Beginning to regret laser collimator purchase

[Bart]

Bought a laser collimator and twistlock adaptor recently and first time I used it, got it spot on. Second time, again, excellent. Tonight though it seemed all over the shop. It even seemed the secondary was well off, even though I had fantastic views of Jupiter over the last couple of nights, even got the GRS for the first time. Basically lost the whole night messing with it. I think I'll probably stick to the Cheshire . Anyone else had similar experiences?

Bart

[GazOC]

Yep, I've had a few nights where I've got too involved in naling down some small techincal issue and had the entire nights observing slip away from me.

[streaky1]

Did you line up ok before you purchased the twist lock?? is it possible when you twist lock it can move the line up out. also is your colimator true,the guy i got my laser put it in a v block and rolled it to show it was pin point on the wall..??

[ollypenrice]

...and just to add that you can make a perfectly good V block with 4 big nails banged into a lump of wood. Nail them in pairs the right distance apart for your collimator and so that they cross each other to make a V.

I use a laser, which I collimate from time to time, very regularly and without issues. I rate it highly but my Newt is too big for practical single handed collimation without a laser.

Olly

[Bart]

yes Streaky1 made a rest for the laser and it doesn't move

[Bart]

yes Streaky1 made a rest for the laser and it doesn't move

[Bart]

thanks Olly that's the dilema, without the laser, its a real pain. Especially a star test as the scope keeps moving . At least with a Cheshire you just have to look inside the scope.

[ollypenrice]

I'm surprized the laser is giving grief if its collimated. I'm not familiar with the Twistlock. Is this a collet EP holder of some kind? I just use my laser in a normal 2 inch adapter. It isn't perfect but is good enough to get good images and quick enough for the 'get on with observing' principle to be applied!

Olly

[steppenwolf]

If you've checked that the laser itself is collimated (and apparently it is) then you can't really blame the laser, the fault must lie elsewhere in the chain. I have a real cheapo (but collimatable) laser and provided I ensure a good fit in the EP holder (I use tin foil for making a tight fit) it is just such a joy to use.

I'd check out the twist lock next.

[Kai]

How about play in the Focusser ?

Also are you putting the collimator in the same position each time ? , i have mine marked to make sure everything is in line.

[Bart]

Yes Gents, both of you are probably right as I even checked last night again and the laser is collimated. And yes, there is wiggle in the adaptor, so I'm guessing thats where the problem lies. I was just surprised when after all the messing in the garden, that when I inserted the laser, it was about 2cm away from the circle on the primary. Would a load of moving the primary 'collimating' mean that it was possible to move it sufficiently that the laser reflection off the secondary no longer hits the centre circle on the primary? As I say, I was moving it A LOT in the dark in the garden.

I wont despair yet as I thought i had great collimation using the laser up until last night, but the hand trolley ride to the garden last night wasn't as smooth as usual, so thought I should check it. Should have left it I suppose.

I should think of this as 'getting to know my scope' but the clear nights are at a premium and i was very dissapointed to lose one last night. Not to mention my poor back.

2 Diphenes and some Solpadol and off to bed to give the back a break!

Bart

[moflaher]

I bumped my 200P a forthnight ago. I checked the secondary (and repositioned it), checked secondary on primary, and correct it, checked the primary and corrected it. Star test, nice concentric circles. The following night, the primary was off, and since then, I need to collimate the primary every session (before it was less often)

I use the barlowed laser method, which I understand doesn't need a perfectly collimated laser (http://stargazerslounge.com/primers-tutorials/84752-barlowed-laser-collimation-method.html)

[Moonshane]

I agree with Martin. I am not a fan of lasers personally but have used the barlowed laser method in the past and it works a treat on the primary adjustment which is of course the critical one.

The secondary can be a little out and not affect the view greatly (visually anyway).

perhaps try a home made collimation cap and then barlow your laser? any cheapo barlow will do.

[JamesC]

I use the barlowed laser method too. I adjusted the secondary when I first got the scope and again after I removed it for a wash. That's it. Otherwise I just adjust the primary which is pretty easy.