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Mount PST to Dobsonian?

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#1 John Wunderlin

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Posted 05 February 2013 - 11:21 AM

Has anyone ever tried mounting a PST to a Dob? I just picked up a PST and would like to do this. I have an EQ platform for my dob, so this would allow me to having tracking for whitelight and Ha at the same time- very handy for outreach...

#2 csrlice12

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Posted 05 February 2013 - 11:35 AM

As long as the dob doesn't catch fire........

#3 John Wunderlin

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Posted 05 February 2013 - 11:37 AM

Yes, I have a solar filter for the Dob :)

#4 btb

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Posted 05 February 2013 - 12:22 PM

I have not mounted a PST to a dob but I do have both. The PST does have 1/4 X 20 threaded holes for photo tripod mounting so drilling a couple of holes in your dob is possible. Now do you want to drill some holes or are you looking for some other kind of mounting options? Also depending on where you mount your PST you are going to need some counter weights on your reflector. :cool:

#5 Zamboni

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Posted 05 February 2013 - 12:22 PM

What kind of dob do you have? If it's a solid tube 6" to 10" then you could get a set of tube rings from Orion where one of the rings has a built in piggyback adapter and just clamp that to the tube.

#6 John Wunderlin

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Posted 05 February 2013 - 12:31 PM

What kind of dob do you have? If it's a solid tube 6" to 10" then you could get a set of tube rings from Orion where one of the rings has a built in piggyback adapter and just clamp that to the tube.


I've thought about the tube ring- I may even have one laying around (yes I buy too much astro gear). My Dob is a 10" XTi- one of the first and it's showing its age, so I'm also not opposed to drilling holes. I would like it to be fairly easy to setup/break down.

#7 Paul Hyndman

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Posted 05 February 2013 - 03:23 PM

Seems like a much better mounting solution than mine. :grin:

So long as you remember to always have the Newt' and any finder scope covered/filtered, you'll be good to go. As a bonus, it's always interesting to compare active regions in white-light vs Ha in real-time and I'm certain you'll enjoy it.

Bon app├ętit!


Paul

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#8 John Wunderlin

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Posted 05 February 2013 - 04:04 PM

Overengineer much? ;)

Actually I may have found my answer- not sure if this would be strong enough for the PST's weight, but it would allow alt/az adjustments so I could line up both scopes:

http://www.optcorp.c...23-672&kw=&st=0

#9 Paul Hyndman

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Posted 05 February 2013 - 04:34 PM

Another solution is to use a precision adapter (with 1/4"-20 threads). These are relatively inexpensive and work quite nicely, allowing almost micrometer-like adjustment on both axes.

Paul

#10 MikeBOKC

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Posted 05 February 2013 - 04:34 PM

These will attach to the bottom of the PST viia screw. Then mount a 7 inch Vixen style dovetal to the Dob OTA and kist slide the PST onto it and screw tight.


http://www.astronomi...vixen-black_...

I piggyback my PST alongside my TMB92L with a dovertail mounted on the top of the refractor's rings. Gives me side by side white light and H-alpha.

#11 btb

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Posted 05 February 2013 - 04:45 PM

Are you going to mount right on tube or build a longer bracket to mount to? A PST is about 3 pounds if I remember and that contact point with the single screw looks a little small. Have you thought about where you want to mount the PST? On top of OTA puts the eyepiece kind of high and in an awkward position, especially if you do outreach programs with kids. If you mount on the side like a normal reflector eyepiece you lose your alt/az adjustments.

#12 btb

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Posted 05 February 2013 - 05:00 PM

My comment was in reference to the mount that John linked to, not any others they were posted while was typing my reply.

#13 John Wunderlin

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Posted 05 February 2013 - 05:04 PM

Another solution is to use a precision adapter (with 1/4"-20 threads). These are relatively inexpensive and work quite nicely, allowing almost micrometer-like adjustment on both axes.

Paul


We have a winner! That's perfect- thanks much!

#14 John Wunderlin

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Posted 05 February 2013 - 05:08 PM

I'm planning on mounting it near where the tube attaches to the base. That will be kind of low, but it should help with balance. I'm also planning on adding a better counterweight system. My scope is so heavily modded and has so many attachments it's almost unrecognizable as an XT10i :)

#15 btb

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Posted 05 February 2013 - 05:20 PM

Would a bracket like this be one be of any use, you for an idea? Might need to turn upside down. Should work with the precision adapter.

#16 John Wunderlin

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Posted 05 February 2013 - 05:29 PM

Thanks- I think the only thing I want yet will be a way to attach the slow-motion control to the base- I won't want to leave it on all the time. There are a ton of options for camera connectors I just need to weed through and find something. A quick release would be good as long as it doesn't introduce any movement.

#17 kfiscus

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Posted 05 February 2013 - 08:45 PM

To throw a wrinkle into the works, I also use a PST for outreach, but no one looks through the PST itself. I use a Meade electronic EP and a 12-foot cable into a small monitor. I've piggybacked the PST on a 8" LX200 and even a glass-filtered Astroscan. The winning setup turned out to be the PST attached to a standard light-duty tripod at its shortest height riding on one of my EQ platforms. I have no picture of the setup. I made a 1/4" plywood disk that rode the paltform and had 3 rings attached to its surface to keep the tripod's feet where they belonged.

#18 GeneT

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Posted 05 February 2013 - 09:17 PM

No--I use my PST as a grab and go.

#19 Paul Hyndman

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Posted 05 February 2013 - 09:51 PM

To throw a wrinkle into the works, I also use a PST for outreach, but no one looks through the PST itself. I use a Meade electronic EP and a 12-foot cable into a small monitor.


I've used a similar approach with a CaK PST piggy-backed onto my Ha setup. It provides another aspect of the active regions as well as something for those waiting to get to the eyepiece.

Here's my 90/90/30 setup at one of the NEAF sessions. We'll be there again this April, and hope to meet up with a lot of you there!

Paul

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#20 Jon Isaacs

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Posted 06 February 2013 - 06:20 AM

Another solution is to use a precision adapter (with 1/4"-20 threads). These are relatively inexpensive and work quite nicely, allowing almost micrometer-like adjustment on both axes.

Paul


We have a winner! That's perfect- thanks much!


My experience with similar "precision slow motion adapters" is that they are not very rigid. Workable for a 35mm camera with a short focal length lens but not for a scope.

Jon

#21 John Wunderlin

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Posted 06 February 2013 - 10:54 AM

My experience with similar "precision slow motion adapters" is that they are not very rigid. Workable for a 35mm camera with a short focal length lens but not for a scope.


I probably won't use this for imaging- just for visual. At the price, it's low risk anyway.

#22 hbanich

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Posted 06 February 2013 - 04:33 PM

Has anyone ever tried mounting a PST to a Dob? I just picked up a PST and would like to do this. I have an EQ platform for my dob, so this would allow me to having tracking for whitelight and Ha at the same time- very handy for outreach...


Hi John, I've mounted a PST to my 28" by using a car window camera mount. Google turns up bunches of these gizmos - I found mine at a local camera store. The 1/4 - 20 attaches to the PST and the clamp to an altitude bearing, making this a quick and easy way to go. It's a fairly stiff attachment but not totally solid like a set of mounting rings would be. Still pretty good though and much more solid than putting it on a EQ-1 mount.

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#23 faackanders2

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Posted 07 February 2013 - 11:13 PM

Another solution is to use a precision adapter (with 1/4"-20 threads). These are relatively inexpensive and work quite nicely, allowing almost micrometer-like adjustment on both axes.

Paul


We have a winner! That's perfect- thanks much!


I use the precision adapter for my 25x100 binos, and previously used it for my Solarmax 40 with great sucess. Just try to avoid reaching the limits (since it will screw out).

#24 John Wunderlin

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Posted 08 February 2013 - 03:36 PM

To throw a wrinkle into the works, I also use a PST for outreach, but no one looks through the PST itself. I use a Meade electronic EP and a 12-foot cable into a small monitor.


Hey Ken,

I just tried hooking up a couple of cameras to my PST and it looks like I don't have enough in-focus. Did you have to do something special to get it to come to focus with your camera? I tried my SPC900 and Starshoot Autoguider- neither could quite reach focus. I also tried my Orion Shorty+barlow- no good.

#25 kfiscus

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Posted 08 February 2013 - 06:22 PM

No. The Meade electronic EP (a stretch to call it a camera) reaches focus fine. I originally tried this because the stock EP just gave too small a view. The Meade produces something similar to a 4mm EP.






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