Not always an “upgrade”

[Chaz2b]

I have a Celestron 100ed, a great scope with FPL53 glass, however, the focuser is a single speed rack and pinion type with a built in star finder slot. The r&p is good enough but I really wanted finer focusing, so set about “ upgrading “ to a better two speed crayford focuser as I want to enjoy better visual viewing.

The first part to get was the adapter from the USA, this screws into the tube and the focuser slides into the adapter to be retained by three screws.

After looking for a second hand focuser I started getting impatient so purchased a brand new focuser from Germany. This has now arrived and I have fitted it to the Celestron refractor.
Great! or so I thought. Turns out I have lost about three inches of back focus, that means if I wish to retain the new focuser on the refractor I need a tube extender to reach focus on some of my eyepieces…one step forward two steps back came to mind.

oh well, live and learn.

chaz

[apaulo]

i was considering upgrading the focuser on my 200p ota. i had a look at the prices and thought again.  i had a look at the skywatcher auto focuser and liked the price. its turned out 1 of my best buys.  excellent product , i dont even have to touch the scope to focus it. so no vibes etc. so maybe an option for you without breaking the bank.

[RobertI]

25 minutes ago, Chaz2b said:

I have a Celestron 100ed, a great scope with FPL53 glass, however, the focuser is a single speed rack and pinion type with a built in star finder slot. The r&p is good enough but I really wanted finer focusing, so set about “ upgrading “ to a better two speed crayford focuser as I want to enjoy better visual viewing.

The first part to get was the adapter from the USA, this screws into the tube and the focuser slides into the adapter to be retained by three screws.

After looking for a second hand focuser I started getting impatient so purchased a brand new focuser from Germany. This has now arrived and I have fitted it to the Celestron refractor.
Great! or so I thought. Turns out I have lost about three inches of back focus, that means if I wish to retain the new focuser on the refractor I need a tube extender to reach focus on some of my eyepieces…one step forward two steps back came to mind.

oh well, live and learn.

chaz

That’s a massively long focuser tube on the right! Do you do straight though viewing?

[Mr Spock]

I have an 80ED. Nice optics but the original focuser, like yours, is pants. Now I have a 102mm it sits on a shelf unused.

[Chaz2b]

17 minutes ago, RobertI said:

That’s a massively long focuser tube on the right! Do you do straight though viewing?

Good grief no! I would need the tripod standing at full height! The Japanese like straight threw viewing, but not me.

[Chaz2b]

Both Celestrons with “upgraded “ focusers, but not really thoroughly thought through….thru thru thru…uuugh!

chaz

[RobertI]

On the positive side I suppose it’s better to have to add extensions than to not have enough in focus, and not be able to focus at all! This is a problem I have with one of my scopes - the only solution is the take a hacksaw to the tube! 😉

[LDW1]

On 16/10/2022 at 05:06, Chaz2b said:

I have a Celestron 100ed, a great scope with FPL53 glass, however, the focuser is a single speed rack and pinion type with a built in star finder slot. The r&p is good enough but I really wanted finer focusing, so set about “ upgrading “ to a better two speed crayford focuser as I want to enjoy better visual viewing.

The first part to get was the adapter from the USA, this screws into the tube and the focuser slides into the adapter to be retained by three screws.

After looking for a second hand focuser I started getting impatient so purchased a brand new focuser from Germany. This has now arrived and I have fitted it to the Celestron refractor.
Great! or so I thought. Turns out I have lost about three inches of back focus, that means if I wish to retain the new focuser on the refractor I need a tube extender to reach focus on some of my eyepieces…one step forward two steps back came to mind.

oh well, live and learn.

chaz

 

[LDW1]

Will the cost of the extension brake the bank vs the benefits of the new focuser ?

[LDW1]

On 16/10/2022 at 07:29, RobertI said:

On the positive side I suppose it’s better to have to add extensions than to not have enough in focus, and not be able to focus at all! This is a problem I have with one of my scopes - the only solution is the take a hacksaw to the tube! 😉

A Televue ' in focus ' adapter should solve the problem if you only need a few mm more, it did for me for a few $'s.

[LDW1]

19 minutes ago, LDW1 said:

 

How many of your eyepieces are affected ?

[Chaz2b]

32/40 tv plossls, but I do have extension tubes.

chaz