Starting my obsy

[Dave_D]

So, the missus has decided that getting the obsy done is now one of the priorities (she's good like that). Anyway, we recently had the back concreted which is at least 5 inches thick. Would bolting down a metal pier be advisable? Although obviously preferable, I don't really want to cut a hole in the concrete to make a massive foundation block. There will be an AZ EQ6 Pro carrying a 10" newt.

 

[Budgie1]

What's the plan for the obsy, are you going to be walking on the concrete or will there be a raised floor?

You could try putting a washing up bowl of water on the concrete and walk around it to see if there are any ripples created. A bit crude but it may give you an idea if there's likely to be any movement or vibration.

The other alternative is to bolt down the pier, stick the mount on it and give it a go, before building the obsy. If it doesn't work then you'll be digging out the holes you made for the bolts anyway. 😉

[Franklin]

1 hour ago, Dave_D said:

I don't really want to cut a hole in the concrete to make a massive foundation block. There will be an AZ EQ6 Pro carrying a 10" newt.

I would, an EQ6 with a 10" newt aboard is a lot of weight to be bolted into 5" of concrete plus you don't know how strong the mix is that was used to pour the printed concrete area. I'm sure there will be others who can advise on the physics behind it.

[tooth_dr]

I installed two piers inside a shed - one is installed on a large cube on concrete, the other on the floor itself, similar to your situation, about 5” deep.  Both feel solid.  I haven’t tested the one bolted to the 5” floor yet for Imaging, but it definitely isn’t going to fall over.  I used M12 x 100mm thunderbolts.  If you have the facility to place these yourself, drill a test hole, place a bolt and try to pull it out. 

[tooth_dr]

Also you could give the guys who placed the concrete a call and ask what strength they used.

[Cleetus]

What about a metal pier on wheels with brakes. No digging required.

[Stuart1971]

If that printed concrete is the same as ours then it’s bonded with fibres too, which makes it even stronger, there is no problem at all bolting a pier to that, it’s not going anywhere….

[Dave_D]

4 hours ago, Stuart1971 said:

If that printed concrete is the same as ours then it’s bonded with fibres too, which makes it even stronger, there is no problem at all bolting a pier to that, it’s not going anywhere….

almost 100% sure they said it was fibre bonded... 

[Stuart1971]

We had the London Blue cobble pattern…

 

Edited November 15, 2023 by Stuart1971

[tooth_dr]

5 minutes ago, Stuart1971 said:

We had the London Blue cobble pattern…

 

That looks really good Stuart. 

[Stuart1971]

10 minutes ago, tooth_dr said:

That looks really good Stuart. 

Thanks, but I guess I went a bit off topic…😂

Edited November 15, 2023 by Stuart1971