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Part 6 - Cooling tray
Alchemist
Top  #76 Print Post
Posted on 07/03/2008 1:28 PM
Of course it will be some heavier, but not that much more. A little extra aluminum angle and the skin.

OK, since you have me moving again, I submit the following for you to wrap your head around. It is the support system for the stirring motor.

So you know what you are seeing, there will be four vertical supports (in red). They will be used to anchor a horizontal mount for the motor, running front to back (green). Two of the three mounting screws on the motor will attach to this piece. Will then attach a smaller piece of angle aluminum (blue) to the green piece and attach the motor's third screw. We are doing it this was because experience has shown me that plotting and drilling three non-linear holes "blind" with measurements in metal never seems to work. They always mis-align. Finally, due to the weight, I want a lower support for the motor to set on (purple). The motor will just sit on it and keep torque off of the green support.

Again, this is just for you to wrap your head around. Dimensional drawings will follow (after you get me the blower dimensions).

Questions?
Alchemist attached the following image:
motormount[994].jpg
 
David
Top  #77 Print Post
Posted on 07/04/2008 4:18 PM
The 3/4" angle is a bit snug also. :@

So, shall I grind away some metal to accommodate the 14" cheesecake pan?

Or, slit the side of the pan and shrink it's diameter a bit?

Or?? :(
 
Alchemist
Top  #78 Print Post
Posted on 07/04/2008 6:17 PM

Quote

David wrote:
The 3/4" angle is a bit snug also. :@

So, shall I grind away some metal to accommodate the 14" cheesecake pan?

Or, slit the side of the pan and shrink it's diameter a bit?

Or?? :(


Ok, well, welcome to design smile Let's hammer out why it is snug and we can go from there. I looked up your previous dimension. You gave

14 3/16th is the ID at the top and the metal is about 1 mm thick.

What I get from that is:

14 3/16 = 14.1875"

1 mm = 0.0393"

The OD of the cake pan should be 14.1875 + 0.0393 x 2 = 14.26624".

I/we designed the frame to be 16" across OD. With 3/4" aluminum, ID should be 14.5".

Clearly (IMO) the numbers work out. I am going to take an educated guess here and trust your first number and predict in that you free hand bent the frame, it is under 14.5" diameter (under 14.25 " even).

Check that and let me know. If that is the case, then the solution is to go ahead and build the bending jig I and mentioned off and on and bend the frame around it so it is exactly the shape and size we want.

Otherwise, check my numbers above and see which does not agree with your building measurements.

Oh, and don't fret - that's what this cooling 'test bed' is all about. It's numbers and math - it HAS to fit smile
 
Alchemist
Top  #79 Print Post
Posted on 07/08/2008 7:20 AM
David, at some point you asked about a pouring spout for the roasted beans. I personally don't see the need for one. We can design it if you wish, but this is how I pour my beans up every time. My hands are the guiding spout/funnel.

It's why I designed our cooling tray to be removable - for just this method.
Alchemist attached the following image:
coffeepour0[997].jpg
 
Alchemist
Top  #80 Print Post
Posted on 07/08/2008 7:22 AM
Is there a way to attach more than one photo per post?
Alchemist attached the following image:
coffeepour1[998].jpg
Edited by Alchemist on 07/08/2008 7:24 AM
 
Alchemist
Top  #81 Print Post
Posted on 07/08/2008 7:27 AM
Basically, I just hold my bag of choice with my thumbs, against the tray, and tip the whole thing. The beans flow right in guided by my hands.
Alchemist attached the following image:
coffeepour2[999].jpg
 
Alchemist
Top  #82 Print Post
Posted on 07/08/2008 7:28 AM
My forearms are on the lip of the tray, so no beans get out that way.
Alchemist attached the following image:
coffeepour4[1000].jpg
 
Alchemist
Top  #83 Print Post
Posted on 07/08/2008 7:29 AM
I have done up to 5 lbs this way with nary a bean spilled.
Alchemist attached the following image:
coffeepour5[1001].jpg
 
Alchemist
Top  #84 Print Post
Posted on 07/08/2008 7:30 AM
What do you think?
Alchemist attached the following image:
coffeepour6[1002].jpg
 
David
Top  #85 Print Post
Posted on 07/08/2008 8:29 AM
Kewl. We'll just send a set of your forearms, hands and thumbs out with each model! Heh-heh.

Well, you were right again. The circle is not uniform. But there is enough flex and give in the metal to bring it around to the right shape, probably. I'll let you know.

I'm trying to visualize how the vertical supports go together in the frame. :(
Would you kindly post a simple "wireframe" model with *all* the support members illustrated? A hand sketch would be fine.
 
David
Top  #86 Print Post
Posted on 07/08/2008 11:20 AM
Or, here is a starter sketch.

I have the cooling tray in it, but not the motor yet.
David attached the following image:
Cooler3d[1003].jpg
 
Alchemist
Top  #87 Print Post
Posted on 07/08/2008 1:55 PM
Sweet drawing. You're hired - I'll use paint, you render in graphic 3-D!!!

I am glad I was right about the frame being out of true. Let's do it this way. What I would like you to do is lay out on a piece of plywood a bending frame. Basically you have the dimensions EXCEPT it needs to be the thickness of the angle more narrower all the way around as it has to match the ID and the drawings I gave show OD. Make sense? What is the thickness? 1/8"? If that is so, then the measurement across would be 16 - 1/8 - 1/8 (both sides) = 14 3/4".

And yes, I will get you a frame drawing with better measurements after you get me the amount we need for the cooling fan. And while we are at it, and making sure our ducks are in a row, the other blower needs to fit too. Mostly, check and see if 12" gives us what we need.
 
David
Top  #88 Print Post
Posted on 07/08/2008 9:44 PM
For those who are curious:

The software is called "Alibre" It's free open-source CAD software. s:2

There is a larger paid version, but so far I'm OK with the Express version.

I got it from download.com

David
 
Alchemist
Top  #89 Print Post
Posted on 07/11/2008 7:32 AM
See how this works for you. The trick here is to get some working language between us. Are you familiar with this kind of dual view? Basic engineering detail showing the detail from one angle, then 90 degrees. With the assist of the color coding (not normal in engineering drawings) you should be able to match the pieces up in a 3-D fashion.

The black pieces are your frame you have already produced. The red is the vertical supports. Note they will attach inside the frame. Blue are the two rivets holding it together. Also note the thickness of the left hand line of black frame, and red support. This is showing the thickness of the metal we are working with and assists with giving you orientation of the piece.

Let's start there . Does that make 100% sense? If so, I will continue on with the other details. If not, then try and explain what does not make sense and I will see what I can do.
Alchemist attached the following image:
corner detail[1006].jpg
Edited by Alchemist on 07/11/2008 7:34 AM
 
David
Top  #90 Print Post
Posted on 07/12/2008 3:34 PM
Yes, I can read and understand the drawings just fine.
Please go ahead with the construction details.

I'll be checking out the minimum height requirements this afternoon.
 
David
Top  #91 Print Post
Posted on 07/12/2008 6:39 PM
Uh-oh, big problem. :@

Quote

Alchemist wrote:
You come down 8" and start cuts 1" apart for 25 inches. You then start at the other end, go 16", make a V cut, another 8" from the center of the V and you would be within 0.13" of that last cut of the 25.


I didn't catch the error in this instruction until five minutes ago when I was laying out the form to bend the metal around:

Quote

that last cut of the 25

I did the 25 cuts. Grin
But I should have made 26 cutsShock
because 25 only defines 24" of circumference, not the 25" we need. c:4
No wonder it came up small!

It is clear from the larger context what you meant, but I took this last part literally each time I laid out my cuts.

What now? :(
 
Alchemist
Top  #92 Print Post
Posted on 07/13/2008 9:04 AM
In the scheme of things, it won't be 'perfect' but this is just the frame and all sins will be covered.

What comes to mind is to pick a couple spots and cut another couple slots. As it is, more slots will not really hurt, and most likely will only help as it will give you space to over bend and allow the frame to 'snap back' to the correct shape. The only thing I would suggest is symmetry. With the round section toward you, four additional cuts at 4,5, 7 and 8 oclock should do wonders. Yes, it is more than you need, but so? What you don't want to do is put additional cuts at 3, 6 or 9 as we will be attaching supports there and don't want to cut it too close.

OK, I am just about to start posting a lot of photos and an instructional in the Construction and framing area. Total scrap work I am doing, but it shows the techniques I want to pass along and all the little details. It is my hope that it takes some of the mystery or re-inventing of this work out of the equation. One last comment. Please ask questions if you don't get or understand something. Especially why I am doing a particular step. In my mind this Project is about TWO things. Building a roaster and maybe even more important, passing along the knowledge on HOW to build any roaster with a particular set of (Alchemist Zen?) techniques.
 
Alchemist
Top  #93 Print Post
Posted on 07/20/2008 10:11 AM
I was putting together the next stage of drawings for the frame and discovered that we need to decide upon what top skin this is going to have, or more specifically how thick it will be. The cooling bin will set on top of it, but the bottom much be a particular distance from the stirring motor so the vane shaft meshes correctly. If we are using sheet metal, either the stainless or mild steel, those are thin enough not to worry over. If OTOH we are going to use a wooden plywood top, we need to decide of that thickness. 1/4" would work (and keeps to the light weight, minimalist idea) , as would 1/2". We just have to decide.

You thoughts on this would be appreciated. Keep in mind that cutting a circle out of the stainless is going to be VERY time consuming, labor intensive and tool intensive. Mild would be ok. Wood will be easy and give us simple rigidity.
 
David
Top  #94 Print Post
Posted on 07/20/2008 10:00 PM
I prefer the wood.
It's a lot more forgiving, and I need some forgiveness at this point. Grin

Say, do you think they make toilet seats with 14" round holes? Tha'd save a lot of work, and it would have a nifty fold-down cover for protection between uses!
Uh-oh, more forgiveness needed. c:4 OK, I'll cut it out. I promise....

Let's go with some nice, smooth 3/8" plywood. Then we could paint it the color of our choice. Hmm, would it just sit on top of the frame, or perhaps be partially enclosed by the outer skin?
 
Alchemist
Top  #95 Print Post
Posted on 07/21/2008 12:15 PM
OK, wood it is for that part. It could sit or just 'tack' down with two or three screws. and I would bring the outer skin all the way up and cover the edge or go obvious lip the other way. Pure aesthetic decision.
Alchemist attached the following image:
woodtop[1034].jpg
 
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