Posts Made By: Bill Byrd

[COLOR="Purple"]For my 18.75" project, NEWT tells me I need at least a 20.6" front aperture to avoid vignetting of the 75% rays.

For transport design reasons, I'd like to keep the opening to about 20". Is this going to be a significant issue for visual only use?
Bill [/COLOR]

[COLOR="Purple"]Anyone have experience with these? I'm trying to confirm the weight, which was quoted as 3 pounds (for a 24" bearing) in an e-mail I got from Jim.
Bill[/COLOR]

[COLOR="Purple"]The tube connectors arrived so I tried them on two of the short tubes that I have that I'm hoping to make into one longer tube that can be broken down into two pieces. Seems to work well! The assembled tubes are over 7' long and when screwed together are very stiff at the joint.

The two pole sections do not line up exactly; offset laterally from each other due to the "slop" in the connectors. When screwed together, the entire tube is straight, just offset a little at the joint.

The hardware adds about 4 ounces to the tube weight, acceptable in relation to the total weight of the long tube, not to mention the convenience of being able to transport the tubes broken apart instead of in a single 7' length.

1st pic is the hardware used to join the poles.
Bill[/COLOR]

[COLOR="Purple"]I'm thinking of asking "Santa" for a new router for Christmas. My 25 year old Sears model is just not up to the job any more. Sooo...I'm eyeing the Bosch and Dewalt fixed + plunge base kits. Anyone have any comments, good or bad, about these tools? My use is certainly not heavy duty but I'd like something that will stand up to occasionally cutting upper cage rings from 3/4" plywood. Should I get the more powerful model or would the lower powered version do okay?
Thanks for your thoughts!
Bill[/COLOR]

[COLOR="Purple"]Slowly, way too slowly, working on my latest ATM masterpiece, an 18.75" cellular mirrored truss dob. I was drawn to the cellular mirror for quick cool down and light weight. The mirror box has come together nicely and is fairly light, even before I do some cutouts. I found a good deal on a 26" pair of nice aluminum alt bearings. I knew they weren't exactly super light but these puppies weigh about 10 pounds EACH! That's another 20 pounds on a mirror box I'm trying to keep manangable by one person, me. Sooooo...I'm drawn to the composite alt bearings offered by Star Splitter. 24" bearings weigh 3 pounds each! 6 pounds vs 20 pounds saves me 14 pounds on the mirror box. The composite bearings are a little pricey but not outrageous, in my opinion. I'm going to order a pair with some Christmas $ I have coming. Anyone here have any experience with the composite bearings? Guess I'll spruce up the aluminum bearings and list them for sale on Astromart.

Tomorrow, the curved spider is due to be delivered! That's another story.
Bill[/COLOR]

In addition to working on my large scope project, I've been collecting parts for a little 4.25" f/4 RFT reflector. To that end, I've acquired these little gems.

The focuser is a KineOptics HC-1 for 1.25" EPs. The spider is from 1800Destiny and is the little brother of a B I G curved spider that will be used on the 18.75" OTA.

The quality of these units is very nice. It's good to see that there are still some artisans out there making parts for us willing to purchase them.
Bill

[COLOR="Purple"]Here's a pic of the two curved spiders I'll be using on the current scope building projects. The big one is built and wired to have a dew heater behind the seconday. Not enough room for any dew heater on the small one.
Bill[/COLOR]

I'm planning to use a single upper ring on my latest creation.

Reasons why: Lighter weight, looks cool.

Reasons why not: Harder to attach focuser & finders, harder to baffle, more prone to dew on secondary.

Who here has a single ring up top and why?
Thanks!
Bill

[COLOR="Purple"]After a long layoff for the holidays, and a pinched nerve, I got back to working on my 18.75" ATM project. During the layoff, I sold several scopes and used the funds to buy some new woodworking equipment for this build.

Here's a pic of the almost done upper ring along with the new router and circle cutting jig. These new tools made this job relatively easy.
Bill[/COLOR]

[COLOR="Purple"]New router worked great to make the upper ring for the 18.75" project! Here's the curved spider installed on the ring. Pretty minimalist up to this point. 8)
Bill[/COLOR]