Tal 100rs Focuser

[wookie1965]

Did anyone know there are  different focusers on the Tal 100rs 

There is this one https://www.astrobuysell.com/uk/propview.php?view=166309

But on mine its totally different mine has a rotating ring so I can turn the diagonal around then lock it in place.

[markse68]

Yours looks much more serious! I’m missing the focuser so plan to fit a moonlite...when i get round to it

[RobertI]

52 minutes ago, wookie1965 said:

Did anyone know there are  different focusers on the Tal 100rs 

There is this one https://www.astrobuysell.com/uk/propview.php?view=166309

But on mine its totally different mine has a rotating ring so I can turn the diagonal around then lock it in place.

Yes mine is like yours but with a different knob. There was a long thread about the different Tal 100 focusers, all I could find was this, but there is a longer one somewhere and the conclusion I believe was that there were at least four types of Tal100 focuser!

[markse68]

off topic question but i’ve noticed on old threads that get resurrected or referenced there’s an absence of likes etc- was that feature added later or were astronomers different back then?

[wookie1965]

23 minutes ago, RobertI said:

Yes mine is like yours but with a different knob. There was a long thread about the different Tal 100 focusers, all I could find was this, but there is a longer one somewhere and the conclusion I believe was that there were at least four types of Tal100 focuser!

I had the knob made its larger than the original one for fine focus.

[wookie1965]

1 hour ago, markse68 said:

Yours looks much more serious! I’m missing the focuser so plan to fit a moonlite...when i get round to it

Good luck with that I was going to fit a dual speed focuser but I was told it was very hard because of the way the tube is made thats why I got the bigger focuser wheel.

[wookie1965]

7 minutes ago, markse68 said:

off topic question but i’ve noticed on old threads that get resurrected or referenced there’s an absence of likes etc- was that feature added later or were astronomers different back then?

I cannot answer I always like or say thanks its just polite.

[RobertI]

14 minutes ago, markse68 said:

off topic question but i’ve noticed on old threads that get resurrected or referenced there’s an absence of likes etc- was that feature added later or were astronomers different back then?

Interesting question, perhaps the mods can answer. I suspect if you go back far enough it just hadn't caught on in forums such as this, also fewer members perhaps?

[wookie1965]

As said in that thread I had problems focusing with a 4mm eyepiece what I did was to buy one of these https://www.firstlightoptics.com/adapters/baader-low-profile-eyepiece-adapter-for-steeltrack.html

gave me a extra 8-12mm infocus.

[DaveL59]

the RS I have has the focuser in the ABS pics. That too you can release a lock screw to turn the diagonal. Not tried a 4mm so far but focus travel generally is pretty reasonable on this one I think. Will see if I can test with an Or4mm 0.965 EP in a 1.25 adaptor next time I have the TAL out under the stars.

[RobertI]

I find focussing on mine is fine with a 1.25" diagonal but problematic with a 2" diagonal (I think the same problem everyone else is referring to?). The Hyperions work fine as they can sit further inside the diagonal, but the BST 5mm is too close even with a low profile 2"/1.25" converter, it can JUST reach focus but there is no room to go any further, so not really suitable for fine focussing back and forth. 

[wookie1965]

21 minutes ago, RobertI said:

I find focussing on mine is fine with a 1.25" diagonal but problematic with a 2" diagonal (I think the same problem everyone else is referring to?). The Hyperions work fine as they can sit further inside the diagonal, but the BST 5mm is too close even with a low profile 2"/1.25" converter, it can JUST reach focus but there is no room to go any further, so not really suitable for fine focussing back and forth. 

Mine has the 2" diagonal on with that low profile adapter usually they have a 10mm  lip but mine has a 1mm lip which gives me 8/9mm and the few mm I had left, I did use a BST 5mm in and it worked I just got rid of it as I could not get on with it. I have a a 4.5mm and a 6mm TMB which I have yet to try but I have a generic 4mm that works fine. 

[DaveL59]

ahh ok, I only have the 1.25 diagonal so I can't really compare fairly for you with the 2-inch one.

[Stu]

1 hour ago, RobertI said:

Interesting question, perhaps the mods can answer. I suspect if you go back far enough it just hadn't caught on in forums such as this, also fewer members perhaps?

That’s right, the ‘like’ function was added at a previous software upgrade some years ago and hasn’t been there from the start of the forum.