Author Topic: What's the Biggest Dob That Would be Good for Me?  (Read 192 times)

Christopher Buchanan

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What's the Biggest Dob That Would be Good for Me?
« on: December 28, 2017, 03:53:10 AM »
Dollies, hand trucks and wheelbarrow handles would be useless for me. I own a two-story condo (paid off!) with no private yard, no basement, no garage. I would probably need to store the Dob upstairs. If I can't bring the Dob down one flight of stairs, around a landing, down another flight of stairs, out the front door, onto a porch, down the porch stairs and out to my Subaru Forester, I can't deal with the Dob.

Keep in mind that I have to take the largest section through a standard front door. No patio doors. No big garage doors.

Also, I want to sit at all positions of the Dob. (I'm 5'7" tall.)

And although I do a 100 pushups every other day, and walk about 4.5 miles every good weather day, I haven't weight trained since the early '80's. I do not want my observing session to be a work out.
Now what would be the largest aperture Dob these factors would limit me to?

Mike



Tarence Allen

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #1 on: December 31, 2017, 06:58:32 PM »
I depends on how much land you would like to rent in a dark location.

It also depends on how big your friends' telescopes are.

Just thinking outside the condo.......

suctoleshe

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #2 on: January 04, 2018, 02:15:17 AM »
I would like to not only think outside the condo but also move out of it.

But that won't happen for at least another five years when I retire. I only live four miles from my work. Any place I want to move to would mean a long commute. Also, since I don't have a house payment, I can maximize my savings.

It's good to think outside the box, but then you should make a decision that makes good sense.

I have free access to dark sites, so renting land would make no sense. I would not feel comfortable storing gear someplace where I don't live. In any case, I would probably never use the big Dob here at home. It would only be for transport to dark sites.

I have friends with bigger Dobs. But that doesn't count. I want my own.

Mike

pregdefciato

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #3 on: January 09, 2018, 02:02:00 AM »
Quote
I would like to not only think outside the condo but also move out of it.  But that won't happen for at least another five years.

I have free access to dark sites, so renting land would make no sense. I would probably never use the big Dob at home. It would only be for transport to dark sites.

I have friends with bigger Dobs. But that doesn't count. I want my own.

Mike

Then the answer would be the biggest one that will fit into your vehicle.

proporasat

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #4 on: January 10, 2018, 07:22:06 AM »
Buy a van and keep the Dob in it, ready to go whenever you are.

Jim Snyder

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #5 on: January 10, 2018, 02:19:38 PM »
I recently underwent the process of finding out "what is the largest dob I can handle".

My restrictions were different: I own a 2 story house (no debt too!) with a garage, so I can keep it in the main floor. However, I have a herniated disk in my lower back.

I lifted and weighted furniture until I found what was the maximum weight I could comfortably handle (handling meaning lifting the OTA from the ground and placing it on the base.... not carrying it downstairs). It turned out 33lb was the max for me, so a 10" collapsible skywatcher was the choice. Once it arrived I found out I chose well. Collapsibility was important for my very compact car too.

You could do the same experiment, but I think:

* 6 inch is not worthy. Unless you really need to save money, I'd rather have a Celestron 6SE than a 6" dob on a condo.
* 8 inch is easy to carry. Go for a Orion XTPlus for a more lightweight base (which is heavier than the OTA) and it'll be very easy to carry each part separately (at most, 25lb each part)
* 10" is where it starts getting interesting. There are 6 wheel hand trucks meant for use with stairs. Perhaps one can work for you. Otherwise, you'll need to lift some furniture, find which you can take up/downstairs, and measure it's weight.

calbeyrefrows

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #6 on: January 10, 2018, 07:26:40 PM »
Quote
Quote

I would like to not only think outside the condo but also move out of it.  But that won't happen for at least another five years.

I have free access to dark sites, so renting land would make no sense. I would probably never use the big Dob at home. It would only be for transport to dark sites.

I have friends with bigger Dobs. But that doesn't count. I want my own.

Mike

Then the answer would be the biggest one that will fit into your vehicle.
The Forester has plenty of room in the back. I gave up buying cars with trunks many years ago. They make no sense for amateur astronomers who travel to dark sites.

But ... the size of my vehicle is not all you need to consider. Keep in mind all the other limitations on Dob size.

No garage. No land for a shed. I need to store the Dob in my condo, probably upstairs in my bedroom. I need to bring it down stairs in my house, out a standard front door, then down stairs from my porch.

Mike

schemsucopost

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #7 on: January 11, 2018, 09:11:13 AM »
Quote
Buy a van and keep the Dob in it, ready to go whenever you are.

No, not happening. People I know have stored big Dobs in trailers and vans. They get stolen.

Also, I don't store any optical equipment in a vehicle. Too many changes in temperature. Hot, cold, hot, cold. It's one of the worst places to keep your optical gear. I keep all my telescopes and binoculars in my house. They're only in the vehicle when going to and from the dark site.

Mike

imasatex

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #8 on: January 11, 2018, 12:35:03 PM »
What about these ultralight high-end Dobsons from http://nauris.de/ind...echanik/mirrage ?

The 14" weighs about 33lbs; 16" about 41 lbs and 18" about 50 lbs.

Felix

kondcongrese

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #9 on: January 12, 2018, 04:33:43 AM »
Quote
I recently underwent the process of finding out "what is the largest dob I can handle".

My restrictions were different: I own a 2 story house (no debt too!) with a garage, so I can keep it in the main floor. However, I have a herniated disk in my lower back.

I lifted and weighted furniture until I found what was the maximum weight I could comfortably handle (handling meaning lifting the OTA from the ground and placing it on the base.... not carrying it downstairs). It turned out 33lb was the max for me, so a 10" collapsible skywatcher was the choice. Once it arrived I found out I chose well. Collapsibility was important for my very compact car too.

You could do the same experiment, but I think:

* 6 inch is not worthy. Unless you really need to save money, I'd rather have a Celestron 6SE than a 6" dob on a condo.
* 8 inch is easy to carry. Go for a Orion XTPlus for a more lightweight base (which is heavier than the OTA) and it'll be very easy to carry each part separately (at most, 25lb each part)
* 10" is where it starts getting interesting. There are 6 wheel hand trucks meant for use with stairs. Perhaps one can work for you. Otherwise, you'll need to lift some furniture, find which you can take up/downstairs, and measure it's weight.

I have a 10" f/4.8 Dob now. I can carry the OTA up and down my stairs pretty easily. The weight is 38 lbs when I leave the rings on. I think the size and length are more of a problem than the weight itself.

I could probably handle more weight if it were more compact, in the form of a rocker box or mirror box. My eyepiece case is probably heavier than the 10" OTA.

No, I'm not going to move optical equipment up and down stairs in a hand truck. I would be worried that something would come lose or break.

Mike

revekosque

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #10 on: January 13, 2018, 06:46:58 AM »
12.5" f/ 4.8 with a regular size mirror to have some weight for balancing heavy EPS.

Or

14.5" f/4.1 with 60" FL with a thinner Quartz mirror. My quartz mirror is 1.35" thick and I don't have any balance problems.Since multiple trips involved with stairs, I believe 12.5" is the way to go.

I am also 5' 7" tall. Mine is 64" FL and I need to stand viewing Zenith. If it is 4" shorter I could lean on my observing chair. I am pretty comfortable at the lowest angle. Its not too low to sit with this FL. I could fit in my Honda accord back seat.My chair this.

https://www.amazon.c...astronomy chair

David Reynolds

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #11 on: January 20, 2018, 08:49:35 PM »
Here I'm sharing are some of my notes from back when I was looking for a dob:

6" Solid tube Skywatcher:
OTA weight: 15 lb
Base weight: 10 lb

8" Solid tube skywatcher
OTA: 20lb
Base: 25lb

Z8 / AD8 Solid Tube:
OTA: 25lb
Base: 28lb

8" Skywatcher collapsible:
Tube collapsed is 33"
Base diameter: 20"
OTA weight: 24 lb
Base weight: 26 lb

10" Skywatcher Solid tube:
OTA: 28 lb
Base: 25 lb

10" Skywatcher collapsible:
Tube collapsed is 31.5"
Base diameter: 525mm
OTA weight: 33lb
Base weight: 26lb

Z10 / AD10 solid tube:
OTA weight: 35 lb
Base weight: 31 lb

I didn't dwelve too much into 12". The ES seem to be the lightest of the mass produced ones:

12" Explore Scientific:
The ES states the total weight of their 12" to be 66.2 lbs

Edit:
16" Explore Scientific:
Primary Mirror box Weight: 66.1 lbs
Rocker Box Weight: 22 lbs.

for comparison, Celestron SCT OTAs:
C5: 6 lb
C8: 12.5 lb
C6: 8 lb

sandsibyno

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #12 on: January 21, 2018, 02:23:17 PM »
Quote
What about these ultralight high-end Dobsons from http://nauris.de/ind...echanik/mirrage ?

The 14" weighs about 33lbs; 16" about 41 lbs and 18" about 50 lbs.

Felix
The 14" would be doable. About comparable to my 10" solid tube OTA. The 16" would be borderline. The 18" would be out of the question. My weight lifting days are long gone.

Mike

David Reynolds

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #13 on: January 30, 2018, 08:40:06 AM »
Quote
12.5" f/ 4.8 with a regular size mirror to have some weight for balancing heavy EPS.

Or

14.5" f/4.1 with 60" FL with a thinner Quartz mirror. My quartz mirror is 1.35" thick and I don't have any balance problems.Since multiple trips involved with stairs, I believe 12.5" is the way to go.

I am also 5' 7" tall. Mine is 64" FL and I need to stand viewing Zenith. If it is 4" shorter I could lean on my observing chair. I am pretty comfortable at the lowest angle. Its not too low to sit with this FL. I could fit in my Honda accord back seat.My chair this.

https://www.amazon.c...astronomy chair

I want to at least go up to a 14" Dob, since I have a 10" now. That would about double the light grasp.

If I got a 12" or 12.5", it would be to replace the 10" as a scope for home, not so much as a scope to transport to dark sites.

Mike

Sam Noble

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Re: What's the Biggest Dob That Would be Good for Me?
« Reply #14 on: January 31, 2018, 08:46:45 AM »
My 12" Orion Truss dob is not terrible... a few extra pieces in that you have the tube in 2 pieces, and a bag with the trusses