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Light Bucket Dob Advice

PostPosted: Mon Jun 29, 2020 4:06 pm
by william-sager
HAS members:

I know that a number of you have light bucket Dobsonians because I have seen a few at the dark site. I would like to get a 16-18 inch Dob and would like to hear about your experiences with your scopes. I live in a townhouse in the middle of the city with limited storage space, so I am looking at ultralight Dobs. Does anybody have experience with the Explore Scientific 16, the Hubble 18, or the Skywatcher 18. I am thinking of getting one with a drive so I don't have to keep bumping the scope at high power.

Will Sager

Re: Light Bucket Dob Advice

PostPosted: Wed Jul 01, 2020 8:41 am
by joe-khalaf
I'm listening in here, as I am looking for a similarly-sized Dob. I've heard from a few folks that the Ultra-Compact Dobs have issues holding collimation, so I've started looking at more of the traditional truss-style Dobs (all-wood design), but would like to hear from others.

Re: Light Bucket Dob Advice

PostPosted: Wed Jul 01, 2020 9:22 am
by chuck-hale
I have an older Obsession 20" F5 it is big but very solid feel to it I just put a Servocat system on it. All of the scope you named looks like they use thinner mirrors these days The Explore Scientific 16" looks pretty good no go/to you would have to ad servocat for tracking and go/to the other two are Ultra compact design I have not used one enough to know how they feel when using, I see a few out at the dark site maybe they will chime in.

Re: Light Bucket Dob Advice

PostPosted: Wed Jul 01, 2020 11:43 am
by steve-goldberg
I have a 14.5" f/5.2 truss tube scope. It breaks down into several pieces: upper cage, poles, mirror box, rocker box. Since it is a "long" scope, a ladder is required. The only "electronics" I have on the scope (besides a Telrad and illuminated retical) is a tracking platform. No go-to of any type. Once you polar align the tracking platform, it will track for about 45 minutes, then reset it for another 45 minutes. It will hold a 13mm eyepiece FOV for a good while. Here is a picture of my scope on the platform. ... G_3458.jpg
If you have any questions, please ask.
Steve Goldberg

Re: Light Bucket Dob Advice

PostPosted: Wed Jul 01, 2020 11:45 am
by chuck-hale
The HUBBLE OPTICS ULTRA LIGHT DOB is cool here is a video made at TSP 2019 at vender shac you can see the mirror close to the end
video shows scope good

Re: Light Bucket Dob Advice

PostPosted: Wed Jul 01, 2020 3:12 pm
by william-sager
Hi Folks,
Thanks for the input. Size and weight are (of course) big issues. I had a CPC-11 and the fork/ota and the JMI case weighed 100 lbs. I was getting worried that one night I would throw my back out getting it up into the back of my Subaru SUV. I live in a townhouse and have to go to the dark site or a star party to see anything, so scope assembly is going to be my life. I can roll it out into the driveway but will only see about 20 degrees of sky straight overhead and maybe 2 stars because of the light dome. I expect that any scope that you have to take apart you will have to collimate once it is set up. This is what you get for living close to work in the city.

So it seems like designing for less weight is good, but if you look at the Explore 16, Hubble 16/18, and Skywatcher 18, they are really stripped down.

I'm also curious to hear from others about drives. I would think that you get tired of bumping the scope along and it would be nice to have a drive. There are equatorial platforms, but I don't think you can use setting circles or go to with them. Some of the scopes have drives.

Thanks on the tip for the Obsession. I looked at it online, but with the ServoCat drive it is >$10,000. You can get a Hubble or Explore for a lot less.

BTW. I found these reviews online in case you are interested. Dennis DiCico really liked the Skywatcher 18, but it doesn't sound very easily moved around. The Dakota Starry Skies guy found the Explore to be a crappy build, but that was an early version. He liked the Hubble better. The video by Deep Sky Dude of the Hubble at TSP make it look like a home brew.

Explore 16

Hubble UL 16

Skywatcher 18 ... ril-issue/

Clear Skies,