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snwcmpr
02/23/2019 9:17 AM
Ethiopian natural Gesha today .. tasting it tomorrow.

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02/13/2019 4:49 AM
Thanks again Ginny.

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02/12/2019 3:29 AM
Good morning all. Just finished a few days with Yemen Red Harraz. We liked it.

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02/11/2019 10:05 AM
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02/11/2019 10:01 AM
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Modifications to flour sifter for roasting?
ruddhess
"Most poppers have a thermostat built in somewhere (roasting chamber side wall or in the heater/fan assembly). If you haven't bypassed that yet, I suspect the temperatures you have been measuring are a function of their respective thermostats. Any of the wattages you listed are capable of producing 500F+ inlet air, for some amount of air flow. My Nostalgia APH200 has the melted plastic to prove it :-)! Lots of detail in that forum."

I did move the thermostat on my Air Crazy this weekend and last night I measured the temps down in the chamber (remembering that the first time I did so, it was plugged in to a power strip at the end of a 25 foot extension cord - the measurements on the other poppers were sans the power strip) and got a reading of 400°F in 60 seconds and 420°F in 90 seconds (now it makes sense because this 1040W popper is the only one that I've altered the thermostat. I know those NiChrome coils will get to about 2000°F? or a little more on their own without any air flowing through them (I keep reading about 1400°F max "operating" temperature for NiChrome?). I rewired my little pottery kiln recently (ordered 13 gauge A1 Kanthal wire from Euclid's Elements & Pottery Tools and wound the coils myself - the calcs on resistance is easy with the chart they provide). Now I find myself mulling over how to make a coil that isn't as "powerful" as the ones in the popcorn poppers - they are designed to heat up "immediately" - people want their popcorn RIGHT NOW, dang it! LOL. The calculations that include heat loss and the amount of heat energy that can "come out" of various coil configurations, though, is much more complicated than just determining the length of a given gauge of element wire (all I did was approximately match the resistance of the existing elements and ensure that I could jam that length of coiled elements into the kiln effectively).

Anyway, thanks for the tip on the popper forum. I need to check that out. :)
 
AMRoberts
ruddhess wrote:

... I did move the thermostat on my Air Crazy this weekend and last night I measured the temps ... and got a reading of 400°F in 60 seconds and 420°F in 90 seconds ... I know those NiChrome coils will get to about 2000°F? or a little more on their own without any air flowing through them ...

(bold text emphasis by me) ... Obligatory safety comment: The coil(s) in your air popper may tolerate operating without air flow, but the surrounding materials (connections and wiring to the coil(s), support structure for the coil(s), fan rotor and body, motor, and the popper shell) probably won't.

My modded popper will not supply power to the coils without power also being supplied to the separate DC supply that runs the fan; and I still consider it a tool for use only by an informed and competent adult, since the operator (me) is responsible for fault detection.

You'll find some discussion of operational safety issues/strategies and tales of burned-out poppers in the popper forum.


Now I find myself mulling over how to make a coil that isn't as "powerful" as the ones in the popcorn poppers - they are designed to heat up "immediately" - people want their popcorn RIGHT NOW, dang it! LOL.

Your other option is to control the average power running through the coil(s). You can do this with purchased manual controls (the HF router control is one example), purchased digital controls (when you see discussion of a "PID controller," I imagine that every variant people are buying and using these days is internally microprocessor-based), or DIY it (there is another HRO forum https://forum.hom...rum_id=133 that has lots of fun reading). Note that control DIY doesn't mean "designed from scratch", you can follow the trails blazed by others, there is lots of good work out there.

The bad news is that you can spend more on control and instrumentation than an air popper costs. The good news (or rationalization?) is that with some thought you can expect some/all of your controls and instrumentation to migrate to the next roaster (although I guess this assumes you are moving on to a new roaster, not accumulating an ever-growing fleet of roasters :-)

Cheers,
Alan
 
ruddhess
"(bold text emphasis by me) ... Obligatory safety comment: The coil(s) in your air popper may tolerate operating without air flow, but the surrounding materials (connections and wiring to the coil(s), support structure for the coil(s), fan rotor and body, motor, and the popper shell) probably won't.

My modded popper will not supply power to the coils without power also being supplied to the separate DC supply that runs the fan; and I still consider it a tool for use only by an informed and competent adult, since the operator (me) is responsible for fault detection.

You'll find some discussion of operational safety issues/strategies and tales of burned-out poppers in the popper forum."

I have heard about people forgetting to turn off the heating elements first and letting the fan blow to cool them down a bit or trying to run the popper without turning on the fan (all of this after separating the two circuits). Which is something I tried last night with my Orville. Except that I couldn't see that the tiny (almost human hair thickness - or thinness, if you will) secondary coil was connected to the same high temp rivet/eyelet (I can actually put a safety pin through the center of the "rivet" that goes through the mica card) as the main heating coil. Ended up with a completely dead end circuit for the fan (after hacking the thermostat out with a dremel), then got to looking much closer and spied the dual connection at the hot lead from the cord. I like the modification that separates the main coil and then uses the HF router controller to limit voltage to the main coil and thus slow down the roast a bit. (I have no desire to slow the fan down at all. The main coil is PLENTY powerful even with full fan power blowing through it all the time.) I still have to get over to those popper forums and check all of that out soon.

"Your other option is to control the average power running through the coil(s). You can do this with purchased manual controls (the HF router control is one example), purchased digital controls (when you see discussion of a "PID controller," I imagine that every variant people are buying and using these days is internally microprocessor-based), or DIY it (there is another HRO forum https://forum.hom...rum_id=133 that has lots of fun reading). Note that control DIY doesn't mean "designed from scratch", you can follow the trails blazed by others, there is lots of good work out there.

The bad news is that you can spend more on control and instrumentation than an air popper costs. The good news (or rationalization?) is that with some thought you can expect some/all of your controls and instrumentation to migrate to the next roaster (although I guess this assumes you are moving on to a new roaster, not accumulating an ever-growing fleet of roasters :-)"

LOL!! I gotta watch myself and prevent that! (I have a garage full of old vintage sewing machines) I only have four poppers so far - proud of myself - passed up one yesterday at GW (it was just like one I already had). HF router controller is more my level. PID?? What, lol? I had to look that up on Wikipedia the other day, lol. I'd heard of them before, but filed that away in the "electronic wizardry" folder inside my brain. And I had heard that the computer controlled stuff can get pricey. Then there's this: there is just something inside me that goes "yuck!" when I see all that electronic stuff attached to the roaster/popper. I'd rather "engineer" (I am an architectural & engineering drafting tech - and GIS mapping tech by day) something more mechanical than to endeavor to learn (at the tender young age of 61) an ever advancing field of "electronic wizardry", lol. Being lazy for sure, I'll admit. Lots of available electronic components on second hand stuff at the thrifts (like the DC motors and controllers off of old tread mills, etc), that can be had for a reasonable amount. But there is something about "keeping it simple" that appeals to me too.

And I am on the verge moving to the "next level"of cheap DIY roasting by using my cheap two stage HF heat gun to try a roast with my sifter. I even have the 'end caps' for a wooden stand - I found two giant baluster caps (each one only a dollar) the other day at a local thrift that I am going to use. I'm also keeping an eye out for one of the red (really fancy) metal housing multi-step heat guns - they seem like an ideal heat source for roasting with the sifter. I've seen a couple really nice/cool ones that use those fancy red heat guns. Finding (or building) the proper transition from nozzle to bottom of sifter seems like a key element too.

Cheers,
Rodney
 
AMRoberts
Hi Rodney,

ruddhess wrote:

... (all of this after separating the two circuits). Which is something I tried last night with my Orville. Except that I couldn't see that the tiny (almost human hair thickness - or thinness, if you will) secondary coil was connected to the same high temp rivet/eyelet (I can actually put a safety pin through the center of the "rivet" that goes through the mica card) as the main heating coil. ...

From what I've read its a nearly-standard pattern for poppers. The secondary coil's purpose is to drop mains voltage to match the fan motor's requirements. If your popper's fan motor is a DC motor, you'll also see a rectifier of some flavor. On my popper that was four individual diodes soldered directly to the motor terminals.

Rivets, crimps, or other such connectors get used on coil ends because you are operating well above the typical electrical solder's melting point of course.


... (I have no desire to slow the fan down at all. The main coil is PLENTY powerful even with full fan power blowing through it all the time.) ...

Simplifies things for you, on my popper I have to drop airflow to reach the higher temperatures needed to keep the roast going near end of roast.

I believe you'll find fluid bed roaster users in the forums who prefer to set a power level for the heater and control speed of roast by varying airflow.


... Finding (or building) the proper transition from nozzle to bottom of sifter seems like a key element too.

Something like a canning funnel: https://www.amazo...less+steel might be an off-the-shelf place to start, if you can find one with an upper diameter that matches your sifter, and a lower diameter close enough to your heat gun's outlet.

Cheers,
Alan
 
ruddhess
Hello Alan,

Thanks for the reply. (I can't seem to figure out the "quotes" feature on this forum, so I will keep doing it "my way" as I have been.)

"From what I've read its a nearly-standard pattern for poppers. The secondary coil's purpose is to drop mains voltage to match the fan motor's requirements. If your popper's fan motor is a DC motor, you'll also see a rectifier of some flavor. On my popper that was four individual diodes soldered directly to the motor terminals."

I had read about that (the secondary coil acting as voltage reducing component) along with lots of comments about "poor design". I don't understand the electrical aspect to know for sure whether it is a poor design, but I have seen photos of the very first/early popcorn poppers (and I think I actually had one of them in the very late 70s or very early 80s) and the 120VAC fan/blower motors (and they seem infinitely more robust than the dinky little DC brushless motors - but brushless is cool). I have been collecting a few small vacuums at the thrift stores for $5 and $6 in hopes that the motors can be used in a DIY roaster that I am contemplating. My popper does indeed have the four diodes wired in at the base like you mention.

"Rivets, crimps, or other such connectors get used on coil ends because you are operating well above the typical electrical solder's melting point of course."

And rivets and crimps are cheap (a manufacturing plus as seen from their end of things). I am accustomed to seeing the REALLY "robust" electrical connections on the elements in my electric pottery kilns. Now THOSE are sturdy!! LOL

"Simplifies things for you, on my popper I have to drop airflow to reach the higher temperatures needed to keep the roast going near end of roast."

Hmmm, I may have to rethink this aspect then - possibly add the oft suggested dimmer switch to my fan circuit, just in case it is needed. I've passed up a dozen or more up at thrifts thinking that I'd never have a need - doh!! I have actually noticed that my main popper has been "struggling" to reach temp (this is the one that I haven't modified the thermostat on yet). I did take voltage readings on my plugs and cords: 122.3V and 122.4V - which surprised me a little considering it is summer and everybody is running their A/C units full blast. Maybe the power company boosts the volts during the summer because of this? I measured my volts at the outlet on my balcony (coffee roasting takes place in the garage, so different building, etc.) last winter and it was only reading 117V. Close enough to 120V either way.

"I believe you'll find fluid bed roaster users in the forums who prefer to set a power level for the heater and control speed of roast by varying airflow."

That makes a lot of sense. Especially if a true 120VAC blower motor were in use - I suspect they could really throw the beans!! I have a lot of tinkering/toying around to do. I'm not one to merely follow the step-by-step. I rewired my little Cress pottery kiln to be ON/OFF (using the kiln sitter switch only - a bit inconvenient, but it works and it's simple and no more delicate electrical relays and timers, etc. to go bust on me - and they want an arm and a leg to replace some of that stuff - I'm not cool with proprietary parts - sewing machine parts and cord connections is one of those areas that gives me a burr under the saddle). I'm a geezer.

"Something like a canning funnel: https://www.amazo...less+steel might be an off-the-shelf place to start, if you can find one with an upper diameter that matches your sifter, and a lower diameter close enough to your heat gun's outlet."

Precisely!! I actually have been looking with a keen eye when perusing my local thrifts for canning funnels. I found a little aluminum one - not a good fit, but bought it anyway. Might be able to use it down the road. Those stainless steel ones look like a good fit. Thanks for the link. I actually found a stainless steel Cory style vacuum coffee pot part that looks like a funnel at one of my local GW stores yesterday - a little over $1!!!!! I didn't know what it was until I got up to the counter to pay and a nice lady asked me about it and told me what it was. I guess they came with a kind of glass rod with bumps or channels on/in them that went down into the skinny tube and that glass rod allowed the liquid from the bottom part (I don't have that part or the rubber gasket that goes between - apparently they are available though by contemporary "third party" suppliers) to siphon up the tube without letting too much or any of the coffee grounds to come up with the liquid. I'm fascinated with all the old coffee related 'accoutrement'.

I ended up dremeling the two rivets that hold the mica pieces together (I plan to replace the rivets with tiny nuts/bolts - there are porcelain "guard" tubes inside the mica sheets to protect the rivets/bolts from heat) and getting in there to break the tiny secondary filament off from it's post/rivet (leaving the main coil attached). That separated the two circuits. (Sorry, no pictures. It's always 94-98 degrees out there even after 8PM and I haven't thought to take pics yet.) I was able to stretch the end of the secondary element enough (concurrently ensuring that no two coils of the element were touching) to run the end under the vertical mica support and up through the rivet that connects to the return (ground) wire for the fan. I fussed with it until I could just barely grab it with my needle nose pliers and fish it up a little more to begin putting a coiled "knot" in it so it wouldn't slip back down through the rivet. It now has a little "ball" of coiled wire element in contact with the rivet and metal bar that attaches to the wire leading to the fan motor. I tested the fan and it runs. I have been contemplating leaving it as-is or attempting to silver solder it. I will probably test the fan some more by letting it run to ensure that the "ball end" retainer (as I'll call it) doesn't uncoil. (That's the cool thing about NiCr wire opposed to Kanthal A-1; the NiCr wire still bends after repeated heating and cooling - that Kanthal wire gets mighty brittle after a few cycles in a pottery kiln.) I don't expect this little fan to last forever, but one never knows with this stuff. Sometimes the things you expect to fail keep plugging along for quite a while. I will just have to be ready to turn the main coil off if the fan quits working. I don't plan to put the guts back into the plastic housing anyway. If anything, I'll but it inside a custom made metal vent/flue pipe or something similar that won't melt or burn. I'll try to take a pic or two to post in case you're interested in seeing my mess, LOL.

Cheers,
Rodney
 
ruddhess
Alan,

A couple of pics to show. Sorry about the blurry focus. In the really blurry photo, you might be able to see the end of the secondary element sticking up out of the rivet hole at the end of the metal tab connected to the red wire. Also you can see in the overview pic where I completely cut out the bi-metal thermal control and the "big white sharpening stone looking thingy with two wires sticking out of each end", lol. The other picture is of the 4 diodes on the little DC motor. I fired the fan up again a few minutes ago and let the coil get "red" (looks more like orange to me) hot. Everything held up fine. It is all sitting on a second hand pizza stone (my ceramic/pottery work space) so it won't scorch or burn anything. I felt how hot the mica board got - not too hot, but couldn't touch it for very long with bare fingers. BTW, do you know what those "strings" are made of inside each of the elements/coils? Looks like kevlar, but I'm assuming it is some kind of kaolin type substance. Hope you enjoy seeing the photos. And thanks for looking.

Cheers,
Rodney
ruddhess attached the following images:
img_20180615_140105_small.jpg img_20180615_140045_small.jpg img_20180615_140027_small.jpg
 
AMRoberts
ruddhess wrote:

Alan,

A couple of pics to show. Sorry about the blurry focus. ...


No worries, they are pretty much what I expected from the hacking I've done on my popper and a lot of reading on the popper's forum here.

I got a bit luckier on mine than the one you've been modding ... The thermostat limiting my temps was mounted on the side wall of the chamber. Line voltage for the main coil was wired through this, but the wiring was crimped-on spade terminals, I just had to yank them off the thermostat to bypass it. So I didn't disassemble the fan/coil(s) unit. There may be a one-time thermal fuse on the insulating board of the heater, but if so mine hasn't failed (yet), even taking air temperature slightly over 500F.

The discrete diode bridge rectifier on the base of my motor looked exactly like your picture. Once I knew I had a DC motor I decided to use an external DC power supply and a DC voltage controller to run the fan. I removed bridge from the motor terminals and put wires on the motor which exit the popper. A leftover printer power brick provides the DC, and an off-Amazon PWM controller (a DC equivalent of the Harbor Freight router speed controller) adjusts fan speed.

This probably cost me a little bit more than an AC light dimmer feeding the secondary coil would have, but the DC supply and PWM controller can be re-tasked to the motor I'm planning to turn the axle on my sifter roaster.

Since I didn't need the secondary coil to drop line voltage to match the fan motor, I just wired it in parallel with the main coil. Provided a slight increase in total heat available.

I put mine back in the original shell, since that gave me a way to dump the beans at end of roast using only a work glove. So I have four wires exiting the popper, a pair for AC voltage to the coils, and a pair for DC voltage for the fan. I put connectors on these wires since I half-way expected to be replacing burned up poppers (this was before I fully appreciated the too-small batch size and too-much noise issues). Taking a cue from stories in the popper forum, these connectors will not allow anyone to plug my hacked popper back into a power outlet; they only mate with the corresponding connectors on my DC and AC controllers.

Regards,
Alan
 
ruddhess
Hey Alan,

Thanks for sharing the information about the modifications that you made to your popper! After reading your account of modding with the DC transformer and PWM, I can now see why so many people go this route. And wiring the two coils in parallel is a good route as well (I've just recently "boned up" on the differences between circuits in parallel and in series - I understood the "in series" because of my pottery kiln element replacement, but I knew essentially nothing about kilns wired "in parallel" - only that there were many kilns wired so - mostly bigger 240V kilns - and now I know why).

Great idea using the electrical connectors that way - to prevent someone from being able to plug the modified appliance into the outlet. I put a piece of tape on my Air Crazy stating that the thermostat has been moved and that the popper isn't "safe" anymore. The tape "could" fall off someday, but I didn't remove or bypass it, just took it away from the side of the RC and let it dangle in the space below. I may put it back with high temp silicone sealant and small rivets. That popper has a really anemic blower motor, even though it gets plenty hot. So I might abandon it as a usable roaster.

I think of myself as lucky in that my only "failure" (not exactly a failure) was one roast which was a "teeny bit" under roasted/developed due to trying to roast a full cup of beans (too large a batch - I don't weigh my "charges"). I attribute my luck to the popper I used first to roast with - West Bend Air Corn Popper 5209 (which I think has the same "guts" as the Poppery II) which seems to roast extremely well completely unmodified (aside from roasting too quickly - which is a characteristic of popcorn popper roasting). I really don't know why I want to roast larger batches. I can barely drink the fresh roasted batches quickly enough before they start to lose their best flavor. The small batches I'm doing are really ideal as far as size is concerned. To drink the freshest coffee, one needs to roast every 3-7 days (it seems).

Cheers,
Rodney
ruddhess attached the following image:
wb_5209_small.jpg
 
lmc
i modified my sifter in two ways: replaced the bails with paddles and moved the center of rotation about 1/4" from stock. this causes the near paddle to just miss the screen holding rib, but the far paddle clears the rib by about 3/8" to clear the beans. inside ends of both paddles clamp on the pivot rod with 4 screws and nuts. if you don't want to make paddles, just moving just the bail slightly off center will keep the beans from getting trapped between bail and screen rib. just make sure you rotate the bails (or paddles) in the correct direction!
 
allenb
Welcome to HRO!

Please post some photos so others can see details. This sounds like a nice improvement for the sifter method.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Spyderman24-7
ruddhess wrote:

Alan,

RE: Bushings: those bushings look like JUST the thing! I "googled" bushings the other day and saw some "oil impregnated" ones that look similar (supposedly Home Depot has them), but I don't know if they would be food safe, so it looks like you have found just the very item for the job!

RE: Flour Sifter Durability: I haven't been roasting with my flour sifter that long to be able to say whether it will last very long under the heat conditions. I do though appreciate the simplicity of them and that they are cheap. The big 8 and 5 cup stainless steel ones with the black turn knob look fairly robust too. I just found my 5 cup sifter at the Goodwill for $3-4. It has flowers painted on the side, lol. I was a little worried about the paint, but it seems to be unaffected by the temps subjected to it so far.

BTW, the roast from last Wednesday that took 12 minutes to go from green to yellow and then only 4 minutes from yellow/tan to 1st crack or just a bit beyond was SO much better than the roasts that I had been doing with jus the air popper alone (4 minutes or less? Just now starting to use my phone/stop watch to try and keep tabs on my roasts). I'm a "newbie" roaster who likes the tinkering with gadgets as much as I like to drink the coffee.

Rodney


This is an older, but interesting thread. I've been using my HG/FS setup a bit over 2.5 years now and the 8 cup/6" sifter has held up great. I'm surprised the screen hasn't given out with the heat/friction, but still working great. There is some wear where the axle enters the housing on both sides, but this thing has seen a TON of RPMs. I've looked through my stash of bearings, bushings, etc. to fill the gaps, but nothing that will fit just yet. The rigidity of my heat gun keeps the alignment pretty solid though. As mentioned in my thread I've done at least 600 batches (200 grams each) which equals around 265# and all is still going well.

https://forum.homeroasters.org/forum/viewthread.php?thread_id=5776&pid=67571#post_67571
 
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