LGDSO

Does anyone know how to make/reguate a dew heater for a Celestron 9.25?  I dont mind spending 80$ for the heater but not $500 for a controller and power supply??
My plan is to buy the ring dew heater from Celestron or HIgh Point and run it to a small 12vdc power pack of 2.8MAh.  I could put  one of my a variable resistors in line to control the voltage.

Any other suggestions as to how to control dew?  I do have and use the long dew shield.

The front glass of my telescope has small imperfections/or blemishes on the inside.  There are about 20 of them scattered all around.  Dont know how anything woulld get on the inside as I keep the back cap on all  the time.  And scope is contained in this toolcase all the time.
So I sent a request for a warranty replacement/repair.............and Celestron sent me this!

"Looks like it needs to be cleaned.
We do that, you would need to send your OTA in.

For a EDGE 9.25" it is $300+ shipping to Clean, lubricate, collimate,
do a complete corrector alignment & perform a final evaluation."

It looks like they want me to repackage the who telescope and pay $300.  Sounds like a lot of repackaging and $500 or so!!!

So the question is:  why wont they replace a the glass lens/how would dirt get on the inside/why cant I just take it our and clean it myself/ etc
Help!!!  Would the local Celestron Rep help since he can see what the problem is.  Or can someone look at it for me?

Can I use Office Depot "Cleaning Duster" to blow off dust from my scope? "removes dust and debris from electronic equipment"  But contains difloroumethane?

The latest issue of Sky & Telescope had an article on Cassini.  I especially like his meridian sun line a cathedral  floor in Bologna, Italy. The movement of the sun marked Easter and the seasons.   I am trying to replicate that thru my lanai, unto my driveway.  It's a slow summer!

It seems to be easy, ( just drill a hole in my roof )  except that my aluminum  roof over my covered driveway is 4" thick! So to accomodate a sun angle of 86 degrees ( for summer sun) and 40 degrees ( for the winter sun), I have calculated that the hole would have to be about 8" in diameter.

That is too big.    One solution is to cut a slot in my roof ( still 8" long), oriented due south, of course.

But I am looking for a simpler way.  Is there a way to bring down to the floor a circle of light that transmits whatever angle it sees of the sun..to the floor.
   That is, sending the noon sun along a meridian ( south-north )  line .  Must go thru a 4" thick roof.

I wonder how Cassini did it thru very thick stone walls??

Anyone have any ideas?