Permission to build a pier - GRANTED!

CarlJoseph (Carl) · #1 25-01-2012, 02:48 PM

I've had permission to build a (semi)permanent pier in our backyard. Great news for me because I really hate lugging out my EQ6 tripod and mount every night.

I've pretty much settled on the location so the first decision is made.

Next decision is whether to build a concrete or steel pier and I'm 80% settled on a steel pier. Although, I have a friend who owns a sheet metal factory and I'm wondering if a thick enough piece of that rolled into a tube would do the trick?

Will try to keep this up to date with pics, progress and questions over the next month or so.

Cheers,
Carl

astronobob (Bob) · #2 25-01-2012, 03:34 PM

Hi Carl, congatts on the good news and a concrete or steel peir will be a great advatage over a tripod; though I highly doubt some rolled sheet would serve the porpose that well, I have two steel peirs, one at home and one at my observatory, the observatory peir is 6mm wall thickness and it is satifactorely Solid, But my smaller home peir is only 3mm wall thickness and does vibrate and flex somewhat ? ?
Hope this helps mate !

CarlJoseph (Carl) · #3 25-01-2012, 03:56 PM

Thanks for that Bob. Just been researching a little more and thinking either a square pipe (at least 6mm thick like you say) or a tube. Now just to find somewhere to grab one on the cheap!

I'm thinking 1300mm all up. 600mm footing, 300mm gap from ground level to deck, 1000mm above deck. Although the 1000mm is debatable at this point.

Cheers,
C.

CarlJoseph (Carl) · #4 25-01-2012, 06:09 PM

Okidoke, starting off pretty fast here although I know I'll slow down as I start digging that hole!

Found a guy who can supply me with a 229mm outer diameter steel tube, 5.9mm thick. This will do nicely I think. Yes?

The question is, how tall does it need to be? I'm thinking anywhere from 800mm to 1000mm above the floor level would work. I have a short refractor but may purchase other larger scopes in the future.

I'm taking these two sites as my guide for design/construction ...

http://www.iovene.com/314/#comment-186115
http://www.asignobservatory.com/inde...telescope-pier

Any things I might want to be aware of before placing my order for the steel tube?

Cheers,
Carl

CarlJoseph (Carl) · #5 27-01-2012, 02:17 PM

Hi everyone,

I've gotten the dimensions and design for my steel pier. I have a mate who can construct this all for me which is awesome too. Now to book a time in the factory to get it all milled, drilled and welded together.

Cheers,
Af.

astronobob (Bob) · #6 27-01-2012, 09:22 PM

Lookin' Good Carl, Are you considering any Gussets to reinforce the peir to base plate ?

CarlJoseph (Carl) · #7 27-01-2012, 09:52 PM

Thanks Bob. Yeah, definitely. I just didn't get a chance to draw them in. I'll be having a mate help me to draw up the actual pieces so they can put it through their machinery to get put together.

gregbradley · #8 30-01-2012, 03:15 PM

Don't make it too tall. My pier is only about 1 metre tall and its really a tad tall with a Paramount ME and CDK17. Really I suppose its about right as it looks over the walls quite well but 1 metre sounds about right.

It would also be good to have a top plate welded on with holes predrilled for your mount.

Greg.

cventer · #9 30-01-2012, 07:28 PM

I am not totally convinced that Pier height is that big an issue if its designed well. Mine is 1.7 meters tall with 4 gussets running entire length at 90 degrees apart. My RMS for all sky pointing is 8 arc sec which means I dont think this is flexing very much.

CDKPhil · #10 30-01-2012, 08:08 PM

Quote:

Originally Posted by cventer

I am not totally convinced that Pier height is that big an issue if its designed well. Mine is 1.7 meters tall with 4 gussets running entire length at 90 degrees apart. My RMS for all sky pointing is 8 arc sec which means I dont think this is flexing very much.

Hi chris
I was just deciding on my pier hight today. I had wondered how high you could go. Like you said it would depend on how well engineered it was.

Hi Carl
Unlike you I am going to buy my pier pre made from Software Bisque.
I don't have the right equipment to make my own.
Your dimensions sound very good, considering the SB pier has a 254" diameter tube that is only 3mm thick, 12.7mm base and top plate. There are no gussets.
I was going to go for a hight of about 800mm. That hight is quite comfortable for me to lift the OTA onto the mount.

Cheers
Phil

CarlJoseph (Carl) · #11 30-01-2012, 08:09 PM

Quote:

Originally Posted by cventer

My RMS for all sky pointing is 8 arc sec which means i dont think this is flexing very much.

RMS?

I will be using mine for both photography and some visual so the height will matter a little for comfort reasons. Phil, how much are the Software Bisque piers out of curiosity?

CDKPhil · #12 30-01-2012, 08:15 PM

Quote:

Originally Posted by Afro Boy

RMS?

I will be using mine for both photography and some visual so the height will matter a little for comfort reasons. Phil, how much are the Software Bisque piers out of curiosity?

They are $680 US plus shipping. I would think you will be able to make yours quite a bit cheaper than this.

Cheers
Phil

gregbradley · #13 30-01-2012, 08:58 PM

Quote:

Originally Posted by cventer

I am not totally convinced that Pier height is that big an issue if its designed well. Mine is 1.7 meters tall with 4 gussets running entire length at 90 degrees apart. My RMS for all sky pointing is 8 arc sec which means I dont think this is flexing very much.

I agree, a bit longer shouldn't make a lot of difference in flex.

I was referring to height for comfortable viewing etc not from a flex viewpoint.

The point being make sure you allow for how high the mount will extend up plus the scope so its at a comfortable position.

RMS = root mean square which is a statistical measure of the differences in variables- its the square root of the mean average of the values in a series of numbers) of the squares of the item being measured. In this case the item being measured are the errors in pointing from what they should be.

Greg.

blink138 (Pat) · #14 02-02-2012, 08:32 PM

permission to look smug sir!?
pat

CarlJoseph (Carl) · #15 04-02-2012, 11:02 PM

Okidoke, haven't built anything yet but have been doing more research. Read this thread and watched the vids and am totally rethinking my design.

Has anyone seen the AC282 pier in the flesh?

http://www.pulsar-observatories.com/...inal/Owls1.jpg

I am wondering if the mounting plates are available separately for sale?

Also, the video talks about drilling the slab and gluing the bolts into it (using a 2 part epoxy type glue). What's the difference between doing that and allowing the bolts to cure into the wet concrete as it dries?

Cheers,
Af.

mswhin63 (Malcolm) · #16 05-02-2012, 02:32 AM

Quote:

Originally Posted by Afro Boy

Also, the video talks about drilling the slab and gluing the bolts into it (using a 2 part epoxy type glue). What's the difference between doing that and allowing the bolts to cure into the wet concrete as it dries?

Cheers,
Af.

I used to use Chemset, I still have the gun for it. I found it brilliant for drilling very solid holes into concrete. This was sometime ago now so i actually use Self tapping bolt for concrete, these are good for floor mountings while I still use Chemset for wall mountings.

I use to install public telephone booths and these had to be rock solid for the sake of vandalism. ATM also use Chemset too.

I was considering selling the gun but may keep it now after looking at this thread.

jenchris (Jennifer) · #17 05-02-2012, 02:17 PM

Chemset using the epoxy are basically for cured concrete but if you get the chance to use wet concrete and inserting the j bolts, that is much stronger