36" Pompeii in St Louis

[plastered]

Some progress this weekend. I understand the tapered inner arch but it's starting to give me a little trouble so I'm going to spend the day messing with it. I need to make a more firm pencil holder on my IT so that my lines are consistent. I've looked at so many pictures on here of the tapered arch and it makes sense, I just can't tell if I need to bevel my cuts or not.

Also starting to do some grinding to combat the inverted v's.

Learning about the hidden cost in mortar ($90 for a 50lb bag)

[UtahBeehiver]

You will be happier not having to adjust (at least as much) the IT. It does help to check the IT periodically to make sure nothing has loosen up or changed.

[Kvanbael]

This is so much simpler indeed. No more need to adjust. I also have my dome center flush with the floor. Just make sure the wooden tool can handle some light beating with the mallet.

[plastered]

I got rid of the caster and am just using a couple eye bolts and hardware. I feel better about this design as the center point is more center (vertically and horizontally), also a tad closer to the oven floor.

[plastered]

UtahBeehiver I think I understand now, how a little bit of either vertical or horizontal offset accumulates. I spent some time in solidworks understanding this. I guess to combat this, for each course I should measure from true center to make sure I maintain the 18" radius, and adjust my IT as I go? I know I've seen a sketch like this before, but now I understand.

(Origin is blue dot, 36" diameter circle, I drew a triangle to simulate the caster shape, arbitrarily offsetting it by 0.66" in the vertical (from floor) and 0.75" from the true center. You can see the 18" IT radius go off course)

[UtahBeehiver]

Let me make a stab verbally, the vertical pivot point should be at the center of the dome at floor elevation. At floor elevation, the ID of the oven for example, if 36", then at floor level, the oven radius is 18" but as you move up in courses and eventually to the top, the oven radius changes to 18" plus what distance of the pivot point off the floor. The height difference in itself is not an efficiency issue but it does affect how the dome ties into the tapered arch. The tapered arch is fixed and unchanging vs the IT pivot point changes with each course. So you can use the current set up but you need to adjust the length of the IT so the domes ties into the tapered arch efficiently.

[plastered]

UtahBeehiver -- I did make it adjustable (hard to see in that pic) because of all the other posts that you suggest to do this . Definitely doing a tapered inner arch too per your recommendations on every thread. When you say offset, is there a visual representation you can show me. In my brain, if the dome is a perfect half sphere, this IT would be fine. Or are you saying in general, any minor offset (from the floor, or in the tool itself) will manifest itself up the dome?

[UtahBeehiver]

The offset both horizontal and vertical will affect the dome dimensions as you move up. In addition, if you are doing a tapered inner arch (which I recommend) the same offsets will affect how the dome ties into the arch. It is doable but you will have to adjust the lengths as you move up in courses. From what I can see the IT does not look adjustable.

[plastered]

Does my IT make sense? Red is origin, yellow lines show that the origin should sit right at the floor (a little offset of the caster). The important thing is that this yellow radius line extends from the origin to exactly halfway up a brick, perpendicular to its surface, right?

[plastered]

Thanks GreenViews for reminding me to leave a lip for the door. I was planning on doing that but I completely forgot how I was going to do it. For the heat break, maybe I'll work something in but I wasn't really planning on incorporating anything like that.

[GreenViews]

I'm wondering if you planned for a door reveal just outside the inner arch so you can close your dome with a door so heat can't get out the chimney? Also, I'm not seeing a heat break at the place of your door. Both of these you can do without, but will not as efficiently hold heat well for cooking after pizza making or retaining heat overnight. Some people just have a small gap just outside their inner arch where the door closes off the dome. You can look up other's designs if you have questions. If the floor is all done, you could perhaps still make a saw cut if you decide you want to. Just a thought.

[plastered]

A length of electrical conduit works pretty well because you can bend it in the middl, which shortens it a bit allowing easy removal from the brick it supports.

I like the idea, I take it you mean the PVC conduit? For a second I thought you meant the galvanized kind and I was like how the heck do you bend that!

[david s]

A length of electrical conduit works pretty well because you can bend it in the middl, which shortens it a bit allowing easy removal from the brick it supports.

[plastered]

Chobbs I'm building mine as we speak -- I just grabbed a caster, a wooden dowel, and a little metal 90 deg angle. I may 'upgrade' to a better one if my 10 dollar one fails me.

[Chobbs]

Looking great! I will be starting my build soon so watching yours with eagerness!

Which IT did you go for?