Holiday Pier project

[morls]

Hi,
This should be fun...got the mounting plate and micro piles from Surefoot in Coburg, looking forward to getting this set up over the next while. My site manager can be seen inspecting the hardware...
Cheers
Stephen

[morls]

Cut the micro-piles down to 450mm and installed the footing today. Took 1 hour, and seems very solid.

[morls]

And the finished job. Of course it's cloudy, but all seems very stable. It'll be interesting to compare this setup to the tripod.

[sharpiel]

Most of the good imagers and engineers here say (and logic seems to reinforce) that having a lovely rugged gusseted pier is let down by the weak link of the long bolts in the rat cage arrangement you have supporting the base of your beautiful pier. The longer those bolts (and yours are looooong) the more vibration and instability you'll introduced to that stiff pier.

Seek the advice of IIS members Wavytone (engineer) and Peter Ward (award winning imager).

Are you doing visual only (less important) or imaging?

[morls]

Hi Les,
Doing both visual and imaging. This is really a test run, as we'll be moving house at the end of 2020. That's one reason the micro piles were cut down, in order that removal would be easier.
These are long bolts, so I'll see how things go and hopefully will be able to do away with the rat cage in the next installation.
Cheers

[morls]

I think I might have posted this thread in the wrong forum - maybe "ATM and DIY projects" is a better fit.



How can I get in touch with a moderator to get this moved?

[DarkArts]

If you really want to get the attention of the mods, the quickest way is to post a lot of spam .... :P

PM 'RB" or 'houghy' ... those are the mods that I recall.

But I think this forum is fine for the subject matter - no need to move it.

I like the pier btw, but personally I would have used the larger size foundation (S500) and more pins, even for an EQ6.

[Outcast]

Stephen, I'm really watching this with interest... I'm keen to read about your progress, as well as your analysis on whether or not you think it's stable enough between now & your eventual move...

Would you mind elaborating on cost of the plate you used (I'd never seen those before) & whether you already had the pier or purchased it complete/had it made for you, etc... & rough costs...

I'm contemplating a few backyard options at present although my needs are a little different to yours as I also have a dob I want to settle on a more stable base rather than just grass. At present I'm contemplating a circular concrete pad, done in such a manner as to look like a decorative feature that I can mark a nth/sth line on for setting up my CG 5 but, the pier footing you have shown is also very interesting indeed...

FWIW, I have no issue with where it is either but, if you are super keen to have it moved you can either PM one of the mods as suggested, Al Sheehy is another mod or, there should be a red x at the top right of your original post which reports the post & you can make a comment in there asking them to move it...

Cheers

[sharpiel]

Would it be possible to make that decorative feature a sundial in any way even if your Cardinal points weren't NS alone...? Just a thought...

[Outcast]

:rofl::rofl::rofl::rofl::rofl:

It's funny that you say that; I literally had that conversation with my wife last night....

My thinking is that Solar Noon position of a stick as described in other threads regarding finding true South would, provide the Midday (or near enough) position for a sun dial. The Northern position would be the 6....

When laying the concrete, it occurred to me that if I put a piece of conduit or dowl in the centre as part of the form work then work out solar noon, paint a lovely sundial pattern & voila... Sundial by day, Astro pad by night & everybody's happy...

Cheers

[morls]

Hi Carlton,

A quick session the other night was promising, but there is some instability. I've reduced the gap between pier and footing as much as possible without removing the nuts between, and will see what fifference this makes. I wasn't too fussed about getting the footing completely level, my reasoning being that the rat cage would make this adjustment once set up. I think in the next installation I'll try to make sure the footing is as level as possible so I can attach the pier directly to footing. We started with it level, but as the first pile was driven in the plate shifted. It was at that point that I decided to let the rat cage do the levelling. My next step will be to remove the pier and widen the mounting hole in the base. I bought it from another IIS member, and these holes are just too close for a clean fit onto the footing. A few minutes with a file will sort this out.






The pier was purchased through this forum, from Bo (traveller). The total cost for footing plate, micro piles and nuts/bolts/washers was $220. The plate was $150, so the next install will be much cheaper.
I bought the S400: https://surefootfootings.com.au/pile-cap-s400/


Cheers

[Outcast]

Many thanks Stephen...

I would like to put a pier in as it would save some equipment lugging & make alignments & PA so much easier but, alas I suspect Min. War & Finance will not be keen on a pier & a circular pad...

I'm still thinking through my pad design & whether to mix the concrete myself or get someone in to do it professionally (significant cost differential I think). The marking out, digging & form work will be all me.. Min W&F wants it slightly subsurface but, I'm not entirely sure how to accomplish that with good screeding (I think that's the term). Still gotta contend with how deep (or not) the old septic tank is...:rofl:

Once I get my Nth/Sth line reliably down, I'll probably look to make some indentations in the pad to enable me to place the tripod feet in the same spot time after time after time...

Not withstanding cost of your pier, seems like a fairly cost effective outcome...

Cheers

[morls]

Yes, I'm happy with the cost considering it's able to be moved. I had another session last night, and will be making some further adjustments. I think I might reduce the height of the extension, as this seems to be where a lot of the instability is.
Nice to have a project...

[morls]

After recent rain I decided to move the pier. The process of removing the micropiles was very straightforward, and I took the opportunity to bolt the pier directly to the footing. I hope this will add stability.
I haven't tested yet, but it's very solid now. It still vibrates if I give it a tap, but I'm not sure if this is unavoidable. It this normal? When I say tap, I mean a moderately strong hit with my hand. The NEQ6 head vibrates for several seconds before settling. It seems to settle more quickly after this second installation.
Sorry about the sideways pics, can't rotate them as attachments...

[Outcast]

Would introducing say 5mm of high density rubber between the base & the mount perhaps provide some vibration damping without compromising the stability of the pier/mount?

Just a thought bubble...

[Sunfish]

The pier is quite tall and the gussets quite short. My guess is the shs is also not as thick as could be. So vibration. Longer gussets or tek screw pipe braces from the pier base corners.

[Sunfish]

And then use welds at the plate / micro pile connection. 450 is not very long for a pile.

[DarkArts]

Welds may make the foundation piles difficult to remove.

Stephen - How did you get the micropiles out anyway? What tool(s) did you use?

[morls]

I'm not sure. The vibration seems to be some sort of harmonic resonance type of response, and so I think it's a function of the pier itself.



Yes, the piles are short, and could be longer. It all seems rock solid at the base though, so I don't think this is the issue. Hesitant to weld because I like the option of disassembly.

Longer gussets might do the trick.


After removing the tek screws I used a pipe wrench to rotate the pile, and with upward pressure as I turned it moved quite easily.

[morls]

Last night was clear so I was able to test the setup. It's much more stable now compared to the previous install, and when slewing at rates of 3 - 5 there is no vibration visible through the eyepiece.

While adjusting focus there is some movement, but once this settles down it's very good. I think with practice I can reduce the lateral movement when adjusting focus, so I'm very happy overall.