the yesyes observatory - let the planning begin

[Gina]

A nice big cable duct is a good idea. Make sure you use nice gentle bends though not sharp elbows for the cables to drag on when installing. I have 40mm drain pipe up the outside but up inside the pier would have been nicer - but I didn't do it

[yesyes]

The idea was to use 45 degree bends instead of 90 degree. That should make it easier to pull USB plugs and the like through....

[Astrokev]

A nice big cable duct is a good idea. Make sure you use nice gentle bends though not sharp elbows for the cables to drag on when installing. I have 40mm drain pipe up the outside but up inside the pier would have been nicer - but I didn't do it

Absolutely. I once installed ducting underneath my lounge fireplace to take HiFi cables. I used a small bore tube and it was a nightmare!

[yesyes]

YES!! I just got 16 square meters of hard-wearing office carpet floor tiles from work. We're moving office and these are the spare ones we kept just in case. That's the obsy floor sorted then...

[opticalpath]

It's worth putting some underlay down before the carpet, Chris. Don't know if that's what you intended but I'd recommend it: it makes the floor even more forgiving if you drop something, and less tiring to stand on for long periods.

Adrian

[malc-c]

Like others I used the interlocking foam tiles from e-bay in the scope room. Saved a few eyepieces over the years

[yesyes]

That was my original plan. Then I saw them wanting to throw away the carpet tiles today. Could not resist...

I might still use these foam tiles under the carpet in the scope room, or only use the carpet tiles in the warm room... not sure yet.

[fwm891]

YES!! I just got 16 square meters of hard-wearing office carpet floor tiles from work. We're moving office and these are the spare ones we kept just in case. That's the obsy floor sorted then...

Nice touch Chris - watch for damp though carpets are a devil to dry out if they get wet/moist!

[Astrokev]

That was my original plan. Then I saw them wanting to throw away the carpet tiles today. Could not resist...

I might still use these foam tiles under the carpet in the scope room, or only use the carpet tiles in the warm room... not sure yet.

With 16sqm to play with, I reckon you could do both, and use the left over tiles as a second layer to save on the underlay!

That's also given me an idea. I also managed to pick up a load of office tiles a few years back (when I picked up my iar ducting tube) which are stacked in my shed. Mmm, must give this more thought....

[yesyes]

Thanks for the suggestions.... I'll give this carpet business a bit more thought. Anyway, carpet will be one of the last things to do .. ;-)

[yesyes]

Right. Back on track....

I've been making some progress with the Sketchup drawing last night. I've started designing the roof. I've got the warm room roof done for now. Does this look OK?

Screenshot and Sketchup file attached (again, remove the .pdf extension from the Sketchup file).

I have now also put everything on different layers. So it is now possible to hide the floor joists and walls for example to get a better overview. I couldn't see the wood for the joists any more..

Any comments on the design are most welcome. Am I over-engineering this? I want the obsy to be as stable and last as long as possible. But I don't want to exaggerate and spend too much money on timber where it's not necessary.

yesyes observatory_6.skp.pdf

[Lonestar70]

Looking good Chris... just one cautionary suggestion though.

From you Sketchup drawing it would appear that you are proposing to use 4" x 4" (100mm x 100mm) for the floor supports.

This is not good engineering practice when spanning best part of 8 - 9 ft between concrete supports... they will almost certainly bow downwards between the pillars when any weight is applied to the internal floor.

You would be best using at least 6" x 3" (or even 6" x 4") for the outer frame with 6" x 2" minimum for any remaining floor support joists (these can be attached to the outers using metal joist hangers.

Be sure and use pressure treated (tanilised timber) not ordinary (interior grade) timber.

Keep up the great work.

Best regards.

[yesyes]

Thanks Sandy.

It's been suggested to use two 6x2" next to each other for the floor frame. I take it that would be OK? That would also solve the problem with the 6x2" floor joists hanging below the 4x4 frame.

And yes, I'll buy pressure treated timber.

[Gina]

Wooden railway sleepers make good floor frames and they will last a very long time without any further treatment. I too would not consider 4"x4" as sufiiccient for the floor frame. Mine are 8"x3" (200mm x 75mm) reclaimed oak barn roof frames. These are supported on concrete pads spaced 2.4m apart.

[Astrokev]

Hi Chris

Is there a particular reason for choosing a flat roof over a traditional apex design? I've been pondering on which to choose for my own build. A pent roof may be lower giving better access above the roof once rolled off, but will it have as much strength?

[opticalpath]

It's interesting to see where people put the most effort/ investment in obsy construction. I most certainly over engineered my concrete base and pier ....... but when I see how others have built 'proper' buildings, I really wish I had done more with the superstructure. Although it was scratch built and beefed up, my shed is just that: a shed, built on 2"x2" framing, with floor bearers resting on a concrete slab base - no anchors. Foundations? DPC? Hmm, didn't really think about that at the time! Well, it's still standing after 8 years ...... and I think the pier would hold it down if it comes to it. Probably.

Adrian

[Lonestar70]

Hi Chris,

It's been suggested to use two 6x2" next to each other for the floor frame. I take it that would be OK?

Yes that would be fine and it makes the boards easier to handle (2" not as heavy as 4"), however, it would be normal practice to bolt them together using coach bolts and large washers( or bearer plates ).

On 6" wide timber you need 2 rows of bolts... a top row say 2" down from the top and pitched at about 2ft intervals.

A second row 2" from the bottom also spaced at about 2ft intervals but offset by 1ft from the top row... you end up with a sort of zig-zag pattern.

The reason for bolting them like this is to more evenly spread the tensions through both and minimise each board warping in a different direction to it's partner.

Some buildings I have seen glue the 2 boards together and put 1" dia pegs through both boards in much the same pattern.

Hope that all makes sense.

Best Regards.

[Whistlebare]

Right. Back on track....

I've been making some progress with the Sketchup drawing last night. I've started designing the roof. I've got the warm room roof done for now. Does this look OK?

Screenshot and Sketchup file attached (again, remove the .pdf extension from the Sketchup file).

I have now also put everything on different layers. So it is now possible to hide the floor joists and walls for example to get a better overview. I couldn't see the wood for the joists any more..

Any comments on the design are most welcome. Am I over-engineering this? I want the obsy to be as stable and last as long as possible. But I don't want to exaggerate and spend too much money on timber where it's not necessary.

HI Chris,

What budget have you got in mind for all the materials i.e completed structure minus the internal fittings etc? The only reason I ask is, I designed my shed and passed the plans to a chap on ebay who made sheds. The wood was tanalised 4x2 with 19mm tongue and groove, shed size 14ft x 8ft penthouse style, with an internal partition and the roof felt was included, it is solid. So the complete shed with all the trimmings plus delivery was £1k...I couldn't have bought the wood for that price. They even offered to erect it...although I declined this as I was still building the pier.

Take a look >

[Astrokev]

HI Chris,

What budget have you got in mind for all the materials i.e completed structure minus the internal fittings etc? The only reason I ask is, I designed my shed and passed the plans to a chap on ebay who made sheds. The wood was tanalised 4x2 with 19mm tongue and groove, shed size 14ft x 8ft penthouse style, with an internal partition and the roof felt was included, it is solid. So the complete shed with all the trimmings plus delivery was £1k...I couldn't have bought the wood for that price. They even offered to erect it...although I declined this as I was still building the pier.

Take a look > http://stargazerslou...ot/page__st__40

Ah, so you didn't actually build the shed yourself? Your thread failed to mention this, ....and there was me thinking you'd done it all yourself

[Whistlebare]

I'm pretty sure there's a post on where I got the materials etc... Strange, must have mentioned it in another post somewhere...

Anyway when you say 'build' you mean cut and nail the wood together? Well no I did not do that part. The design was mine, the base was built by me as was the pier. The shed came in 11 parts along with all the trims, felt iron mongering... So still a lot of building was to be done, oh and then there was the roll on roof, that was designed and put together be me also. :-) I could go on about the insulation and internal work, wiring etc which was all done, by my good self...

I was more than capable doing it all from scratch, but like I said the price was the key factor, it worked out cheaper for me doing it the way I did and the amount of time saved was also a bonus.

Too many people in my opinion obsess with over engineering their builds, remember it is after all a glorified shed we have all built and not a house which must conform to building regulations. ;-)

As one of my teachers used to say "work smart, not hard"... Smart was an acronym but I can't remember what it stands for... Not smart enough to remember ;-)

Anyway good luck with your build, I love seeing all the cool ideas people come up with... And no matter how much planning you do, once you've finished you'll be saying to yourself 'I wish I'd done that, or maybe it would have been better if...'

[Astrokev]

I'm pretty sure there's a post on where I got the materials etc... Strange, must have mentioned it in another post somewhere...

Anyway when you say 'build' you mean cut and nail the wood together? Well no I did not do that part. The design was mine, the base was built by me as was the pier. The shed came in 11 parts along with all the trims, felt iron mongering... So still a lot of building was to be done, oh and then there was the roll on roof, that was designed and put together be me also. :-) I could go on about the insulation and internal work, wiring etc which was all done, by my good self...

I was more than capable doing it all from scratch, but like I said the price was the key factor, it worked out cheaper for me doing it the way I did and the amount of time saved was also a bonus.

Too many people in my opinion obsess with over engineering their builds, remember it is after all a glorified shed we have all built and not a house which must conform to building regulations. ;-)

As one of my teachers used to say "work smart, not hard"... Smart was an acronym but I can't remember what it stands for... Not smart enough to remember ;-)

Anyway good luck with your build, I love seeing all the cool ideas people come up with... And no matter how much planning you do, once you've finished you'll be saying to yourself 'I wish I'd done that, or maybe it would have been better if...'

No worries, only jesting there. The important thing is the end result, not how you got there. It's a difficult balance between costs and time, and I'm certainly struggling on the latter (and not doing too good on the former, come to think of it ).Yes, I remember you building the base, and a fine job you did too. You're right about the tendancy to over-engineer, particularly regarding the piers and pier blocks, and also the need (or not) for pier isolation (as I recall was mentioned by someone in your build thread). Too many folks build a base strong enough to dock an aircraft carrier, and then stick their OTA on a mount supported by 3 or 4 spindly bolts. Having said that, I suspect I'll end up doing the same myself . No matter what I end up doing, as you say, I'm sure I'll wish I'd done things differently once it's finished!

[Whistlebare]

No worries, only jesting there. The important thing is the end result, not how you got there. It's a difficult balance between costs and time, and I'm certainly struggling on the latter (and not doing too good on the former, come to think of it ).Yes, I remember you building the base, and a fine job you did too. You're right about the tendancy to over-engineer, particularly regarding the piers and pier blocks, and also the need (or not) for pier isolation (as I recall was mentioned by someone in your build thread). Too many folks build a base strong enough to dock an aircraft carrier, and then stick their OTA on a mount supported by 3 or 4 spindly bolts. Having said that, I suspect I'll end up doing the same myself . No matter what I end up doing, as you say, I'm sure I'll wish I'd done things differently once it's finished!

It's ok I did not take any offence The beauty of this site with its large community is that you can look at all the great builds and decides what works best for you and your location and take the best bits from other builds and implement them in your own.

One thing I wish I had done differently was the direction my roof rolls off...my one rolls off to the south which blocks anything low on the horizon, so I have to wait a few hours for it to move around into view. I can push the roof right back and get a better view but the hanging rubber seals to stop water ingress gets pinched when bringing the roof back on after viewing. I built it this way to keep the kids happy as it would have meant removing their trampoline...I'll wait a few years and when they have grown up I'll build some runners so it rolls off to the north side.

[ncjunk]

One thing I wish I had done differently was the direction my roof rolls off...my one rolls off to the south which blocks anything low on the horizon, so I have to wait a few hours for it to move around into view. I can push the roof right back and get a better view but the hanging rubber seals to stop water ingress gets pinched when bringing the roof back on after viewing. I built it this way to keep the kids happy as it would have meant removing their trampoline...I'll wait a few years and when they have grown up I'll build some runners so it rolls off to the north side.

You're not the only one, i put mine rolling off to the south as well...big mistake.

1. For the obvious low down targets.

2. All wind and rain rolls up from the south. The face of the roll off is not as well protected, when closed, as the sides so one f the sides should have been south facing.

Sent from my GT-I9003 using Tapatalk 2

[Whistlebare]

You're not the only one, i put mine rolling off to the south as well...big mistake.

1. For the obvious low down targets.

2. All wind and rain rolls up from the south. The face of the roll off is not as well protected, when closed, as the sides so one f the sides should have been south facing.

Sent from my GT-I9003 using Tapatalk 2

DO you get any rain in Spain? Thought it mainly fell on the plain...

[ncjunk]

Hah! I wish! It's like Wales where we live, been a very wet and cloudy six months but at least summers usually good.

Enjoying reading this thread though. Designs are coming along nicely.