Undercuts - annoying or what...

[Mr Spock]

I've had enough of them. It's bad enough swapping eyepieces without trying to drop them without having to wrestle them out of compression rings as well.

My orthos and SLVs are smooth, so no problem; but those LVWs... grrr! 🤬

But, what if I told you...

...the body of the LVW fits a 2" perfectly 😲

I don't know if it is intended or not, but I'm happy with the result 👍

[Mr Spock]

And, if I fit the nosepiece of my 2" x2 Barlow to that 35mm extension tube, the LVWs give x1.63 when used like this. An added bonus!

[Louis D]

7 hours ago, Mr Spock said:

I don't know if it is intended or not, but I'm happy with the result

Yes, they were one of the earliest eyepieces with the dual fit barrel (1.25" and 2").  Of course, Tele Vue had their 2" skirts before that, which Meade copied, but boy were/are they annoying.  There's not enough 1.25" barrel left to securely fasten it into a 2" to 1.25" adapter, so you have to use it in 2" mode, even if that means having to crank the focuser way out to reach focus.  I fixed that with my 12mm NT4 with a 2" extension ring and 5 O-rings:

Which dovetails nicely with your topic because that lowest O-ring sits on the lower taper of the 2" skirt's undercut.  That made it impossible to get a parfocal ring to tighten on the slope where I wanted it to be.  It kept wanting to slide down into the undercut where it was too wide, so the ring wanted to tip.  I gave up on the parfocal ring and switched to the O-ring solution as a result.

7 hours ago, Mr Spock said:

I've had enough of them. It's bad enough swapping eyepieces without trying to drop them without having to wrestle them out of compression rings as well.

Right there with you.  I've had eyepieces become nearly inextricable after snagging the compression ring and pulling it up and out of its channel, jamming the eyepiece in the tube in the process.

Edited August 13, 2022 by Louis D

[Don Pensack]

I have 14 eyepieces in my kit box and one coma corrector.  The 2" adapter for that CC, and the 3 eyepieces with undercuts all got the treatment with copper tape

to fill in the undercuts, and now slide right in and out.

The copper tape technique works quite well.

[Voyager 3]

6 hours ago, Don Pensack said:

I have 14 eyepieces in my kit box and one coma corrector.  The 2" adapter for that CC, and the 3 eyepieces with undercuts all got the treatment with copper tape

to fill in the undercuts, and now slide right in and out.

The copper tape technique works quite well.

Let me guess,

3.7mm,4.7mm,6mm,8mm Ethos 

11mm Apollo 11

22mm Nagler

30mm UFF 

4.5mm,6.5mm,9mm,12.5mm,14mm,17.5mm Morpheus 

What's the missing one? 24mm UFF?

Edited August 14, 2022 by Voyager 3

[Alien 13]

I like undercuts but I only use my focuser with a FR/FF for imaging and they provide a very secure connection.

Alan

[Zeta Reticulan]

In eyepieces, yes, annoying. In some diagonal noses, surprisingly useful. Some undercuts have lower lip tapers (GSO, Tele Vue) and I basically have no real issues with these. 

9mm volcano top Circle T orthoscopic. Contrast, colour separation and acuity are excellent. Has a volcano top, also excellent. Barrel is beautifully made (chromed-brass) and superbly baffled. Threads are smoother than silk and compatible with every filter I've ever tried in it. Basically eyepiece perfection.

Except it has an UNDERCUT!

[MalcolmM]

20 hours ago, Mr Spock said:

wrestle them out of compression rings

Totally agree! I have a couple of eyepieces with undercuts and they do snag often when being removed from the diagonal. Interestingly they are not too bad in the Tak diagonal. Worst for me is trying to remove my Stella Lyra Binoviewers (with biggish undercut) from my Lunt 50.

Malcolm 

[Mr Spock]

My Circle-T orthos don't have undercuts 

With my 12" f5 Newt and a x2 Barlow, I get 18mm x178, 12.5mm x257, 9mm x356 and they are exceptionally crisp and clean.
But as you can see, I'm missing a 5mm from the collection... 😭

[Ricochet]

5 hours ago, MalcolmM said:

Totally agree! I have a couple of eyepieces with undercuts and they do snag often when being removed from the diagonal. Interestingly they are not too bad in the Tak diagonal. Worst for me is trying to remove my Stella Lyra Binoviewers (with biggish undercut) from my Lunt 50.

Malcolm 

I'm about to blow your mind. 

Wait for it... 

 

Well it blew my mind at least when I discovered you can just unscrew the original eyepiece clamp. 😂 

[Zeta Reticulan]

5 hours ago, Mr Spock said:

My Circle-T orthos don't have undercuts 

With my 12" f5 Newt and a x2 Barlow, I get 18mm x178, 12.5mm x257, 9mm x356 and they are exceptionally crisp and clean.
But as you can see, I'm missing a 5mm from the collection... 😭

Nice collection. That missing 5mm would seriously aggravate my OCD.  

[badhex]

Not sure if this stuff is available in the UK but I liked this idea:

 

[MalcolmM]

1 hour ago, Ricochet said:

I'm about to blow your mind. 

Wait for it... 

 

Well it blew my mind at least when I discovered you can just unscrew the original eyepiece clamp. 😂 

Fab thanks I'll look into that. Also really like the replacement focuser. I find the stock helical fine with eyepieces but it does struggle a bit with a Binoviewer

Malcolm 

 

 

 

 

[Don Pensack]

11 hours ago, Voyager 3 said:

Let me guess,

3.7mm,4.7mm,6mm,8mm Ethos 

11mm Apollo 11

22mm Nagler

30mm UFF 

4.5mm,6.5mm,9mm,12.5mm,14mm,17.5mm Morpheus 

What's the missing one? 24mm UFF?

7mm APM XWA

[Ricochet]

2 hours ago, MalcolmM said:

Fab thanks I'll look into that. Also really like the replacement focuser. I find the stock helical fine with eyepieces but it does struggle a bit with a Binoviewer

Malcolm 

 

 

 

 

The focuser is a great upgrade and I wouldn't be without it now. I didn't actually realise quite how bad the original was until I used the replacement. 

With regards to the Clicklock you can also use the one with the micro focuser at the top (it's a t2 thread on top of the diagonal). I went for the reducer variant on my diagonals as it has the lever arm and a collet whilst the micro focuser grips with a pair of rollers. The downside is that the position of the lever isn't adjustable and is probably orientated randomly with respect to the threads on the underside of the Clicklock. 

[Don Pensack]

All Baader Click Lock attachments have a series of very tiny screws that allow you to rotate the ClickLock to place the pin in the most convenient place.

You can see them in this picture:

https://www.baader-planetarium.com/en/baader-2"-clicklock-eyepiece-clamps.html

[Louis D]

1 hour ago, Don Pensack said:

https://www.baader-planetarium.com/en/baader-2"-clicklock-eyepiece-clamps.html

404 ERROR: SORRY, THE PAGE YOUR ARE LOOKING FOR WAS NOT FOUND

[Ricochet]

This isn't a 2" Clicklock, Don, it's the 2"-1.25" reducer so it doesn't have the screws around the bottom. It does have one screw at the top opposite the pin. Someone asked on the Baader website if this screw could be loosened to rotate the pin position but Baader replied that it cannot and so I haven't tried it. 

[Don Pensack]

1 hour ago, Louis D said:

404 ERROR: SORRY, THE PAGE YOUR ARE LOOKING FOR WAS NOT FOUND

That is the page I went to using a Google search:

https://www.baader-planetarium.com/en/baader-2"-clicklock-eyepiece-clamps.html

When going to the Baader site and searching, I came up with this page:

https://www.baader-planetarium.com/en/baader-2"-clicklock-eyepiece-clamps.html

Same page.

The link leads a different place.

try typing in  click lock in the search box on the Baader site and choosing Baader 2" ClickLock eyepiece clamps (from T-2 to 4,1")

Oddly, that leads to the same page as the other links.

Edited August 14, 2022 by Don Pensack

[Zeta Reticulan]

Links to the Baader site often end up 404. I don't know why. 

[cajen2]

I had a similar problem with undercuts: I'd spend ages finding a target, then try to change the EP to something with higher mag. The undercut would immediately hang up, pulling the scope off line.......sigh, start again.

I independently tried a Clicklock and the problem has gone. Expensive for what they are but may have saved me from having a heart attack...😄

[Sunshine]

Undercuts are nonsense gibberish phoey! i hate them

[Roy Challen]

Ah, the age-old favourite discussion. Yes, undercuts are nonsense gibberish phoey, and I hate them too. But they're not the problem, as shown by Baader Click lock type holders. It's the 'compression' rings on traditional holders that are the problem. Damn things should be banned, I had a Televue 2x barlow, can't remember what eyepiece I put in it, but the ring somehow snagged so badly that I couldn't get the eyepiece back out without brute force. I think I threw them both in the bin in disgust. Now, I remove the compression rings and use nylon tipped screws instead.

[Mr Spock]

I like the look of the Baader stuff, but at £71 the adapter is a bit expensive. The 2" diagonal looks nice too. But when you add them together it comes to £305 😲

As my LVWs are the only eyepieces I have with undercuts and can be used 2", I don't need to do anything. It also means I can switch from the 42mm, which is 2", to any of the others without having to fiddle with an adapter.

Perfect for my double star setup as I use the 42mm as a finder.

[bosun21]

8 hours ago, cajen2 said:

I had a similar problem with undercuts: I'd spend ages finding a target, then try to change the EP to something with higher mag. The undercut would immediately hang up, pulling the scope off line.......sigh, start again.

I independently tried a Clicklock and the problem has gone. Expensive for what they are but may have saved me from having a heart attack...😄

You are most definitely not alone