1Justieranleitung ASA Astrograph/Collimating. 01/2013

your ASA-AstrographCollimAting

In principle any good collimation tool can be used to collimate the ASA Astrograph. Our experience has shown, that the laser collimation tool from Howie Glatter in the US is one that works very easy and at the same time is very precise (can be ordered directly from ASA, article number LCOLL).

First you need to acquaint yourself with the adjustment screws situated on the secondary and main mirror.

In order to adjust the secondary mirror, a total of three screws are available (See image 1). Make sure, that you only loosen two screws at any given time. The screw in the middle can be adjusted carefully at the end of the collimation process, in case it got loose (which normally will not happen).

Locating screw

Adjusting screw

ASA Astrosysteme GmbH Galgenau 19 A-4212 Neumarkt i. M. Phone +43 (0) 72 42/21 14 46-30 office@astrosysteme.at www.astrosysteme.at

Image 1

2Justieranleitung ASA Astrograph/Collimating. 01/2013

The traction and pressure screws for collimating the main mirror can be accessed directly via the three holes in the telescope back plate (see image 2 and 3).

Image 2 Image 3

Image 4 shows the telescope main mirror cell with the collimation screws without the telescope back plate.

Pull screw

Push screw

Push screw

Pull screw

Image 4

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To collimate the telescope, make sure that the tele-scope is allready connected to your mount and that the telescope is pointing towards the Zenith (see image 5).

Image 5

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Now place the collimation tool into the focuser (see image 6).

To simplify the collimation process, the ASA main mirroris marked with a triangle and a hole in its middle (see image 8).

Your astrograph will be delivered with a set of allen wrench keys so you can turn the collimation screws. Start by collimating the secondary mirror with the help of the three screws. Pay attention that not all three screws are loosened at the same time (see image 7).

Turn the laser on and turn the adjustment screws of the secondary mirror until the laser will fit directly into the whole of the triangle (see image 9).

Image 6

Image 8

Image 7

Image 9

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In the next step, you can collimate the main mirror with the help of the traction and pressure screws. First loosen the traction screw by turning your allen wrench key counter clockwise (see image 10).

While collimating make sure that the laser point is approaching the triangle when looking throught the focuser. You need to to make adjustments until the reflecting laserpoint (see image 12) will be congruent with the radiated laser (see image 13).

In order to collimate the main mirror, start by first turning one of the pressure screws (max. 5 mm) then fasten with the help of the traction screw while turning the second pressure screw until end stop (see image 11).

Image 10

Image 12

Image 11

Image 13

To avoid tension of the main mirror, we recommend fixing the collimation screws hand-tight.The main mirror is supported by three plastic screws. The distance is adjusted at the factory and should not be modified. For a subsequent collimation we recommend to loosen the three pull screws and slightly tighten them again after collimation has been done.

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The secondary mirror will fully illuminate the focuser tube. The so called offset is a misalignment of the sec-ondary mirror. Especially in very fast optical systems a correct alignment is very important. The offset in ASA Astrographs is correctly adjusted in the factory. In case you need to remove the secondary mirror any time thereafter, knowing how to correct the offset will be necessary to make sure the focusser tube is fully illuminated.

Start by opening the secondary mirror holder with the help of the middle screw and detach the mirror from the spider.

Now place a piece of paper on the opposite side of the focuser tube and turn the laser on. The laser will project a dot onto the paper. With the help of a pen draw a line where the laser is projecting the dot.

Adjusting the Offset (only for advanced users):

Make sure, that the piece of paper is not moved and attach the secondary mirror again. Do not turn the sec-ondary mirror towards the tube, but turned 90 degrees toward the tube wall.

With the help of the three collimation screws, try to find the correct distance so that the laser dot is brought back onto the line drawn before. Make sure, that the three adjustment screws are at the same distance towards the secondary mirror holder.

TIP: When looking at the main mirror, you can now see a delicate red line which „separates“ the second-ary mirror.

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If you want to remove your mirror cell, e.g. for cleaning the mirror, follow these steps:

Removing the main mirror cell

Now you can remove the 3 traction screws.

CAUTION: Hold the mirror cell at the handles. It might fall out of the telescope after removing the traction screws.

Then you can carefully pull the mirror cell out of the scope.

Remove the carbon fibre cover.Use the 3 mirror cell handles (included in the delivery) and screw them into the threads where the cover was fixed in before.