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RICHARD COFER

VdB 141 Ghost Nebula

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Posts Made By: Stephen Collett

December 13, 2005 11:39 PM Forum: Telescope Making

A question about vibration

Posted By Stephen Collett
Floyd: the first thing I would look at is any flexure where your truss tubes connect to the mirror box or the upper. Stiffining this may kill the vibration, or may make it take LONGER to dampen but with shorter oscillations. Don't know the physics involved, but as you know I believe that a scope must first and foremost be stiff.

January 7, 2006 05:53 AM Forum: Telescope Making

spider orientation

Posted By Stephen Collett
glenn littledale said:

as long as there is room, is there a disadvantage to orienting the spider so that a vane will be along the line of the focuser? i'm about to drill a 16" aluminum uta and was thinking this way would make offsetting the secondary a little easier.

I've built a lot of newts, and I learned early on that the important factor in the design and orientation of the spider is to make sure that the vanes don't block access to the collimation screws for your secondary!!

March 4, 2006 09:51 PM Forum: Home Observatories

My roll-off shed

Posted By Stephen Collett
Here are the panels before assembly.

March 9, 2006 05:47 AM Forum: Telescope Making

I'm In Way Over My Head...Literally!

Posted By Stephen Collett
Hey, nice work!!! Keep us up to date on the rest of the project.

Don't worry about the height. From the look of your picture, you must be young and vigorous to handle going up and down two or three steps a few hundred times a night.

For six years, I used an 8 foot ladder and typically three or four steps with the 20" f/5.5 in the picture (John Hall mirror -- awesome!). Alas, I sold it a few years ago when money was tight. sad

March 12, 2006 02:53 AM Forum: Telescope Making

To Spoke...or Not to Spoke...That is the Question

Posted By Stephen Collett
SPOKE!! Use a Forstner bit at the corners of your triangles, and cut carefully between them with a saber saw. Finish by sanding with a drum sander on a drill press or an oscillating spindle sander.

March 12, 2006 02:55 AM Forum: Telescope Making

To Spoke...or Not to Spoke...That is the Question

Posted By Stephen Collett
SPOKE!! Use a Forstner bit at the corners of your triangles, and cut carefully between them with a saber saw. Finish by sanding with a drum sander on a drill press or an oscillating spindle sander.

March 12, 2006 02:58 AM Forum: Telescope Making

To Spoke...or Not to Spoke...That is the Question

Posted By Stephen Collett
To answer your original question, I believe it is important to have enough material in the bearing so that it not flex on you, but you want to keep the weight down. If you locate the centers of the bearings along the center of the box & truss, you will have a slight balance bias toward the forward end, but I believe this is usually minor.

April 20, 2006 02:26 AM Forum: Equipment Talk

Bino Mount

Posted By Stephen Collett
Looks good. I've built a bunch of similar ones using a bandsaw and disc sander (yours is WAY better) with oak tripods. Tried to sell a handful at RTMC in the $300 range and lost money. Doesn't hurt to try it out, though.
OBTW, my old lathe is a 12x24" Southbend hiding under a Crafstman label.

May 15, 2006 03:38 AM Forum: Equipment Talk

Another scope! :^0

Posted By Stephen Collett
Thanks for the nice plug, Floyd!! Here's my nearly-finished walnut & copper equatorial / ED 80.

June 13, 2006 07:02 AM Forum: Telescope Making

Inserting Tube Connectors

Posted By Stephen Collett
If you have a drill press, you can chuck up a piece of 1/4" threaded rod or a long 1/4-20 screw, thread the insert onto the screw, and use the drill press to force the insert in. It helps to have a piece of angle material to hold the tube square on the table of the drill press.

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