Mewlon 250 Collimation

[matt]

Does anyone have any links or easy-to-understand reference material regarding the push-pull collimation screw process of the M250 they can share with me.

I've read the user's manual, but it doesn't make a lot of sense.

I've searched the internet, but there's not much out there.

Thanks

[Dennis]

Hi Matt

I’ve got no experience on the M250 with its motorised secondary, but I found the following stuff from the RCOS website to be useful in just gaining some back ground knowledge as I found it all quite daunting initially.

http://rcopticalsystems.com/support/

Scroll down to the bottom of the “Archived On-Line Resources” Table for the “Collimation Video by Ken Crawford” which shows an RCOS being collimated using the Tak Collimation ‘scope.

I found my M180 Secondary Allen Key bolts to be very tight and difficult to turn and so I replaced them with a set of Bob’s knobs. A couple of years later one of the heads sheared off so I removed all the Bob’s knobs and replaced them with the original Tak bolts and now use the Allen Key to make very fine adjustments.

I haven’t touched the collimation in some 5 years now and it seems to hold up very well.

http://rcopticalsystems.com/support/images/rcos_alignment_collimation.pdf

Above opens the pdf in your browser.

Cheers

Dennis

[loc46south]

Hi - First question is does it need collimation - I own one and I have had it since 2008 and it has never needed to be collimated. Once they are locked down they rarely move.

The screws are not push pull screws - one set are locking screws and the other set are adjustment screws.

If it needs adjustment it is simple enough to do - the primary mirror is fixed - the secondary is the only mirror with adjustments. Release the locking screws and collimate the donut as you would a SCT (until the shadow of the secondary is centered. Just remember that after each adjustment you must re-centre your image.

Cheers
Geof Wingham

[beren]

http://www.astromart.com/forums/viewpost.asp?forum_post_id=787302&poll_id=&news_id=&page=

[matt]

Thanks Beren

Found some additional material which may prove handy for others going through the same process :D

http://www.cloudynights.com/topic/426449-mewlon-250-collimation-same-as-sct/