darylf96
Pooh-Bah
Reged: 08/28/04
Posts: 1391
Loc: Danville, California
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Fellow CNers:
I installed the Losmandy encoder kit on my G-11. I am very impressed with the fit and finish, and the gear and bearing covers make the installation very clean looking. For those who plan on this installation, after making all the errors posible, I can provide several tips and things to avoid. My question concerns the settings for Sky Commander re the encoder resolution. The encoders are 2048 line, so I believe I enter 8192 steps in the setup for Sky Commander. Is this correct? Thanks in advance!
Daryl
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Intes Micro MN66 - Meade 10" SCT
Orion EON 120mmm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon SXi
SBIG ST-8XE
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GolfSierra
member
Reged: 12/27/08
Posts: 24
Loc: Kansas
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It is 2:1 gear ratio, should be 4096. Reference from the DSC manual from Losmandy.
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TSA102 SV110 SV80 AT66 MN56
PST
Canon XTi,SSII,SSAG
GM8 LXD75
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7331Peg
professor emeritus
Reged: 09/01/08
Posts: 725
Loc: North coast of Oregon
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How well does that setup work, Daryl? I've already got the Sky Commander on a DM-6, and have wondered about adding the Losmandy encoders to my G11 (non-GOTO), but the price of the encoders has made me hesitate. If the accuracy is very good, it might well be worth the investment.
John
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Eddgie
Carpal Tunnel
Reged: 02/01/06
Posts: 2703
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I had the same setup on my GM8. Pointing was excellent. Everything hit inside the field of my C9.25 with a 35mm Ultima (1.25" eyepiece, so not a big field of view).
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Celestron C14, CGE (Big Al)
Astro-Physics 6" f/8 (Buffy)
Televue 101 (No name, but I call it my Widescreen HD Space TV)
The night sky is my mistress. She seduces me away from all other lovers.
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darylf96
Pooh-Bah
Reged: 08/28/04
Posts: 1391
Loc: Danville, California
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Quote:
It is 2:1 gear ratio, should be 4096. Reference from the DSC manual from Losmandy.
Thanks Much!
I will correct the setup to 4096. I did not see figures on the gear ratio. It should be on the installation instructions, but is not.
Daryl
--------------------
Intes Micro MN66 - Meade 10" SCT
Orion EON 120mmm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon SXi
SBIG ST-8XE
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darylf96
Pooh-Bah
Reged: 08/28/04
Posts: 1391
Loc: Danville, California
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Quote:
How well does that setup work, Daryl? I've already got the Sky Commander on a DM-6, and have wondered about adding the Losmandy encoders to my G11 (non-GOTO), but the price of the encoders has made me hesitate. If the accuracy is very good, it might well be worth the investment.
John
John:
I think I will work out the problems, but it is not the same as use with the DM-6. I really like the setup on that mount. There are some issues with the G-11. Pushing around the DM-6 is easy, and the Sky Commander is nicely positioned on the mount to see the LCD readouts and enter info. Pushing around a large GEM is not so easy, and since you must change positions to move the mount around, you almost have to hold the SC unit in your hand much of the time, and there is no really ideal place to mount the unit. With a 120mm EON refractor and 80mm finder scope, manually moving is not so smooth with the G-11. It would work much better with servo motors or high torque stepper motors to slew to the target on each axis. I don't know, however, if the electronics units for the standard stepper motors will work with motors capable of slewing. If someone is up on this, I would appreciate a heads-up. I am about to call Scotty at Losmandy to find out. It would be an excellent setup if slewing with the HC were possible. Also, I had a problem with the external power connector keeping good contact while moving around with the SC unit, so I must find a way to keep the connector firmly in place. I only had a few hours to work with, and had the wrong setting for the encoder resolution, and had to give up with little positive results, other than to learn that the encoders were working nicely and the installation looks very neat and tidy. I hope to solve some of the problems next time out. If anyone has faced and resolved these problems, would like to hear your comments.
Regards
Daryl
--------------------
Intes Micro MN66 - Meade 10" SCT
Orion EON 120mmm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon SXi
SBIG ST-8XE
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7331Peg
professor emeritus
Reged: 09/01/08
Posts: 725
Loc: North coast of Oregon
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Thanks for reply, Daryl. I can see your point with regard to moving the GEM around manually. It does keep both hands occupied. From what I understand, the motors on the non-GOTO models are not designed for higher speed slewing, though. Would be glad to hear if that's not the case.
I wondered about mounting the Sky Commander. On a large SCT - probably eight inches or larger, it might be possible to velcro the Sky Commander to either the top or the back of the scope. A refractor doesn't give you as much surface area to work with, but there may be a way to attach the Sky Commander to the top of the rings, or maybe even to attach it to an accessory plate designed to slide into a finder shoe. Is there enough cable between the Sky Commander and the encoders to do something like that?
Glad to hear Eddgie's comments about accuracy. Hope your setup is that accurate also. If so, I'll probably take a shot at this.
John
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darylf96
Pooh-Bah
Reged: 08/28/04
Posts: 1391
Loc: Danville, California
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John:
I'm no expert re the motors, but it seems to me that Losmandy could come up with a high-torque stepper motor option that would work with respect to the firmware now installed in their electronics unit. Other mounts use high-torque stepper motors that provide descent slewing speeds.
Daryl
--------------------
Intes Micro MN66 - Meade 10" SCT
Orion EON 120mmm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon SXi
SBIG ST-8XE
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k5apl
sage
Reged: 05/19/06
Posts: 398
Loc: Arkansas
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Hi Daryl
I had the same set-up and liked it very much.
My SkyCommander settings were:
GERMN
NORTH
NORM RA
REV DEC
08192
08192
12V
On
9600
OFF
I would suggest a very accurate Polar Alignment. I needed
the optional Polar Scope for best accuracy.
I found a one-star alignment was easier and very accurate.
Check the SkyCommander Group (Yahoo) for more info. Have
fun with it.
Wes
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gnowellsct
professor emeritus
Reged: 06/24/09
Posts: 730
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If you *really* want accuracy you'll need to get an Argo Navis unit. These offer mount modeling which will improve pointing accuracy from about 20 arc minutes (what you will have with a polar scope alignment) to about 4 arc minutes of pointing error.
I would certainly try the setup at 8192. The gearing is 2x but if memory serves a 2048 encoder is actually 4192 tics because of the way the thing counts black/white/black/white etc. I think the phrase is 2048 encoders with 4096 "at quadrature".
If you're using a refractor or a fast newt with a wide field it probably won't matter. (The wider your field of view, the less it matters how accurate your dscs are, unless you are trying to "land on a chip.")
good luck,
Greg N
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"Aperture will get you through times of no money better than money will get you through times of no aperture."
featuring selected astrojunk:
bunch o' widefield eyepieces
bunch o' narrowfield eyepieces
couple o' Barlows
couple o' scopes
couple o' mounts
couple o' tripods
and a pier 'n' stuff
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TomN
sage
Reged: 01/14/09
Posts: 264
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Where can one see a photo of those encoders and the installation? What vendor supplies these? I also have a G11 and I am thinking about DSCs.... THanks!
Tom
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Amateur Astronomer since 1962.
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gnowellsct
professor emeritus
Reged: 06/24/09
Posts: 730
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Your best bet for speedy delivery of the hardware is Argo Navis (Wildcard Innovations) in Australia which actually stocks the hardware to facilitate sale of the computer. The computer really is the best of the dscs but it is pricey.
You should nose around Yahoo! Losmandy for pictures.
http://groups.yahoo.com/group/losmandy_users
Membership is free.
Greg N
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"Aperture will get you through times of no money better than money will get you through times of no aperture."
featuring selected astrojunk:
bunch o' widefield eyepieces
bunch o' narrowfield eyepieces
couple o' Barlows
couple o' scopes
couple o' mounts
couple o' tripods
and a pier 'n' stuff
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darylf96
Pooh-Bah
Reged: 08/28/04
Posts: 1391
Loc: Danville, California
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Thanks, Wes!
Well, I had the resolution at 8192, so that means that
the information on the assembly sheet took into consideration the gear ratio.
Daryl
--------------------
Intes Micro MN66 - Meade 10" SCT
Orion EON 120mmm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon SXi
SBIG ST-8XE
|
darylf96
Pooh-Bah
Reged: 08/28/04
Posts: 1391
Loc: Danville, California
|
|
Quote:
If you *really* want accuracy you'll need to get an Argo Navis unit. These offer mount modeling which will improve pointing accuracy from about 20 arc minutes (what you will have with a polar scope alignment) to about 4 arc minutes of pointing error.
I would certainly try the setup at 8192. The gearing is 2x but if memory serves a 2048 encoder is actually 4192 tics because of the way the thing counts black/white/black/white etc. I think the phrase is 2048 encoders with 4096 "at quadrature".
If you're using a refractor or a fast newt with a wide field it probably won't matter. (The wider your field of view, the less it matters how accurate your dscs are, unless you are trying to "land on a chip.")
good luck,
Greg N
Greg:
Since I have the Sky Commander and it works great with my DM-6 mount, I will stick with it. I have no problem with perfect polar alignments. Using the polar finder I can align so well, and the mount tracks so well, that I can center a star in the square of double cross-hairs and it will remain dead center for hours. I seldom need to fine tune with drift alignment. I'm sure I will be fine next night out, thanks to all on CN!
Regards
Daryl
--------------------
Intes Micro MN66 - Meade 10" SCT
Orion EON 120mmm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon SXi
SBIG ST-8XE
|
darylf96
Pooh-Bah
Reged: 08/28/04
Posts: 1391
Loc: Danville, California
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|
Quote:
Where can one see a photo of those encoders and the installation? What vendor supplies these? I also have a G11 and I am thinking about DSCs.... THanks!
Tom
If you enter Sky Commander XP4 Flash in Google, you will find the home page. Also, I believe that Losmandy sells the same unit. I downloaded the user manual for the Losmandy DSC Computer and the unit is the same except for the position of the buttons. The price is the same, as well.
Daryl
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Intes Micro MN66 - Meade 10" SCT
Orion EON 120mmm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon SXi
SBIG ST-8XE
|
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