Oh yeah, I remember. I don't normally recommend unthreading just any eyepiece drawtube though as the lens elements can drop out on the floor lol. Not good. Most Plossls can have their drawtubes unthreaded though.

 

I might just try that Don. I always worry about the tape coming undone though and causing difficulties. My 6mm Hutech ortho' has been reunited with its original draw tube as I've been using it a lot in a TV x2 Barlow and in a Baader helical focuser that both have compression rings.

 

There was a time when undercuts didn't bother me, then I acquired a lot of things with compression rings . Some undercuts seem to work OK though. TeleVue have basically sussed this with their flared lower lip. I'm guessing TV have patented this as it hasn't been taken up by other manufacturers AFAIK. The only undercuts which seem to be problematical are on the lighter aluminium draw tubes used by GSO predominantly on their Plossls. Although GSO have recently abandoned undercuts, unfortunately there is a lot of stock around still with the undercuts.

As I'm disabled and my right arm and hand are partially paralysed any tape cutting is going to be extremely difficult for me. However, I am getting more dexterity and range back into my arm and fingers and can do things now I couldn't have dreamed of doing 18 months ago.

I'm still a little ambivalent about undercuts as a whole, they have actually saved EP's of mine being dumped on the ground, but I've also had to spend time carefully coaxing eyepieces out of my Baader helical focuser. As a rule now I match the eyepieces to the focuser and I've discovered which extract easily through trial and error.



The modified Celestron AstroMaster Kit box above contains the eyepieces I regularly use as a grab'n'go box for various scopes. At the moment I'm using them a lot on my 130mm Newtonian. I like to keep them safe in that box as they were all expensive. The 10mm Baader Eudiascopic and 6mm Astro Hutech have no undercuts, the 8 & 11mm TV Plossls work fine and the undercut on the 15mm Antares (Masuyama clone) is no real problem as its barrel is chromed brass and the undercut is relatively shallow. The two eyepieces to the left are mainly used as finders in conjunction with my RACI. The wide angle 15mm Celestron Kellner has a smooth draw tube but the 32mm Celestron (GSO) Plossl has an aluminium draw tube with an undercut. I also sometimes take out a 9mm Celestron X-Cel with the grab'n'go bag. Out of all of them, it's only the 32mm Plossl that will cause any problems.

 

OK, add one Celestron T-Adaptor and an old GSO draw tube to two basic Celestron Barlows and an old Barlow/T-Adaptor combo and the result is two T-Adaptors (one with an undercut, one without) and two perfectly serviceable decent achromatic light Barlows with removable elements.



I really need the clouds to clear ... soon ... as I'm getting too anorak about this lol.

 

With additional 18mm smooth draw tube Astro Hutech Abbe orthoscopic.