Math Midget

[130mountainside]

I am at row 5 and the process I am using to cut the taper and radius ain't 'cutting' it. I understand the string jig. I mark the brick with a string starting from the center of the oven floor to mark the radius cut, however, how in the world is the taper/angel cut measured?? (To avoid confusion, I am referring to the change in the vertical cut that is done tilting the brick). I know this brick should end up looking (front view) like a trapeziod, however, I am doig it by Trail and error- mostly error. I have studied Hondo's cutting tool, however, this slow mind just cannot wrap istelf around how to measure and trasnlate the compound cut. What is everyone doing?

HELP...Thanks. This forum has been very helpful.

[Les]

Re: Math Midget

I had an idea, but we are dealing with brick. Trial and error worked for me. Granted, some cut's required 2 or three trips up the stool to check for fit. After a couple of brick, you will get a pretty good idea on the size of the shim you need to use to get the correct angle. On the upside, your legs are going to be in great shape.

Les...

[130mountainside]

Re: Math Midget

Les,

I presume once you 'dial't in you set up the remaining bricks to the same cut? I am trying to make life easy with a jig....

[Les]

Re: Math Midget

I tried to do that with a template and a shim. It looked good on paper, but the plan fell apart. To stay on bond, the cuts will get about 5/8 inch thick at the top - extremely hard to do by hand. If I had it to do over again, I really believe I could get closer - or buy the kit

Les...

[eprante]

Re: Math Midget

130Mountainside,
Check out the build thread Geisen. He detailed a very simple way to cut the trapezoid shape bricks for the courses using some wedges and door shims from HD. I used his system and was able to adapt it as the angles changed as I got more vertical( thought the last 2 rings got away from me a little). Good luck.
Eric

[fxpose]

Re: Math Midget

To minimize exposed mortar in the chamber, I plan on experimenting by making a sharper compound cut only on just one side of each brick, instead of cutting a trapezoid shape.
I can see this working in my head.

[Neil2]

Re: Math Midget

That's what I did - just cut / bevel one side. Once you get going you will get the hang of judging how much bevel to slice off. This will change slightly with each row if you are doing a semi-elliptical dome.

[GianniFocaccia]

Re: Math Midget

Wow...what a concept. According to Les, a 5/8" bevel on each side of the brick (depending on the course) would suggest a noticeable non-vertical joint.

The mating of beveled-sides and non-beveled sides match up ok?

The immediate benefit I can see with this approach is fewer cuts not to mention that one larger cut should be more accurate than two smaller cuts.

[fxpose]

Re: Math Midget

The mating of beveled-sides and non-beveled sides match up ok?

Well, yes and no. As the 2 bricks are angled towards you as you look straight at them, then yes, they appeared to line up. But there was a slight offset where the beveled cut and non-beveled cut meet, at the bottom. When I saw this, I scrapped the idea and went with the trapezoid.

George

[Les]

Re: Math Midget

Wow...what a concept. According to Les, a 5/8" bevel on each side of the brick

No - what I meant was that at the top of the dome, the bricks will be around 5/8 in wide to stay off bond (the bricks will get thinner and thinner as you climb). The angle cuts on each side of the brick was around 3/16 of an inch.

Sorry for any confusion.

Les...

[SCChris]

Re: Math Midget

Mountainside,

Take a look at the jig I built in "my brick cutting tool" "http://www.fornobravo.com/forum/f28/my-brick-cutting-tool-12478.html". I think you could make a bunch of throw away jigs by cutting wood blocks to mirror the front to back course angle and add a bit of plywood for stability. You'd still have to set the course radius by estimation or building an extension to the rolling cutting bed and wood block jig.

As I've said before, people understand things in different ways, brain wiring etc.. I hope this helps..

Chris

[GianniFocaccia]

Re: Math Midget

Les,
Duh! Confusion was all mine. With the top-of-the-dome bricks being so small, would you consider pre-building a keystone 'plug' on the workbench and drop it in?

John

[130mountainside]

Re: Math Midget

Thanks, yes, as you get higher, the cuts get ridiculous. My circle shape is far from it- more oval- so the consistency of the cuts becomes irrelevant and I needed to custom cut evey brick- nightmare. Just glad this is the last row before putting in the Keystone. Les, did you even cut the faces of your bricks?

[Les]

Re: Math Midget

Les, did you even cut the faces of your bricks?

I first cut every brick in half. The cut surface is exposed to the inside of the oven. It just looked cleaner to go that route because the outside edges of my brick were "ugly".

Les...

[fxpose]

Re: Math Midget

I layed 19 wedges on my last course this afternoon and almost every wedge had varying trapezoid angles.....anywhere from 4 to 10 degrees on my compound miter saw and it was a pain in the butt going back and forth, cutting a degree or two either on one side or both sides of each wedge.
Now I'm left with a nice round 6.5" diameter dometop opening. I don't want to add any additional height to the dome so I will cap this opening with 3 fitted pieces which will fit flat across the top.

George