topbanner.gif
Login
Username

Password




Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Shoutbox
You must login to post a message.

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

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

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

Husamka
02/11/2019 10:05 AM
probe diameter

Husamka
02/11/2019 10:01 AM
probe dimension

Users Online
Guests Online: 2

Members Online: 0

Total Members: 5,824
Newest Member: blabbermouth
In Memory Of Ginny
Donations

Latest Donations
PRABHATH COFFEE WORKS - 10.00
John Despres (Scene... - 25.00
snwcmpr - 10.00
Ozo - 20.00
Josh Woodrow - 10.00

View Thread

Who is here? 1 guest(s)
 Print Thread
Modifications to flour sifter for roasting?
AMRoberts
Hi,

So I'm feeling the need to move on from my modified popcorn popper ... Larger batch size is my primary goal, not having to wear ear protection while roasting is a secondary goal (my popper with the fan at high speed to get the beans moving at start of roast is loud).

For my next DIY I'm planning on using a large flour sifter for mechanical stirring of the beans, with my Camp Chef SB30 providing the heat.

For those of you who have constructed a flour sifter-based roaster, do you modify the shape of the sifter bails? If so is it to achieve better stirring/mixing of the beans? It seems like the "stock" shape has to be about making contact with the bottom screen (to force flour/sugar/etc. through), but beans don't benefit from this close contact especially at the (possible) cost of lack of stirring/mixing closer to the rotation axis for the bails.

If this is previously-explored territory, could somebody point me to any posts/threads that talk about it? While the actual flour sifter is probably the least costly part of my planned build, I don't want to waste time and risk possible part breakage doing experiments if there is already a good answer.

Thanks,
Alan
 
ruddhess
I modified my sifter last night and it worked really well. Before this modification, the beans kept getting stuck between the screen and the beater wires. It wasn't easy and took a few tries to get it right, but in the end it worked well. I will try to describe what I did: I grabbed the wire at the apex of the arc with my left hand and pulled toward my body, while pushing down/away hard with my right thumb against the right side of the wire down in the sifter between the axle and where my left hand (really just two fingers or so) was. I did this for all four beaters. Then I rotated the sifter 180° and repeat. I did this whole operation a couple of times (the wires/beaters are really stiff). What I ended up with was a sort of spiral affair. But it works great and the beans don't jam up the works. The sifter tends to push the beans left and rearward, though, leaving part of the screen bare to the fore and right of the screen. Hope this will help you some.

Rodney
 
ruddhess
This is what it looks like.
ruddhess attached the following image:
sifterbailsmall.jpg
 
AMRoberts
Hi Rodney,

Thanks, the description and picture are helpful. I hadn't thought about beans getting stuck between the beaters and the screen.

I've got to figure out how to take the axle out of my sifter, since there are some plastic bushings between the axle and the sifter sidewalls ... I'm assuming these need to come out before roasting heat gets applied! So perhaps I'll be able to make use of some pliers or something to help with bending, while the beater assembly is out of the sifter.

Thanks,
Alan
 
ruddhess
Very welcome! Hope to see some pics of your modifications and your roaster set-up. I am in the process of setting up a different roaster myself. I roasted last Wednesday using the 5" diameter sifter just held with my hands as steadily as I could against the top of my popcorn popper (in an effort to slow the roast down - well it surely did slow it down a tad too much - 12 minutes to yellow) so I ended up dumping the beans in the popper hopper at that point and in 4 more minutes (after 1st crack had simmered down quite a bit) the roast was done. So I am going to build a wooden stand like I have seen others do. At least I have my sifter dialed in. Good luck on your mod Alan.
Rodney
 
ruddhess
Alan,

Can you get away with just cutting the plastic bushings out with a utility knife?

Rodney
 
ruddhess
I have been tossing around in my head the idea of building a "mega" duty sifter out of 1/16" stainless steel with teeny tiny little bearings for the axle, and beefy super duty "french curve" bails/beaters. Might get around to it one of these days. Flour sifters seem kinda cheesy/cheap/flimsy for what we want to do with them. I can understand companies not building the Rolls Royce of flour sifters if all people are going to do is sift a bunch of flour through it once in a while. But coffee roasters really put the cranks to some of their sifters, LOL.

Cheers,
Rodney
 
renatoa
You can borrow ideas from a design that I am envisioning and gathering parts for a future roaster, described below.
Made from an ice bucket and a stainless strainer, check the picture.
Both parts are under $10 each, strainer diameter is 22 cm, and intended capacity 500 grams.
Heat source will be up, not bottom, consisting of a TO central part, without glass, mounted on a custom cut stainless steel lid. There will be a window in the lid, with double purpose: beans charge opening and beans monitoring through a glass, after charge.
Beans drop done by tumbling the sifter around the beater shaft.

Still thinking how to integrate a cooler stage at the bottom of the ice bucket. And chaff management...
...
renatoa attached the following image:
dsc07969.jpg

DIY: TO based IR to bean 800g
Moded commercial: Dieckmann RoestMeister, Nesco, popcorn.
PID/ramp/soak controllers, MS6514 USB/Artisan/Apps/popC/ESP32
Grinder: mod'ed Porlex to 47 conical burrs
 
AMRoberts
ruddhess wrote:

Alan,

Can you get away with just cutting the plastic bushings out with a utility knife?

Rodney

When I next get the sifter I've purchased out of the box I'll take a look and see if I think I can get a knife in there.

One reason I was thinking of pulling the axle (assuming that is how it was assembled and that I can disassemble/reassemble) would be to replace the plastic bushings with something like:

http://catalog.bu...d-bearings

if the axle diameter matches up with the I.D. of an off-the-shelf sleeve bearing. A super-quick Amazon check suggested $3-4 for a pack of several bearings, so I wouldn't feel bad about adding that much more cost to the $15 I spent for the sifter.


... Flour sifters seem kinda cheesy/cheap/flimsy for what we want to do with them. ...

I take the point; have you had a sifter break or wear-out while roasting? My DIY roaster approach is it either should be durable or it should be inexpensive/replaceable. So I'm thinking of the sifter as replaceable part, but I am interested in whether anyone who has been using one knows how long they hold up as a roaster.

Cheers,
Alan
 
AMRoberts
renatoa wrote:

You can borrow ideas from a design that I am envisioning and gathering parts for a future roaster, described below.
Made from an ice bucket and a stainless strainer, check the picture.
...
Beans drop done by tumbling the sifter around the beater shaft.
...


Renatoa, let me make sure I understand where you are going with this ... Are you planning a horizontal axle across the sifter with some sort of beater/stirrers attached, instead of the vertically-oriented motor turning stirring arm(s) that I've seen in most of the "KKTO" pictures on other threads?

Cheers,
Alan
 
renatoa
Yes, you got it right.
Using a TO lid as heating source is better than a hotgun imo, and their usage are not limited to KKTO designs.
 
ruddhess
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
 
ruddhess
I like using the flour sifter for a mechanical agitation without having to rely solely on the air for agitation. To me, air is a WONDERFUL conveyor of heat, but a much poorer agitator (much less air "pressure" is needed to merely convey the heat efficiently; and trying to achieve that "balance" between enough air to agitate the beans, and not too much air that sufficient heat from the element is maintained to control temp, just seems to me to be a less than ideal solution). I know it can be done - lots of people are doing it, but . . .

I've been messing with three or four air poppers and fiddling with moving the sifter up and down and just now beginning to fashion some transition pieces between the poppers and the bottom of the sifter in an attempt to slow down my roasts (opposed to becoming an electronic wizard, lol - though I did go to HF this weekend and get one of the router speed controls to play with - but only after I put the main coil heating element on it's own circuit - doesn't make sense to slow the fan down and the heat down at the same time - in fact, I can't really see any reason to slow the fan down at all).

I have a heat gun, but haven't fooled around with it yet, just with the poppers.

Sorry to ramble, just some thoughts.

Cheers,
Rodney
 
ruddhess
renatoa,

I like your idea. Please keep us posted on your progress with your build. :)

Rodney
 
ruddhess
Alan,

I just now took a look at that Camp Chef SB30 inline - and it reminded me of something I saw at Home Depot this weekend:

https://www.homedepot.com/p/STOK-Tourist-104-sq-in-Single-Burner-Portable-Propane-Gas-Grill-in-Black-with-Insert-Compatibility-STG1000HD/206467954

Of course my mind went to COFFEE ROASTER! LOL

Rodney
 
AMRoberts
renatoa wrote:

... Using a TO lid as heating source is better than a hotgun imo ...

Assuming you have the part in-hand, how do you rate the TO's noise compared to typical heat guns and air popcorn poppers?

Just curious, so far I've run across one used TO at a Goodwill store, an older "Galloping Gourmet" model. Since they had a test outlet at the store I cranked it up. Unit ran, but the noise level seemed in the same ballpark as my hot-rodded air popper (the current roaster) and my heat gun. I was wondering if the noise level was nominal for all such TOs or if I was listening to an older and/or badly worn unit.

Cheers,
Alan
 
AMRoberts
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!

Time will tell, assuming I can get the axle/beater unit disassembled and the axle diameter is a reasonable fit for a bushing. I'm assuming it can't be any worse than the axle working against the stainless steel edge formed by the thru-hole in the sifter, but there is the old saying about the dangers of assuming :-).

The same company has a standard line of oil impregnated bushings where they recommend a maximum working temp of 220F, and a oil/PTFE lubricated series that is rated to 460F. That is actually what the web site recommends for slow-speed applications, but I have to believe that temp above 460F is going to be possible as you near the end of a roast.

Also note that the conforming spec for even the Dri-Plane bushing reads: "... when impregnated with MIL L-17331 oil." I haven't gone hunting for that (yet), but I'll speculate it is something like a high-temp turbine/air-compressor oil. I think you can find high-temp oils repackaged into small containers; it gets sold for maintenance on small electric motors, blowers for wood-stoves and BBQ/smokers, etc. A small bottle ought to be a lifetime, multiple-project supply for DIYers.

Intuitively I wouldn't want to use an bushing impregnated with a low temperature oil for a roaster part. After all, when you season your cast iron skillet or grill grates, the typical procedure is a thin coat of oil and into a 500F oven for a hour. What emerges is a polymerized layer; not what you want to happen between the axle and the bushings.

Cheers,
Alan
 
ruddhess
"Time will tell, assuming I can get the axle/beater unit disassembled and the axle diameter is a reasonable fit for a bushing. I'm assuming it can't be any worse than the axle working against the stainless steel edge formed by the thru-hole in the sifter, but there is the old saying about the dangers of assuming :-)."

LOL! I have wondered as well whether the axle/beaters can be removed easily. I did see in one place that someone had used the brass acorn nut in conjunction with a hex driver of the same size and a battery powered drill of some sort to power the beaters. And I wondered why put the acorn nut on there if the axle couldn't be taken out. So hopefully it is. The beaters on the 6" diameter 8 cup sifter look mighty beefy - and (here's where I get to assume, lol) therefore, difficult to bend into a new configuration. But perhaps the clearance is better on that type of sifter and the beaters might not need to be modified?

"The same company has a standard line of oil impregnated bushings where they recommend a maximum working temp of 220F, and a oil/PTFE lubricated series that is rated to 460F. That is actually what the web site recommends for slow-speed applications, but I have to believe that temp above 460F is going to be possible as you near the end of a roast."

I have been taking temperature "measurements" (albeit with a used turkey fryer mechanical/coil spring dial thermometer from Goodwill) down inside the bottom of the roasting chambers of my popcorn poppers. FWIW, the 1440W Presto (Mod. No. 0482107 - center screen) measured 440°F; the 1240W Presto (Mod. No. 0484602 - center screen) measured 350°F; the 1200W West Bend "Hot Air" (No model number that I could find - side vents) measured 375­°F; and the 1040W West Bend Air Crazy (Mod. No. 82418? - discontinued; didn't write it down - side vent model) was (as I recall - again, didn't write this one down) 375°F (which surprised me because it is only 1040W. But all this is mute if you use a propane burner to power your roast with the sifter. You could easily go over 460°F in the roast. In fact, I have to wear a welding glove to hold onto the handle of my sifter with my popcorn poppers. If I can dig out/find my single burner propane camp stove from inside my garage, then I think that I'll modify my sifter with a DIY handle that stands well off to the side out of the path of the rising heat current.

"Also note that the conforming spec for even the Dri-Plane bushing reads: "... when impregnated with MIL L-17331 oil." I haven't gone hunting for that (yet), but I'll speculate it is something like a high-temp turbine/air-compressor oil. I think you can find high-temp oils repackaged into small containers; it gets sold for maintenance on small electric motors, blowers for wood-stoves and BBQ/smokers, etc. A small bottle ought to be a lifetime, multiple-project supply for DIYers."

I have wondered what kind of oil would be the best if I used the tiny "skate" style bearings on my super-duper DIY sifter. I think the oil/grease that I found for food safe application was WAY expensive. If the bearings are cheap enough, I'd try leaving them dry and replacing if they seize up.

"Intuitively I wouldn't want to use an bushing impregnated with a low temperature oil for a roaster part. After all, when you season your cast iron skillet or grill grates, the typical procedure is a thin coat of oil and into a 500F oven for a hour. What emerges is a polymerized layer; not what you want to happen between the axle and the bushings."

Yes, I was leery of the oil in the impregnated bearings as well. But I didn't think about the possibility of it turning to polymer. It might not have too much of an effect if the bearing area was really small (similar to the thin metal of the sifter sides against the small diameter axle), but then again it would suck if it seized up during a roast because of it.

If I recall correctly the bearings you linked were good to 700°F? That should work fine - better "over engineered" than under. So the ones you referred to are probably an excellent fit. Thanks for the link. :) Plenty of powdered metal flange bushings/bearings on Amazon, so good for Amazon Prime people (just got it recently).

Rodney
 
AMRoberts
ruddhess wrote:

LOL! ... I did see in one place that someone had used the brass acorn nut in conjunction with a hex driver of the same size and a battery powered drill of some sort to power the beaters. ...

I plan to use a 24VDC, 60RPM motor to turn the beater on my sifter. I hadn't made up my mind yet whether to use a hex driver on that nut, or attach a disc to the motor shaft with a cut-out to match the crank handle.

The beaters on the 6" diameter 8 cup sifter look mighty beefy - and (here's where I get to assume, lol) therefore, difficult to bend into a new configuration. But perhaps the clearance is better on that type of sifter and the beaters might not need to be modified?

They are beefy, and out-of-the-box they are in rubbing contact with the screen (makes sense given the purpose it was built for), so changing them to avoid jams, have better stirring action, and maybe reduce noise still seems like a good idea.

I have been taking temperature "measurements" (albeit with a used turkey fryer mechanical/coil spring dial thermometer from Goodwill) down inside the bottom of the roasting chambers of my popcorn poppers. ...

Have you browsed the Popcorn Popper roasting forum, https://forum.hom...rum_id=121? 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.

Cheers,
Alan
 
renatoa
Nope, that unit you tests should have bearings/bushings/motor busted.
The noise of TO unit itself is a LOT less than the noise made by 500 grams of beans turned at 60 rpm by two paddle.
You can hear FC without any effort.

AMRoberts wrote:

renatoa wrote:

... Using a TO lid as heating source is better than a hotgun imo ...

Assuming you have the part in-hand, how do you rate the TO's noise compared to typical heat guns and air popcorn poppers?

Just curious, so far I've run across one used TO at a Goodwill store, an older "Galloping Gourmet" model. Since they had a test outlet at the store I cranked it up. Unit ran, but the noise level seemed in the same ballpark as my hot-rodded air popper (the current roaster) and my heat gun. I was wondering if the noise level was nominal for all such TOs or if I was listening to an older and/or badly worn unit.

Cheers,
Alan
 
Jump to Forum:

Similar Threads

Thread Forum Replies Last Post
Roasting Coffee Roasting Coffee 2 01/16/2019 6:02 PM
roasting with popper - help installing dimmer Popcorn Popper roasting 2 01/04/2019 8:39 PM
Repeatability Issues Due to Chaff Combustion During Roasting?? HotTop Roaster 5 12/31/2018 8:14 PM
Need advice on Kenya AA roasting About this forum, The Art of Roasting 3 12/18/2018 9:46 AM
Roasting in the Old Days New Members say hello or you may update your profile. 3 12/16/2018 7:49 AM
Homeroasters Association Logo, and all Content, Images, and Icons © 2005-2016 Homeroasters Association - Logos are the property of their respective owners.
Powered by PHP-Fusion Copyright © 2019 PHP-Fusion Inc
Released as free software without warranties under GNU Affero GPL v3
Designed with by NetriX