Telekit 18 Inch Telescope V2

My 18” TeleKit Project

I ordered the 18” Astrosystems TeleKit on September 16 2008 and received the bulk of the order late October / early November. I also ordered an in-stock primary mirror from Astrosystems [f4.5]. For me, Astrosystems was a one stop shop. I finished the project on January 15 2009 after putting in around 100 hours of work. I had a great time and one day, when I’m retired, plan on building a 30” TeleKit. The 18” TeleKit is sized so I can wheel it out of my office door; I have about ½” of clearance on either side of the transport handles. I’m still waiting on first light because the weather has been so darn cold. It’s been low single digit [F] every night which is too cold for me. Hopefully things will warm up soon. I will update this presentation as time and events dictate.

That’s it for now. Astrosystems [ www.astrosystems.biz ] provided outstanding support throughout this project. BTW, this presentation is l-o-n-g and probably way boring for most people. So that’s your warning. Otherwise enjoy.

Scott Ghiz

scottghiz AT yahoo DOT com

18” TeleKit Project

NOV 8 2008 : Most of the boxes and components arrived in late October. Here they sit in my shop. Truss tubes, covers, and some other parts arrived a week or so later.

NOV 8 2008 : My carpeted work table built on top of an old Craftsman Workmate

NOV 8 2008 : My workshop with some of the parts scattered about.

NOV 8 2008 : Labeled boxes, primary mirror is on bottom.

NOV 8 2008 : The shop

NOV 9 2008 : Building upper cage. OOPS. Astrosystems sent cage supports for a 16”. Astrosystems sent the 18” supports that day.

NOV 15 2008 : Edge grain of an upper cage ring. Nice stuff to work with.

NOV 14 2008 : Sanded filter box / focuser mount.

NOV 15 2008 : Gluing truss attachments to lower ring of upper cage.

NOV 16 2008 : Ground board feet and TeleKit manual.

NOV 16 2008 : Gluing up ground board feet

NOV 16 2008 : Gluing up ground board feet

NOV 16 2008 : Gluing up ground board feet with azimuth brake knob acting as a spacer.

NOV 16 2008 : Gluing up ground board feet [again]

NOV 16 2008 : This is what I used to fill end-grain voids

NOV 16 2008 : ‘Natural’ color worked well without adding pigment

NOV 16 2008 : Glue drying on ground board feet and upper cage

NOV 25 2008 : Gluing feet to ground board

NOV 26 2008 : Masking ground board feet in preparation for laminate attachment

NOV 26 2008 : Weights pressing the laminate to the bottom of the ground board feet after applying contact cement

NOV 26 2008 : Gluing upper cage together, trying to make it square

NOV 26 2008 : Gluing upper cage together, trying to make it square… MORE TAPE!

NOV 26 2008 : Upper cage just about ready for urethane

NOV 26 2008 : Gluing on baffle stops to filter box

NOV 30 2008 : Looks like upper cage, filter box, and ground board are ready for urethane

DEC 2 2008 : Beginning assembly of rocker box

DEC 2 2008 : Rocker box glue up

DEC 3 2008 : About to attach rocker box bottom

DEC 3 2008 : Rocker box bottom attached

DEC 4 2008 : Flush routing rocker box finger joints… what a mess! Shavings get everywhere.

DEC 5 2008 : Rocker box getting done. It looks routed and sanded.

DEC 10 2008 : Sanding dust and router shavings get spewed all over the place. This is my technique to keep that stuff out of my beer. Dixie cup over the top… I hope it was a clean cup.

DEC 11 2008 : Applying contact cement to rocker box laminate

DEC 11 2008 : Using weights to press laminate flat onto bottom of rocker box

DEC 11 2008 : Using 3/8” round over router bit on bottom of rocker box. I liked this radius better than the recommended 3/16”. I didn’t want to kick the laminate loose while using the telescope.

DEC 11 2008 : Rocker box bottom after round over routing

DEC 11 2008 : Upside-down rocker box. Looks ready for urethane.

DEC 11 2008 : Flood! Typical when we get 2” of rain or more in a short period.

DEC 16 2008 : Rocker box getting first 50/50 urethane coat

DEC 16 2008 : Ground board, upper cage, filter box, and accessory board getting first 50/50 urethane coat

DEC 19 2008 : Final urethane coat on upper cage

DEC 21 2008 : Not bad for a non-sprayed finish

DEC 21 2008 : Finished ground board with one of three azimuth roller bearings installed and azimuth break installed

DEC 21 2008 : Another view

DEC 21 2008 : Filter box blackened on part facing inside of upper cage

DEC 21 2008 : Filter box blackened on part facing inside of upper cage

DEC 21 2008 : Filter box attached to upper cage and double sided tape applied to inside of upper cage for light baffle attachment

DEC 22 2008 : Light baffle [inside painted flat black], spider, and secondary mirror mount attached to upper cage

DEC 22 2008 : Another view

DEC 22 2008 : Feathertouch focuser mounted

DEC 22 2008 : Filter slide with el cheapo filters. Someday I’ll save my pennies and get Thousand Oaks filters

DEC 22 2008 : Accessory board mounted. This will eventually have a Telrad attached.

DEC 22 2008 : Looking inside upper cage with filter slide and internal accessory board mounted [bolts not yet blackened]

DEC 22 2008 : Getting ready to blacken the inside bottom of rocker box

DEC 22 2008 : A dope at Home Depot talked me into using a latex primer and latex paint to coat on top of the spar urethane…

DEC 22 2008 : I was told, “ don’t even bother to sand. This stuff will bond to glass .” Apparently not. I returned both the used primer and used paint for a full refund.

DEC 26 2008 : Recoated with a brushed on oil based black paint. Much better results and it dried much less shiny.

DEC 26 2008 : Rocker box mounted to ground board

DEC 27 2008 : Beginning to build the mirror box

DEC 27 2008 : Gluing up the mirror box

DEC 30 2008 : Sanding mirror box

DEC 30 2008 : Blackening aluminum parts of the 18-point mirror floatation system

JAN 1 2009 : Filling end-grain voids of the mirror cell with wood putty

JAN 1 2009 : Gluing truss tube stops onto bottom of truss tube clamps

JAN 1 2009 : Gluing location posts, mirror sling mount posts, and travel posts to mirror cell

JAN 2 2009 : Forming rocker bearing laminate to rocker bearing. Let it sit overnight to make attaching the laminate to the bearing easier.

JAN 2 2009 : A screw-up by me makes the mirror cell better? I glued 3/8” t-nuts where no t-nut was supposed to go. I drilled out the threads and created metal sleeved collimating bolt mounts. Very nice.

JAN 2 2009 : The other side of this screw-up. I’m actually pretty happy about this.

JAN 2 2009 : Using contact cement to attach laminate to a rocker bearing

JAN 2 2009 : Making sure mirror cell attach points are accurately placed

JAN 3 2009 : Gluing truss tube clamps to inside of mirror box

JAN 3 2009 : Truss tube mounts and mirror cell attachment points

JAN 4 2009 : Rocker bearings with attached laminate

JAN 6 2009 : Miles of sanding in the mirror box with lots of corners and surfaces

JAN 6 2009 : Mirror box, upper corner detail

JAN 6 2009 : Mirror box, rocker bearings, mirror cell, transport handles and mirror cover ready for urethane

JAN 7 2009 : Masking rocker bearing laminate prior to urethane

JAN 7 2009 : Small parts getting urethane [tops of truss tubes, truss tube clamps, mirror retaining points]

JAN 7 2009 : Mirror cell

JAN 7 2009 : Mirror box with mirror cover in background, right

JAN 9 2009 : Rocker bearings and mirror cell

JAN 10 2009 : Transport handles

JAN 10 2009 : Blackening truss tube clamps and mirror retaining points

JAN 10 2009 : Finished mirror cover with side pads

JAN 10 2009 : Truss tubes getting end plugs glued in

JAN 11 2009 : Masking off, preparing to blacken inside face of mirror cell

JAN 11 2009 : Drilling truss tubes for connection to upper truss tube plates

JAN 11 2009 : Mirror cell, blackened

JAN 11 2009 : Mirror cell

JAN 11 2009 : Finished truss tube assemblies

JAN 11 2009 : Truss tube plates attached to truss tubes

JAN 11 2009 : Inside of mirror box blackened

JAN 11 2009 : Wiring mirror cell

JAN 11 2009 : Mirror box, done

JAN 11 2009 : Mirror cell, complete with mirror sling and mirror floatation system in place

JAN 12 2009 : Mirror box with rocker bearing attached

JAN 12 2009 : Rocker box with altitude roller bearing installed. The other bearing is Teflon on laminate

JAN 12 2009 : Mirror box, rocker box, and ground board assembled

JAN 12 2009 : Mirror cell [bottom] installed in mirror box

JAN 12 2009 : Mirror cell [inside] installed in mirror box

JAN 13 2009 : I wanted to power the secondary mirror heater with power from the mirror cell, so I built this little thing to fit in a corner of the mirror box with in-line fusing and DC [N-type] connector

JAN 13 2009 : Another view. I built this out of $2 of 1/8” thick hobby shop Mahogany. I doubled the top and put a large epoxy filet on the bottom side attachments.

JAN 13 2009 : Mounted in mirror box directly under a truss tube clamp

JAN 13 2009 : Close up

JAN 13 2009 : View from underneath. The wire harness will pass through a hole drilled in the bottom of the visible truss tube clamp assembly

JAN 13 2009 : 18” primary mirror. It’s just a $3000 piece of glass.

JAN 14 2009 : Installing primary mirror… yikes! And the telescope is taking shape.

JAN 14 2009 : Looking in from the top of the upper cage toward the primary mirror

JAN 14 2009 : Top / front of the telescope

JAN 14 2009 : Storage / travel configuration

JAN 14 2009 : All packed up with truss tubes and upper cage in their storage bags

JAN 15 2009 : Assembled with shroud installed

JAN 15 2009 : Secondary heater wire assembly going from the top of a truss tube to a DC [N-type] connector which is mounted to and through the light baffle

JAN 15 2009 : Believe it or not, after squaring up the optical components, collimation was a snap with a Barlowed laser collimator tool

JAN 15 2009 : Secondary heater wire harness passing out of the bottom of a truss tube, through a hole drilled in the truss tube clamp, and finally attaching to the DC connector in the mirror box

JAN 15 2009 : Secondary heater wire harness inside of upper cage and passing along the top of a spider vane. Spot directly opposite focuser can be seen for squaring optical components.