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Orion 10 inch deep space explorer parts needed

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#1 rcollis50

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Posted 03 January 2021 - 01:28 PM

Hi I inherited an old 10 inch Orion deep space explorer from my brother and I'm currently in search of a tube for it and also the secondary mirror/focuser for it. I've looked on the Orion website and can't seem to find anything. Thanks -Rich
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#2 ngc7319_20

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Posted 03 January 2021 - 01:33 PM

Pictures might help...  Does the tube just need repair?  Or is it missing altogether?   Are you good with repairing / building things or do you need an off-the-shelf solution?


Edited by ngc7319_20, 03 January 2021 - 01:40 PM.


#3 rcollis50

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Posted 03 January 2021 - 01:49 PM

I'll add some pictures, but it needs a whole new tube. The whole focuser/secondary assembly is missing, just a hole.
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#4 ngc7319_20

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Posted 03 January 2021 - 02:15 PM

OK, is there a "big" tube 5 feet long and about 12 inches in diameter?


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#5 mfoose

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Posted 03 January 2021 - 02:29 PM

Hi I inherited an old 10 inch Orion deep space explorer from my brother and I'm currently in search of a tube for it and also the secondary mirror/focuser for it. I've looked on the Orion website and can't seem to find anything. Thanks -Rich

 

I'll add some pictures, but it needs a whole new tube. The whole focuser/secondary assembly is missing, just a hole.

 

Hi Rich, it sounds like you just have the 10" primary mirror and a skeleton of the rest of tube and mount. Pictures would help, especially of the mirror to see what condition it is in.

 

If you want to use the Orion 10" DSE (deep space explorer) primary mirror you could build a very nice scope around it. The out of the box Orion DSE left a lot to be desired functionality wise. A lot of Dobsonian's, not just the Orion DSE, lack features out of the box and typically owners customize them how they like with larger finders, better focusers, better secondary mirror, basically everything. Rather then trying to restore the Orion DSE back to its original state, I would suggest custom building a Dobsonian telescope around that 10" mirror 

 

I built a 10" Dobsonian around a mirror I custom made and used a tube. However, you could build a truss tube Dobsonian around the 10" Orion DSE mirror as well, which helps transporting and storing it. If you have some experience some wood working experience you could build a very nice Dobsonian by yourself. Even if you have no experience you can learn along the way, they aren't hard to make. Or you could buy an already built Dobsonian skeleton and put the mirror in it. Hard to go wrong.


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#6 Jon Isaacs

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Posted 03 January 2021 - 02:45 PM

Rich:

 

Hello and :welcome: to Cloudy Nights.

 

The Orion Deep Space Explorers were built by Discovery Telescopes for Orion, this was in the 1990s.

 

These scopes are quite standard in the sense that you do not need exact replacement parts, you could buy the secondary and focuser most anyplace and the spider from Astrosystems.

 

The tubes were made from Sonotube, Sonotube is used as forms for pouring concrete columns.  There are different grades and the lightweight grade is available at places like Home Depot.

 

I will disagree somewhat with Mfoose, these scopes can be quite effective and the thermal properties and ease of working make Sonotube a nearly ideal tube material. Truss scopes are easier to transport in the larger sizes but a 10 inch can be pretty easy.

 

Choosing the right secondary and focuser requires knowing a little more about the scope, photos will help.

 

Jon


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#7 rcollis50

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Posted 03 January 2021 - 03:20 PM

I attached a picture.  From what all you guys are saying is that they're pretty generic.


Edited by rcollis50, 03 January 2021 - 03:22 PM.


#8 mfoose

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Posted 03 January 2021 - 03:22 PM

The tubes were made from Sonotube, Sonotube is used as forms for pouring concrete columns.  There are different grades and the lightweight grade is available at places like Home Depot.

 

I will disagree somewhat with Mfoose, these scopes can be quite effective and the thermal properties and ease of working make Sonotube a nearly ideal tube material. Truss scopes are easier to transport in the larger sizes but a 10 inch can be pretty easy.

I do agree that cardboard tubes are a nearly ideal tube material, I built my 10" f/6 with one. If you decide to build a solid tube Dobsonian, I would highly recommend a cardboard tube. Not a Home Depot one though, they are a little on the thin side which could warp and it was difficult for me to find one at the size I needed, most around where I live go up to 4' or so. Longer ones can be found at building supply store, but they are more expensive and in my opinion you can find a better cardboard tube from a place like Yazoo Mills or Shapes Unlimitied at the price. 

 

Truss Dobsonians are easier to transport, but like anything they have pros and cons.

 

I believe the Orion 10" DSE mirrors have a 56" focal length so the tube would be around 60" or so. I think it depends what is going to allow you to observe more. If you have to drive to your observing location and have a smaller car I would suggest a truss tube. If you have a backyard to observe in or a larger vehicle then a solid tube is what I would suggest.

 

My 10" f/6 has a 63" long tube and is just at the limit in my Ford Escape and I don't regret building it solid tube.



#9 mfoose

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Posted 03 January 2021 - 03:29 PM

I attached a picture.  From what all you guys are saying is that they're pretty generic.

Rich, I am not seeing the picture. 

 

Click on the "more reply options" button at the bottom, then under "attach files" click "choose file", select your file (which needs to be under 500KB to be uploaded here on CloudyNights, then click "attach this file" to add the picture to your reply.



#10 rcollis50

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Posted 03 January 2021 - 03:29 PM

I do agree that cardboard tubes are a nearly ideal tube material, I built my 10" f/6 with one. If you decide to build a solid tube Dobsonian, I would highly recommend a cardboard tube. Not a Home Depot one though, they are a little on the thin side which could warp and it was difficult for me to find one at the size I needed, most around where I live go up to 4' or so. Longer ones can be found at building supply store, but they are more expensive and in my opinion you can find a better cardboard tube from a place like Yazoo Mills or Shapes Unlimitied at the price. 

 

Truss Dobsonians are easier to transport, but like anything they have pros and cons.

 

I believe the Orion 10" DSE mirrors have a 56" focal length so the tube would be around 60" or so. I think it depends what is going to allow you to observe more. If you have to drive to your observing location and have a smaller car I would suggest a truss tube. If you have a backyard to observe in or a larger vehicle then a solid tube is what I would suggest.

 

My 10" f/6 has a 63" long tube and is just at the limit in my Ford Escape and I don't regret building it solid tube.

Hmm, I'll go to the sonotube website and see what they have.  Some generic focuser and secondary mirror would work you think?


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#11 mfoose

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Posted 03 January 2021 - 03:49 PM

Hmm, I'll go to the sonotube website and see what they have.  Some generic focuser and secondary mirror would work you think?

Yes, a generic focuser and secondary mirror would work. The used and new market is plentiful with these. I would suggest a 2" focuser, but there is some info you need before deciding on which focuser and secondary mirror to buy. The size of the secondary mirror matters a lot so not just any size will do.

 

First thing I would do is determine the focal length of your mirror. If you build your tube around a mirror with a focal length of X, but it turns out that your mirror has a focal length of Y, you would be in trouble.

 

Here is a famous instructional video of John Dobson making a Dobsonian telescope: https://www.youtube....7JJlSZvw&t=655s The beginning is him demonstrating how to grind and polish a mirror, but you already have a completed mirror so you don't need to see that part. At the 36 minute mark he talks about the focal length and why it is important. He then demonstrates a simple way to find the focal length I suggest using the method with a flashlight that he uses to find your mirror's focal length. After you find out the focal length you will generally know what length of tube to buy. You will also need the inside diameter of the tube to be greater then 10". A snug fit is good for shoes, but not for your mirror you want enough room for air to flow around the mirror. For a 10" mirror a 12" inside diameter tube is typically used.

 

I'd also suggest just watching the full John Dobson video sometime because it is very informative and a ton of fun to watch.


Edited by mfoose, 03 January 2021 - 03:54 PM.


#12 rcollis50

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Posted 03 January 2021 - 04:01 PM

I measured the mirror and the tube. It's an 8 inch! So the tube is 9" inside diameter.
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#13 mfoose

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Posted 03 January 2021 - 04:06 PM

I measured the mirror and the tube. It's an 8 inch! So the tube is 9" inside diameter.

An 8" means it has a focal length of 48" + or - an inch or two. If you still have the old tube you may be able to use it if it isn't water damaged. An 8" f/6 Dobsonian is a great scope and very portable.



#14 rcollis50

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Posted 03 January 2021 - 04:20 PM

Rich, I am not seeing the picture. 

 

Click on the "more reply options" button at the bottom, then under "attach files" click "choose file", select your file (which needs to be under 500KB to be uploaded here on CloudyNights, then click "attach this file" to add the picture to your reply.

I think the file is too big, I'll  see what I can do.



#15 ngc7319_20

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Posted 03 January 2021 - 05:19 PM

I think the file is too big, I'll  see what I can do.

Sometimes if you just open the file and re-save it in "jpg" format the file size will shrink.  If you are in Windows you can use Paint and open the file, then home > resize and put some number like 33% or 50% and save it again.


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#16 rcollis50

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Posted 03 January 2021 - 05:45 PM

1200 mm, I did some research. About 47.2 inches.

I've never actually built a telescope before so does this distance have to be precise? Is focal length measured from the center of the primary?

Thank you
An 8" means it has a focal length of 48" + or - an inch or two. If you still have the old tube you may be able to use it if it isn't water damaged. An 8" f/6 Dobsonian is a great scope and very portable.


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#17 mfoose

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Posted 03 January 2021 - 06:56 PM

Sometimes if you just open the file and re-save it in "jpg" format the file size will shrink.  If you are in Windows you can use Paint and open the file, then home > resize and put some number like 33% or 50% and save it again.

That's good advice for downsizing pictures. 

 

1200 mm, I did some research. About 47.2 inches.

 

I've never actually built a telescope before so does this distance have to be precise? Is focal length measured from the center of the primary?

 

Thank you 

If I sat the mirror on a table top backside down I would start measuring the focal length from the top surface (the coated surface).

 

The distance between the primary mirror and the focal plane needs to be precise. So, yes, the distance does need to be precise. However, eyepieces can focus the light at different distances which is why we have focusers to make up for the distance between various eyepieces. So, no, the distance does not need to precise because a focuser allows for the different distances in eyepieces. All that to say, you do not need to perfectly mount the primary mirror, secondary mirror, and focuser precisely down to the millimeter or everything is ruined. You have some wiggle room because of the focuser allows for it, but you want all of your eyepieces to be able to come to focus. You only have so much distance in the focuser racked in and racked out so the goal is hit that range. Many telescope makers have mistakenly calculated this distance and couldn't get their eyepieces to focus, like me.

 

Where you mount the secondary mirror and focuser depends upon two things: the focal length of the mirror and the height of the focuser. Focusers can be different in how you operate them and in their build. Some focusers sit lower to the tube then others and some sit higher up.

 

So now that you have your focal length you need a tube and you need a focuser. You may also need one more thing, a mirror cell. A mirror cell is what holds the mirror in the tube. I am not sure if you have one already or not. 

 

An excellent source for more reading is the Stellafane website. Here is a link on how to build a Dobsonian: https://stellafane.o.../dob/index.html


Edited by mfoose, 03 January 2021 - 06:59 PM.


#18 rcollis50

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Posted 09 January 2021 - 03:40 PM

I found a book on Amazon on how to build an 8 inch dobsonian. I'll base the deep space explorer on these plans.
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