202 replies to this topic

[Rustler46]

As design decisions have largely been made, and much of the needed materials have been purchased, I did a quick "what's next - To-do List".

 

 

So far the cost for materials has been $612, with around $225 more for roofing and miscellaneous items. If I hire James for a full 8 hour day, that will add another $280. This will bring the total cost to less than $1200! If this all comes to be, it will be simple (i.e. cheap) and hopefully functional. If Ocean Observatory is as useful as the 1985 Klamath Observatory, I'll be quite pleased. 

 

More to Come,

Russ

 

Edited by Rustler46, 28 March 2024 - 01:42 AM.

[billywjackson]

I would be very leery of using that splice with much tension. It would be a lot better to pick up some regular wire rope clamps.

[Rustler46]

I would be very leery of using that splice with much tension. It would be a lot better to pick up some regular wire rope clamps.

The cables will be under very little tension. Their only purpose is to hold the diagonals to the same length after the roof frame has been squared and all bolted together. I would expect that the cables might even sag a little bit, since I will not be applying much tension at all. Yeah, I do understand why such a loop is not in accord with safety requirements for cables used in industrial settings, like logging.  Such cables are often stressed to some percentage of the "safe working load", which is quite a bit less than the breaking load of the cable. For sure, inserting a non-approved cable end loop would greatly compromise the safe working load. But in my application, the load will be very low.

 

I'll just be ensuring the diagonals remain equal. So in this case it's not like logging or even rocket science. But now that you mention it, I do have some very light duty wire rope clamps that may well work for some of the needed loops. I'll have a look at how many I have in hand. I need at least 4 loops for the ends of two cables.

 

Edit:

I have one 3/32" Ferrule & Stop Set that would likely work OK on my 1/16" cable. Since I saved around $400 by painting the side walls (rather than using polycarbonate sheets), I'll make another trip out to Englund Marine Supply to buy 3 more. This will make the cables look at lot neater. And it's always fun to make a short trip to Englunds in the little fishing village of Charleston, near the mouth of Coos Bay. Thanks for the suggestion, Billy.

 

CS,

Russ

Edited by Rustler46, 28 March 2024 - 02:14 PM.

[Kitfox]

Here's a nice link that shows how to make what is know as a "farmer's eye" loop in the end of a braided steel cable;

• Really Quick Wire Rope Eye-splice

It's really amazing how that simple technique makes a quite useable loop at the end of the wire cables. I have purchased 25 feet of 1/16 inch steel cable for the roof's diagonal braces. 

 

Here's an example of the finished loop.

 

Farmer's Eye Loop.jpg

 

Best Regards,

Russ

 

Cover that end with a piece of heavy heat shrink tubing.  Much more durable and long-lasting than electrical tape.  Those braided wire ends are dangerous...

[Rustler46]

Cover that end with a piece of heavy heat shrink tubing.  Much more durable and long-lasting than electrical tape.  Those braided wire ends are dangerous...

Thanks for that tip. That's what I'll do to remove the hazard of those loose tails hanging off the loop. Doing so will make for a neat looking loop at each end of the cables.

 

Russ

[Rustler46]

Cover that end with a piece of heavy heat shrink tubing.  Much more durable and long-lasting than electrical tape.  Those braided wire ends are dangerous...

That's what I did with my roof cable diagonals.

 

 

The "farmer's eye" loop connects cables to the turnbuckles. There will be an eyebolt (like at lower left) in each of the 4 corners of the roof where the cables will be connected.

 

Edit:

Looks like James is finished with another job that took longer than expected. Next week is a possibility for us to put the fame and walls together. I'm heading to Roseburg for an out of town shopping trip tomorrow. Will get SunTuff wiggle-wood and special screws with gaskets from Home Depot. It's always dangerous going in there. Both Renee & myself are prone to coming out with more than we intended to buy. 

 

 

Clear Skies,

Russ

Edited by Rustler46, 30 March 2024 - 01:43 AM.

[Rustler46]

I'm heading to Roseburg for an out of town shopping trip tomorrow. Will get SunTuff wiggle-wood and special screws with gaskets from Home Depot. It's always dangerous going in there. Both Renee & myself are prone to coming out with more than we intended to buy. 

Other than a load of groceries at better prices than can be obtained locally, I didn't get much of what I was hoping to get. The SunTuff roofing, special screws and plastic wiggle-board were not in stock at either Lowes or Home Depot. The best price for the roofing is at my local hardware store that gives me a small senior discount. Wiggle-board and screws are available online from Home Depot.

 

I did score one important hardware item - 5 lbs. of 1-inch screws for treated wood. This was marked at a clearance price of $25 at a farm supply store. It seems like 1-inch screws in quantity are not commonly available. Both Lowes and Home Depot had only 1-1/4 inch or 1-1/2 inch. But one inch is exactly what is needed to secure 3/8" plywood to 3/4 inch thick 1X4 purlins. I didn't want anything longer because the excess length would protrude inside the structure, ready to wound people in the dark. So the 5 lbs., approximately 1200 screws is plenty to secure the plywood on all 4 walls.

 

So things are coming along.

 

Russ

Edited by Rustler46, 31 March 2024 - 12:51 AM.

[Rustler46]

Update 2024-April-1:

 

James & I have tentatively scheduled this coming Friday to do the bulk of the construction, weather permitting. Time will tell if conditions will permit starting the carpentry phase of construction. So things could start looking like an observatory before too long.

 

Edit:

I did measure the elevations of the 5 concrete footings for the structure, using a laser level. This is not a particularly high quality level. So I also used a straight member and carpenter's level to verify the laser measurements. Relative to the southeast corner footing at the door opening, the elevations ranged from +2-1/4 inches in the opposite northwest corner to negative 1-3/4 inches at the northeast corner on the adjacent east side. The southwest corner is at +1-1/2 inches.

 

So the site is not exactly level. But we can cut the 4X4 corner posts to lengths which will provide the correct elevations at the top of the walls. The north wall will be 1 foot higher than the south wall, producing a 1-1/2 inch rise per foot.

 

I won't be able to install the roof until next week when the plastic wiggle-board arrives from Home Depot. But even before then I can build the roof frame using metal rafters and 1X4X10 foot purlins. This will be trued up using the two diagonal tension cables already on hand. If rain comes before the roof is complete, I can drape a tarp over the frame. I intend to paint the walls with several coats, ending up with a light color. I have a lot of paint on hand.

 

I picked up the SunTuff roofing and found the price had gone up since last quote. I chose white, which will let in some light but repel some of the heat. Also got hardware for the door - hinges & hasp.

 

At this point the total cost for materials is under $1100. I still need to acquire some SunTuf compatible roofing screws. But at this point it looks like the total cost of my simple observatory will be under $1400, materials and labor. 

 

Clear Skies!

Russ

 

Edited by Rustler46, 01 April 2024 - 09:51 PM.

[Rustler46]

Construction has moved up to tomorrow, since Friday had a higher chance of rain. Most all supplies are on hand, and James is ready to go with the build. I'll be his "gofer" support crew. Since all roofing materials are not on hand, I'll just tarp the finished walls to keep things dry until the roof is finished. There's some clear weather coming next week to finish the roof.

 

Edit:

Purchased the last materials - a 250-pack of special Palram 1-inch screws w/ EDPM gasket washers. Total cost of materials is $1096.50. The material cost will go up a bit when I add the support track for the roof in its open position. Until then I'll just support the opened roof with 55 gal drum, set back about 8 feet from the north wall. 

 

So needless to say, I'm quite excited to see "Ocean Observatory" coming on online soon. Renee' will be taking pictures of the whole building process. So I'll share these with the forum. 

 

Next week promises a string of sunny days. When all of the roofing materials are on hand, I'll finish construction with that. Then I hope to have first light with the new and improved Ocean Observatory. With its permanent pier in its present location, it has been known by the same name for a decade or so. That same pier was known as Klamath Observatory in two different residences. The first in 1985 at the original "simple observatory" near Somes Bar, California, and in 1995 in Happy Camp, both on the Klamath River.

 

Clear Skies,

Russ

 

Edited by Rustler46, 03 April 2024 - 10:53 PM.

[Rustler46]

The observatory walls are up. James spent 8-1/2 hours getting that done. Most of the day was sunny, partly cloudy. Will share lots of photos. Here are two.

 

 

 

Just after I got the structure covered with tarp, the rain came down in a deluge. The 5 metal rafters were laid loose with tarp over top. All loose ends and corners of the tarp were tied off to resist wind. It shed water quite well off the lower end. Next week I have a few days of dry weather to work on the roof and painting.

 

Edit:

There will be a few more expenses for materials:

• 3 8-foot metal flashings to seal top of plywood skin at upper ventilation openings
• 3 more treated 1X4X8 foot trim for sealing vertical wall connections at corners
• Metal door handle

Purchased door handle and treated 1X4X8'. Total cost so far for materials and labor is $1458. 

 

When the rains stop for a few days next week I can remove the tarp and construct the roof. Next will be the process of securing the walls with caulking, trim, flashing and paint.

 

James gave some very useful suggestions for finishing the structure that will make it more long lasting. His work and skills are amazing to observe. The structure with plywood skin is rock solid. The technique of providing shear strength via plywood secured to purlins and vertical fill in material is something new to me. I had always assumed one needed diagonal bracing for a solid frame. This structure has very little of that. James' prior experience included (among other things) commercial building of boats.

 

I couldn't resist releasing the tarp enough to get inside my developing observatory. It will have plenty of room inside for my C-11 on Losmandy G11 mount plus 2-3 visitors.

 

Clear Skies,

Russ

 

Edited by Rustler46, 05 April 2024 - 07:35 PM.

[Rustler46]

Here are some more photos of yesterday's construction.

 

James taking a short coffee break after getting the four corner posts set. The top of each post was cut at an angle to match the rise of 1 inch per foot for the roof track- ~5°.

 

Making the 45 degree cuts for each of the 4 top rails for what he calls a "picture-frame". All treated wood cut ends were painted with additional preservative.

Edited by Rustler46, 06 April 2024 - 03:12 PM.

[Rustler46]

James is adding the roof track top rails. I reduced the recommended rise of 1-1/2 inch per foot, to just 1 inch per foot. For the side-slope and high-end ventilation openings, both will be reduced to a maximum of 8 inches. I was concerned that there would be too much blow-in of rain. The roof overhang is only 1 foot. There should still be enough area in the lower and upper ventilation openings to provide for moisture control via natural convection or wind.

 

This shows the south wall and door opening. The 1X4 horizontal purlins are shown with some of the vertical fill-in wood between these. This will provide the best shear strength with the 3/8 inch plywood skin. 

Edited by Rustler46, 06 April 2024 - 03:24 PM.

[Rustler46]

Getting a 4X8 foot sheet of 3/8" plywood ready for cutting to size.

 

Attaching the plywood skin to the underlying shear structure used 1-inch screws at purlins and 1-3/4-inch screws at major structural elements. The 1-inch screws are short enough not to extend a sharp point inside the purlins, which could cause injury of astronomers in the dark. The 1-3/4 inch screws going into 2X4s and 4X4s give good attachment shear- and tensile-strength at the these thicker shear structure elements.

Edited by Rustler46, 06 April 2024 - 04:18 PM.

[Rustler46]

Here James is building the door frame using 1X4 and 1X6 inch wood. These were glued & screwed together with 1/4-inch plywood skin over that. Still to be done is adding the vertical fill in wood between the horizontal members. Another of the great tips from James was that this door is lighter and stronger than one made from 2X4s and diagonal bracing.

 

This shows the major structural members - corner posts, horizontal 2X4s above the lower ventilation openings, mid-span vertical 2X4s, along with horizontal purlins. The finished door is seen lying inside, waiting for the glue to fully cure.

 

That's it for now. I can share more photos as needed in reply to comments or questions. I am so pleased to have hired James to do this work. At times I told myself that I could just do it myself. But in retrospect that was erroneous thinking. Given the energy level still available at my 78 years of age, it would have taken weeks to finish the work. More importantly it would not have been done correctly, efficiently and optimally. It would likely have cost more.

 

When Ocean Observatory is functionally in service, I'll give progressive reports on how things are working, particularly regarding ventilation and condensation control. That was one issue of concern, having a native soil floor.

 

Best Regards,

Russ

 

Edited by Rustler46, 06 April 2024 - 04:22 PM.

[desert_sage]

Wow, real progress!

 

Looking very tight and usable.

Edited by desert_sage, 06 April 2024 - 10:41 AM.

[Rustler46]

Wow, real progress!

 

Looking very tight and usable.

The small footprint just fits inside the available space. Along the east and west walls there is just a 2 foot wide walking space. The north wall butts up against a raised garden bed, that formerly held some strawberries and blueberries. These have or will be moved to other locations less affected by shade. Renee is considering using that space for another mushroom growing area.

 

Yesterday as I inspected the inside space, it seems quite roomy. Over the last 60+ years of amateur astronomy, I've been by myself for 99 percent of the time. Just recently some teenagers and other youngsters have joined me a few times for some observing. As enjoyable as it is, the times are still infrequent. So I'll be quite pleased with tight & useable.

 

One activity that will be enhanced with the observatory will be EAA (electronically assisted astronomy). That is in my assessment, the best melding of visual and photographic observing. 

 

Clear Skies,

Russ

Edited by Rustler46, 06 April 2024 - 02:58 PM.

[Rustler46]

Today I'll be working on building the slide-off roof. Looks like there'll be a rainless period of 3-4 days for that. First will be building the framework of metal rafters and 1X4 wood purlins. The 1/16th inch steel cables in tension will keep the roof square. I'll post some photos later on.

 

Edit:

Pretty close to maximum of Oregon's partial solar eclipse. With my Oberwerk 8X32 SE binocular I can confirm that Gallileo was correct - the Sun is not perfect, it has a spot on it. 

 

Today's work:

• Removed tarp & folded it back up
• Cut 2" off the swaged end of all 5 metal, 10' rafters
• Cut 4 wood inserts that go inside the rafters at the locations where the tension cable eyebolts will be attached.
• Attached 4 eyebolts 

 

CS,

Russ

Edited by Rustler46, 08 April 2024 - 07:13 PM.

[Rustler46]

Today I'll be working on building the slide-off roof. Looks like there'll be a rainless period of 3-4 days for that. First will be building the framework of metal rafters and 1X4 wood purlins. The 1/16th inch steel cables in tension will keep the roof square. I'll post some photos later on.

 

.....

 

Today's work:

• Removed tarp & folded it back up
• Cut 2" off the swaged end of all 5 metal, 10' rafters
• Cut 4 wood inserts that go inside the rafters at the locations where the tension cable eyebolts will be attached.
• Attached 4 eyebolts 

 

Things take longer than expected. Cutting the rafters worked best using a jigsaw. Hand hacksaw, tin-snips were not the way to go. The wood inserts needed to be a tight fit to avoid excess crushing of the rafter. The insert was driven down inside to the correct position to be drilled through for the eyebolt. The wood will also provide a solid anchor point at the 4 corners of the frame for the compression and tension elements (purlins and cable). This combination of compression & tension forces will provide for keeping the frame square. Here are a couple of photos.

 

Two of the eyebolts are shown here. The farthest one has a screwdriver through the eye.

 

This shows how the 1/16-inch tension cables will lay across the rafters before the purlins are attached. These cables must be on top since the lower sides of the rafters are what slide along the support track when opening or closing the roof.

 

After a break and snack I was able to spend some more time working on the walls. A few screws were missing or missed the mark. Others were screwed in a bit too far, protruding inside. So these few defects were corrected. Now I can start applying putty over the screws and begin applying the first coat off paint on the outside.

 

But before the painting comes getting a roof in place. The plastic wiggle-board should arrive tomorrow. With the next 2-4 days of clear, non-rainy weather, the roof should be ready to shed water when the rain returns this weekend.

 

Clear skies,

Russ

Edited by Rustler46, 08 April 2024 - 10:41 PM.

[Rustler46]

As might be expected, I'm getting quite excited to see this observatory come to be. I'm confident it will serve the purpose, since its predecessor worked fine back in the mid- to late-1980s. While there are a few more items to buy, I expect the total cost will be around $1550. There have been a few cost saving items, such as using some available pieces of wood. I save just about all scraps left over from previous projects, even down to pieces less than 6 inches in length. Wood is just too expensive to waste. I still have a sack and a half of QuickCrete for the remaining two foundation pods.

 

Also the exterior paint will be utilizing left over house paint, that I've been keeping for years. After living in this location for 22 years, I still haven't finished painting the whole house. So the paint won't be missed for that ongoing project. And the paint is a standard Sherwin-Williams color mix, which can be replaced when the need arises.

 

Still to buy:

• 2 treated 4X4X8' posts for supporting the end of the roof track when in the open position.
• 2 SimpsonTie post to concrete metal brackets
• 24 feet of 8-inch aluminum roll flashing to protect the upper end of the plywood walls from water intrusion at the upper ventilation openings
• 10 feet of galvanized corner trim that will be fashioned into a rain gutter of sorts. This will route most of the water away from the low end of the roof to reduce splashing on the south wall.

But for the short term, the above items won't be needed until later on when I construct the open roof support track. Just getting the roof on will allow leaving the telescope on its mount inside the padlocked observatory. The roof can be slid off either to the north or south with one end still supported by the wall. The other end can either lay on the ground or be supported by something like a 50 gallon drum. But that would just be a temporary measure allowing me to being observing the night sky.

 

So it has been just over three months since I began "thinking of another simple observatory". It should be ready for first light by the end of this week, weather permitting. Yes, I'm quite excited about that!

 

Best Regards,

Russ

 

Edited by Rustler46, 09 April 2024 - 01:04 AM.

[Rustler46]

Work continued today on getting the roof framing ready for the SunTuf roofing. First I laid two strips of wood along the outside edges of the top frame runners that the outside rafters will slide on. These strips prevent the rafters from moving laterally when being slid open or closed. The box section consisting of two outside rafters and two wood purlins was completed and the diagonal cables given a bit of tension. The center rafter was installed, being attached by hollow wall anchors. Tomorrow I hope to have the last two rafters in place and can work on attaching the rest of the purlins. Work has been slower than expected due to my limited energy.

 

The plastic wiggle-board has been delayed due to shipping errors by FedEx. When the package arrived in the Portland area it next traversed to the other end of the state. The next day it went back to Portland and is scheduled to arrive tomorrow. No harm, since I wasn't ready to install the wiggle-board yet. But the roof does slide back and forth easily, even without waxing the runners. 

 

Clear Skies,

Russ

[astrohamp]

Your progress account is near nail biting to read and am enjoying the process.  Hope you get first light real soon.

 

And yes...more mushrooms please.

[Rustler46]

Your progress account is near nail biting to read and am enjoying the process.  Hope you get first light real soon.

 

And yes...more mushrooms please.

 

Thanks for your comment and encouragement. The project has been fun designing and building. I'm definitely not an experienced builder, but am learning as I go. One problem is the steps are few - for instance just 5 concrete footings need to be established. By the time I got to number 5, I knew better how to do it. But I did manage to get the metal post to concrete brackets in place accurately enough for the building to be nearly square. James was able to compensate for the errors I made.

 

I may have to be patient for first light. While the roof is quite light, I'm thinking it might be best to build the roof-open support tracks before sliding the roof fully open. The prior version of the observatory had a very light roof. The present roof is a bit heavier. I'm not sure if it would be a good idea to just prop the slid-off roof on the ground and adjacent wall. The metal rafters are sufficiently strong overall. But they might not like being propped on a sharp edge like the top of the wall. I don't want to dent the metal. But we'll see what works out.

 

Today more rafters and purlins will be attached. I may get some wiggle-board attached as well. Two more clear days before next rain.

 

All the Best,

Russ

Edited by Rustler46, 10 April 2024 - 03:42 PM.

[HenkSB]

Hi Russ, great progress, looking good too.  I just want to chime in because like you, I built a small observatory with a slide-off roof.  I had a concrete pad from an old shed that I tore down.  Instead of building from scratch I used a $400 or so 6'x8' metal lean-to shed from Wayfair with the low wall 5.5' tall.  I added 2x2s around the wall tops with some recycled plywood strips to turn the roof into a lid.  The roof is secured by 4 nails that I shove through the 2x2s in stormy weather.  Eventually I added a counterweight mechanism to make the roof lifting a breeze.  Just slide off until the tipping point, flip it and the weights take care of the rest.  Check it out at this thread.  It was one of the best things I ever did for my hobby.  Messing with the metal panels having to peel the plastic off each one is a bit of a drag but the kit contains everything I needed, which is great.  Maybe the counterweight idea is something you could use.

[Rustler46]

Hi Russ, great progress, looking good too.  I just want to chime in because like you, I built a small observatory with a slide-off roof.  I had a concrete pad from an old shed that I tore down.  Instead of building from scratch I used a $400 or so 6'x8' metal lean-to shed from Wayfair with the low wall 5.5' tall.  I added 2x2s around the wall tops with some recycled plywood strips to turn the roof into a lid.  The roof is secured by 4 nails that I shove through the 2x2s in stormy weather.  Eventually I added a counterweight mechanism to make the roof lifting a breeze.  Just slide off until the tipping point, flip it and the weights take care of the rest.  Check it out at this thread.  It was one of the best things I ever did for my hobby.  Messing with the metal panels having to peel the plastic off each one is a bit of a drag but the kit contains everything I needed, which is great.  Maybe the counterweight idea is something you could use.

Thanks for your comment. While I admire those who choose to make more elaborate observatories, for many of us who are perhaps less skilled and less willing or able to spend lots of money, the simple slide-off roof observatory is a good option.

 

Edit:

In your link above, I like how you used some cables to assist in pulling the roof back on the walls. I may do something like that, since it seems like my roof is getting a bit heavy for this 78 year old astronomer to do long-term. In my case just some pulleys and some 1/16 inch cable might be what's needed. A Pulley at the far end of the open roof track could pull the roof open. Getting it closed may be accomplished with a little gravity assist in that direction. I'll give that a little idle time thought to come up with a workable design.

 

Thanks for the hint, HenkSB!

 

Kind Regards to All,

Russ

 

Edited by Rustler46, 11 April 2024 - 02:46 AM.

[Rustler46]

Here is a progress report. 

 

There was only less than 1/2 day available for construction. But I was able secure all the rafters and add two more purlins to the structure. As work on the roof has progressed I'm beginning to get the knack of how to install the hollow-wall anchors that secure the purlins to the metal rafters. These light duty connectors were never meant to be structural members. But they should do the job if I add one or more sheet metal screws at each location.

 

So here are a few things I've learned in the process. It is difficult to get these anchors to fully tighten down on the purlins. One problem is that if one isn't careful, the washers on the Phillips-screw end will spin in the wood surface. The washers have short spikes that are meant to protrude into the wood to secure it. But it can just as easily spin and auger out the wood surface. So I'm now holding the washer end with a vice-grip to prevent its spinning. Once the anchor begins to pull the wood down onto the metal rafter, the washer is allowed to pull into the wood without damage to that surface. 

 

So after struggling with many of the hollow-wall actors, the technique I use is now working well. But another issue has become apparent. The washer itself is extremely light duty and barely larger than the size of the hole needed to insert the anchor. So I intend to remove all the Phillips-screws and add a larger washer that will make it unlikely the anchor will pull through the wood. Now I feel that very high wind loads could still rip the roof off. Such is the fate of a self-designed "simple observatory". But should there be forecasts of gale- or storm-force winds, you can bet I'll do whatever I can to keep the roof in place. Why even a couple nylon straps wrapped over the roof, down around more solid wall structures would help a lot.

 

In any case here are some more photos.

 

Just three more purlins to go.

 

A few days ago when the walls were covered with a tarp another issue came up. Water running off the lower end of the tarp would splash up on the south wall. This isn't good even if the walls are painted. So it seemed like some sort of rain gutter would be the solution. But a gutter cannot extend down very far below the roofing, lest it run afoul of the side rails on the sliding roof track. So this is what I came up with.

 

This is some sort of galvanized steel flashing. Likely I'll cut off about 1/2 of the right hand side to reduce weight. The section shown on the left is 3 inches long. It will lay on top of the lower end of the metal rafters with a purlin connector holding it in place. The little rain-gutter V will route water away from the south wall.

 

Another slight design change:

I removed the two diagonal tension cables. They were just too much in the way for my being able get ladder access to the top side of the roof structure. After thinking things over I decided that these tension cables will not lay in straight lines from corner to corner. With the purlins secured to rafters in locations formerly occupied by the steel cables, these will now just have to find their place over the rafters and around the purlins.  The resultant direction the cables end up being in really doesn't matter. Their purpose is to provide some tension at each corner to maintain the squareness of the roof structure.

 

The plastic wiggle-board showed up today. Tomorrow with a full day available for construction, I'l hoping to get the roofing installed before the rains on Friday.

 

Best Regards to All,

Russ

Edited by Rustler46, 11 April 2024 - 01:02 AM.