Focusing

[Jazzo111]

Hello everyone, im currently having trouble focusing my xt8 classic dob, it wont focus with 2 inch eye pieces, what will i need to buy to get it to focus? I tried my celesteon omni xlt 150 extender adapter on it but wouldn't focus, any suggestions? It is a crayford tocuser on this xt8. 

[John]

Maybe the XT8 does not need the extender / adapter ?

The focuser on the Orion scope might be a straight 2 inch fitting. The Omini XLT is not which is why you need the adapter.

Did you get an idea if you were running out of focuser travel inwards or outwards with the 2 inch eyepieces in the Orion ?

[Jazzo111]

It wouldnt go far enough outwards which is why i gelt i need a adspter 

[Jazzo111]

https://www.amazon.co.uk/gp/aw/d/B0069VXODO?ref=ppx_pt2_mob_b_prod_image

 

I did try this buy wouldnt fit had to send it back

[John]

5 hours ago, Jazzo111 said:

It wouldnt go far enough outwards which is why i gelt i need a adspter 

At least something can be done about that - an extension tube / adapter of some sort will sort that out.

What were you focussing on by the way ? - if it's something nearby (ie: less than a few miles away) the focuser might well run out of outward movement before the eyepiece comes to focus.

If you run out of inwards focuser travel, it's quite a lot harder to sort out.

[Jazzo111]

Focusing on stars it ran out of outward travel i then tried my 2 inch extension tube that came with my celesteon 150 and it then ran out of inward motion.. which confused me and the one i bought didnt fit, any suggested alternatives would be welcome

[John]

One way is not to use the extension tube but to loosen the eyepiece screws so that the eyepiece can be slid partially out of the holder while you are peering through it, until it reaches focus. Then you will have an idea how long an extension tube you need. It's obviously somewhere between 2 inches and zero inches !

 

[Jazzo111]

4 hours ago, John said:

One way is not to use the extension tube but to loosen the eyepiece screws so that the eyepiece can be slid partially out of the holder while you are peering through it, until it reaches focus. Then you will have an idea how long an extension tube you need. It's obviously somewhere between 2 inches and zero inches !

 

That was pretty obvious so simple i over looked it thanks haha