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Unitron draw tube questions?

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42 replies to this topic

#1 K Gephart

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Posted 21 February 2024 - 09:24 PM

I have mentioned before I have a model 128 form the early 60s that  I would like to use 1.25 eyepieces with  Currently I am using the Unihex tube  with the 1.25 holder from the Unihex  stuck in it.   Very mickey mouse but works, sort of.

 

Below is a pic of my focus tube  plus  a pic of some adapters that have been offered to me.  I am not familiar with these. Would they work or some combo?  The third pic is the one I know would work but cannot find  Thanks

Attached Thumbnails

  • 1.25.jpg
  • 1.25d.jpg
  • DT.jpg


#2 jragsdale

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Posted 21 February 2024 - 10:26 PM

Do you have any drawtubes? The pic of your focuser looks like it doesn't have the drawtube in it. 



#3 K Gephart

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Posted 21 February 2024 - 10:40 PM

Correct. The only draw tube I have available is from the Unihex. In order to use a 1.25 diagnosed with that I have to take the 1.25 inch holder off the Unihex and stick it in the Unihex draw tube. The whole thing is not exactly tight, somewhat of a friction fit, but very convoluted.

#4 K Gephart

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Posted 21 February 2024 - 11:22 PM

This what I am using  Not ideal  It is the Unihex tube and the 1.25 holder from the Unihex and then stuck into the Unihex tube which in turn goes into my focuses and is clamped

Attached Thumbnails

  • 1.25g.jpg
  • 1.25h.jpg

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#5 starman876

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Posted 22 February 2024 - 09:42 AM

two of the tubes are for the Unitron camera


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#6 Terra Nova

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Posted 22 February 2024 - 10:49 AM

two of the tubes are for the Unitron camera

Yes, this is definitely for the camera:

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#7 K Gephart

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Posted 22 February 2024 - 11:14 AM

I guess the point is neither of those two help me at all?



#8 starman876

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Posted 22 February 2024 - 12:05 PM

I have mentioned before I have a model 128 form the early 60s that  I would like to use 1.25 eyepieces with  Currently I am using the Unihex tube  with the 1.25 holder from the Unihex  stuck in it.   Very mickey mouse but works, sort of.

 

Below is a pic of my focus tube  plus  a pic of some adapters that have been offered to me.  I am not familiar with these. Would they work or some combo?  The third pic is the one I know would work but cannot find  Thanks

the one picture shows the 1.25" adapter.  You just screw it into the focusing tube.   One end is for .965" eyepieces and when you flip it around it now takes 1.25" eyepieces. 


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#9 K Gephart

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Posted 22 February 2024 - 11:53 PM

There are no threads in my focus tube  Just friction fit which the Unihex drawtube fits into and then is clamped



#10 starman876

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Posted 23 February 2024 - 09:09 AM

There are no threads in my focus tube  Just friction fit which the Unihex drawtube fits into and then is clamped

you got the wrong tube then.   All focus tubes had threads in them.



#11 K Gephart

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Posted 23 February 2024 - 02:56 PM

Not sure how it could be wrong.  As far as i know it has never been touched .  It operates just the way it should and the Unixes tube fits nice and tight in it and then is clamped. It operates  as it should   Usually you can tell when something is not right or screwed around with.

  For now I used the 1.25 holder from  the Unihex and wrapped  1 loop of tape around one end and stuck it in the Unihex tube  Nice and tight   No movement   I can then use the friction fit for eyepiece as intended or do what I did on my RV6  Drill a hole and glue a nut over it for  a set screw  .

Attached Thumbnails

  • 1.25j.jpg
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  • 1.25l.jpg
  • 1.25m.jpg


#12 starman876

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Posted 23 February 2024 - 02:59 PM

Not sure how it could be wrong.  As far as i know it has never been touched .  It operates just the way it should and the Unixes tube fits nice and tight in it and then is clamped. It operates  as it should   Usually you can tell when something is not right or screwed around with.

  For now I used the 1.25 holder from  the Unihex and wrapped  1 loop of tape around one end and stuck it in the Unihex tube  Nice and tight   No movement   I can then use the friction fit for eyepiece as intended or do what I did on my RV6  Drill a hole and glue a nut over it for  a set screw  .

it looks like there is something inside the focuser tube.  It maybe the draw tube you are looking for.


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#13 starman876

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Posted 24 February 2024 - 02:07 PM

so did it work out for you?



#14 k5apl

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Posted 24 February 2024 - 10:23 PM

If there are still questions, I can take photos of my 114 focuser, the drawtube for .965 diagonal/eyepieces and the Unihex with it's drawtube. I need to remove the .965 drawtube to insert the Unihex drawtube in the focuser.  I call it .965 drawtube but I

also have an adapter from Scopestuff that converts to .965 or 1.25 inch accessories.

Wes



#15 K Gephart

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Posted 25 February 2024 - 08:18 PM

Hi,  There is nothing inside It is just a focus tube you stick other tubes into and clamp them for rough focus and use the knobs for fine focus

Attached Thumbnails

  • 1.25p.jpg
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#16 K Gephart

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Posted 25 February 2024 - 08:25 PM

 I have a Unihex draw tube  that goes right in  the focuser tube and clamps for rough focus then use the knobs for fine focus .  I  unscrewed the 1.25 holder from the Unihex and stuck it in the Unihex tube to use a 1.25 diagonal.  I would rather have the drawtube that allows one to use 1.25 with out all the screwing around   Even a .965 drawtube and then use the SS adapter.

 

This is my focus tube maybe 4 or 5 inch long  There is nothing stuck in it  it is what it is

Attached Thumbnails

  • 1.25p.jpg
  • 1.25r.jpg

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#17 Kasmos

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Posted 26 February 2024 - 01:13 AM

I've never taken my pull tube out so don't understand why the inside of the rack tube is stepped just past the slit?

If the pull tube fits the inner sleeve that's recessed inside, what's the compression slit for?



#18 starman876

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Posted 26 February 2024 - 08:07 AM

I've never taken my pull tube out so don't understand why the inside of the rack tube is stepped just past the slit?

If the pull tube fits the inner sleeve that's recessed inside, what's the compression slit for?

that is a good question.  I have had so many of these scopes and have never seen that step inside the focuser.  


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#19 starman876

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Posted 26 February 2024 - 03:10 PM

so what looks like a lip is really a recessed ring in the focuser.  The picture deceiving.  First time I really paid attention to it.   Bottom line is you need  a focusing tube with inside threads for the visual back to screw into.  



#20 Kasmos

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Posted 26 February 2024 - 03:16 PM

so what looks like a lip is really a recessed ring in the focuser.  The picture deceiving.  First time I really paid attention to it.   Bottom line is you need  a focusing tube with inside threads for the visual back to screw into.  

I'm puzzled, so I'll go look at mine and snap a photo if it's different.



#21 Kasmos

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Posted 26 February 2024 - 07:24 PM

My 114s focuser has never been serviced and it's draw/pull tube has been practically too stiff to use,

so I took it apart for a cleaning and re-grease.

 

R-Tube-Recess.jpg

It was pretty hard to tell what was going on inside the rack tube until it was removed and cleaned.

From each end it looked like another tube was in it or it had a step,

but like starman876 said it is a recess cut right at the compression slit.

It was even hard to tell what was going on when running my finger over it.

 

114-Pull-tube.jpg

For referrence here's what my draw/pull tube looks like.

My scope is from about 1957 and off hand I can't say how long they remained the same.

 

114-VB.jpg

The .965" visual back is two pieces with the collar being plastic and the compression end brass.

Sometime later the style of the slit cut in the end piece changed from a 'T' to sort of a U-shape cut and was brushed chrome.


Edited by Kasmos, 26 February 2024 - 07:30 PM.


#22 starman876

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Posted 26 February 2024 - 10:46 PM

My 114s focuser has never been serviced and it's draw/pull tube has been practically too stiff to use,

so I took it apart for a cleaning and re-grease.

 

attachicon.gif R-Tube-Recess.jpg

It was pretty hard to tell what was going on inside the rack tube until it was removed and cleaned.

From each end it looked like another tube was in it or it had a step,

but like starman876 said it is a recess cut right at the compression slit.

It was even hard to tell what was going on when running my finger over it.

 

attachicon.gif 114-Pull-tube.jpg

For referrence here's what my draw/pull tube looks like.

My scope is from about 1957 and off hand I can't say how long they remained the same.

 

attachicon.gif 114-VB.jpg

The .965" visual back is two pieces with the collar being plastic and the compression end brass.

Sometime later the style of the slit cut in the end piece changed from a 'T' to sort of a U-shape cut and was brushed chrome.

I looked at other 75mm focusers and they all have the recess.  Now to figure out why.  Maybe it is supposed to trap lubricant so it stays inside the focuser and not out one the draw tube.  



#23 Kasmos

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Posted 27 February 2024 - 12:33 AM

I looked at other 75mm focusers and they all have the recess.  Now to figure out why.  Maybe it is supposed to trap lubricant so it stays inside the focuser and not out one the draw tube.  

If it was thick like the rest of the tube it wouldn't be flexible at the slit. This way it has spring to hold and release the drawtube. 



#24 K Gephart

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Posted 27 February 2024 - 02:11 PM

Nonetheless I am still looking fro a draw tube  for .965 then use SS adapter or a drawtube for  1.25  My deal with using the Unihex drawtube and the 1.25  eyepiece holder from said Unihex does work but then precludes getting rid of the Unihex as it  is not complete   They are cool but not useful for me.



#25 K Gephart

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Posted 27 February 2024 - 02:12 PM

FYI  My focuser is pretty smooth




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