Home Made Pier

[Damo636]

Hi everyone, just thought i'd post a couple of pics of my homemade pier. Its going to be bolted down on a concrete base in the field behind house. I still have to source an adapter out of somewhere to attach the EQ5 head and decide what colour to finish it(so far two coats of primer) but overall quite happy with it. The main part is a 5" mild steel pipe 4mm thick. The base is 12mm steel and the top plates are 6mm. The threaded bar is m18 and probably overkill if i am being honest. The whole thing weighs more than my wife!! The holes in the base are a little untidy as i had to use gas to blow these out but when bolted down they will be covered with a washer so not the end of the world.

Cheers

Damo

[JAO]

Damo

Your pier looks excellent. Also in my opinion there is no such thing as overkill when it comes to making mountings rigid. Your investment in strength and soilditity will pay divideneds when that those ancient photons hit your telescopes optics!

Adrian

[Looking Up]

Nice job, it looks very professional! M18 bolts sound good to me - nice and big and strong!

[swag72]

Excellent, just the right pictures at the right time!!

Can I ask what the hole is for on the bottom plate? The screw for the mount fits through the top plate I guess. Also, is this solid or hollow?

[Psychobilly]

You will normally want some sort of Mount/Pier adaptor which is specific to your mount... that would normally require additional mounting holes...

Peter...

[Damo636]

Excellent, just the right pictures at the right time!!

Can I ask what the hole is for on the bottom plate? The screw for the mount fits through the top plate I guess. Also, is this solid or hollow?

Thanks Guys. The hole in the bottom plate was a bit of a boop on my part. I tacked the top and bottom plates together to keep the holes aligned while i punched them out. I forgot to seperate them before punching the centre bolt hole. Doh!! The tube is hollow steel but 4mm thick and very heavy.

[Bizibilder]

You need a hole of some sort in the top plate (or anywhere actually) when welding the thing together - you are making a sealed tube otherwise - with all the associated high and low pressure problems as things heat up and cool down!

Its also quite handy for filling the pier with sand to help stop ringing vibrations.

[swag72]

Brilliant thanks!

[ncjunk]

Swag72,

Its a good example...make the plate at the base of the pier bigger if your not going to bolt it down to your roof and then just need an adaptor to sit on top

[Damo636]

You need a hole of some sort in the top plate (or anywhere actually) when welding the thing together - you are making a sealed tube otherwise - with all the associated high and low pressure problems as things heat up and cool down!

Its also quite handy for filling the pier with sand to help stop ringing vibrations.

Excellent, never thought of that but makes sense. My extra wee hole not such a boop after all.

[rawhead]

Very nice Damo

Those M18s make my M12s look pretty puny.

I will have to drill another hole in the top of my pier. Thanks for that Bizbilder. I think 6mm is my biggest metal drill bit. Not sure how long it will take to fill the mount with sand through such a wee opening

Cheers

[Psychobilly]

M18's there's nothing like a bit of over-engineering to sdo a proper job... thos Victorian era engineers knew a thing or two...

Jon - There are a number "scientific" papers on it if you really want to work it out...... including this one...

Flow properties of granular sands through a circular orifice

Shin Hong Min, Shanghi Rhee and Yong Bae Kim

Abstract

The flow rate of various sand through circular orifice can be measured from a knowledge of a few easily measurable properties of the system. These are the orifice column and particle diameters, the angle of inclination of the orifice with the horizontal and an angle of repose of the granular sand material. Straight lines were obtained when the logarithm of the flow rate was plotted versus the logarithm of orifice diameter. No influence of excessive compaction and bed height was observed and the flow rate increased with decrease of particle diameter. The profile of flow developed the edge of the aperture in a way independent of its size. Linear relationship was observed between the angle of inclination of the orifice and the flow rate.

[rawhead]

Jon - There are a number "scientific" papers on it if you really want to work it out...... including this one...

Flow properties of granular sands through a circular orifice

Shin Hong Min, Shanghi Rhee and Yong Bae Kim

Abstract

The flow rate of various sand through circular orifice can be measured from a knowledge of a few easily measurable properties of the system. These are the orifice column and particle diameters, the angle of inclination of the orifice with the horizontal and an angle of repose of the granular sand material. Straight lines were obtained when the logarithm of the flow rate was plotted versus the logarithm of orifice diameter. No influence of excessive compaction and bed height was observed and the flow rate increased with decrease of particle diameter. The profile of flow developed the edge of the aperture in a way independent of its size. Linear relationship was observed between the angle of inclination of the orifice and the flow rate.

Thanks for that Peter.

I'll get my calculator. (or maybe I'll suck it and see )

[Psychobilly]

lol

[Damo636]

Very nice Damo

Those M18s make my M12s look pretty puny.

I will have to drill another hole in the top of my pier. Thanks for that Bizbilder. I think 6mm is my biggest metal drill bit. Not sure how long it will take to fill the mount with sand through such a wee opening

Cheers

Thank the gods my wee hole is 10mm, should take me about a week less than you to fill with sand!

[fatwoul]

Damo, what I like most is the smaller size of the top plates of your pier. The Altair/SlyShed ones some of us use have very broad top plates, which makes some positions a no-no, because you risk collisions between pier and telescope. Your design should make those positions much easier to obtain.

[malc-c]

Very nice,

If you ever go into production let me know

[swag72]

Can you post sizes of the base plate and top plates please? Also, would something like this be OK for my HEQ5? It only has 1 screw holding it to my tripod legs, so I just need to get the right size screw hole?

Sorry for the dumb questions and I hope you don't mind me asking them in your thread Damo.

[ncjunk]

Can you post sizes of the base plate and top plates please? Also, would something like this be OK for my HEQ5? It only has 1 screw holding it to my tripod legs, so I just need to get the right size screw hole?

Sorry for the dumb questions and I hope you don't mind me asking them in your thread Damo.

Yes it is only one screw but..

Its not just a case of screwing your mount to that top plate, you need to get an adaptor made up which matches the top of your tripod It is the blue thing in the second foto in the following link. Then you attach the adaptor to the top plate and both adaptor and top plate have a hole in them to screw the mount down to:

Altair Pier Adapter CG5 EQ5 HEQ5 EQ6 (Sky Watcher & Celestron)*::*Telescope Mount Accessories*::*Mounts & Tripods*::*Altair Astro

I would get a quote from your local spanish expert bodger rather than buy one from someone though. That little blue adaptor will go on the top plate. I would only put 3 M18 screws to attach the top plate with the adaptor to the pier so that it is easier to level.

The guy that makes the adaptor can get the measurements from the HEQ5 if you take it with you.

[swag72]

Ahh, so that adaptor screws onto the top plate, then you're ready to go!

[Psychobilly]

hmmm 3 or 4 screws always a subject of debate... remember havign a long discussion with Arthur from Ambermile about this a few years ago when he was designing and manufacturing the FLO/SGL pier...

For pier tops I personally use 4 .. the two axes can then be adjusted independently...

Billy...

[JamesF]

Looks very nice. The only alteration I might be tempted to make would be to weld in bracing gussets between the base plate and the pipe to increase the strength of that join as it's probably the place that will take the highest loads.

As far as filling it with sand, I'm unconvinced that it will make a significant difference to the overall stiffness of the pier. It may improve damping, but in terms of resisting deflection in the first place diameter appears to be by far the most important factor.

James

[Adamski]

Not to be confused with home made beer, hey. I'd like to make one but i don't think my wife would appreciate it in the middle of the patio. I do have plenty of room but the patio is a good level area to set up.

Adamski:D

[Damo636]

Can you post sizes of the base plate and top plates please? Also, would something like this be OK for my HEQ5? It only has 1 screw holding it to my tripod legs, so I just need to get the right size screw hole?

Sorry for the dumb questions and I hope you don't mind me asking them in your thread Damo.

Hi Sara

The pier would work equally as well with your HEQ5. The base plate is 400mm square and the top plates are 160mm square. I kept the top plates as small as i could to allow as much clearance as possible while the scope would be pointing high in the sky. The tube length is 1050mm. I punched the center hole 10mm but will need additional holes to fix mounting plate whenever i get it. The Altair adapter looks the part and not overly expensive. As suggested i will probably weld a couple of gussets at the base for additional support.

Hope this helps

Damo

[Bizibilder]

On mine I put a radius on all four corners of the top plate(s) - two reasons - a bit more room for the scope to move and (more usefully) any cables simply slide round as the mount moves rather than snagging on the corner.