Obsy build for the summer...

[JamesF]

I think, though I am not certain, that it is the iOptron tri-pier.

James

[fwm891]

9 minutes ago, JamesF said:

I think, though I am not certain, that it is the iOptron tri-pier.

James

Correct James.

I've chosen to use a mixed pier/tripod to give me some flexibility should I take the scope to a location with a wider horizon. The feet of the tri-pier will locate in holes in the obsy so when things are returned the re-alignment of the PA will be simpler, the tri-pier will have its leg/column height set to maintain the leg spread.

It's VERY SOLID!!!

Currently waiting for a couple of material quotes to arrive from local suppliers. Not ordered the wheel/tracks yet either...

Edited June 5, 2019 by fwm891
text added

[mckinnell]

Very nice mount,  as the name implies, two in one, but then I checked out the price,   OUCH!!!, that's a rather big price my friend, still, yes, it sure does look like it could handle quite a heavy work load.

 

                                                                                                  Very best regards my friend,                Tom.

[fwm891]

On ‎05‎/‎06‎/‎2019 at 22:50, mckinnell said:

Very nice mount,  as the name implies, two in one, but then I checked out the price,   OUCH!!!, that's a rather big price my friend, still, yes, it sure does look like it could handle quite a heavy work load.

 

                                                                                                  Very best regards my friend,                Tom.

Tom - There is a bigger version at nearly twice the price...

Timber and ironmongery all ordered and due to arrive early next week. Hence the bad weather. Found a softish spot when working on the foundation trench so I'll hammer some broken paving slabs in to it - plenty of those.

[Miguel1983]

On 05/06/2019 at 08:20, Bukko said:

As above, managing a quantity of concrete is a struggle sometimes and it is tough to mix by hand, even a mixer only partly solves the problem as it still needs to be loaded and unloaded.

Fixing a single concrete slab is also not the preferred solution, as ground movement can transfer to the pier, mount and scope. So an isolated footing is usually installed for the pier.

For my build, I did fit a concrete slab, but this also had a separate, isolated footing for the piers.

When I say "I" I really mean the buulders I brought in to help...

Gordon.

Yes of course, when you place a slab usually we're talking volumes of concrete that are not doable by hand so you need to have it delivered by concrete truck and if necessary get it on location by concrete pump, i guess this does ad to the building cost compared with having some blocks as a foundation, so i do understand the choice for a lightweight foundation.

As for the ground movement, i guess this depends on the situation (size, weight, soil type etc...), still a tripod on the lawn has to be worse, try dropping a bag of sand on your lawn.
 

[Bukko]

Absolutely - I would say almost any pier is an improvement over a tripod.

The ground movement does depend in part on the soil - my first pier was undersized with a similar amount of concrete under it that would be used for a fencepost. The soil was a problem and walking around the pier caused enough movement to affect the images (2500mm fl) The good bit was it was much easier to dig out than my last one - a couple of tons of concrete pad and pier footing.. I never want to remove my latest installation, it's even "worse"(better)

The building is not so important to be footed on tons of concrete and the blocks are much easier to manage.

Gordon.

[Miguel1983]

9 minutes ago, Bukko said:

Absolutely - I would say almost any pier is an improvement over a tripod.

The ground movement does depend in part on the soil - my first pier was undersized with a similar amount of concrete under it that would be used for a fencepost. The soil was a problem and walking around the pier caused enough movement to affect the images (2500mm fl) The good bit was it was much easier to dig out than my last one - a couple of tons of concrete pad and pier footing.. I never want to remove my latest installation, it's even "worse"(better)

The building is not so important to be footed on tons of concrete and the blocks are much easier to manage.

Gordon.

Well i didn't isolate my pier from the rest of the slab, as you've seen i do have a raised floor around the pier, and the warm room is fitted with floor insulation, so i'm pretty sure no vibrations will be transferred to the pier, time will tell..

Worst case i can cut the concrete around te pier, i've got the gear for it 😉

[Bukko]

2 hours ago, Miguel1983 said:

Well i didn't isolate my pier from the rest of the slab, as you've seen i do have a raised floor around the pier, and the warm room is fitted with floor insulation, so i'm pretty sure no vibrations will be transferred to the pier, time will tell..

Worst case i can cut the concrete around te pier, i've got the gear for it 😉

With such a big pad and the raised floor, I also doubt you will notice any movement...

Gordon

[fwm891]

On ‎08‎/‎06‎/‎2019 at 07:29, Bukko said:

Absolutely - I would say almost any pier is an improvement over a tripod...

Gordon.

That depends on the tripod and in my case the need for flexibility. The Tri-pier is incredibly ridged and will sit on a concrete foundation isolated from the observatory building. My observatory will offer the quick usability a chance clear night might offer but I also want to go to location with a wider horizon and a pier in that situation is useless.

[Rusted]

It's not all about stability so much as avoiding nasty hurdles in the dark.

I welded up some truly massive piers but always regretted the "sticky out" bits down near the ground.  🤕

And, that was before I fitted ever-larger wheels to try and make them portable. [Oxen permitting.]

[Bukko]

23 hours ago, fwm891 said:

That depends on the tripod and in my case the need for flexibility. The Tri-pier is incredibly ridged and will sit on a concrete foundation isolated from the observatory building. My observatory will offer the quick usability a chance clear night might offer but I also want to go to location with a wider horizon and a pier in that situation is useless.

The context was placing a tripod on the lawn and hoping for stability.

The three legs, or contact points on the ground are a second problem for the unwary and I never managed a whole night without bumping a leg at least once. For visual, not a big deal, but imaging is made more difficult.

And I fully accept the limitation of a pier when transporting one around. It would be a great thing to have a self-boring pier that you can screw into the ground, then take it up again when done.

Hope this clarifies my point a little.

Gordon.

[fwm891]

That's the thing Gordon, I'm imaging only (well 99% anyway as I have aa 10 inch Dob for visual) and work remotely from inside the house so no need to worry too much about tripod legs.  Just need the mount so I can finalise the internal measurements ([removed word] on iOptron… fingers out)

[JamesF]

Ah, hence your frustration with the late arrival of the mounts at FLO?

James

[fwm891]

On ‎11‎/‎06‎/‎2019 at 21:33, JamesF said:

Ah, hence your frustration with the late arrival of the mounts at FLO?

James

Not blaming FLO in anyway - it's beyond their control. Lisa and Grant keeping me updated.

Timber arrived today. All the sheet material went straight in the workshop to keep it dry. All the rest is treated so no problem there. The postcrete is wrapped up with the barrow on top.

Mix of 47x100 (4x2), 47x75 (3x2), 100x200 (4x8) and the shiplap (behind the stack) is 125 x 19 (5x¾) coverage is 119mm (4½)

 

Edited June 13, 2019 by fwm891
text added

[JamesF]

37 minutes ago, fwm891 said:

Not blaming FLO in anyway - it's beyond their control.

Oh, certainly.  It wasn't my intention to suggest that it was :)

James

[fwm891]

Block work foundations are down. Woodworking now 👍

[fwm891]

Made a start on the sleepers today, cutting half-lap joints and adding (taking away!) a bevel to aid water run-off.

Then clear up the created mess...

Into the workshop now to make some layout poles ready to start marking out and cutting the frame timbers.

 

[fwm891]

Rain stopped play for the moment - progress so far today...

Just put in place and held with a couple of clamps. The track support rails are odd bits of 4x2 placed for effect - the proper ones will be 4.3 Mtrs so the roof can extend past the end of the lower fixed wall.

[sloz1664]

Coming along nicely Francis and impressive woodworking skills, may I add. Keep the photo's coming, which is definitely up your street

Steve

 

Edited June 16, 2019 by sloz1664

[fwm891]

Made up the door end frame, put a few temp screws through the bottom rails of each so I can take the clamps into the dry.

I'm still trying to decide on whether to run permanent long tracks or to terminate the tracks at the end of the obsy and add on extension rails when I need to open up. I did this on a previous obsy and it worked well - jury out at the mo 🤔

 

Next stage on this is the dig out the central area below the concrete block level ready for a water barrier.

[fwm891]

OK decision made (for me), SHMBO separate extension frames it is. I've been looking through lots of ironmongery catalogues but apart from some gate hardware nothing really fitted the requirements so I've come up with what I feel will be a solution:

The fixed part of the rail and it's support timbers will extend slightly (100-120) from the end of the obsy rear wall each side. Ali corner plates fitted each side of each extension frame will have a 16mm brass pin inserted through to link the extension with the fixed wall. The bottom of the extension leg will sit in a socket to take the initial weight of the extension frame while the pin is inserted.

A socket is formed by the ali plates and track timbers at the top to align the extension track with the fixed track. Hopefully the sketch will help. I'll do a better job of the drawing or a mock-up at a smaller scale

[fwm891]

Well I had to make a model to confirm that the extension rail support would work. Built to a scale of 1cm to 1 inch.

Photo 1 shows the extension in place with a locking pin in place

Photo 2 shows the two parts with the joint part closed

Photo 3 shows effectively what sticks out from the rear wall of the obsy

Photo 4 shows the joint closed with the locking pin - no aluminium plate (there would be an aluminium plate on both sides of each extension frame(2))

Photo 5 Joint part closed

The Obsy end wall is a piece of OSB in the model - will be shiplap on final build

The aluminium plate also shown as OSB but will be Aluminium for the build.

[Yawning Angel]

I seem to recall, but can't find, a recent build using up-scaled drawer runners to take the roof. This gets away from the need to have a SHMBO approved removable support frame, and keeps all the rolling gear inside the Obs footprint.

It's sure to be more expensive, but it's tidy and you don't need to store the rails when not in use

Something like this: gsfslides.com

[JamesF]

16 minutes ago, Yawning Angel said:

I seem to recall, but can't find, a recent build using up-scaled drawer runners to take the roof. This gets away from the need to have a SHMBO approved removable support frame, and keeps all the rolling gear inside the Obs footprint.

It's sure to be more expensive, but it's tidy and you don't need to store the rails when not in use

Something like this: gsfslides.com

I think I recall the one you mean.  Possibly a Canadian SGL poster?  I think they were rails for fitting to a pickup truck to allow different things to be fitted in the bed.  I'm sure I have posted a link to it before, but at the moment I can't recall enough for useful search words.

James

[Yawning Angel]

17 minutes ago, JamesF said:

I can't recall enough for useful search words

Having a more determined try, I still can't find it...but I did find both James and myself commenting this earlier in this thread. Search 1, Gray matter 0. Sorry