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Anonymous
Unregistered




Dobsonian mount mods new
      #65947 - 03/05/04 01:31 AM

I have a Discovery 10" DHQ Dob. I am having some difficulties moving the telescope around its azimuth axis.
I have read many posts claiming that using "milk jug"
washers tend to alleviate this problem to some degree.
I would also like to try this out, but I am not sure what exactly is, a "milk jug" washer?

Thanks in advance for your advice.

Ken




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Jarad
Postmaster


Reged: 04/28/03
Posts: 5732
Loc: Atlanta, GA
Re: Dobsonian mount mods new [Re: ]
      #66014 - 03/05/04 09:01 AM

A milk jug washer is a plastic washer cut out of a plastic milk jug. It's cheap - the price of a gallon of milk and a pair of scissors (less if you already have scissors and drink milk... ). You could also go to Home Depot and buy teflon washers and/or pads. The idea is to replace the bearing surfaces (the spots where the rocker box rubs on the ground board) with something that slides more smoothly. The "standard" for this is usually teflon on formica, but using plastic washers is cheap alternative (not quite as smooth, but pretty high performance/price ratio!).

Jarad


--------------------


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Willy
sage


Reged: 01/03/04
Posts: 216
Loc: Lincolnshire, England.
Re: Dobsonian mount mods new [Re: Jarad]
      #66024 - 03/05/04 09:26 AM

I put 'magic sliders'under my az mount.....it makes a big difference.
John.

--------------------
John.
ST80
4" Helios refractor f9.8
8" Skywatcher dob/eq f6
West Highland White terrier.


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Craig Simmons
Carpal Tunnel


Reged: 12/10/03
Posts: 1502
Loc: Falls Church, VA
Re: Dobsonian mount mods new [Re: Willy]
      #66078 - 03/05/04 11:16 AM

AOL CDs are reported to work well also. I've used coffee can lids myself, but finally settled on a 12" lazy susan bearing with indoor/outdoor carpet pads on the existing bearing pads for stiction. Easy one finger controlled motion. I used double stick carpet tape to secure the LS bearing and carpet.

Craig Simmons
Falls Church, VA

--------------------
Craig Simmons
Oberwerk 8x56, 20x90
Nikon Action IV 10x50
Barska 15x70
Galileo 20x60
Stellarvue 15x63, 20x85
Orion XT10 pre-Classic
Antares 10
Stellarvue AT1010


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jrcrillyAdministrator
Refractor wienie no more


Reged: 04/30/03
Posts: 30716
Loc: NE Ohio
Re: Dobsonian mount mods new [Re: Willy]
      #66080 - 03/05/04 11:20 AM

When I took my 16" Meade Dob apart I found someone had added a couple of AOL CD's as bushings.

--------------------
John C

Battle Cry of Reno
http://www.wadsworthobservatory.com
My Cloudy Nights gallery

AT12RC
AT65EDQ
QSI683WSG-8
Roper Scientific Quantix 6303E "project" camera
mystery EQ mount on the way


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MMICKELS
Aluminum Knight


Reged: 01/20/04
Posts: 36050
Loc: Land of Shake and Bake
Re: Dobsonian mount mods new [Re: jrcrilly]
      #66107 - 03/05/04 12:11 PM

Quote:

When I took my 16" Meade Dob apart I found someone had added a couple of AOL CD's as bushings.



Was your scope crashing alot?

--------------------
Mark


I'm going outside to stand, so if anyone asks I am outstanding.






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Anonymous
Unregistered




Re: Dobsonian mount mods new [Re: MMICKELS]
      #66129 - 03/05/04 12:51 PM

Thank you so much for responding to my post. Optically,
the telsecope is excellent. The altitude bearings work well, too. The azimuth movement is quite "stiff", making tracking
somewhat difficult. However, thanks to your replies, this problem will soon be fixed.
I will let you know the results.


Thank you again!!

Ken


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jrcrillyAdministrator
Refractor wienie no more


Reged: 04/30/03
Posts: 30716
Loc: NE Ohio
Re: Dobsonian mount mods new [Re: MMICKELS]
      #66162 - 03/05/04 01:58 PM

Quote:

Quote:

When I took my 16" Meade Dob apart I found someone had added a couple of AOL CD's as bushings.



Was your scope crashing alot?






--------------------
John C

Battle Cry of Reno
http://www.wadsworthobservatory.com
My Cloudy Nights gallery

AT12RC
AT65EDQ
QSI683WSG-8
Roper Scientific Quantix 6303E "project" camera
mystery EQ mount on the way


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erik
telescope surgeon


Reged: 01/30/04
Posts: 24789
Loc: Hawaii
Re: Dobsonian mount mods new [Re: jrcrilly]
      #66337 - 03/05/04 08:23 PM

i knew those AOL CD's were good for something!

--------------------
-Erik Wilcox
Starstuff
Homebuilt 16" Truss Dob in Ohia Forest Observatory
(12' X 12' rolloff under Mag 7 skies)
8" Antares f/5 Newt
SV 80mm ED Nighthawk NG on M1 ALT/AZ
Nikon Prostaff 65mm spotter on Trekpod
Konusvue 20x80 binos
Homebuilt 80mm f/5 refractor
Mirador 60mm f/12 1960's refractor


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Tom L



Reged: 01/07/04
Posts: 31037
Loc: Sunny Oregon
Re: Dobsonian mount mods new [Re: erik]
      #66342 - 03/05/04 08:32 PM

Hard to believe that I'm actually wanting one to show up know!

How many did you use???

--------------------
Tom
Tele Vue 102mm f/8.6 on an EzTouch
Vixen 80mm f/5 A80SSWT on a grab-n-go mount


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Craig Simmons
Carpal Tunnel


Reged: 12/10/03
Posts: 1502
Loc: Falls Church, VA
Re: Dobsonian mount mods new [Re: Tom L]
      #66561 - 03/06/04 09:15 AM

When cutting out the milk jug of coffee can lids, be sure to make the holes large enough to go around the T-nut head (if it's being used). Also don't stack the washers too high or the base will be tippy. It may seem slightly tippy with just the base on, but will level out with the extra weight of the OTA. If you use the magic sliders, use four. One with a hole drilled in the middle for the center and the other three to replace the existing pads or along side of them if you don't want a permanent change.

Craig Simmons
Falls Church, VA

--------------------
Craig Simmons
Oberwerk 8x56, 20x90
Nikon Action IV 10x50
Barska 15x70
Galileo 20x60
Stellarvue 15x63, 20x85
Orion XT10 pre-Classic
Antares 10
Stellarvue AT1010


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duaner
newbie


Reged: 05/30/07
Posts: 1
Loc: California, USA
Re: Dobsonian mount mods new [Re: Craig Simmons]
      #3280418 - 08/18/09 07:00 PM

I have a 12" Orion Skyquest Intelliscope with the Locator. The locator works great and I love the scope but I was wondering if I sprayed silicone on the base for the teflon pads to slide over would the azimuth move smoother and not stick anymore?

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donnie3
Carpal Tunnel


Reged: 12/15/04
Posts: 2240
Loc: bartlesville oklahoma
Re: Dobsonian mount mods new [Re: duaner]
      #3282215 - 08/19/09 03:49 PM

duaner, i purchased the same scope about 3 months ago. i had a lot of problems with the azimuth movement( thay fixed the problem on their 12" truss but still selling the solid tubes with the problem. i ordered a ebonystar kit from scope stuff that helped a lot but someone on cn suggested a type wax that has a silicon base called express shine made by turtle wax. it comes in a green spray bottle and you can find it at walmarts in the auto department. its the best wax I've ever used for my dobs and will not stick!!!! try it, i think you will be happy with it. don

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epee
scholastic sledgehammer


Reged: 11/30/06
Posts: 961
Loc: Suh-van-nuh, Jaw-juh
Re: Dobsonian mount mods new [Re: donnie3]
      #3283606 - 08/20/09 10:23 AM

duaner,
The spray silicone might work for a short while but it will trap dirt and grit in short order. Polishing with a hard surface wax that can be removed cleanly when dirty helps. However the best solutions seem to be either the "Ebony Star" kits or the 12' lazy-susan bearing; neither is perfect, the "Ebony Star" needs periodic waxing and the lazy-susan needs some form of pasive braking.

--------------------
Jim Girardeau




Orion XT12 Intelliscope
Celestron 11X80mm binoculars
Celestron C-5




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Rob E
Village......clown


Reged: 05/20/09
Posts: 3432
Loc: Where Independence Was Won
Re: Dobsonian mount mods new [Re: Craig Simmons]
      #3284094 - 08/20/09 02:38 PM

Quote:

When cutting out the milk jug.....




It's also important to note that you should remove the milk from the jug before cutting it..

--------------------
Rob E.

There's two ways to do anything,, Right and Twice!


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kroum
Pooh-Bah


Reged: 08/28/08
Posts: 1047
Loc: Santa Clara, CA
Re: Dobsonian mount mods new [Re: Rob E]
      #3284147 - 08/20/09 03:01 PM

When I tried milk jug washers, all I got for my effort was a very shaky dob. They raised the middle just enough that the base had play in it, which translated to about 5-7sec of vibrations after I let go of the tube.

It's been 5 years since I got my dob, and I believe my lazy susan bearing is getting to the end of its (useful) life. Right now in some positions when I release the tube, it will move just enough to place the object I was finding outside of the field of view, and then stop. When I try to move it back into the picture, it moves out as soon as I let go. Might have to go the ebonystar and teflon route

--------------------
10in Hardin Optical Dob
100mm f6 Orion Achromat
6in Orion Short Tube Reflector
15X70 Barska Binoculars

32mm Astrola, 32mm Celestron Erfle
25mm, 12.5mm Sterling Plossls
9.4mm Speers Waler
7.5mm Orion Ultrascopic
Ultima 2X shorty barlow
Orion 2x shorty barlow
Antares 1.6x barlow
Turn on, tune in, and look through the eyepiece.


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donnie3
Carpal Tunnel


Reged: 12/15/04
Posts: 2240
Loc: bartlesville oklahoma
Re: Dobsonian mount mods [Re: kroum]
      #3285321 - 08/21/09 03:57 AM

epee, i haven't had any problems with dirt or grim using this spray wax, i just spray some on a rag wipe it on the ebonystar ring, let it dry and buff it out. i also modified the connection between the base board and ground board by using a larger diameter bolt, the bolt that came with the scope is smaller in diameter of the bushing causing a side to side movement when moving the scope in azimuth. the mod was a little more detailed then just the bolt but i don't wont to detail it out. im very happy with the results. don

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