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Z12 Trusser???

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#1 cpr1

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Posted 20 November 2012 - 02:34 PM

After visiting with and ordering a AstroSky 16 inch dob from James I think I was inspired by the aspect of building wooden truss dobs and started to wonder about my 12 inch Zhumell that I really only use at home in my light polluted skies.
For me it is just too long and unwieldy for the small vehicles that I own, but I am totally impressed by the views it can produce.

I have a Z10 also and that has been my goto scope when I go to a dark site. But, I don't feel like I am getting my moneys worth out of my 12.
So after much research and reading I decided to give it a go. This would be my first scope structure build. I plan to reuse as much as possible from the Z12 "Carcass". Eventually I decided to use some from the plans from CN member "Pinbout" Danny. which he has freely posted numerous times in posts.

So thanks Danny. :waytogo: Your plans work.

I also used other examples all over the net, and some from "The Book".

I reused the spider, holder, secondary mirror, primary mirror and cell. The focuser is a moonlite CR1, truss poles are 1 inch alum., lower connectors are moonlite, uppers are DIY with bicycle quick release. The moonlite connectors are a dream to use, and the quick release work great. I found examples of those on the internet.

It riding on FRP with Astro Systems bearing kit and pivot kit for Azimuth. Altitude is Ebonystar on Astrosystems teflon.

I am not finished yet still have do a few other things, shroud, electrical, dew heater, finder, so on.

It is definitely not perfect. I had a few mistakes along the way and some are still visible, but the end result is the scope balances well, is smooth, collimates easy, and most important I am happy with it. THX.

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#2 Pinbout

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Posted 20 November 2012 - 02:48 PM

So thanks Danny. Your plans work.



hEY before I read it I saw the alt bearings and said, "wow that looks too familair." :grin:

Glad to here it worked out for you.

#3 Ksearles62

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Posted 20 November 2012 - 02:59 PM

Nice work!! I converted my Z8 a couple of years ago and caught the ATM bug. I finished my second build in June and have already started thinking about the next one.Clear Skies

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#4 cpr1

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Posted 20 November 2012 - 03:14 PM

Thanks Danny and Kenny. Kenny I have seen your scope before and it is truly unique and a work of art.

If it wasn't for my visit with James and seeing his work I probably wouldn't have attempted this. My wife is happy because her house isn't quite the scope factory anymore.

#5 starman345

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Posted 20 November 2012 - 03:24 PM

I don't see any of those visible mistakes you mentioned? It looks perfect to me. Congratulations on a great telescope.
Have you had it under the stars yet?

#6 cpr1

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Posted 20 November 2012 - 03:36 PM

Brian, thanks for the comment. The top ring has a little bow in it from the plywood warping when I purchased the wood. I didn't notice it till later. The circle is fine just one lip rides up more than the other. The bottom ring is fine.

Also I doweled the struts to the rings and when I sanded I sanded too much and sanded through the veneer. I located the altitude bearings wrong and had to redrill. You can see the off white dots in the pics on the bearing. It is filler and as a reminder to myself I decided to poly over the filler without staining. I did that on purpose adds character. ;)

There are a couple other things like that but they are minor. And hopefully I will learn from them. THX

#7 cpr1

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Posted 20 November 2012 - 03:38 PM

Oh I forgot. I have had it under stars only to make sure all my eyepieces would focus and see how much travel I had left.

I hope to first light it over the week sometime. Off for holidays.

#8 Pinbout

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Posted 20 November 2012 - 03:59 PM

would you like some vinyl graphics for your scope...

it's not a problem.

I hooked up some other people...just can't find an example at the moment. :grin:


ah here is one...I made him a "artie" for the focuser board also, not bad for the price of a postage. :grin:


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#9 cpr1

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Posted 20 November 2012 - 07:25 PM

That looks great Danny. Thanks for the offer. If I can think of what I want to do I will let you know. I appreciate that.

#10 cpr1

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Posted 20 November 2012 - 07:33 PM

Here's a couple more shots of it.

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#11 cpr1

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Posted 20 November 2012 - 07:51 PM

That's a 3 lb 31mm axiom. It drifts when at a low angle with eyepiece. I may have to add counter weight when I add the telrad and finder. But I have not added my batteries to the mirror box yet. So will see. THX

#12 Pinbout

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Posted 21 November 2012 - 11:22 AM

After visiting with and ordering a AstroSky 16 inch dob from James I think I was inspired by the aspect of building wooden truss dobs and started to wonder about my 12 inch Zhumell that I really only use at home in my light polluted skies.



Hey Chris.

so how would you comapare movements, from the stock mass produced dob's with small bearings to the K&B truss with large alt bearings?

#13 cpr1

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Posted 21 November 2012 - 12:17 PM

The altitude movements are better than the stock bearings.Just as smooth and easy to start the motion with no stiction. Granted the bearings are new and I haven't put wax on it yet.
On azimuth I used 1.5 inch Teflon on frp It is smooth without being bumpy. I also used a pivot kit which helped.

I think the oversized 21inch bearings helped by giving me the abilty to change eyepieces without having to readjust weights or clutches or both.

Another plus is scope is much more stable.

#14 Pinbout

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Posted 21 November 2012 - 01:53 PM

Another plus is scope is much more stable.



that's funny just this past weekend I was observing Jupiter on my 8in stellafane knockoff and I had the mag up there and was able to track it really well, smooth too.

but the other night I had my tv genesis on my desertsky mount viewing IO's transit infront of Jupiter. It was shaky, I never use to think it was so shaky. I soon moved back to my dob and will leave the desertsky for the wide views or on stuff like the lunar x like last night.

but this morning I had to move my dsv-1 mount and found that I hadn't screwed the head to the tripod very well. [I routinely remove the head for transportation]


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#15 cpr1

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Posted 22 November 2012 - 06:29 AM

I just wanted to add that the original Z12 scope was fine scope. It was the newer model with the adjustable altitude bearings and azimuth bearings. It only needed a small amount of counterweight with the largest eyepieces that I own.

I just did this for portability and because it was something I have not tried before.

Just something about a wooden telescope.
THX.

#16 cpr1

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Posted 24 November 2012 - 12:21 AM

I was able to star test my rebuilt scope last night. Tonight it's cloudy. All my eyepieces come to focus! The first time I tried this they all came to focus but I did not have much inward travel left. So Newt called for cutting almost 3/4 inch off. Which worked out.

I did not have much time to observe and it was cold out and my fan was not hooked up. But, after an hour or so my mirror gave great views of Jupiter and the Orion nebula.
Vibrations were very minimal almost nonexistent actually. The old mount would vibrate for 2-4 second after touching the scope. It was very easy to track Jupiter at 300x. I did not experience any backlash or stiction. I still haven't waxed either bearing. So I am curious what this will do. I may not even do it until I start experiencing problems.

I do need to get a shroud soon. Just have not decided who's to go with. I wish I could sew and make something that would look decent.
Tonight I finished the wiring on the fan and batteries. I bought a cheap float charger from Harbor Freight on sale for Black Friday.

I was very impressed with how the larger Altitude bearings move. It doesn't matter whether I move it fast or slow the force required is the same throughout. And when I stop and let go it doesn't keep going. When I start again it requires the same amount of force to get it going as before. No extra pressure to get it started.

#17 Mr Magoo

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Posted 24 November 2012 - 10:22 AM

Very nice! What is your upper tube made from?

#18 cpr1

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Posted 24 November 2012 - 12:53 PM

Thanks, The rings are 1/2 birch. The struts are 1 inch x 3/4 birch, focuser board and finder board are 1/2 birch too.
The baffle or tube is oak veneer and I spray glued Hobby Lobby project foam sheets to the inside. The sheets are flat black and very light weight. The entire baffle is screwed to the struts with little stainless screws. I used all stainless hardware in the scope's constrution.

THX.

#19 MikeCMP

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Posted 25 November 2012 - 09:01 AM

Wow, I have a Z12 and have thought of doing this myself, yours looks fantastic. Definitely considering this, the views from my 12 are awesome as well, it just takes up the whole car when it comes out. Plus my base got wet when hurricane sandy rolled through our area and flooded my shed just a little bit.

Where are the plans you are referencing? And if you don't mind, about how much did the materials cost?

Mike

#20 Pinbout

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Posted 25 November 2012 - 09:52 AM

Where are the plans you are referencing?



they are hidden deep inside an obscure thread so no one can find them. :grin:

I wouldn't get the home depot ply cause it is lame. :lol:

you might try to make your own truss connectors.

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it could save you $100 per end.

#21 cpr1

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Posted 25 November 2012 - 10:10 AM

The scope is sort of a conglomeration of several designs. I did not follow the K&B book exactly. Many of the measurements and looks came from fellow CN member Pinbout. He has posted some general plans for this size scope in previous posts. I deviated from his plans some. For example the rear cell is wooden in mine to accommodate the Z12 cell which I used. Also my rocker box is 1 inch side as are my bearings. My mirror baffle is inset some not flush.
My ground board is 3/4 and rocker bottom. The feet are left overs from cutting the 4 4inch circles you see on the bearings. I only used 3.
Not that any of the changes I made were better, but it was really more of a personal preference.

As for cost I am still adding it up but the major cost were.

moonlite focuser 195.00 with spacers and shipping. You could probably use the GSO focuser but I didn't have a flat adapter. It comes with a curved one. The motion is smoother with the moonlite and it is lighter.

aluminium poles were 65.00 1 inch.
Moonlite double ball socket connectors. 114.00 shipped.

The wood was somewhere around 80.00-100.00. You could get this lower I bought extra.

Not sure on all the stainless hardware but I don't think it was much.

The bicycle quick release clamps I got on ebay for 5.00 each.

Astrosystems bearing kit 26.00
Astrosystems pivot kit 27.00
scopestuff ebonystar bearing strip 18.00x 2
FRP 33.00 for a 4x8 sheet.

I reused my spider and holder, optics, mirror cell and finder scope and brackets.

I would guess around 600.00 to 650.00. With stains and poly and other misc. things. If one used their original focuser and made their own lower truss connectors you could cut 314.00 or so off of it.

I knew the moonlite focuser would work without any modification on my part and I knew the truss connectors were tested and work great for others so thats why I spend extra on these. There may be a place to purchase a spacer to replace the curved one, but I am happy with the moonlite.

#22 Pinbout

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Posted 25 November 2012 - 10:14 AM

My mirror baffle is inset some not flush.



that looks nice since it makes the moonlite connectors frush btw. :applause:

#23 cpr1

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Posted 25 November 2012 - 10:16 AM

Where are the plans you are referencing?



they are hidden deep inside an obscure thread so no one can find them. :grin:

I wouldn't get the home depot ply cause it is lame. :lol:

you might try to make your own truss connectors.

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it could save you $100 per end.



I used the Home Depot ply, and it does have voids in it. I filled them but the filler is only cosmetic and does not help the structure.

#24 cpr1

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Posted 25 November 2012 - 10:21 AM

Thanks Danny.

#25 Pinbout

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Posted 25 November 2012 - 10:39 AM

another reason I dislike HD ply is that if you look at the cross-section of plies they're not straight. wavy wiggly layers... :o

but when there isn't anything else available, gotta use what you can.






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