Collination issue!

[Deacon]

Hi

I am using the Hotech laser to collimate my SW 200p dob with no issues at all. However I noticed by accident that after I collimated the scope then removed the laser and then fitted it back into the scope the laser showed the optics were out again albeit not by much.

Is this normal or am I doing something wrong?

Thanks

Deaky

[Starlight 1]

That normal as you never get it back the same ,When you move the screw to hold it in will move it abit.

les

[DarkerSky]

I'd imagine its to do with a slight difference in the tightness of your eyepiece holding screws on the laser tube when you pop it in the eyepiece holder. The discrepancy is likely very small and best fine tuned with a star test outside. Nothing to worry about I'd imagine

[RikM]

If you are using the Hotech with the self centring adaptor then it should self centre and be in the same place every time. Try turning the laser in the focuser and see if the dot moves in a circle on the mirror. If so, then your laser itself needs collimating.

[ggreene1]

If you are using the Hotech with the self centring adaptor then it should self centre and be in the same place every time. Try turning the laser in the focuser and see if the dot moves in a circle on the mirror. If so, then your laser itself needs collimating.

RikM,

I have a Hotech lazer collimator and I seem to get a larger almost star like image when I use it. Not a dot as I expected. The scope is very close using a star. How do you collimate a collimator ? Thanks for any input.

[8kids]

It will be movement in the draw tube, when you tighten the screw it shifts the collimator. It's very annoying, I'm sure a shiny new focuser would solve it.

[RikM]

RikM,

I have a Hotech lazer collimator and I seem to get a larger almost star like image when I use it.QUOTE]

No idea about that, sorry. I had an Antares laser but stopped using it due to it not being as accurate as a Cheshire but that gave a sort of squarish dot???

The scope is very close using a star.

If you mean de-focus and check that it looks like a Polo mint that is not a valid star test. You need a well cooled scope, a very high magnification (highest mag you have available) and defocus just a little bit with the star in the exact centre of the field. When in good collimation you should get a nice set of perfectly concentric rings. The air in the UK is very rarelt stable enough to do a star test properly and the difference between sort of concentric and perfectly concentric is subtle at best.

How do you collimate a collimator ? Thanks for any input.

Make a v-block and sit the laser in it pointing at a wall as far away as practical (30ft is good). Turn the laser in the blocks and check that the dot stays in exactly the same spot on the wall. If the dot moves (makes a little circle) as you rotate the laser, the beam is not pointing straight (out of collimation). There are normally some little adjustment screws to bring it back on target but I am not familliar with the Hotech.

If you have the self centering adaptor, you don't need to tighten the focusser thumbscrew as well.

[Stephen]

If you suspect your Hotech is out of collimation, you should NOT attempt to fix it yourself. This is one of the reasons for buying a Hotech. Consider contacting their technical support / the retailer you purchased it from if you think this is the case.

As has been said before, you don't use the thumbscrew or compression ring on the focuser, the Hotech has its own self centering adaptor so it should seat correctly / the same each time you use it.

[pajr777]

Have a look on FLO's product page here: http://www.firstlightoptics.com/collimation/hotech-sca-laser-collimator.html

Scroll down and there are images of what you should see.

[Deacon]

Hi guys

I have tried collimating the scope a few more times using the Hotech and each time it has been spot on. I think the initial problem was caused by not tighting the adapter enough into the focuser.

Im 100% the laser doesnt need collimating, not that I would even dream about fiddling about with it.

Thanks for all your input.

Deacon