Today's the day we started the Obsy!

[Mikyg]

I've been looking into this a lot and most say never use screws for joist hangers as they dont have the strength to supports the joist so i think i might stick to my original plan of using nails for the joist hangers and screws and bolts for the rest of the project. Im thinking of using screws and bolts for the framing.

[Mikyg]

A screw gun will fit where access to drive a nail is difficult. Drywall screws are strong enough, and a coat of paint weatherproofs.

Think i might use nails on the base of the hanger but screws on the joist going across so i can still strip it down if ever needed.

[kalasinman]

General advice based on engineering standards for general housing are fine, and obviously you must do what you feel most comfortable with, but having built homes as a carpenter, I was trying to offer an alternative that would work for your structure. It looks great and I'm sure will give you years of pleasure. Take care, and Clear Skies.

[Mikyg]

It would be better for me to use screws, its just the site i went on suggested not to use screws based on strength but now u mention it mine will not have to deal with anywhere near the amount of weight as a house would. Would u say there is any danger of splitting the timber. Thanks again for your advice

[Gina]

Drill pilot holes.  These are holes about the thickness at the base of the thread and reduces the risk of splitting enormously.  Also, with hardwood you would find driving screws without a pilot hole can result in breaking the screw.

[Mikyg]

Oh yes i plan on doing that anyway but until the joist hangers come i didn't know how close to the edge the nail holes are. But i'm sure if kalasinman is a carpenter and used screws before then they should be fine. I'm not a complete beginner ive just never used joist hangers before. Thanks guys and girls

[Mikyg]

My old man now wants some decking and benches building. We plan on putting some bamboo/cain under the beams so it has a little patio area for the family when not in use

[Mikyg]

Spent today putting concrete blocks for the base in. Hoping to get them filled in this week and get the floor joist ordered

[kirkster501]

How high does the pier need to be above the level of the decking to make the obsy usable? 

[Mikyg]

The walls on mine are 7ft so my piers gonna be about 5&half ft above the floor to compensate for the mount and when the scope turns upright from the parked position it will just poke above the wall but before i put the pier in i'm gonna sit and work it oit properly

[Mikyg]

How high does the pier need to be above the level of the decking to make the obsy usable?

[kalasinman]

On the pilot holes, good idea. Don't make them too big, or the screws won't have good grip. You can eyeball the size of the drill and choose a size same as the center, non threaded part of the screw, or slightly less, so entry will be eased, but all the thread will bite the wood.

In general , one reason why pros prefer nail guns and screws is that there is less splitting, and less pounding on the structure which jars other components out of line. Of course if one were building to code, one would use only the specified fastener, as that will be inspected.

One thought on wall, pier height, if the center line of the scope to the top of the wall is a little less than 20 degrees, that will suffice. There is seldom any use in going below 20 degrees in altitude.

[Mikyg]

Just got the 6x2" floor joist ordered and should be here on saturday ready for me to start the floor.

[kalasinman]

Joists on 18" centers?

[Mikyg]

16" centers. Had a phone call to say they will be here on friday so that will keep me busy on saturday lol

[SacRiker]

I just noticed you have a 5SE...how do you like that scope?

[Mikyg]

I just noticed you have a 5SE...how do you like that scope?

Hi sorry i thought i'd replied. Yes ive got the 5se which has been good for general viewing use but not really great for astrophotography but with the set up we'll be using soon i hope to use for that. The 5se is a good scope though and the optics are good. I think it all depends on what your using it for. The problem i had with using my DSLR with it was it was too heavy for the mount so i had to tighten the bolts slightly. Hope this helps

[Mikyg]

Started the floor today ready to lift into place when the concretes set.

[Mikyg]

Has anybody had experience with these roofing sheets? Looking into putting these on the obsy.

[Astronut1982]

Hi there,

That's a great obsy you'll have once it's finished.

I was looking through your thread for your build & spotted your drawing for the pier. I wanted to do the same when I built mine [ie. put the pipe all the way down & keep it separate] but I was told by several people on here [Can't find the thread to link to] who had already build piers that this was a bad idea & that the concrete should be all one block. The pipe should only come down to ground level & that you should put steel reinforced bar in through the pipe & almost all the way down through the concrete to strengthen it.

If you do it that way, you won't have much problem with vibration. As an extreme test, I set up my scope & started guiding. Once this was running, I took a long run at it & kicked the pier with all I had & the mount barely moved, there was a little egg shape on the stars but nowhere near what you would expect. A metric ton of concrete was massive overkill for the mount & was probably unnecessary as I have now realised. I also put about 30mm of building expansion foam between the concrete & the ground for the slabbing to go on just to be extra certain of killing vibration.

I'm not saying you shouldn't use a metric ton, only that you should realise that a metric ton is massive overkill so you won't need to worry very much about vibration & that having the pipe all the way down adds to vibration as because they are separate, there is room for movement.

Cheers,

Jeff

[Mikyg]

Hi there,

That's a great obsy you'll have once it's finished.

I was looking through your thread for your build & spotted your drawing for the pier. I wanted to do the same when I built mine [ie. put the pipe all the way down & keep it separate] but I was told by several people on here [Can't find the thread to link to] who had already build piers that this was a bad idea & that the concrete should be all one block. The pipe should only come down to ground level & that you should put steel reinforced bar in through the pipe & almost all the way down through the concrete to strengthen it.

If you do it that way, you won't have much problem with vibration. As an extreme test, I set up my scope & started guiding. Once this was running, I took a long run at it & kicked the pier with all I had & the mount barely moved, there was a little egg shape on the stars but nowhere near what you would expect. A metric ton of concrete was massive overkill for the mount & was probably unnecessary as I have now realised. I also put about 30mm of building expansion foam between the concrete & the ground for the slabbing to go on just to be extra certain of killing vibration.

I'm not saying you shouldn't use a metric ton, only that you should realise that a metric ton is massive overkill so you won't need to worry very much about vibration & that having the pipe all the way down adds to vibration as because they are separate, there is room for movement.

Cheers,

Jeff

Hey jeff, thanks for that. So would u say to only do the pipe half way through the concrete and not all the way through into the clay?? I got told on here somewhere to make sure i keep the pier concrete block separate from the base of the shed to limit vibrations. Thanks for checking out the thread

[Mikyg]

[Astronut1982]

I've attached a pic of what I was advised to do & what I have. Make sure though, when you put the rebar in that you leave room for the pier top bolts & at the bottom to stop the bar from rusting quicker by touching moist soil underneath.

As I said, my pier is absolutely rock solid & held my old 10" quattro on the NEQ6 with ease in fairly strong winds.

Jeff

[kalasinman]

If you don't want the rebar touching soil: lay a piece of sheet black plastic in the bottom of the hole, set them on a couple of stones or cinder block, pavers, etc.

[Mikyg]

I've attached a pic of what I was advised to do & what I have. Make sure though, when you put the rebar in that you leave room for the pier top bolts & at the bottom to stop the bar from rusting quicker by touching moist soil underneath.

As I said, my pier is absolutely rock solid & held my old 10" quattro on the NEQ6 with ease in fairly strong winds.

Jeff

Thanks alot for that, i never thought of the steel rods decaying but that would be a big problem so i think ill be best just setting in concrete like u say.