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deejayoh 07-26-2012 03:37 PM

Dome spreadsheet calculator
2 Attachment(s)
This may (or may not!) be my contribution to the forum. After quite a bit of futzing and relearning of trigonometry, I have put together an Excel spreadsheet that can calculate most of what you need to build a dome.

User only needs to input the diameter of the dome you want to build, distance of the IT pivot from the floor, and standard brick dimensions - and the spreadsheet will calculate the number of courses, height for each course, bricks per course (ignoring the arch!),the jig settings (assuming a twist and tilt approach), and the length of the IT. It also gives a rough count of bricks that will be needed for the dome.

The only other thing you might want to enter is the width (at the outside) for the bricks in each course. That is builder preference.

Big qualifier is that the spreadsheet assumes that the builder is using a fixed length IT. You want to change the length during the build, I am not able to deal with that one.

Anyway - the entry cells are in orange, all others are calculated.
Attachment 37872

Update as of 8/5/2013: I just uploaded a new version of the calculator that includes angle calculations for both styles of jigs
1) A "chipster" style jig where the brick is tilted inward at an angle from the side as shown in this post
2) A "Hendo" style jig where the brick is tilted in from the back as shown in this post.

IMHO, the first approach is far more straightforward and easier to cut with a 10" brick saw. This is based on my experience going with the second...

Edit:7/31/14: Added a google docs version. Here is the link

Happy Cutting!

UtahBeehiver 07-26-2012 07:01 PM

Re: Dome spreadsheet calculator

Very impressive work. What I had thought was a good idea you turned into reality. This will really help the next generation of builders. I wish it had been available when I started. I plug in some numbers from my build and found your spread sheet matched for the most part since I had some variables that skewed a perfect build. Congrats on a contribution well done..............

bluecrow 07-26-2012 08:00 PM

Re: Dome spreadsheet calculator
There is too much lightning for me to measure presently, but the calculations based on my 36" diameter Pompeii oven and IT specs are really close. I am working on course 6. I'll measure carefully tomorrow.

Thanks! Don

Bacterium 07-27-2012 12:08 AM

Re: Dome spreadsheet calculator
Thanks Deejayoh....... I'm still to get my base finished before I get to dome but have tried out your spreadsheet

Grunt44 07-30-2012 07:50 PM

Re: Dome spreadsheet calculator
Can you check the zip file , tried to open , comes up with invalid or corrupted
Best Grant

Bacterium 07-31-2012 12:01 AM

Re: Dome spreadsheet calculator
Worked ok on my smartphone

videts38 07-31-2012 04:22 AM

Re: Dome spreadsheet calculator
I'd really like to see the spread sheet but I also could not unzip, I also error out with invalid or corrupted.

Spinal 07-31-2012 10:24 AM

Re: Dome spreadsheet calculator
Works here (excel 2003)

videts38 07-31-2012 10:55 AM

Re: Dome spreadsheet calculator
Got it!, I just don't have the latest version of Excel, I had to download a Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats.

Download: Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats - Microsoft Download Center - Download Details

Once I did this everything was fine.
Thanks for the work put in on this spread sheet it will help tremendously when I get started on the dome!!:D

Tomweb 08-23-2012 10:08 AM

Re: Dome spreadsheet calculator
Deejayoh and all,

Thank you all for your input and participation in this forum. As a newbie,
( hoping to begin construction in the next few weeks...) there's a wealth of resources, talent and encouragement here...

Regarding hearth base placement within the dome, FB instructions note two options: One method places dome over hearth base, another suggests having dome surround the firebricks.

If one were to choose to place the bricks 'inside' the dome perimeter, how do you cut the slight radius required for each brick?? ( or is it a matter of scoring and chiseling...)

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