i saw pictures of this setup that the fork arms and the telescope tube are in the opposite sides (looks like X shape)...

thank you very much!!!

note: when i write north i also mean the direction of polaris and the north celestial pole...

[michael8554]

I've got an 8inch Meade LX200 on a wedge, so similar setup.

With the eyepiece between the forks the scope should point at NCP, as you have it.

But there should be a preset position for the start of alignment, for the Meade it's like above, but the finder is under the ota.

You should read the Celestron instructions for wedge mounting.

 Michael 

[schmeah]

Yikes, that’s backwards! It’s supposed to look like this. I used to have one. It’s a fine piece of kit.

 

Derek

 

[hubble space telescope]

Wow that's was very helpful! Thanks! I will fix my setup...

And one more thing...

I cant move the setup left and right (with the azimuth pin i think... Im not sure...) i rotate the weights in the side but the wesge don't move... How does this section looks for you? Because also the the pin of the azimuth adjuster its not in the middle of its track...

Thank you!!!!

[schmeah]

Did you loosen the (three?) nuts that secure the base of the wedge to the tripod before rotating the Az wheels? It won’t move if you don’t. The movement is fairly minimal/fine with each crank of the wheel, so it might not be very noticeable at first. 

 

Derek

 

[michael8554]

19 hours ago, schmeah said:

Yikes, that’s backwards! It’s supposed to look like this. I used to have one. It’s a fine piece of kit.

How so Derek?

The Celestron forks are pointing at NCP.

Your image, forks are pointing at NCP. 

Your ota happens to be pointing south, but if tilted to point at NCP, would have the finder underneath - the Meade wedge mounted setup position, like I said.

Michael

[schmeah]

If you tilted the OPs scope to point at NCP in the current configuration , the top of the OTA / finder scope would still be on top. Nearly every SCT on wedge I’ve ever seen is rotated 180 degrees. With the forks in that position, you may never be able to get close to zenith as the imaging train could collide with the fork base. So the fork arms need to be rotated 180 degrees. Why would it be any different Meade vs Celestron?

https://www.telescopesplus.com/products/celestron-9-25-inch-cpc-deluxe-hd-eq-wedge-telescope

Derek

[Davey-T]

48 minutes ago, schmeah said:

Why would it be any different Meade vs Celestron?

My Meade on wedge, on tripod, tripod leg pointing north, wedge sloping towards north, forks pointed north, scope pointed north upside down finder underneath.

Dave

[hubble space telescope]

this is ok?

and if so, how do I do polar alignment? my telescope tube in directed to the opposite direction from polaris/NCP...

thanks!

[Davey-T]

47 minutes ago, hubble space telescope said:

my telescope tube in directed to the opposite direction from polaris/NCP...

I there enough room to upend the scope to point north ?

Is there a 0 RA  mark ?

If there is you can lock the dec clutch with the scope parallel to the forks and then adjust the bolts to get Polaris in the FOV using something like a 26mm eyepiece then you can spin it in RA and adjust so that Polaris rotates in the FOV this is a good starting point to refine PA.

Dave

[michael8554]

No Wedge Mounted Celestron users out there?

Dave's Celestron link shows their setup is the same as Meades, with the finder underneath when pointed at the NCP, probably some RA index marks to line up as he suggests?

As others have said, very difficult to observe whether the scope is pointed at the NCP in this configuration.

You have several choices after setting the latitude on the wedge, roughly levelling, and pointed roughly at the NCP.

Drift align with a crosshair eyepiece, scope pointing south, then east or west.

If you have a guidescope, use the two PHD2 Polar Alignment routines, scope pointing at the NCP,  then refine with PHD2 Drift Align.

My old Meade LX6 had a Right Angle finder with a polaris circle on the graticule, so you could adjust the wedge while upside down and pointing at the NCP.

Michael

 

[hubble space telescope]

im a little confused...

the thing that i need to do is to point the fork arms to the north and the telescope tube and it need to look like that? your telescope tube its pointing to the north? if not how do you do the polar alignment?

im sorry for all the question, but im think that im not fully understand it...

[hubble space telescope]

10 hours ago, Davey-T said:

I there enough room to upend the scope to point north ?

Is there a 0 RA  mark ?

If there is you can lock the dec clutch with the scope parallel to the forks and then adjust the bolts to get Polaris in the FOV using something like a 26mm eyepiece then you can spin it in RA and adjust so that Polaris rotates in the FOV this is a good starting point to refine PA.

Dave

yes there if enough room, the roof can open.

But then I go back to my starting point, that the equipment was reversed...

[Davey-T]

Not familiar with the Celestron but is there a zero RA mark ?

With the forks rotated pointing north the zero mark should line up. then to get near to polar aligned do as I said, line the scope up pointing north parallel to the forks and adjust the bolts to get Polaris in the FOV with a short focal length eyepiece.

As you say normally the scope would not be in this position and you would park it up to the south at zero Dec.

Rotate in RA and and adjust the until Polaris rotates in the eyepiece, this is good enough for visual use, if you are imaging then the best way to get it spot on after this operation is using the DARV method with a camera attached.

Dave

https://www.cloudynights.com/articles/cat/articles/darv-drift-alignment-by-robert-vice-r2760

 

[schmeah]

From the position that my OTA is in, if I tilt it straight pack so that it is in line / parallel to the fork arms, then it is pointing at Polaris in the polar home position. But I never used Polaris to polar align with my setup (view was blocked). I always drift aligned.

 

Derek

[ngwillym]

Doe this help?

https://www.celestron.com/blogs/knowledgebase/what-is-the-overall-procedure-for-polar-aligning-my-wedge-mounted-fork-arm-alt-azm-mount

Neil 

Ex-owner of a Milburn wedge

[ngwillym]

On 03/05/2018 at 02:04, Davey-T said:

My Meade on wedge, on tripod, tripod leg pointing north, wedge sloping towards north, forks pointed north, scope pointed north upside down finder underneath.

Dave

Surely, if you rotate the forks through 180 degrees, the finder will be the right way up?

[Davey-T]

6 minutes ago, ngwillym said:

Surely, if you rotate the forks through 180 degrees, the finder will be the right way up?

But the zero RA mark, presuming its got one, needs to be at the bottom.

Dave

[ngwillym]

Ah, that's the difference between the Meade & Celestron - the Celestron doesn't have a zero RA mark, it does its alignment differently.

Neil

[Davey-T]

16 minutes ago, ngwillym said:

Ah, that's the difference between the Meade & Celestron - the Celestron doesn't have a zero RA mark, it does its alignment differently.

Neil

Shouldn't matter which way up it is then.

Dave

[ngwillym]

Indeed, but better to have finder on top to help find Polaris - saves a lot of neck & back ache

[hubble space telescope]

can you send me pictures of how this should look like? or summarize the whole setup and what should look how? because im not sure that i understood how to do all of this setup and how should it looks like, and what need to point where...

because i want to make sure that my polar align is good enough...

thank you so much for all your help!!!!!!

[schmeah]

This is a good overview. It is with a Meade, but describes alignment from polar home position which should be similar for all wedge fork SCTs I would think.

https://m.youtube.com/watch?v=zw0_O3tUhLo

 

 

[Davey-T]

18 minutes ago, schmeah said:

This is a good overview. It is with a Meade, but describes alignment from polar home position which should be similar for all wedge fork SCTs I would think.

https://m.youtube.com/watch?v=zw0_O3tUhLo

 

 

The Meade goes upside down as I said , apparently this is not the case with the Celestron.

Dave

[hubble space telescope]

it is a little bit confusing...

all the time the telescope is turn on, but the man is moving/touch the telescope clutch... this is ok?

and, the step by step and the direction of the telescope is a little confusing me again... (sorry)

what i need to do:

1) to put polaris in the finder scope and adjust the wedge to my location (telescope in turn off) and the setup looks backwards...

2) turn on my telescope and choose from the menu eq north align (im in the northern hemisphere), choose the stars and listen to the orders on the screen

3) after eq north align to do a normal align? or the polar align is enough?

4) when i need to enter in the menu to the polar align section? because even in celestron website they mention this...

thank you!!!!