Extension tube.

[cjdawson]

Hi all.

 

I'm looking to get hold of an extension tube for my flip mirror.  What I'm after is something similar to this...

http://www.rothervalleyoptics.co.uk/antares-125-extension-tube-2-long.html

 

However, the 2" extension that I have is too long.  And a 1" extension that I have is too short.  Anyone know where I can get a 1.5" extension from?

I've checked out a few places but haven't managed to find one yet.

[Putaendo Patrick]

I've no experience of this, so if I'm talking rubbish please forgive me!

But, could you use the 1" extension tube you have and extend the flip mirror with a couple of spacers? Something like these:

http://agenaastro.com/blue-fireball-1-25-spacer-ring-0-25-extension.html

Alternatively if you know anyone who knows anyone with precision milling equipment, one should be pretty easy to make.

[Dave In Vermont]

I don't know if you have a 2" aperture on your optical-pathway before it goes to 1.25" up the line towards the scope. But if you do, this would buy you the other 1/2" you need - coupled with the 1":

http://www.scopestuff.com/ss_scet.htm

Now if this works, hunt around over there for one. ScopeStuff does ship international, but the post and any VAT might be killer.

Dave

[Alan64]

Would a 1.6" work...

http://telescopes.net/store/adpt1ext-extension-tube-1-25-inch-dia-x-1-6-inch-ht.html

http://www.buytelescopes.com/jmi-125-x-16-length-extension-tube

The JMI part number: ADPT1EXT

[cjdawson]

14 hours ago, Putaendo Patrick said:

I've no experience of this, so if I'm talking rubbish please forgive me!

But, could you use the 1" extension tube you have and extend the flip mirror with a couple of spacers? Something like these:

http://agenaastro.com/blue-fireball-1-25-spacer-ring-0-25-extension.html

Alternatively if you know anyone who knows anyone with precision milling equipment, one should be pretty easy to make.

 

14 hours ago, Dave In Vermont said:

I don't know if you have a 2" aperture on your optical-pathway before it goes to 1.25" up the line towards the scope. But if you do, this would buy you the other 1/2" you need - coupled with the 1":

http://www.scopestuff.com/ss_scet.htm

Now if this works, hunt around over there for one. ScopeStuff does ship international, but the post and any VAT might be killer.

Dave

 

Thanks both.  I'm currently doing something like that already using a 1" extension tube, a 1" eyepiece barrel extension and a parfocal ring.  It works, but it's not ideal for my liking.

 

7 hours ago, Alan64 said:

Would a 1.6" work...

http://telescopes.net/store/adpt1ext-extension-tube-1-25-inch-dia-x-1-6-inch-ht.html

http://www.buytelescopes.com/jmi-125-x-16-length-extension-tube

The JMI part number: ADPT1EXT

This would be perfect.  I'll take a closer look when I get home from work, about shipping to the UK, or sourcing a 1.6" in the UK.     The problem was that the 2" version that I have is just that little bit too long, and a 1" is a little bit too short.  So this should be just right.

 

For those that don't know, I'm using it to parfocal an eyepiece with when plugged into a flip mirror.  The par focal part is against my Canon 70D.  So, it's basically a Dslr on one side of the flip, and the eyepiece on the other.  I've found that I need to extend the eyepiece tube as the focal point is behind where the camera is.

[cjdawson]

Just had a look and couldn't find one in the UK.

Telescopes.net had the best overall price, so that's one ordered.  Hopefully this will mean that once again, I don't need a par focal ring (I have issues with them as I tend to fiddle)