wont come to focus

I have an F5 10" dobson and recently purchased a 17mm Antares, Speer Waler EP. 1.25 inch barrell. The problem is that it wont come to focus. When the focuser is fully retracted it feels like it is a few mm short of achieving focus. There is a reducer that came with the scope that can be removed to allow use of 2" EP's and the shoulder on this is about 8mm high.
Question: is there another 2" - 1.25 inch reducer with a shorter shoulder?

if its not possible to use.....then it's not a major deal, cause it works in my 70mm skylux......just wonderin

"Tme flys like an arrow.....fruit flys like bananas"

If your telescope will allow it, slide the primary mirror cell *up* the tube (towards the secondary mirror) by half an inch or so and secure it again. This will mean drilling three new screw holes to fix the cell inside the tube. This will allow your eyepiece to reach focus. If your primary mirror cell attaches to the bottom end of the tube then you will have to remove about half an inch of material from the lower end of the tube *carefully*!!

Phil.

Congrats on the EP - those Speers Walers are supposed to be the bees knees!

There are some ultra-low profile 1.25" to 2" adaptors on the market but. The one that came with my newt focuser is only about 3mm at the top but it means that the thumbscrew in the 2" adaptor needs to reach through a hole in the 1.25" so the EP is secure. It's a bit of a pain so Philip's advice is better for those purposes.

You may not need to make new holes though if you have a bit of play in your collimation you could use them to push the mirror up a few mm, i.e. by turning the 3 collimation screws at the bottom of the scope clockwise by the same amount - or anti-clockwise if they are wingnuts. This is what I had to do on my old GSO.

Trev

You may not need to make new holes though if you have a bit of play in your collimation you could use them to push the mirror up a few mm, i.e. by turning the 3 collimation screws at the bottom of the scope clockwise by the same amount - or anti-clockwise if they are wingnuts. This is what I had to do on my old GSO.
Trev

Good thinking, Batman! I have a box of spring-washers that might help take up the slack of loosening off the collimation bolts if you need some.

Phil.

thanks for the advice everyone. the thought of sawing off the blunt end of my scope sound a bit drastic for the purpose of enjoying one EP. I like the idea of getting the EP a little closer by using a low profile adaptor. I will rig something up and give it a go......otherwise i will just enjoy it in my skylux

declan