A guest blog: More than a Telescope

Posted by David Eicher
on Tuesday, July 08, 2014

Credit: Jeff Hutton
When I was a young amateur astronomer growing up in southwestern Ohio, I had the pleasure of getting to know quite a few amateurs in the Cincinnati and Dayton areas. One of these was a kind and brilliant telescope maker named Dick Wessling, who sadly died in 2010, and we lost one of the most gracious friends and telescope experts around. One of Dick’s Cincinnati friends, Jeff Hutton, who is a an academic officer at Xavier University, contributes this special remembrance of Dick — “More Than a Telescope.”

Enjoy.


More Than A Telescope
A 16-inch, f/4.3 reflector is the final token of a 42-year friendship


In 1968, my father noticed my developing interest in astronomy and drove me to a meeting of the Cincinnati Astronomical Association, which was being held in the basement of the Cincinnati Observatory.   Even then I wondered why a “meeting” would occur in the basement of the 1873 facility.  When we arrived, we noticed no activity behind the aged windows and finally located an unlocked door leading to the bottom floor.

We were surprised that this “meeting,” was actually a gathering of “glass-pushers” patiently walking around oil drums who seemed to be massaging glass disks of various diameters.  I caught the eye of one of these mirror grinders. He was about my height and seemed to carry special authority with his peers.  His name was Richard Wessling but insisted on being addressed as "Dick."  As an awkward early teen, I was unprepared for Dick's friendly ways and the ease in which he ignored my attempts to appear to already know all about telescopes (I didn't).

My father passed away a year later, and Dick sensed my loss by supporting my growing interest in astronomy and telescope making.  He was disappointed that I found mirror grinding tedious but nevertheless taught me much about telescope design and construction.  What I didn't know was that Dick was well known in the telescope making community, counting Richard Buckroeder and Robert Cox as good friends.

At this time, his optical talents were recognized by an entrepreneur who had started a custom plastic optics firm called U.S. Precision Lens (USPL).  This firm lacked the leadership of an expert in optics.   After he was hired by USPL, Dick was largely responsible for most of the bubble lens arrays used in early Texas Instruments calculators, as well as the reason a Technical Oscar was awarded to USPL for their work in projection television optics.  In August of 1988, Dick shared the stage with President Ronald Reagan as the result of U.S.P.L.'s success at exporting American products overseas — largely the results of Dick's work.

Nearing retirement, Dick began the Pines Optical Shop at his home in Milford, Ohio, and later became a full-time telescope optician.  It is well known today that a Wessling mirror is one of the best.  As a result of his friendship with Richard Buckroeder, Dick became interested in building a Tri-mirror Buckroeder-Schiefspiegler telescope, which he speedily produced in 4.25, 8, and 12 inch sizes.  These were counted among his many instruments, all painted in Wessling yellow and known to his many friends as "Yellowscopes."

In 2007, my wife and I had a serious discussion about obtaining one of Dick's famed 16-inch short-focus mirrors.  Dick's powers as a mirror maker were legendary, but we wondered if Dick, at age 72, would continue making mirrors.  Against all fiscal logic, we decided to ask Dick if he would produce a 16-inch mirror for us.  He agreed, and as Dick was completing the mirror, I set about building the best 16-inch dob I could, knowing that this scope would probably be my largest, as I was now looking ahead to my own retirement.

My philosophy regarding any telescope is that it should be as transparent to the observing experience as possible.  That is, I want to remember viewing or imaging an astronomical object, not setup or what the telescope would or wouldn't do.  A welded steel rocker box seemed to solve many of the bulk, heat retention and rigidity issues many of my friends experienced as they used their large dobs.  This resulted in a stiffer structure and allowed easier integration of the 18-point mirror cell.  Luckily, a willing friend happens to be an iron worker and a skilled welder.  Trusses were made from aluminum, which employ a unique configuration to allow for just 4 articulated units which slip into the four square tubes that define the corners of the mirror box.  This greatly simplifies field assembly.

Having never built a thin-mirror reflector of this size, I was concerned with the proper construction of an 18-point mirror cell, including the correct placement of the contact points on the rear of the primary.  Thus, I contacted Alan MacRoberts at Sky and Telescope who kindly referred me to an Internet site, which provided this needed information.  Initially, I fixed the side mirror supports to the outer steel cage of the mirror box but quickly learned that was a bad idea as they prevented the mirror from seating securely on the 18 contact points at the back of the mirror.  I later placed them on an outrigger that moved with the cell during alignment.

The upper ends of the truss tubes are chamfered to rest together for upper cage assembly. The cage rests on flats formed by cutaways on the tubes.  The mating ends then slip inside the upper cage and are secured by cam clamps on the side and threaded fasteners from below.

The secondary assembly is made from plywood and phenolic material wrapped in aluminum flashing. The spider is constructed from more flashing material and consists of two continuous strips that are strung through stainless steel pins in the diagonal assembly.   The spider vanes were cut on a router table using a 1/8-inch spiral cut router bit.  Final trimming was done with a jointer with the rough-cut strips sandwiched between wooden carriers.  Experience in woodworking is a big plus.    Accurate pin location on the spider hub results in alignment in opposite vanes.  Development using a drafting program helped in producing the curve for the aluminum housing around the diagonal mirror and for pin location.  CAUTION: if you machine aluminum on woodworking machinery always use a face mask.  I don't recommend trying any of the above operations unless you are an experienced wood or metal worker.  If an operation doesn't appear or “feel” safe, don't do it!

The rocker box is of conventional design except that one side uses a reclaimed radial arm saw carriage bearing, aligned with a teflon on laminate bearing on the opposite of the mirror box.  This eliminates rocking sometimes experienced when four contact points are used.  It also allows for easy mounting for a positioning encoder.

During the summer of 2009, Dick completed the primary mirror, had it coated, and delivered to me.  Originally, I intended to wait until my retirement a few years hence to build this telescope.  The thought of a near perfect 16-inch mirror waiting five years to be used was just too much to bear, and I decided early to move ahead with the project.  By September, 2009 I was drilling holes in the mirror box when a previously undiagnosed medical issue sent me to the hospital for emergency surgery.  The aftereffects of the anesthesia prevented me from reading so I spent much of my hospital recovery time fine tuning the design for the primary mirror cell.  

By January of 2010, I had recovered sufficiently to resume construction.  Both mirror cells were complete, as was construction on the upper cage.  On March 6, I performed my focus check.  The mount was not yet ready so the tube assembly rested on a temporary stand and pointed to the zenith.  I placed milled pine sticks in the corners of the mirror box to adjust the primary-to-eyepiece spacing.  It was on this night that my friend, Dick Wessling, suffered the stroke that was to end his life 11 days later.  

I had one last conversation with Dick.  Although he couldn't open his eyes, he was conscious and we discussed, among other things, my choice of the eyepiece focuser.  Later that week, my wife, Reda and I joined Dick and our friends for a last prayer circle together in Dick's hospital room.

Our group calls itself the Midwestern Astronomers, and we primarily gather for public star gazes.  At some point during any given event, somebody will relate an anecdote about Dick or something funny will occur, followed by "...wouldn't Dick have gotten a kick out of this!"

In 2011, Reda and I traveled from our home in Kentucky to the annual Stellafane Convention in Springfield, Vermont.  I entered the 16 inch in the telescope competition and was fortunate enough to win first place in the design and construction categories.  Sadly, because I had not produced the mirror, the telescope was eliminated from the optical competition.  In 2000, another telescope of my construction, using Dick's optics did win the Robert Cox award at Stellafane for an 8-inch tri-mirror Schiefspiegler.  

Dick's leadership and friendship is remembered by a great number of astronomers, both amateur and professional.  An asteroid, discovered in 2006, was named in his honor, and has been designated 242830 Richardwessling.   I think he might have preferred “Dick.”

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