Bino Chair - R.A.C. 1000
Posted 31 July 2005 - 10:35 PM
Finally bought a pair of binos to go with my 6" Newt and found out right away if you want to spend much time at all with them you have to have some sort of mount even for the 15 x 70s. Found the Starchair 3000 on the internet but at $4950.00 it's way out of my reach. Soooooooooo..... since the project is as important as having the toys for me I built the "R.A.C. 1000"
It is the prototype, predecessor to the R.A.C. 9000 which will be motorized and trailer mounted.
Here's a link to the rest of the photos:
Posted 01 August 2005 - 06:40 AM
Posted 03 August 2005 - 10:58 AM
When all is said and done..............say that ya had a good time building it !!!!
Posted 03 August 2005 - 12:56 PM
Posted 03 August 2005 - 01:04 PM
Posted 03 August 2005 - 01:29 PM
What's the maximum support weight for a setup like that? I'd like to build something like that for my Celestron 25X100 (~17 lb).
Posted 03 August 2005 - 07:39 PM
Posted 03 August 2005 - 08:16 PM
The difficult part of this was controlling where the slip happened. The bolt turned, didn't turn, the inside slips and one outside, the inside and both outsides etc. etc. Finally determined can't control it so had to get the whole assembly tight enough to hold the weight and slip wherever it wanted without loosening.
The top mount plate bolts I had were not long enough for jam nuts and it loosens. Next trip to Lowe's I'll pick up some longer ones.
The final touch that got the thing working was adding the small 1/4" nylon flat washers under the head of the bolt and the nut. If you will look at the picture you can see how they are squishing out and wrapping around the head of the bolt and the nut. I don't expect them to last too much longer. I'll have to change them to something more substantial which brings me to today's purchase.
Went to a plastic supplier today and bought some 1/4" mechanical CHMW to replace the record used for the azimuth bearing on my 6" dob. Will have some drop so plan on cutting some bearings for the chair and trying that. It is much harder than the nylon and WAY more slick. I replaced the azimuth bearing on the dob tonight and OMG! I can't imagine the azimuth slewing any better.
Posted 03 August 2005 - 08:22 PM
How is it tensioned and positioned?
Tremendous amount of tight on the nuts and bolts, way more than one would think. No, there is no loosening to move, was able to get the tension adjusted so can move the mount and it still hold once positioned. Understand, it's not a smooth mount but with the FOV on the binos and the elevation and azimuth slewing actually being accomplished with the chair it doesn't matter.
Notice in the second picture how the mount plate moves. The entire mount is articulated at three points. The bolt washer combination on the mount plate is not correct. I ran out of washers and didn't have bolts long enough, will fix that soon. However, several hours of continuous use last night by myself and two other people and I only had to tighten the top mount bearings once.
How much weight will it hold? I don't know, but think it would stand up to appreciably more than the Celestron 15 x 70s I use with it.
Posted 03 August 2005 - 08:30 PM
Posted 04 August 2005 - 07:40 AM
One way to tell how much weight it will carry is to attach weights of some kind to the saddle until it starts drooping. I've found to get extra support (on my bino bed project) is to add an extra arm to one pair of the swingarms that runs from the saddle bolt (or near it) down to the lower swingarm forming a triangle which can be and use a female clamping knob to tighten. You can then take some of the compression load off of the middle swingarm and saddle bolts and washers. The lowest swingarm bolts on the vertical supports still needs to be tight though.
Also I noticed the binos sit very high on the saddle plate. If you change the flat saddle to a squared U-shape you will lower the binos center of gravity and they will balance better with less tension on the bolts and washers.
Posted 04 August 2005 - 09:18 AM
Posted 04 August 2005 - 09:40 AM
Posted 04 August 2005 - 10:16 AM
Posted 04 August 2005 - 11:12 AM
Posted 04 August 2005 - 11:41 AM