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Pumper chimney
rasqual
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Posted on 05/16/2006 8:33 PM
Thanks Mike!

The pyrex bread tubes fit perfectly.

http://snipurl.co...

A good replacement for the hurricane lamp chimney.
rasqual attached the following image:
IMG_0938-1[40].jpg
Edited by Mike on 05/16/2006 8:38 PM
 
Mike
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Posted on 05/16/2006 8:42 PM
I just edited your post to make the link active (the [URL] tag at the bottom of the reply box).

Glad it worked out - I wasn't totally positive about the size of the counterbore in the Pumper - now we know. Grin

You did end up with the 3 inch tube, didn't you?

Looks like your up into that greater than 250 gm bean load range.

Mike
B)
Edited by Mike on 05/16/2006 8:48 PM
 
rasqual
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Posted on 05/16/2006 8:48 PM
Yikes! That's a huge picture.

I had problems with the first couple roasts -- tipping and scorching like crazy. Couldn't figure out the problem. Agitation seemed perfect. However, I reasoned that the hurricane lamp, which widened as it rose, took some of the pressure off the bottom of the mass. The new tube did NOT do so -- resulting (so I supposed) in worse circulation at the very bottom of the column -- out of sight. With that in mind I added a small tab in the column to break up the downward flow, allowing a looser pack beneath the tab (the tab is on the low side when the popper is tilted).

It worked! Perfect roasts tonight, with much better control over agitation (using Variac'd blower with boost to 140 vac). I have to get used to temperature control with this different dynamic, now.

Who has a recommendation for a turnkey PID solution for this?!
rasqual attached the following image:
tab[41].jpg
 
Mike
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Posted on 05/16/2006 8:56 PM
Not quite turnkey, but the Fuji PXR 3 or 4 is what I use. There are a lot of folks in the coffee community using these, so collegial support is at the other end of your keyboard. If you buy it with the RS485 communication option, it allows you to swap profiles etc. with other roasters. There are Beta level real time PC control programs for controlling fuji equipped roasters, around also.

How are you measuring temperature? I don't see a TC in the roast chamber.

Mike
B)
Edited by Mike on 05/16/2006 9:00 PM
 
rasqual
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Posted on 05/16/2006 8:58 PM

Quote

Mike wrote:
You did end up with the 3 inch tube, didn't you?

Looks like your up into that greater than 250 gm bean load range.


3" on the money. And yeah -- 250 would be easy.

Here's a funny one -- I'm seeing more smoke. With the hurricane chimney, the top was smaller so the air velocity blew the smoke away before I had a chance to see it. Lower velocity out the top of this thing, so I'm seeing the smoke for a change.

;-)
 
Mike
Top  #6 Print Post
Posted on 05/16/2006 9:56 PM
Do you roast inside? If so there are some intersting ventilation options. Check out the second Poppery modification article. Jim has done some nice vent mods. I finally ended up installing a small through the wall bathroom vent fan near where I roast in the kitchen - - smoke/chaff problem solved....Totally. When you use the small flexible ducting and everything it actually superchages the roaster fan a bit.

Mike
B)
 
rasqual
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Posted on 05/16/2006 10:42 PM
It's nicer weather now so I'm roasting outside -- but if I roast inside the thing I used to just set over my hurricane lamp chimney now actually fits snugly -- not tight, just snugly -- onto the pyrex. I did a roast with it, outside, just to see what would happen. I didn't use a chaff filter, and the chaff did get hung up in the ducting. I didn't give it a very straight shot through, though. Anyway, I have a couple novel ideas for chaff collection to make this snug ducting pay off.

Thanks again for the pointer to the bread tubes. So cool.
rasqual attached the following image:
venting[42].jpg
 
rasqual
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Posted on 05/16/2006 10:54 PM

Quote

Mike wrote:
How are you measuring temperature? I don't see a TC in the roast chamber.


First pic, you can see the digital. It's just a hole in the side of the chamber. I've chopped my Pumper down, you'll note. None of the bakelite-like stuff (you can see that clearly in the second pic).

The probe tip terminates about 2/3 of the way across the chamber. Actually, with the better agitation in this thing now, I wish the hole came from the other side. That's fine; I'll tip it the other way when I get a TC. Actually, I have a cheapo somewhere, but I sure wanna PID this thing.
 
Mike
Top  #9 Print Post
Posted on 05/17/2006 12:18 AM
If you decide to PID it you'll need to install a permanent TC probe anyway, so you may as well start planning.

In the interest of repeatability of indication between different folks - hopefully this will make it easy to swap profile/PID programs etc., the majority of folks have been settling on center of the chamber. 1.5" from the bottom and the sides for the tip of the probe. This should be just above the fully fluidized bean/hot air mix in the lower inch of the chamber.

Probes from Omega are about $24 but you can also make a permanent probe with a TC junction, a short piece of 1/8" brass tube and a screw that you can plug up one end of the tube with. A 1/8" NPT to 1/8" tubing brass fitting gives a good mounting fixture for the probe.

It seems like I just posted this pic in another thread but I can't find it.

w3.saw.net/~mldhab/TC%20fitting.jpg

I had to reposition a probe one time (poor pre-planning on my part). I threaded the old hole, got a brass screw the right size, put it in hard and smoothed the inside back to the roast chamber wall with a dremel and various other instruments of destruction.

Mike
B)
Edited by Mike on 05/17/2006 12:25 AM
 
rasqual
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Posted on 05/19/2006 1:17 PM
Glad of the counsel on standardizing location; it's a huge value to control for variables so different roasters can compare notes.

I think something else should be standardized, though -- the TC entry point's location relative to the chamber's tilt. I'd think it could make a difference whether the probe shaft in-chamber was sinking airflow heat, or bean heat. Surely there's some conductivity along the shaft to the probe tip? Also, the shaft would impede loft on the up-side (though that's where I have my own), but on the down-side it could perform the interference function I found necessary enough to add a tab to control for better lower chamber agitation.
 
Mike
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Posted on 05/19/2006 6:03 PM
I put a P1 chamber together with three probes coming into the chamber 120? apart with the ends all within 1/8" of each other. I was asking myself the same questions regarding 'Hi' vs 'Low' side and heat conduction throught the probe tube itself.

I thought I had identified a 3? difference but when I moved TC thermometers from TC to TC it didn't hold up - for all intents (within instrument error) identical.

Now the benefit to lower chamber agitation, that is a different question. I ended up with my probe at the location I use based on keeping the TC cable out of the way when emptying the roast.

Mike
B)
 
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