Bath Interferometer Kit for testing telescope mirrors

Description

An hour or two of assembly required!  Just the stage.  I have detailed instructions showing how to assemble the stage.  For stage assembly you will need a metal file, a small adjustable wrench, some 5 minute epoxy, a phillips screwdriver and it saves about 30 minutes if you have an electric drill.
I have built several interferometers using this kit and every one has been better than 1/50th wave (one interferometer was tested on a traveling reference mirror which was also tested with a ,000 PSI Zygo and agreement was to 1/70th wave - that interferometer tested my own reference mirror which I then used to confirm the accuracy of the other Bath Interferometers).
Your parabolic mirror must be above the red line in the graph (see images).  Also this bath only covers mirrors to about F/3.4 (if you need to test insanely low F/# mirrors then contact me as I have alternate laser and diverging lense combinations and I will put together a custom package for you on ebay).  But don't expect to test anything below the red line.
Includes laser (with calibrated wavelength supplied), XYZ stage kit with standard tripod mount, optical parts, hex driver.  Includes 9mm focal length diverging lens.
You will need:
standard USB 5V power source (e.g. an old iphone charger or a laptop)
A 4 megapixel (or higher) DSLR camera with live view and a lens of fixed focal length (between 50mm and 100mm works great) (zoom lenses won't work)
2 tripods (one for bath one for camera)
A mirror holder to hold your mirror on edge with proper support (either sling support or 2 90 degree center of mass supports)
A windows PC computer to run the free software DFTFringe
Plastic parts are 3d printed. Colors may differ from photo. Parts may not be as beautiful as expected but it will function perfectly.
Instructional videos - consider to maybe watch before buying:
On youtube search "dftfringe quickstart version 2"
and in that same channel watch "setting up and using a bath interferometer"
Colors of plastic parts may vary from photos.