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Posts Made By: Bob Chester

March 22, 2004 11:24 PM Forum: Telescope Making

Mirror edge beveling

Posted By Bob Chester

Roger,
I have used a sharpening stone to create a bevel BUT I always did so before I started grinding, with a little bit of bevel maintanance done during rough grinding. Now that you have it already polished and a sharp edge I would suggest using a very fine grit oil stone lubricated with water and be very careful of the grit that tends to shed off the stone. The last thing you need is a 360 or 400 grit scratch in your nicely polished surface. Also, the sharp edge may tend to chip a bit as you grind the bevel so be gentle.
Others may have better advice on putting a bevel on an already polished mirror. On your next mirror (mirror making is addictive) bevel the edge first and check it again after you have rough ground the desired curve.
Good luck to you and clear skies,Bob

March 22, 2004 11:35 PM Forum: CCD Imaging and Processing/Solar System

Double Transit!

Posted By Bob Chester

Remarkable! Thank you for sharing and keep m' coming.

Bob Chester - grandson of Yu Way

July 14, 2004 12:27 AM Forum: Equipment Talk

Nebula filter question

Posted By Bob Chester

Goran,
Floyd is correct. The Antares is a broadband filter more along the line of Orion's Skyglow® or Lumicon's Deep Sky® filter. The UHC has a narrower band pass and is usually considered visually more effective. Orion's Ultrablock® is an acceptable sub for the UHC.
Bob

August 12, 2004 03:13 PM Forum: Equipment Talk

marking a mirror

Posted By Bob Chester

Trace a circle on a piece of paper using the mirror as a template. Cut out the circle. Fold the paper in half, then in half again so that you have a pie shaped 1/4 circle. Cut the pointed tip. Now you have a circle with a hole in the center. Lay it over the mirror and place your mark.
Bob

August 12, 2004 06:07 PM Forum: Equipment Talk

Re: Cave mirror inscriptions?

Posted By Bob Chester

Or maybe the 202nd mirror produced in 1975.

August 13, 2004 09:12 PM Forum: Telescope Making

Flockling Problem

Posted By Bob Chester

Ed,
What is the tube made of? Can the strips you applied be removed?
You may just have to start over.
I didn't trust the peel and stick adhesive by itself when I flocked my tube and added a coat of 3M Scotch 77 spray adhesive. The stuff works great and is available in most hardware stores.
If the flocking can be removed, respray it with 77 spray and reapply in the tube.

Good luck, Bob

August 14, 2004 01:30 PM Forum: Telescope Making

Source for thumb screws (small quantities)?

Posted By Bob Chester

Have you tried Scopestuff?

http://www.scopestuff.com/#Threaded%20Things

Bob

August 27, 2004 01:31 AM Forum: Telescope Making

Aluminum tube - "Au Naturel" ?

Posted By Bob Chester

Mike,
If you want to keep it 'Au Naturel' (short of getting it silver anodized) I can recommend a clear-coat after sanding or buffing to desired level. A fully oxidized tube is a dull gray and still seems to get you dirty when wet with dew.
Attached is a photo of a 7" tube that was sanded with a 220 grit sponge and clear coated with Blair Matte Clear spray (available in most art supply stores). It has maintained it's lustre and does not fingerprint or mar like bare aluminum.

Also pictured is a 5" reverse insulated alum. tube. The interior is flocked and the exterior has a layer of cork covered with a Mahogany veneer. It is comfortable to use in cold weather. The bare alum.(regardless of color) gets really cold in winter (I dare ya to touch your tongue to it). I've had ice form on the clear coated tube AFTER bringing it in the house on cold winter nights. If you observe a lot on those cold Canadian winter nights you might consider insulating the exterior, as discussed in the "cooler than ambient" thread.
My 1/50th a buck, Bob

September 6, 2004 07:27 PM Forum: Equipment Talk

Opinions please (Apo's of course)....

Posted By Bob Chester

Paul,
One advantage of trying the ED100 is that it uses the same rings, probably the same mount you're using now, and (if you got your solar filter from Orion) the same filter. In other words, no additional expenses. If you don't like it you can sell it here on A-M at a very little loss.

Also, if you plan on ever imaging in Ha (ala-Coronado solar max), you may not need over 100mm of aperture ( I believe the largest filter is 90mm and expensive). In fact, if solar imaging is your "thing", the money might be better spent on a solar-max setup for the ed80.

Gary suggests a pair of very good 6" alternatives but they do require all new accessories including mount. But, 6" is a big improvement over 80mm in resolution.

A side question that your post causes me to ask:
How important is the Apo-Achro issue when it comes to solar viewing? With the extremely narrow pass of Ha filters I can't see that it would make any difference. But what about white light filters?

Bob

October 5, 2004 07:05 PM Forum: CCD Imaging and Processing/Solar System

Mare Imbrium widefield

Posted By Bob Chester

Can't compete with the web-cam pros, but this is my best digi-cam close-up to date.
Clavius is the dominant crater.
5 or 7 images stacked in Registax, I don't recall.( it was really late last night) smile

Bob