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Re: First Build - Octagon pit

Posted: Mon Jun 15, 2020 2:42 pm
by k.a.m.
I like the exhaust very nice work. I would reduce the horizontal part as much as I can and still weld out.

Re: First Build - Octagon pit

Posted: Mon Jun 15, 2020 3:08 pm
by AG.AUS
Thanks kam.

Aiming to trim it down to about 1” horizontal out of the cool chamber..

I’m debating in my mind whether to design it so it can be reverse flow too (movable chimney / chimney ports, to each end and enough tuning plates to enact it)

Don’t know if it is worth the extra time.. / likely to be used that often... ([mention]k.a.m. [/mention] what’s your preference with your hybrid cooker?)

A


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Re: First Build - Octagon pit

Posted: Mon Jun 15, 2020 4:15 pm
by k.a.m.
AG.AUS wrote:Thanks kam.

Aiming to trim it down to about 1” horizontal out of the cool chamber..

I’m debating in my mind whether to design it so it can be reverse flow too (movable chimney / chimney ports, to each end and enough tuning plates to enact it)

Don’t know if it is worth the extra time.. / likely to be used that often... ([mention]k.a.m. [/mention] what’s your preference with your hybrid cooker?)

A


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Straight cooker with tuning plates is my preference.
I built the Hybrid because I had an idea I wanted to see come to life but never really used her any other way than the tuning plates.

Re: First Build - Octagon pit

Posted: Mon Jun 15, 2020 7:22 pm
by AG.AUS
[mention]k.a.m. [/mention] , thanks for the advice..
I’ll take that info under my wing, and forget trying a RF setup! (And save me time planning and fabbing up the setup.

Next up for me is awaiting some insulation material to add to my dual skinned firebox..

Then start putting metal together..


Andrew


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Re: First Build - Octagon pit

Posted: Mon Jul 06, 2020 11:59 am
by Weaverspit
Allen's welding on you tube built a similar one ...nice job ..

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 3:37 am
by AG.AUS
Hey all,

Yeah, spotted his channel..
The octagon is somewhat easier to organise than getting a full cylinder.. (not many propane tanks over here in Aus)

Finally got a chance to get a crack at this smoker again.. (few weeks between drinks)

Got onto:

* the main chamber seams welded
* Firebox sized and welded (incl. the big door & air vent)
* Tack welded the main chamber end walls (incl the chimney)
* created a fire grate for the wood/charcoal to sit on
* Welded on the main door, and got it working (with some store bought hinges)

Image

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Mock up of the final look..

Image


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Smoke collector to be finalised. And might change the support to some 45deg pieces instead of just the one..

Next on the list to do:

* add the support strips for the FB dual skin
* install insulation
* buy and install 3mm flat plate for FB (~1/8”) skin
* design some uprights to support FB from the base
* tuning plate supports & angled baffle (to direct smoke down)
* chimney cover/baffle
* main cook grate supports
* weld everything and grind everything.. (you know.. the easy part!! Haha)
* paint and add some gaskets for good measure..

Maybe a few more days in it..

Thanks for reading
*all keep safe in and about the place.

Andrew


Total Hours - 24h
Total Cost $ 900AUD


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Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 6:54 am
by Rambo
looking great keep us posted

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 9:21 am
by k.a.m.
Looking good Sir!!! :salut: :salut: :salut:
If you find you are not geeing enough smoke to your meat because of the low exhaust put an upward deflector on the opening between the firebox and cooking chamber. That will force the heat/smoke up then down like a Jambo pit.

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 9:47 am
by hogaboomer
For some reason I'm feeling skeptical about that choice of smoke stack.

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 10:20 am
by k.a.m.
On your fire grate lay a piece of expanded metal on it to reduce the gap. I have found the ideal gap for bars is about 1/2" to 3/4" max.

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 10:21 am
by k.a.m.
hogaboomer wrote:For some reason I'm feeling skeptical about that choice of smoke stack.

What has you wondering brother?

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 11:05 am
by hogaboomer
Looks too skinny to me, but I guess he'll see if it works when he fires it up. It's certainly not anything that can't be changed, if necessary.

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 2:06 pm
by k.a.m.
hogaboomer wrote:Looks too skinny to me, but I guess he'll see if it works when he fires it up. It's certainly not anything that can't be changed, if necessary.

Not ideal but I think he has the volume needed. Best I can calculate on an octagon anyway lol.

Re: First Build - Octagon pit

Posted: Fri Jul 10, 2020 4:41 pm
by AG.AUS
Hey all,

Thanks for looking...
[mention]hogaboomer [/mention] , [mention]k.a.m. [/mention] ,
I’ve put all the sizes through the calculator, and the smoke stack being 100mm x 50mm (4”x2”) has the same area as a 3” circle (close-ish)

So I put in 2.75 for chimney size.
Used that value to get a stack height of about 28”
If not drawing smoke properly, can trim down to the 23” if I used 3” in the calculator..

* it’s fun converting everything into imperial from metric & sorting the volume from my octagon shape! Haha*


http://feldoncentral.com/bbqcalculator. ... 8.26,26.79

It’s all abit hit and miss with the octagon.. and ultimately I could probably get some actual tube for a chimney if needed...

Re charcoal basket.. hard to find the expanded mesh easily here.. but may buy a purpose built charcoal basket ($70).. it’ll fit in my FB..


Thanks for reading and commenting.. nice to have some more thoughts on this..

Cheers

Andrew


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First Build - Octagon pit

Posted: Fri Jul 10, 2020 5:52 pm
by AG.AUS
[mention]k.a.m. [/mention] ,

Is this the design you are talking about? (Hard to tell on the photo..) but a markup of maybe?
- just screenshot from the Jambo Pit website..

Image



This will then negate the use of tuning plates..

I’ve currently got plans for tuning plates to be used... (the other way, direct smoke down and under the grates)


Ultimately I can easily flip the smoke exhaust over, so I’ll be higher.. (or even nearer the top edge)

Image
- current plan of design..

Image
- Chimney lifted higher.. (with the idea of tuning plates along the bottom)


Andrew


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