Newtonian Collimation using SCA Laser Collimator

Newtonian telescope laser collimation using HOTECH SCA Laser Collimator
- http://www.hotechusa.com/2-SCA-Crosshair-Laser-Collimator-p/sca-2c.htm
- Product home page: http://www.hotechusa.com/category-s/22.htm

Category:

Science & Technology

Tags:

• laser
• collimator

[biggrex]

doesn't work with focusers that have a recessed tube circumference of more than 1.25", my focuser only has a 1.25" ring that is about 1/4" wide, so my new hotech is worthless, it moves around more than any screw tightener would!

[HoTechUSA]

@biggrex,

Don't really understand what you mean by more than 1.25" focuser circumference. I think you try to address three issues in one sentence.

1. Focuser fitting issue:

The compression ring can expand to fill the standard mfg. focuser opening tolerance +/- 0.05". If it still doesn't fill the opening, it is the focuser's problem where the mfg. has VARY sloppy quality. Upgrade one if possible.

[HoTechUSA]

@biggrex,

2. Unstable movement after installation:

It is possible that the focusing gears are loose causing the entire assembly to move even if the collimator is secured in the focuser. Please double check the movement source.

3. Focuser inner contact surface too shallow (1/4”?):

Many mfg. cut corners to save material by shortening the depth of the focuser. Try to upgrade a new focuser.

The quality of the focuser is out of our control.

You can email me for faster response. Thanks.

[waheex]

good video , but there is no compressorring on the 1.25 inch collimator? instructions are different with this model. Do you tighten the grip ring before you insert the collimator into the focuser?

[HoTechUSA]

@waheex,

You can either tighten slightly on the compression ring first for a snug fit, then tighten further down to secure the collimator in the focuser. Or you can just insert the collimator in the focuser, then tighten the collimator. The mechanism should keep the laser from wobbling in the focuser for a repeatable collimation.

[m4n52k10]

i dont have a donut what should i do

[FrauGrimhild]

Laser is fine for last part of collimation (adjustment of primary) but not for adjustment of secondary. The laser can 'lie', here; i.e. just because laser is spot on primary ring marker does not guarntee secondary is at desired angle to optical axis. The only way to ensure perfect adjustment of secondary with a laser is to employ a diffraction grating.

[HoTechUSA]

@biggrex,

Is your focuser a 2" version with a low-profile 2" to 1.25" adapter inserted? If this is the case, you can either find a new 2" to 1.25" adapter that does not have the recess for more adapting space and inner tube adapting area, or upgrade to a 2" collimator to collimate straight on the 2" focuser. I only wish you can utilize the SCA mechanism fully when collimating.

[biggrex]

@biggrex ...rely on the compression ring, just my hand keeping the collimator pushed into the focuser as far as it would go and rest it there steady while I made the necessary mirror adjustments.

[biggrex]

@HoTechUSA

It's difficult to explain without a photo. Essentially the eye focuser is not 1.25", maybe it's a cheap design, but I would say the tube itself is closer to 2" and then it has an inner ring on the end of the tube where you insert the eye piece that is 1.25", but the ring is right on the end, so the compression area on your collimator is really just dangling and surrounded by open air. I finally just pushed the collimator and held it pushed in so it was flush and didn't rely on the..