Tim Gilliland
professor emeritus
Reged: 03/28/09
Loc: Sand Springs Okla.
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Re: Tracking platform
[Re: GShaffer]
#5215577 - 05/10/12 01:49 PM
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I just wasnt into repositioning the transport handles to compensate and leaving additional holes in the wood....my own anal retention issues kicking in 
I can easily see where that would be a very real issue with many of the works of art some of these larger scopes are. Not so with mine! 
I have made a number of mods to mine. All are ugly but very function very well. Guess there are more holes in the future for the old Discovery base.
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G Blandin
Vendor (equatorial platforms)
Reged: 03/12/12
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Re: Tracking platform
[Re: Tim Gilliland]
#5215766 - 05/10/12 03:22 PM Attachment (58 downloads)
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There have been a number of people who have asked about using DSCs with the platform so I put them on my 10" and took some pictures to show how simple it is. The first picture shows the DSCs azimuth encoder in it's stowed position, it's screwed into the floor of the rocker and can be left there which is what I do. The second picture shows the encoder installed in a modified center pivot bolt. The bolt has a hole in the top for the shaft and a set screw in the side. The bolt does not rotate in relation to the platform, but the rocker does and turns the encoder. It's very simple. You can mod your own bolt or I could provide one based on your specs.
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G Blandin
Vendor (equatorial platforms)
Reged: 03/12/12
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Re: Tracking platform
[Re: G Blandin]
#5215767 - 05/10/12 03:23 PM Attachment (51 downloads)
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Here's the second picture.
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: G Blandin]
#5215787 - 05/10/12 03:38 PM
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Mine is done a bit differently....The bolt comes UP thru the groundboard (flush head on the bottom) and screws into a machined alumimum device that is approx 1" in diameter which goes thru a bronze bushing in the bottom of the rockerbox. It has a big E clip that locks it in....then there is a nylon thumbscrew for installing the encoder.
Will post a pic after tonight....All packed up and ready to head to one of my favorite dark sites up in the mountains about 1.5 hrs away and give this TP its 1st go.....
It actually wouldnt be a major task to install and remove the TP but I like keeping things as quick and simple as possible....Less likely to get tired of dealing with it
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: Tim Gilliland]
#5215808 - 05/10/12 03:49 PM
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I hear you
Mine on the other hand while certainly not the fanciest is a good looking scope to me and I think long and hard before modding or changing things to keep it that way (see pic)
 
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I just wasnt into repositioning the transport handles to compensate and leaving additional holes in the wood....my own anal retention issues kicking in
I can easily see where that would be a very real issue with many of the works of art some of these larger scopes are. Not so with mine!
I have made a number of mods to mine. All are ugly but very function very well. Guess there are more holes in the future for the old Discovery base.
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hbanich
scholastic sledgehammer
Reged: 06/17/05
Loc: Portland, Oregon
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Re: Tracking platform
[Re: G Blandin]
#5215872 - 05/10/12 04:28 PM
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I used wheelbarrow handles with my platform and set it up so the wheels are at a height that made the scope the same height as the platform pads when the scope was held level. Then I would go around to the north end of the platform and move it over from north to south until it was over the center bolt.
In a similar vein, I made a small ramp so I could wheel my 20 inch Obsession onto my platform. This worked quite well and the small ramp was real handy to stand on when I needed just a few inches of extra height to reach the eyepiece.
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Tim Gilliland
professor emeritus
Reged: 03/28/09
Loc: Sand Springs Okla.
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Re: Tracking platform
[Re: GShaffer]
#5216206 - 05/10/12 08:22 PM
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I hear you
Mine on the other hand while certainly not the fanciest is a good looking scope to me and I think long and hard before modding or changing things to keep it that
Quote:
Quote:
I just wasnt into repositioning the transport handles to compensate and leaving additional holes in the wood....my own anal retention issues kicking in
I can easily see where that would be a very real issue with many of the works of art some of these larger scopes are. Not so with mine!
I have made a number of mods to mine. All are ugly but very function very well. Guess there are more holes in the future for the old Discovery base.
Don't blame you, nice looking scope.
Edited by Tim Gilliland (05/10/12 08:23 PM)
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: Tim Gilliland]
#5216584 - 05/11/12 05:26 AM
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Ok....got back in about 3am.....Below are a couple of pics I took of the modded groundboard and the positioning handle.....
1st I did not get to actually test the platform as I am fairly certain the clutch was adjusted too light....and as I didnt actually turn it on until after dark. Best I can tell it never moved. I didnt want to fiddle with it in the dark either so I just set it back level and pretended it was sitting on the ground.
The good news is when I tore down I tried it with no weight on it and it worked as it should....So I will go thru the clutch adjusting procedure and give it another shot in the daytime before I take it back out....AND I could tell no difference in stability and moving it felt just as solid with the TP as it did without.
Getting back to the groundboard, as you can see in the pics I can still use it without the TP. With the TP once it locks in with the rails on the TP between the feet and guides its centered and stable....When I am setting up I have a reference point on the base I turn the handle to (stainless steel rod you see in the pics) slide it across the 3/8" pads until it drops in the slots....That part worked really slick....
Another bit closer view....
Last night was awesome....We had the best sky in a couple months.
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demiles
sage
Reged: 11/07/06
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Re: Tracking platform
[Re: GShaffer]
#5216594 - 05/11/12 05:56 AM
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Are you referring to the bolt tension on the polar axis?
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: demiles]
#5216604 - 05/11/12 06:15 AM
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I will take a guess and assume you are asking about my stating directly above that I was unable to use it for tracking as the clutch was slipping....
Has nothing to do with the polar axis bolt....Although if that were too tight I suppose it could cause an issue....
No I am refering to the tension adjustment on the drive itself....it is designed to support small to large scopes, the larger the scope (particularly weight wise) the more tension you need on it...else it wont move. Per Gregg it should have been set on delivery for about a 150lb scope....Mine is considerable more than that. With everything I use onboard it is approx 180lbs. Since it did work properly without the scope on it I can only assume I need to adjust it right now.....
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demiles
sage
Reged: 11/07/06
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Re: Tracking platform
[Re: GShaffer]
#5216666 - 05/11/12 07:54 AM
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Ok that makes sense. Fed Ex has my platform on the truck for delivery so I hope to get it setup tonight. I'll post my results tomorrow.
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: demiles]
#5218511 - 05/12/12 10:56 AM
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Weather moved in here and clouded me out yesterday.....and of course no clear sky predicted for days now.
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demiles
sage
Reged: 11/07/06
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Re: Tracking platform
[Re: GShaffer]
#5220208 - 05/13/12 12:51 PM
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I received my platform from Gregg on Friday afternoon. I hurried up and assembled it and took out for a test run. The first thing that is evident is the stability. It's just as stable as the original grind board. Vibration settles down in 1 second. My first polar alignment wasn't the best but tracking was good. Resetting the platform was tight so I needed to adjust the friction on the drive. Saturday night I was back out again with the adjustment complete and a better level. Skies were partly cloudy so planets were my only targets . At 200x Saturn stayed in the .25 degree field for the full run of the platform. And that was just with an alignment with just a compass. So far I am very happy with its performance.
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: demiles]
#5220277 - 05/13/12 01:26 PM
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Glad to hear that!! As you know I had an issue with the drive clutch being too loose for my scope and didnt get to test the tracking yet....and of course the weather here has really taken a turn for the worse. But your results echo what Gregg said I should get and both our thoughts on stability match.....I have to admit I was a bit taken aback that a 17.8 lb platform would hold my scope just as steady with as without the TP, I felt NO difference nor saw any difference in the EP, steady as a rock focusing etc.....Given its well north of 180 lbs it speaks well of the design.
I have been thinking on how to easily and quickly get a fine polar alignment.....Decided I would find the center of the back lower edge of the rockerbox and mark it....Then align the scope on polaris then look and see how far the mark is off from the center of the southern arm of the mount and slide the southern end arm over to match. I would think that would be plenty accurate enough and take very little effort and time.
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demiles
sage
Reged: 11/07/06
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Re: Tracking platform
[Re: GShaffer]
#5220545 - 05/13/12 04:29 PM Attachment (50 downloads)
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Here is a pic of my scope on the platform
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18UCinVA
professor emeritus
Reged: 10/24/08
Loc: Virginia
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Re: Tracking platform
[Re: demiles]
#5220554 - 05/13/12 04:35 PM
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That looks great!!
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: demiles]
#5220580 - 05/13/12 04:56 PM
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Quote:
Here is a pic of my scope on the platform
Nice! Looks ready for bidness
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GShaffer
Carpal Tunnel
Reged: 02/28/09
Loc: Bogart, Ga USA
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Re: Tracking platform
[Re: demiles]
#5220608 - 05/13/12 05:10 PM
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If that happens to be on your property I have a relatively easy suggestion that will make life simpler....
I found one for free yesterday but I imagine they can be bought for around $30 give or take......one of the pads they use for sitting air conditioning units on. I dug it in level with the ground and of course leveled it. Its low enough to mow over and not add more height to the setup.
Its in my normal observing spot for here at home (live in the country so I am fortunate to have fairly decent sky although I do have a light cone from Athens GA in the east upto almost 30 degrees.
Once the weather allows I will do one really good polar alignment using a modified drift method Gregg suggested and mark the spots for the feet. After that setup should be about at quick and simple as it could be.
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Here is a pic of my scope on the platform
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Tim Gilliland
professor emeritus
Reged: 03/28/09
Loc: Sand Springs Okla.
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Re: Tracking platform
[Re: GShaffer]
#5220767 - 05/13/12 07:06 PM
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Decided to go ahead and order one. Seeing the positive reports and The pictures was enough to help me make my mind up. Thanks guys!
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G Blandin
Vendor (equatorial platforms)
Reged: 03/12/12
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Re: Tracking platform
[Re: Tim Gilliland]
#5221021 - 05/13/12 10:25 PM Attachment (51 downloads)
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Just thought I'd add another picture of my 16" "minimalist" scope designed for travel. It weighs 75 pounds, only 15 pounds more than my 10" dob. Still need to get it anodized, but here it is on a platform ready for observing tonight.
Edited by G Blandin (05/13/12 10:27 PM)
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