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Part 6 - Cooling tray
Alchemist
Top  #51 Print Post
Posted on 04/17/2008 6:12 PM
OK, I know - long time no action. Life got away from me.

Materials: I know you were waiting on me. I have to do some area calcs still, and will, but for the moment, start looking for some mild steel or aluminum. I don't care which. Food safe and "soft" is the key. Gauge - I check out a whole bunch and with as soft as mild or Al is, you have a very open window. Anything from 20-26 should work. 22-24 would be a tighter range if you want it. See what you find price vs amount wise.

Let me know what you find. Are you going to get it local or metalsexpress? I will get some amounts for you.
 
David
Top  #52 Print Post
Posted on 04/18/2008 12:19 AM
Welcome back, sir.
--
I will probably order the metal online.
I'll start pricing this weekend.
 
Alchemist
Top  #53 Print Post
Posted on 04/22/2008 5:46 PM
OK, I am not going to list out the piece by piece addition, but I wanted to get you some parameters to buy materials for. In general, it is the interior walls, bottom and chaff tray. Leaving your Stainless for the outside.

That said, look for aluminum or mild steel. Food safe basically. No galvanized. Technically we could use it in some of the bottom and interior, but I am trying to keep it simple. Look for 22-26 gauge. Kind of a wide range, but we can work with what you find. If you find 24, that is probably a safe better.

We want about (and I stress about) 24 square feet. Minimum 2 feet wide. You can go from there. 4 2' x 3' would work. 2 4' x 3' would work. One 8' x 3' would be ok. We will cut it up. Mostly keep it in 1' increments and we will be fine. I have padded the number there so we should have extra.

Questions? With that in hand, plus a little more angle aluminum we can start the cooler, as far as metal goes.
 
David
Top  #54 Print Post
Posted on 04/23/2008 9:02 AM
Roger that. I'll get on it right away.
 
Alchemist
Top  #55 Print Post
Posted on 05/13/2008 4:06 PM
Ok David, and folks. Getting very close to the first steps. With that in mind, I want to lay out what my plan is in verbal terms with a few approximate number. Basically lecture time. The real "how I do it" and why I say building this pup isn't going to be hard. It just takes time and thought, but no rocket science. Of course, more detailed info will follow. So, this is what has been going on in my head.

We have a roaster. The drum is about 8" in diameter. Lessons learned make me want a 2" clearance around drum. Then I want 2" insulation. 8+2*2+2*2 = 16" wide. I want the cooling try the same for aesthetic purposes. We are going to make the front curve around matching the curve of the cooling try and the back will square up to the roaster. That gives up base dimensions left to right and front to back, i.e. 16". Top to bottom. The tray is 3-4" (to lazy to look it up right now). The motor in question is 4" back to tip. 7-8" there. I again want some breathing room, so 10" high.

Construction: We are going to have an aluminum angle support and cover it with sheet metal. What we get here is a strong, light frame, reinforced by the rigidity of the sheet metal. The recurring theme in forming this roaster will be using some wooden jigs to attach parts to as a guide and for leverage. I wanted to stay away from a break for simplicity sake and approachability. Briefly, we will make a wooden form out of 2x4 and plywood in the shape of the part in question, minus appropriate material dimensions (16" - 1/8" - 1/8" = 15.75" for instance assuming 1/8" angle aluminum. In my mind's eye we will assemble the rough shape in 2x4's, mount the plywood, layout the exact shape and cut it all at once, no muss, no fuss.

The angle aluminum will be notched (see photos somewhere else), mounting and attachment holes pre-drilled (since it will weaken post notching but pre-assembly) and it will be mounted on one end to the jib. With leverage being our friend, and aluminum being soft, we will bend the frame around. Then we repeat with the sheet metal. Remove it from the jib and assemble.

A few notes on this part. I want a support under the cooling try "just in case" and we will need something to mount the stirring motor on. More angle aluminum notched, cut and attached, probably with a small sheet metal piece for support again. The frame I think I want to rivet together and I want self tapping sheet metal screws for the sheet metal attachment. We can decide if we want flush or raise screws for aesthetic purposes (your thoughts?).

The blower we will keep simple. Cut a hole, shove it through, and hold in place with something simple like pipe support. The final thing I want is to tape with aluminum tape all the interior seams for air tightness, just so the air goes right where we want it and no where else.

Ok, that is the basic road map for the cooler and the rough one for the whole roaster. What do you think? How far could you go just from those thoughts in place? Part of this section is to work out how we are going to really communicate construction procedures. What would be easy in person is fussy on line.

Your thoughts please.
 
David
Top  #56 Print Post
Posted on 05/15/2008 5:18 PM
The metal that I ordered has arrived. s:2
I will check it out for workability this weekend.

I understand what you have said above and can picture the roaster in my mind.
I'll be ready to start cutting and bending as soon as you are able to put up the drawings of the specific jigs and templates.
 
Alchemist
Top  #57 Print Post
Posted on 05/19/2008 1:17 PM
So, how is the workability. Did you/me/we guess correctly? The other thing I remembered (again) about specifying the materials was brought home when you mentioned how heavy the metal was, package wise, all in one place. That was one of my complaints about my Zen I - it was too heavy, although no one piece was that heavy. THAT was one of the reasons I was pushing so hard about 24-26 gauge metal and had some reservations about the free stainless you got - purely the weight of the final roaster.

But, at this moment, we have what we have, and we'll see how it works.

I am very glad you can picture the roaster in your mind. That is a great first step because if you can't see it, it is really hard to build it.
 
David
Top  #58 Print Post
Posted on 05/24/2008 2:09 PM
I opened up the package of metal. It does seem quite workable with hand tools. Grin

I see what you mean about weight, however. The next time we do this, I'll vote for lighter even if it means hunting around some more. c:1
 
David
Top  #59 Print Post
Posted on 06/22/2008 7:09 PM
From Alchemist's sketch I marked off the cuts on a 72" piece of 1/8th inch angle aluminum.

Actually, I decided to do two pieces in tandem, so I screwed them down to a spare piece of 2x4.
David attached the following image:
comp01z02z[978].jpg
 
David
Top  #60 Print Post
Posted on 06/22/2008 7:10 PM
After the cuts.
David attached the following image:
03z[979].jpg
 
David
Top  #61 Print Post
Posted on 06/22/2008 7:11 PM
There was 16" left over on each long piece.
So, I cut them in half, giving me the four 8" vertical pieces for the frame.
David attached the following image:
04z[980].jpg
 
David
Top  #62 Print Post
Posted on 06/22/2008 7:12 PM
I drilled some more holes and attached the two pieces to the board at the 8-inch mark, securing it to the board at the point of the first bend..
David attached the following image:
05z[981].jpg
 
David
Top  #63 Print Post
Posted on 06/22/2008 7:13 PM
This allowed me to gently bend the two pieces upwards...
David attached the following image:
06z[982].jpg
 
David
Top  #64 Print Post
Posted on 06/22/2008 7:15 PM
and around
David attached the following image:
07z[983].jpg
 
David
Top  #65 Print Post
Posted on 06/22/2008 7:16 PM
into a semi-circle.
David attached the following image:
08z[984].jpg
 
David
Top  #66 Print Post
Posted on 06/22/2008 7:22 PM
It was tempting to just press down on the remaining 16 tail, but it was too unstable.
I flipped the two pieces upside down and switched the four screws to the opposite end, so I could bend the 16' pieces upward from the board.

Then it got dark and the rains came.

The next step will be to bring the open ends together by attaching them to the vertical braces.
David attached the following image:
09z[986].jpg
 
Alchemist
Top  #67 Print Post
Posted on 06/25/2008 6:49 AM
Wow. Just wow. So how did that go? It looks just fine. A little different than I would have bent it, but attaching it to the board the the exact right in lieu of bending it around a form.

I have to say seeing the drawing go to material is cool. Exact.

OK, now that I have finished crooning over a couple pieces of metal I will try and get re-inspired (maybe the wrong word there - I just have so many irons in the fire right now) and get some the remaining drawings set for this cooler.

GREAT JOB! That curve is perfect. Break - we don't need no stickin' break!
 
David
Top  #68 Print Post
Posted on 06/25/2008 9:44 AM
I'm glad you liked it. I was afraid that I might have missed something important in the bending, perhaps making the square corners squarer somehow.

I used a hacksaw to do the corner notches. I mentally re-invented the miter box a couple of times, before remembering that I had two of them already. I wish I had used one. I had to do a lot of filing and grinding to get the corners to fit.

Also, the hacksaw cuts were just too thin along the curved part.
I was faced with the prospect doing 25 (or even 50) more hacksaw cuts,
but my shoulder protested. :(

Confession: I moved up to using a cutting wheel. s:3
I know, I know, that's not organic; but the width seemed to come out just right, as illustrated. c:1
 
Alchemist
Top  #69 Print Post
Posted on 06/25/2008 12:52 PM
No harm with the cutting wheel. When I tested this out (but you didn't know it) I used my jig saw and flipped the angle over, onto a piece of 2 x 4. Made a cut in the wood (for the blade) and just cut the metal that way. Cut, remove the blade from the metal (left in the wood), move the metal to the next line, cut again. Very fast.

As for bending, not exactly what I meant, but in this case it worked, and it is getting us moving. For the outside sheet metal we will make a wooden frame/jig, attach the metal to one end (like you did here - THAT was perfect) and bend it around so we get the curve right.

And there is a very particular way I want to walk you through for aligning and drilling the construction holes - so no more there until I catch up smile
 
Alchemist
Top  #70 Print Post
Posted on 06/26/2008 7:22 AM
Good start first and foremost.

But I noticed a handful of items I need you to check and we need to account for. This is really pretty good as it shows just what I go through during the design.

First off, it looks like you used 1" angle aluminum. That in itself is fine but that drawing you took your numbers from was before we had found the cooling tray we wanted and accounted for it's diameter. Note the blue supports - they were assuming a smaller tray we needed to support . At the upper edge, you report a diameter of 14 3/8" iirc for the tray. If those things are both true, I am going to look into my crystal ball and predict that the cooling tray is not going to fit in.

16" - (1" * 2) = 14" available space. Can you check that for me and let me know?

If that is the case, this was a great dry run, but that upper frame support (the lower is cool as it will not touch the cooling tray and the OD is the same) may need to be remade from 3/4" stock. And even that will be tight, but so long as it fits, it is ok. Please verify that tray diameter.

Next - minor but important. You drilled holes to attach the metal to the board so you could cut and bend it. That in itself is great but thinking ahead, what size are those holes? More importantly, are they small enough to accept rivets to assemble the frame? Do you have rivets around you can check that?

Finally, you cut 8" risers for the tray, but I don't think I ever set that number in stone. I tossed together the following drawing (often how I design) and whereas 8" just might fit everything in, some extra space there would be better. Do you have any gut feeling or preference for 10 or 12"? I am leaning toward 12" but again want to check that against the roaster area and assure myself that is plenty of room. This is experience talking from the Zen I where I cut the dimensions just a little close and really disliked it. I rather have more than less room.
Alchemist attached the following image:
CTframe[988].jpg
 
Alchemist
Top  #71 Print Post
Posted on 06/26/2008 11:09 AM
I was thinking about the top of the cooler (what the cooling tray would touch) and I noticed the edges would be quite narrow (3/4") in the front. I wonder what you would think about the top of that being wood? Odd I know, but it would be easy to cut, could be stained or oiled nicely and will be in a cool area so fire shouldn't be any concern.

Your thoughts?
Edited by Alchemist on 06/26/2008 11:10 AM
 
Alchemist
Top  #72 Print Post
Posted on 06/27/2008 7:12 AM
While trying to workout how much space we need for the cooler, I realized I didn't have a good set of dimensions for the blower we will use for the cooler. As you set it up in your test, can you give me the cubic dimensions (i.e. maximum height, length and width or the size box that would be needed to fit it inside).
 
David
Top  #73 Print Post
Posted on 06/27/2008 8:34 AM

Quote

I am going to look into my crystal ball and predict that the cooling tray is not going to fit in. 16" - (1" * 2) = 14" available space. Can you check that for me and let me know?


Your crystal ball is correct: Shock
with the 1" angle aluminum, the 14" cheesecake pan does NOT fit. :@

I'll scope out some 3/4" stock.
 
Alchemist
Top  #74 Print Post
Posted on 06/27/2008 12:27 PM
I hate being right some days B)

Before you go cut the 3/4", do confirm the diameter of the cooling tray.

And also, I really appreciate you getting us moving on this again, but, (isn't there always a but) keep in mind the this 'danger'. When I build on my own, I have 100% of the design finished, detailed, drawn, etc, before I make a cut because too many times you design a piece, are sure it will work, and then find out it won't or you can find another component part (that you had planned but not verified) and so you have to change the design. Just like here really. We talked about a smaller tray, but the 14" one was the best fit so the design (3/4" angle vs 1") has to be slightly adjusted to accommodate it.

That isn't to say don't do this again - just keep it in mind with design work.
 
David
Top  #75 Print Post
Posted on 06/30/2008 1:22 PM

Quote

You drilled holes to attach the metal to the board so you could cut and bend it. That in itself is great but thinking ahead, what size are those holes? More importantly, are they small enough to accept rivets to assemble the frame? Do you have rivets around you can check that?



The holes are actually smaller than the pop rivets, so there is some margin to work with.

Quote

Finally, you cut 8" risers for the tray, but I don't think I ever set that number in stone. I tossed together the following drawing (often how I design) and whereas 8" just might fit everything in, some extra space there would be better. Do you have any gut feeling or preference for 10 or 12"? I am leaning toward 12" but again want to check that against the roaster area and assure myself that is plenty of room.


I'm fine with either, it just makes the entire roaster taller.
As long as it's not much h-e-a-v-i-e-r, I'm OK with it.
David attached the following image:
(fix it)[993].gif
 
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