Observer's Eyepiece Bag


Rod Nabholz

 


I have a confession to make, and I know it is at the risk of becoming an outcast forever among my fellow astronomers, but I must take this weight off my shoulders.  Here goes:

I sometimes put my eyepieces in my pockets.......

Oh the shame! I can see the looks of disdain and disapproval from all of you, and I probably deserve them. Exposing those poor defenseless precision devices to lint, and dirt, and gosh only knows what else lurks in those nasty pockets!  How dare you sir!

In my defense, I am careful about it, and never put more than one in any one pocket and never have anything else in there with them, but I admit, it is probably not the best practice.

Why would I do such a dastardly deed?  It is usually when I am at the scope and want to change magnification often.  I grab a few eyepieces out of the box, put one in the focuser, and a couple in my pockets. I don't like to make the trip back and forth to the eyepiece box every time I wonder what an object would look like at a different magnification. Further, moving the eyepiece box round and round the scope becomes a bother quickly.

 I have considered those scope mounted eyepiece racks, but Iowa's dew-laden skies take any eyepiece placed in one out of action pretty quickly. 

Of course, placing them in your pocket exposes them to all kinds of risk.  Dust, lint, dings and scratches, and fingerprints as you fumble to extract them.  Put a UWAN 28 in one pocket and an old style Tele Vue 20mm Nagler in the other, you best tighten up your belt a notch, or your could find your britches around your ankles.....

 

Redemption  is at hand (eyepieces too)


So what to do?  I decided that I needed an alternative method, one that would offer a cleaner, more protected environment and keep them close at hand for quick changes.  Perhaps a bag of some sort would work?  Something worn on the hip with a bandoleer style shoulder strap.  It should hold say,  2 to 3 two inch eyepieces and maybe a couple of 1.25 inchers too. Padding to keep them from colliding or rubbing on each other is a requirement.  Extra room for filters, laser pointers would be welcome too.



I took a trip down to the local Army Navy Surplus store to see just what I could find on their shelves that would meet my needs.  After a search through everything from Canteen Pouches to Swiss Military Gas Mask Bags, I came up with a simple bag, made by Rothco, it is 10"x8"x4" with two exterior flapped pockets, a top flap and a shoulder strap.  While not military surplus, it was trying hard to look the part, olive drab, cotton canvas, and made in India.  For $11 it was mine.


On a typical night out with my scopes, you will find me using eyepieces ranging from my UWAN 28mm for my wide angle/finder needs to a 5mm Long Eye Relief for planetary.  In between may be a couple moderate focal length Naglers and even maybe a plossl or two. 

Using the UWAN 28 as the starting point, being the largest of the group, placing it into the bag, I could see that I could accommodate it, plus a couple more 2" Naglers in the main compartment.  The UWAN with a 16mm and 12mm or 9mm would make for a nice spread, offering a nice range of magnifications for the 2" group.  So I began planning to accommodate that mix.

 

Padding the Results


Simply throwing those three eyepieces into the bag would lead to disaster, I needed to keep them in some semblance of order and protect them from bangs and scratches.  Some foam would work nicely for that purpose.



Some of you may remember that I used a closed cell foam from a camping sleeping pad for  the cushion on the seat of my "Observing Stool 22x4".  I had well over half of that pad left.  It is about a half inch thick, closed cell - will not absorb water - and is reasonably flexible.  I felt  that I could make a cylinder of the foam for each eyepiece to afford them protection and keep order in the bag.


Starting with the UWAN,  I simply measured the circumference of the eyepiece at its largest point.  Not having a cloth measuring tape, I used a bit of nylon strapping, held the mark where it met, and laid that against a ruler to get the measurement. That gave me the length of the pad I would cut for the first cylinder.


Simple enough to determine the height.


A couple of thoughts about fitting the cylinder.  My approach was to make the cylinder's diameter a bit larger than the measurement would have indicated.  The reasoning was that placing and extracting the eyepiece into the cylinder should be accomplished easily, and an unnecessarily tight fit would be aggravating in use.  I added about a half inch or so to the length measurement.

As to height, making the cylinder come precisely to the top of the eyepiece would not allow for a place to grab the eyepiece and would make getting it out difficult.  I reduced the height by a bit as well for convenience.

 

Sticky Situation


With the three strips cut, the process of forming them into cylinders began.  I decided to use hot glue for the job of securing the seams, but rubber cement works just as well.  To secure them while the glue set up, I used some straps that I had laying around. Stout rubber bands, string, twine or even tape would also work. The straps worked very well, and after about 15 minutes, the glue was set.


To maintain the cylinders in some order, I added a base.  Measuring the bag's bottom, I cut a piece of foam to match the dimensions.  I trimmed a bit off of the corners to make for a easier fit.


I then attached all three cylinders to the base using the same hot glue, holding them in place with some barbell weights until set.

 

Out of Pocket


Placing the assembly in the bag, the fit is very good.  With the eyepieces in place, the foam stays perfectly in place and the inch of padding between the eyepieces protects them very well.

There is enough extra space around each eyepiece that they slide in and out easily.

The bag's flap provides cover from dust and dew, but is easy to flip back for access.


The extra space around the foam assembly would afford the opportunity to safely store at least two 1.25" eyepieces (one on each side) between the foam and the bag walls.  There is even room to slide in the smart phone that I use for Alt/Az coordinates.  Even more pocket space opened up!


The two front pockets on the pouch also provide room for a couple of 1.25" eyepieces, or perhaps a filter or two, or maybe a laser pointer.

I adjusted the strap to place the bag low on my right hip when wearing it bandoleer style across my chest.  Very secure and comfortable, my hand falls right to the bag naturally when standing or sitting.

My "Key Reel Red Light Keeper" attaches nicely to the strap.

On those nights when the 2" eyepieces won't be used, the smaller ones will ride just fine in the oversize cylinders and the foam is stout enough to hold its shape in the bag.

 

Conclusion


So for a total of around $15, my eyepieces no longer have to suffer the indignity of being slipped into a lint filled pocket like an old roll of breath mints, and they are safe from collisions and scratches.

I trust this will re-earn the respect of my fellow astronomers and I sincerely hope I will never again hear the question "Is that is a Nagler in your pocket or........."

 

Update

With the recent acquisition of an Orion 180mm Maksutov, and its limited output size, I find that I am making more frequent outings with 1.25" eyepieces. While they can ride just fine in the oversize compartments designed for 2" eyepieces, there is a lot of wasted space.  One of the features of this bag is the ability to swap in inserts that match your needs for the night.  It was time to put an insert together for the 1.25's.


I took a bit of a different approach this time, instead of sleeves for the entire eyepiece, I went with rings to fit the barrel.  For the rings I was able to use off-the-shelf pipe insulation.  Insulation sized to fit 1" pipe had an inside diameter of a bit over 1 1/8" making for a nice snug fit for our 1.25" barrels.

Cutting this foam is easiest if you happen to have an electric knife in the house.  It slices through it like, well, an electric knife...Clean and fast.

I cut some rings that were just over an inch tall that pretty closely matched the length of the barrels on my eyepieces.  I laid them out with plenty of space around each spot to make it easy avoid hitting them on each other during placement and extraction.  The base I cut provided room for six rings.  This insulation is scored to make it easy to split open for placement of the foam on a pipe.  I used a short piece of Gorilla tape over that score to prevent it opening up.

Hot glue was the attachment method- very hard to beat, fast and sturdy.

After attaching the rings and placing the eyepieces, I could see there was an issue.  Because the rings were separated, and they did not rest against each other for support, when placed in the bag and the bag was lifted by the shoulder strap, the assembly would bend, with the end rings tilting toward the center.

To correct that, I fitted some braces that maintained the space between the rings.  Once the braces were glued in place, the assembly became very sturdy and the bending and tilting issue was eliminated.

Into the bag it goes, as you can see,  lots of room, even space to stash a couple of filters in the corners.  Six spots in the bag and two outside pockets gives me the capacity to carry eight eyepieces, that should easily cover my needs.

After a couple of uses with some of my eyepieces with larger body barrels, I noticed there was still some flex in the assembly which brought some of the eyepieces too close to each other for comfort.  I fixed it by cutting a stiffening piece out of some 6mm hobby plywood and gluing it to the bottom of the assembly.   That did the trick nicely.

Update II

As is too often the case, a couple of new eyepieces caught my fancy.  So after some selling of some of the old, and buying of the new, I had three new-to-me Explore Scientific 100 degree eyepieces.  As some of you may know, these are some big honking eyepieces.  So big in fact that I needed to rework my bag.

Placing three of these eyepieces meant that the old green bag would not work, it was not large enough.  Off the the Army/Navy surplus store.  Twenty bucks lighter I returned with this







It offered about 2 inches more in width, along with a couple of nice pockets in front and a couple more in the ends.

Because of the size of these eyepieces, I decided to use a different form of construction for the insert.  I formed and glued the same green foam into a three sectioned box.  








With these three and a couple stashed in the ends, I can cover nearly all my needs without ever leaving the scope.



I welcome your comments and questions at

rnabholz@yahoo.com

 2014   Rod Nabholz

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