Re: ATM Building a Dobsonian, 2 Questions

["Dwight K. Elvey" <dwightk.elvey@amd.com>]

>From: "Steven Hammond" <shammond@northpub.com>
>
>
>
>Hi there,
>
>    I've been lurking for a while and learning a lot. I'm finalizing my
>plans for building my scope and I've got a couple questions. I'm making
>an 8" f/6. I've ground, polished and figured the mirror; and it just got
>back from being coated. Now, I'm working on the tube and mount.
>
>1) I've heard that I should use adhesive backed black velvet on the
>inside of the tube, but on the net I've found many references to
>ultra-flat black paint. Is the velvet enough of an improvement to
>justify the cost and effort to install?

Hi
 Any place that can be seen from the focuser can contribute to
poor contrast. Use that as your rule.

>
>2) I'm looking at using lazy susan hardware to facilitate a smooth
>rotation instead of LP's or teflon. Has anybody tried this? See the link
>below for details and specs.

 Every lazy susan base I've seen wobbles. Use some kind
of three point system.
Dwight


>
>    http://www.rockler.com/ecom7/findprod.cfm?sku=2273&filter=18531&DID=6
>
>Thanks,
>Steve
>
>
>
>
>