Re: ATM Removable bearings for a dob

["at making" <atmaking@hotmail.com>]

Thanks to all for your ideas about those bearings ! I now got plenty of 
solution to investigate. Seems that the biggest part of the problem is to 
find a solution that is easy to make with a foam core design of bearing. I 
will try to find something that I can do and that will be as easy as 
possible to use during the setup of the scope. The mirror will be heavy, 
around 60 lbs, so a bearing that can rotate on itself is a good solution, 
may be only one bearing "ala Francis Milsom", may be smaller 
bearing...possibilitys seems to be endless !

Again, thank to all !

Frédéric Géa
http://www.astrosurf.com/altaz


>From: Chuck Dethloff <telmor@teleport.com>
>To: "at making" <atmaking@hotmail.com>,atm@shore.net,bigdob@yahoogroups.com
>Subject: Re: ATM Removable bearings for a dob
>Date: Wed, 21 Aug 2002 08:51:40 -0700
>
>Frédéric,
>
>Another option to removing the bearings completely is to make a slot in the 
>mirror box that allows for them to rotate down to a lower position for 
>storage. I did this on a flyable 12.5" and it works well.
>
>Each bearing is mounted to the mirror box side with two 1/4-20 machine 
>screws that pass through a arc shaped 1/2" slot in the mirror box side cut 
>with a router. 1/4 to 1/2" bushings ride in the slot and a fender washer is 
>placed on the inside of under the two knobs that loosen quickly on the 
>inside of the mirror box. Once the bearings are in there lower position the 
>knobs are re tightened and the bearings are retained nicely during 
>transportation. as shown in 
>http://home.teleport.com/~telmor/_uimages/insidesuitcase.jpg A light bit of 
>wax in the slot and under the fender washers helps keep the movement 
>smooth.
>
>http://home.teleport.com/~telmor/_uimages/Mboxside.jpg shows the bearings 
>in there normal position and allow you to see the slot in the mirror box.
>
>Chuck Dethloff