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DobStuff Comments - Building from the Kit and Using in the Field

DIY dob
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#26 lphilpot

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Posted 24 October 2020 - 12:15 PM

If there's a particular image or two you're interested in, I can link them here...



#27 brentknight

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Posted 24 October 2020 - 02:26 PM

Yes that's it in the profile pic.  I think it moves great in alt/az, very smooth - better than my lightbridge or es. No problems at all tracking - but highest power used was 5mm Nagler.  So that's x 340 approx.  You get what you pay for.  I have friends in the club with premium dob scopes that I've used - not just looked through.  It's not obsession or starstructure but it's half the price or less.  About the only issue is when I take out or put in the 31N I need to move the counterweight that is on a strut.  Where the counterweight needs to go depends on the angle of the scope.  I don't always find the sweet spot.  Also, I do have some collimation shift when moving the scope in alt\az.  Every mass produced dob I've owned before had some collimation shift.  It's less with the dobstuff but it's there.  Maybe a few MM with a laser when I tested.  But now I use a cheshire and sight tube mostly.   I've had commercial mass produced dobs where the return beam shifted almost out of the crosshair window in the laser collimator when checking this and those were truss.   So I am very pleased with this compared to the scopes this replaced. I don't go around with my laser at star parties and check my club mates Obessions and Starstructurers for collimation shift so I don't know what or how much is acceptable?  Maybe it's a deal breaker for some.  Obviously the 'flex' it's there when or if I look really low.  Usually, I have to refocus a hair if I move the scope a great difference in alt\az..  To me the weight savings is worth it and the views are still ok because I mostly look at galaxies and globulars with the scope and the collimation is 'good enough' for me.  If I wanted a stiffer scope I would go with the double ring and trusses, but "for me" I am happy with the struts\single ring and the scope weighs under 50lbs (I have a thinner mirror too). 

 

As far as changes, issues:

 

#1  Spend the money and get the struts or trusses powder coated black - I did not and due to sometimes traffic lights (rare where I live) I get reflections off the silver struts.

 

 

#2 Well let me just say FIRST Dennis did me right so what I say next is not a complaint about my scope:  I was a bit concerned about the optics originally. It's a Coulter 13.1 mirror and I knew what I was getting into with that so NO blame what so ever towards Dennis even though he sold me the mirror.  No history on the mirror but it had new coatings.  I had a lot of problems in the beginning and some NOT so great views and I do have a Paracorr2.  I am talking astigmatic stars and the views were so bad that my 80mm ED put up nicer planetary images (last year).  Luckily I have some good club mates and I narrowed my visual problems down to #1 running my secondary dew heater too hot causing astigmatism  #2 My laser is out of collimation   So once I got that figured out everything is fine - I am getting pinpoint stars with my P2 and just wonderful sharp planetary views this season so far.  

 

The last thing and this is a compliment - I "think" I should have had Dennis build me a bigger scope cause this is so easy to setup.  I "think" if I could have done it over I would have tried to score a 15 or 16 mirror and have Dennis build me a scope.  That's really my only regret - "I think".  But when talking with Dennis I told him I wanted the biggest scope I could be seated with and want to haul out every night and he delivered.  It's really a perfect size 'for me" hassle factor and all no matter what "I think".

 

good luck with a decision

 

cheers

 

k

Thanks much for your comments.  That's the kind of feedback I was hoping for.

 

My first telescope was the original Coulter Odyssey I 13.1" with the baby-blue mount.  Talk about a beast of a telescope - but I had a blast with it...

 

img20201005_19253505.jpg


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#28 brentknight

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Posted 27 October 2020 - 01:21 PM

If there's a particular image or two you're interested in, I can link them here...

Any that show mods that you did to the base would be great.

 

This is all I'm keeping from the XX14g...

Measured Balance.jpg

 

Dennis is already working on the new rocker and bearings...

14-Brent-RR.jpg

 

Side bearings and attachments to the existing tube..

12-Brent-RR-wALT.jpg

 

14-brent-alt-and-mounting-block.jpg


Edited by brentknight, 27 October 2020 - 04:31 PM.

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#29 lphilpot

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Posted 27 October 2020 - 05:30 PM

Here are a few, not all will apply directly to your setup though.

 

I added a powered ground board, so the thickness of the stainless steel contact rings meant I needed to raise the Teflon pads by an equal amount:
 

SLCPxN9.png

 

I fed the power through to a PowerPole connector:

 

aQo1jia.png

 

I also insulated over the bare contact points. Before the powered ground board, I had made a battery shelf for the rocker box, but that was too much off-axis weight to work well on my EQ platform:

 

IgMGWSH.png

 

I made a stop plate so the OTA wouldn't slam too far down:

 

yO6h1W7.png

 

I rounded over the altitude bearing points to protect my Telegizmo's cover:

 

NLrIpho.png

 

I replaced the little furniture slider feet with hockey pucks:

 

MUmA75N.png

 

I added a mirror fan:

 

jtoNlL6.png

 

I made a top mirror cover / lid. This is easier to put on, half asleep at 3 AM. Plus it gives a little transport space for lightweight / soft stuff (towels, etc.) when both lids are in place:
 

t3EQr7q.png

 

Added a board to mount my DewBuster on the altitude bearing:

 

cNufPn1.png

 

...and painted the front / inside of the mirror board black:

 

VFKtqzi.png


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#30 brentknight

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Posted 27 October 2020 - 05:42 PM

Thanks Len. I’m wondering what you gained by swapping the feet out for hockey pucks?



#31 lphilpot

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Posted 27 October 2020 - 05:46 PM

Thanks Len. I’m wondering what you gained by swapping the feet out for hockey pucks?

Stability. If the ground isn't perfectly level the scope would rock. The glides were only about 3/10" tall, so there was little clearance and we have lots of thick St. Augustine grass where I live. Plus the larger contact area of the puck adds to stability. The glides were about 1" across. It also keeps the ground board a little more above the dewey ground.


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#32 brentknight

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Posted 27 October 2020 - 05:54 PM

I tried hockey pucks on my 10” Dob, but noticed the whole thing was much more sensitive to vibrations. I actually think the problem was more the placement of the pucks. If they are not right under the Teflon it decreases the stability. I might try them again on this mount. It sounds like it would really help when I take it to the woods...



#33 lphilpot

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Posted 27 October 2020 - 07:59 PM

I attached them with contact cement, works great for me.


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#34 brentknight

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Posted 07 November 2020 - 08:48 PM

Finished the Dobstuff rebuild of the Orion.  I think it dropped 70 lbs and 7" at zenith.  So far I'm very happy with the new mount and all the support and great kit from Dennis.

 

BaseCompare-Small.jpg

 

The old Orion Go2 mount.

 

01.jpg

 

I would never do this for real, but that's a good bit of weight on the end, and with the brake applied it does not drop and I can still move the tube.  No extra weight added.

 

02.jpg   03.jpg

 

The family portrait.  10" F6 on the left, AT102ED center and the 14" XX14g on the right.

 

 


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