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-   -   32" Pompeii in Sketchup (http://www.fornobravo.com/forum/f8/32-pompeii-sketchup-6705.html)

arriflex 05-03-2009 11:17 PM

32" Pompeii in Sketchup
 
3 Attachment(s)
Trying to work out some details in sketchup for a 32" build. (Space is limited, and I really don't need any bigger than that)
From the initial rough model, I am finding that about the last four chains below the plug are best served with compound cuts... How anal does one really have to get, or is it just about offsetting the cost of the mortar? A few of you guys have set the bar awfully high lately...

Attached view is from the bottom, looking straight up at the dome. I've also attached a sketchup model, which is a mess as yet.

Opinions please.

ross 05-04-2009 12:44 AM

Re: 32" Pompeii in Sketchup
 
Hi

I Built a smaller 31 ins in England..which Ive finished and used prob 10 or so times..Its very quick to heat and holds it great...Had a party 4 weeks agao and kept it at over 700 for 5 hours
http://www.fornobravo.com/forum/memb...-my-build.html

Id stay away from subing mortor for brick as..this will be weak spots for the heat..the more firebrick in the dome to hold and reflect heat the better the oven will work...

RE:the last 4 chains id try to keep them as buffed together as poss...
I started my first layers of the dome with half bricks ad I got higher I cut them down and then angled them to get a tighter fit using a small hand grinder and lots of abrasive rings ( you can see in my build pics of the inside dome the angles)..its wasnt any harder to do just a little time consuming..the last ring of brick was only a quarter size and I alternatly angled each size so they fitted together realtight...each angle was slightly different..even the keystome worked out well, cut routhly down then ground down into a cone ..this plugged in perfect..

The hardest part of the build with a smaller oven it to make sure the dome is the same all the way round ..I suggest cardboard or thin styrofoam...the bricks can be angled easily against it and it doesnt hold any weight as the dome if built right will support itself...I knocked mine out before the final ring.

hope this helps

dmun 05-04-2009 04:54 AM

Re: 32" Pompeii in Sketchup
 
Lots of builders just mortar in half bricks at the top of the dome, with big mortar gaps. This plan looks rough but works fine. But judging from your sketchup work, you may want to go for a higher standard. Many builders just trim angle slips from the visible side of the brick to get them to fit, and fill the invisible back with mortar.

Good luck with your project, keep us posted

arriflex 05-04-2009 08:24 AM

Re: 32" Pompeii in Sketchup
 
Another question: I have access to large firebrick (18" square or so) that I was considering using to make a large plug with. This would, however, make for a larger flat area in the top of the dome. In some ways I can see this being an advantage, but I am concerned about modifying the energy focus in the oven. I'll test it in sketchup when I get a chance, as well as compound cuts on the chains and share them here.

Sure wish it was as easy to build one of these in the real world as it is in a computer! It would probably be a lot easier if I could just use my woodworking compound miter saw with a wet blade on it.

arriflex 05-04-2009 12:10 PM

Re: 32" Pompeii in Sketchup
 
4 Attachment(s)
You're right on about looking a lot better with tighter joints from the inside. I played with the ratio of brick waste to mortar usage and like this one as a good compromise. I also went ahead and applied minimal compound cuts to the first few courses as they seemed like a good opportunity to practice cutting during construction. The compounds really aren't as hard as I thought they might be (in sketchup), probably build a set of jigs for the real life cutting.

The version with a single large (about 16" diameter) plug is interesting, probably doesn't actually save any work. Probably doesn't add any real value to the energy distribution either, but does lower the highest point by about 1 1/4 inches. One would presumably add a layer of bricks above it to gain mass there; otherwise it would only be 2.5" thick.

The sketchup file still has lot's of things not finished about it, that's why they call it 'sketching':rolleyes:

arriflex 05-04-2009 02:46 PM

Re: 32" Pompeii in Sketchup
 
2 Attachment(s)
Sorry about flooding the forum here, I won't generally be productive...

I tried a different arch approach, and like this better... bummer I can't upload zip files larger than 100k to attach the sketchup file.

asudavew 05-04-2009 03:37 PM

Re: 32" Pompeii in Sketchup
 
Thirds work fine in the later courses.
I had no way to make compound cuts.

Go for it!

DrakeRemoray 05-04-2009 03:39 PM

Re: 32" Pompeii in Sketchup
 
All that modeling at least helps you think it through. If you are handy with woodwork, you might consider forming and casting a vent. Better smoke collection = less smoke stain on the front of your oven.

arriflex 05-04-2009 03:51 PM

Re: 32" Pompeii in Sketchup
 
What factors most affect 'smoke collection' and how? The fluid dynamics of hot gas are not something with which I am familiar... I have read that one can have too large a chimney just as easily as too small of one.

I'd be happy to cast a vent having cast my kitchen countertops twice before I got it right... I just need a design target.

Alternatively, why have a chimney and that extra depth in front of the opening at all if one doesn't care about the smoke stain?

Dino_Pizza 05-04-2009 10:07 PM

Re: 32" Pompeii in Sketchup
 
Thanks for sharing your Sketchup pics. They are really helpful. You're very good at it. I used half bricks thru ring 9, then found in 10, I had trimmed the sides so much, I just went to 1/4 cuts and the V's almost disappeared.

However, your oven is 32", smaller in diameter than my 42" so your "V's" will be larger early on in the rings. I found that the narrower the brick (1/4 brick or less) I wouldn't have to tapper the sides in every brick because the inverted "V" was so small. You'll use these smaller bricks for keeping your joints staggered. I also did "half-ass-tapered-cuts", mostly by mistake but found that tilting the bricks 'in' on the wet-saw with just a slight tilt up, even if I measured wrong and the saw cut did not go all the way thru to the back of the brick still eliminated the V inside the dome, but I still had it on the outside of the dome where it matters much less.

I won't even touch the thought of eliminating the vent BUT if you want the most efficient vent for the space, I agree with DrakeRemoray and cast yourself one with a well tappered shape, even if the vent entry area is less than what you commonly see on this forum. An opening that smoothly transitions to an 8" vent pipe is ideal.

What is your surface dimension of your oven base again? Thanks for posting those great drawings and generating good questions. I look forward to you build, Take care, Dino


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