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EzyStyles
15-08-2006, 04:02 PM
Hi,

Just a quick question. To move the pirmary mirror further away from the focuser (back), its it clockwise or anti-clockwise on the collimation screw?

The problem is i can't seem to get focuse now after taking my primary mirror and secondary mirror out .

Thanks.
rmcpb
15-08-2006, 04:15 PM
Screw 'em in!! Clockwise will pull the cell toward the back of the tube.
EzyStyles
15-08-2006, 04:24 PM
:) thanks rob. silly me heheh
EzyStyles
15-08-2006, 05:04 PM
forgot to ask, does it matter on the number of rotations from the collmation screws? eg: 2 screws are turned 4 times whereas 1 screw turned once (the screw parallel to the focuser).
ving
15-08-2006, 07:32 PM
colimated is collimated eric :)
the primary is sitting flat in its cell isnt it?
RAJAH235
15-08-2006, 10:22 PM
Eric, Please start by screwing all of them right down, till they bottom out, then BACK OFF 1 1/2 to 2 turns. (I say this to get as much tension on your springs as poss).
Provided the cell etc is manufactured acurately, the light path will be reasonably close to correct. (Know what I mean)?
From there, go step by step thru your collimation procedure again, starting with the centering of the focuser in the tube, the 2ndary in the centre of the focuser, (using a sheet of white paper on the opposite side of the tube to see what's going on), etc etc.
Just take your time with it..
HTH. :D L.
EzyStyles
16-08-2006, 01:32 AM
I believe so.. but why does that one of the collimation screw is less turn than others? *shrugs*
EzyStyles
16-08-2006, 01:37 AM
thanks for your reply. I have turned all 3 screws all the way down. I use a laser to collimate my primary mirror. 2 screws seem to be evenly turned while only one takes less turn . weirdd. thanks for the idea of the white sheet. i'll try that.
RAJAH235
16-08-2006, 02:44 AM
Eric, You're welcome. Tell me tho, you did back them off ~2 turns after bottoming them? Need to do this to get some 'room to move' the mirror cell.
The reason for the screws not being turned equally, is simply a cell design/manufacturing tolerance issue. Nothing is perfect.
Glad to be of assistance.
Regards, L. :D
ps. Oh, it helps if you collimate in the daytime too. Can see things clearer. Just point the tube towards an open door or window.(Nice even light source).:D