Flexi-tube Dobs.

[dmk]

Due to the nature of these Flexi-tube Dobs, eg: there must be a small amount of play when extending the tube,do they need collimating at every extension?

[Owmuchonomy]

Not at all.  Mine holds collimation surprisingly well.  I estimate I have to adjust about every five trips out. That's probably more about me clattering the OTA into the back door than anything else. It is easy to check each time by star test if you so desire.

[dmk]

Not at all.  Mine holds collimation surprisingly well.  I estimate I have to adjust about every five trips out. That's probably more about me clattering the OTA into the back door than anything else. It is easy to check each time by star test if you so desire.

Excuse my ignorance,but what is a 'star test'?

[LukeSkywatcher]

Larger flex tube Dobs may need collimating every time you use them, depending on how far they travel. My Heritage 130P has never need collimating because i just carry it out to my back garden.

[Charic]

Flexi-Tube does give the connotation that there is some flex somewhere?  But more often than not, users don't seem to suffer any issues. The `Flex` allowing  more  `flexibility'  in storage by collapsing into itself making it smaller.

Even collapsing has  a connotation!

Astro Baby wrote.........When collimation is complete you may wish to carry out a star test which will confirm the collimation or show small errors which can be fine tuned out.

Check that out here........http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

[dmk]

Flexi-Tube does give the connotation that there is some flex somewhere?  But more often than not, users don't seem to suffer any issues. The `Flex` allowing  more  `flexibility'  in storage by collapsing into itself making it smaller.

Even collapsing has  a connotation!

Astro Baby wrote.........When collimation is complete you may wish to carry out a star test which will confirm the collimation or show small errors which can be fine tuned out.

Check that out here........http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

Now I understand. Thank you.