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Coco

M31 - EOS 5d MKIII & QUATTRO

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Thanks Guy,

I have actually made a collimation tool with a webcam similar to the one from Dion but for me the most problematic bit is the secondary which never seems to be ideally placed. In the case of my 150 PDS it is always offset incorrectly no matter how much I pull it towards the front of the scope. It is so bad that for now I have given up any thoughts of using either the Quattro or the 150.

Regards,

A.G

Dont give up mate...there are a few things you need to do to get it to look right.

1) (unavoidable) Square the focuser, tutorial here:  https://www.youtube.com/watch?v=3LbR1nIx-jw - then ensure your spider is properly repositioned (or if your deft enough and have enough room, you can pop the secondary off and leave the spider in place).

2) Find a way of attaching your collimation tool in a repeatable and secure way. I did that by going all-threaded, the only "weak link" is the self-centring adaptor I use for the cheshire (push down hard when tightening up to ensure its flush).

3) Start you collimation by first blocking off the primary and tightening the centre screw up as far as it will go, making sure its not rotated.

4) Tighten the three collimation screws until they just touch the secondary holder, loosen the centre screw by one turn, then tighten the collimation screws by equal amounts (1/2 turn, 1/4 turn etc..).

5) Repeat until the secondary is far enough down the tube.

6) Remove the paper blocking the primary, then you need to fine tune the tilt to get the primary centre spot done (under the crosshairs).

7) Once your secondary is looking round and aligned with the primary, you will then be able to judge whether it needs further adjustment by looking to see if the gap around the secondary is concentric - it may be that it needs to come futher down the tube (or up).

I need to stress that you need to keep an eye on rotation when adjusting, if youre making a big move - keep a hold of the secondary to stop it rotating.

It can get be be a bit of an obsession when chasing one corner that wont illuminate properly..... :) ... collimation/tinkering sessions can easily go past midnight for me. If there are people out there who can bash a 130 into decent form, then the same methods should translate just as easily (if not better) to the 150. Hope that helps!

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Dont give up mate...there are a few things you need to do to get it to look right.

1) (unavoidable) Square the focuser, tutorial here:  https://www.youtube.com/watch?v=3LbR1nIx-jw - then ensure your spider is properly repositioned (or if your deft enough and have enough room, you can pop the secondary off and leave the spider in place).

2) Find a way of attaching your collimation tool in a repeatable and secure way. I did that by going all-threaded, the only "weak link" is the self-centring adaptor I use for the cheshire (push down hard when tightening up to ensure its flush).

3) Start you collimation by first blocking off the primary and tightening the centre screw up as far as it will go, making sure its not rotated.

4) Tighten the three collimation screws until they just touch the secondary holder, loosen the centre screw by one turn, then tighten the collimation screws by equal amounts (1/2 turn, 1/4 turn etc..).

5) Repeat until the secondary is far enough down the tube.

6) Remove the paper blocking the primary, then you need to fine tune the tilt to get the primary centre spot done (under the crosshairs).

7) Once your secondary is looking round and aligned with the primary, you will then be able to judge whether it needs further adjustment by looking to see if the gap around the secondary is concentric - it may be that it needs to come futher down the tube (or up).

I need to stress that you need to keep an eye on rotation when adjusting, if youre making a big move - keep a hold of the secondary to stop it rotating.

It can get be be a bit of an obsession when chasing one corner that wont illuminate properly..... :) ... collimation/tinkering sessions can easily go past midnight for me. If there are people out there who can bash a 130 into decent form, then the same methods should translate just as easily (if not better) to the 150. Hope that helps!

Thanks for that. I will dust the 150 off yet again once the weather gets better.

A.G

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You can buy flocking paper from

http://www.wilko.com/sticky-back-plastic/d-c-fix-original-deco-self-adhesive-film-velour-black-348-0005/invt/0309578

The same as flo sells

Go the whole hog and pimp it up :)

Hi Guy,

I bought 4 rolls from FLO last winter but I have not got around to doing the scopes up yet. I will first tart the Quattro up as it shows more promise than the 150.  I wish they would mark the centre   on the inside of the tube, opposite  the focuser so there is an accurate datum to start the collimation from but how long did it take them to mark the centre of the primary ?

Regards,

A.G

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