If you are a fan of big, beautiful telescopes (and who isn't), I bet you occasionally day dream about owning a PlaneWave telescope. I would like to tell you that I bought one, but sadly that's not true. However, I did get to do the next best thing; I got to go to the PlaneWave Instruments headquarters in Torrance, California. For those of you not familiar with PlaneWave, they manufacture Corrected Dall-Kirkham telescopes with primary mirror diameters of 12.5" (.32m), 17" (.43m), 20" (.51m), 24" (.61m) and 28" (.7m). All of their scopes have ellipsoidal primary mirrors, spherical secondary mirrors and a two element corrector. Their Corrected Dall-Kirkham telescopes have no off-axis coma, no off-axis astigmatism and a big flat field. They are primarily used for imaging but a surprising number are purchased for visual use (often outreach).
While at PlaneWave Instruments, I met with Rick Hedrick, President, CEO and co-founder; Joe Haberman, Vice President and co-founder; and Allan Keller who is the systems designer for the CDK700 Observatory Telescope System.
Shown below are pictures and additional details of my visit. (Please click on any image to see a larger version.)
PlaneWave currently does all of their mirror grinding, polishing, figuring and testing on site. The following image shows one of their two optical rooms:
This picture shows a 17" mirror being polished:
The masks on this wall are used to test new mirrors:
The image below shows the primary product assembly area at PlaneWave Instruments. The large telescope in the middle of this picture is the 28" (0.7m) CDK700 Observatory Telescope System. The mount on the right is an Ascension 200 mount undergoing testing. (PlaneWave doesn't just make telescopes; they also manufacture German Equatorial Mounts.) The two telescopes on the floor to the left of the 28" scope are CDK17s.
Here's a closer look at the two CDK17 telescopes:
The CDK700 has an optical system with a Nasmyth focus. A Nasmyth focus allows the focal point to be on the side of a telescope. This is accomplished by placing a tertiary mirror in the light path. The tertiary mirror in the CDK700 rotates which allows light to be directed to a focal point on either side of the mount through the altitude axis. This means that an astronomer can install a camera on one side of the telescope and other instruments (like a spectrograph) on the other side of the mount, for example. Cameras, spectrographs, eyepieces, etc. remain at a fixed height regardless of the orientation of the telescope. Heavy instruments can be added to the telescope without any rebalancing. The Nasmyth focus on the CDK700 is located at the optimum height for visual observing by a person in a wheel chair making it a great telescope for astronomy outreach activities. Here's the Nasmyth focus on one side of the CDK700:
This image shows the Nasmyth focus on the other side of this particular telescope (this side is configured to support various types of scientific instruments):
PlaneWave telescopes use a heavy duty focuser called the Hedrick Focuser. Hedrick Focusers use a lead screw to prevent any focus creep even with very heavy cameras. (The CDK 12.5" telescope uses a 2.75" focuser and the 17", 20" and 24" telescopes use a 3.5" focuser.) This is a picture of the Hedrick Focuser that clearly shows the lead screw:
PlaneWave is currently working on a new rotating focuser. This focuser was designed by Kevin Iott who works for PlaneWave in Michigan where about 80% of the machining is done for PlaneWave products. This image shows a prototype of the new rotating focuser:
Finally, here's one more impressive PlaneWave telescope – a CDK24:
With all of these great telescopes you might be tempted to think that PlaneWave will just sit back and take it easy. Nothing could be further from the truth. Rick Hedrick told me that PlaneWave "will ship a 1M telescope and a 1.5M is in the future". In addition, they will be releasing a 14" or 14.5" telescope at some point. I don't know about you but I can hardly wait to see all three new telescopes!