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Nesco 'Professioal Coffee Roaster
oldgearhead
This was formally know as the Zach & Dani roaster. I modified a couple of these and used them for a year or so. The modification was to wire the heating element to a variable auto-transformer, so I had control of the heating element. As delivered the unit is too hot during the 'cooling' phase and not hot enough during the roasting phase, and the maker won't sell you internal parts.

Lots of info here:
http://www.sweetm...5&t=14
oldgearhead attached the following image:
roasterstation2_3.jpg

No oil on my beans...
 
JackH
It seems like a nice machine. I have repaired several small roasters for friends, mainly the iRoast. A lot of the problems with these small roasters are overloading, not cleaning/maintaining and treating it like a commercial roaster (No cool down between roasts).

I really like the mods you did to the Nesco.

--Jack
 
oldgearhead
..It's an okay roaster for up-to 170 grams. However, do pay attention to the words on the front "DO NOT LEAVE THE ROASTER UNATTENDED!", because you can never tell when the tiny blower/auger drive motor may give up or how much heat your particular, non-ceramic, cheap, bearing will tolerate before coming loose.
The smell of burning plastic is unpleasant.

..also I was not successful in winding new heating elements for this beast and "The Mental Ware Company" will NOT sell you a new element, unless you send in the entire roaster and pay them the parts and labor.

Best feature is the roasting chamber design.
oldgearhead attached the following image:
roaster_tc_2.jpg

No oil on my beans...
 
JackH
I see American Harvest is part of Nesco. I own one of their cooking ovens and they were good about spare parts in the past...probably not anymore.

Some companies will sell spare/repair parts and others won't. Any chance of finding a suitable replacement that will fit in the housing? You have probably been through this already.
 
snwcmpr
So many things are now made out of country that they may not even have the parts.
But, you may try calling and asking the receptionist to connect you with the repair or parts dept, not customer service. I did that a few years ago when I called Casio, and got a new crystal instead of paying an authorized service center 3 times the amount to do it for me. I told the guy in the parts dept, I worked in factories all my life, I think I can handle the crystal replacement.

Ken in NC
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
Maturity
I have one of these machines and I find that even the default setting of 20 minutes burns the beans. I can't even imagine 28 minutes, that would leave me with flaming piles of ash. In reading the first post, is this due to the cooling stage being too hot?

My thought has been to build a device to monitor the temperature and control the heater to limit it to avoid the burning. By burning here I am referring to charcoal spots on beans that negatively affect the taste if I don't sort through

One other question for the Nesco experts... Can I bypass the converter and just directly vent from the top of the glass sleeve? My darling spouse does not like the smell left after roasting beans. Yes, you can "do it in the garage" but those -30C days in the winter are not conducive to me keeping an eye on it - plus that much of a temperature delta may make the outcome even less predictable.

Thank you for any thoughts or advise.

M
---
Green to Brown: Nesco "Professional"
Whole to granules: Breville "Smart"
Dry to wet : Breville BES920
 
Koffee Kosmo
Is it possible to open the lid for quicker cooling on the Nesco?
reason I ask this is that users of the Behmor 1600 open the door so the roast doesn't get away from them in the cooling stage

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
https://forum.hom...ad_id=1142

https://docs.goog...lide=id.i0
Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
Maturity
The lid is the conduit for smoke back to the cat unit that presumably reduces the smoke If you lift the lid then there is a a micro-switch that stops the machine operation. However, it is possible to press this and things continue. In fact I have been thinking of making a device that will sit on top and pipe the smoke directly to an exhaust fan so that I can roast indoors in the winter.

In the article listed at the top of this thread it talks about the Nesco being slow when run at 110v. Since our power seems to be in the around 125v I wonder if it is actually running too hot.
(http://www.sweetm...5&t=14)

On thing I did try in the past is to put washers under the bean cavity to blead off some of the hot air. This does make it longer to roast but I think the air is still simply too hot.

If I have done it right you will find attached a picture of the effect that I am talking about:

M
Maturity attached the following image:
beans_4.jpg

---
Green to Brown: Nesco "Professional"
Whole to granules: Breville "Smart"
Dry to wet : Breville BES920
 
soundklink
https://www.googl...ffee+beans

http://www.home-b...13587.html

Had the same problem, the above should help
Rancilio Silvia-PID, Rossi RR45, manual Drum roaster-gas
 
oldgearhead
Did you clean the top assembly?
Did you read the entire SM Nesco section (above link)?
 
Maturity

Quote

Did you clean the top assembly?

Yes, and the roasting chamber as well, both after *every* use. The top is not scoured like the picture shows but it is clean with no oily residue.

Quote

Did you read the entire SM Nesco section (above link)?

Yes, at least twice ;)

My Nesco unit has done this ever since the very first use when I ran it at 20 minutes (the default) and got an unusable batch of burnt beans. I measured the line voltage this morning and by the display on the UPS at about 9:30AM it was 122 volts. I have seen it close to 130 and I did not look yesterday when I last did beans.

M
---
Green to Brown: Nesco "Professional"
Whole to granules: Breville "Smart"
Dry to wet : Breville BES920
 
Maturity
Today has been a successful day of experimentation. I was running the Nesco with the lid off and the switch held down so it could run. Also I made a device that would allow me to limit the heat it generates. Reducing the heat to where the machine was only drawing about 600W to 650W instead of almost 800W made a HUGE difference. No craters, no tipping, wow. The roasted coffee smells better, I can't wait to try it.

Next I plan to put a thermocouple into the airflow being injected into the roasting chamber and control the heat based on temp rather than just using a watt meter. Looking at the insides I'm even wondering about simply replacing the existing control board. In theory then I should be able to detect a stalled motor for and shut it down to avoid the roasting plastic issue ;)

BTW, thanks to soundklink for the link to the pictures that describe different issues.

M
---
Green to Brown: Nesco "Professional"
Whole to granules: Breville "Smart"
Dry to wet : Breville BES920
 
oldgearhead

Quote

Maturity wrote:

Today has been a successful day of experimentation. I was running the Nesco with the lid off and the switch held down so it could run. Also I made a device that would allow me to limit the heat it generates. Reducing the heat to where the machine was only drawing about 600W to 650W instead of almost 800W made a HUGE difference. No craters, no tipping, wow. The roasted coffee smells better, I can't wait to try it.

Next I plan to put a thermocouple into the airflow being injected into the roasting chamber and control the heat based on temp rather than just using a watt meter. Looking at the insides I'm even wondering about simply replacing the existing control board. In theory then I should be able to detect a stalled motor for and shut it down to avoid the roasting plastic issue ;)

BTW, thanks to soundklink for the link to the pictures that describe different issues.

M


So if you are running without passing the exhaust through the afterburner,
I do not see why you are not reading the current draw of the afterburner.
Did you disconnect the power from the afterburner?
From my old notes:
__Max safe current for main heating element = 560 watts @ 148 volts
__Stock main element current = 440 watts @ 120 volts
__Afterburner current = 220 watts
__Motor & electronics = 110 watts

Measured wattage of a stock CR 1010PR @ 121 VAC supply = 770 watts.

I roasted a lot of coffee with 3 or 4 highly modified Zach & Dani machines.
I simply moved the main heater connections to a 20% boost variable auto-transformer and left every thing else the connected. I found that if the drying and finishing phases are performed at a lower main heater wattage tipping will not be a problem. However, the 'ramp to first crack' phase needs a higher than stock wattage (500+) to complete a nice roast.

A BMT probe may be easily mounted in the chaff cup.

I just cannot see how not closing the top lowers the wattage.
Did you measure the wattage 8 minutes into the roast?
What was the voltage?
//
oldgearhead attached the following image:
dsc_3487.jpg
 
Maturity
Hi Oldgearhead,

For this test I did not disengage the heater in the cat. Previous to this I had tried just setting a small fan on the top of the roasting chamber to increase the airflow and this alone helped a lot bit I don't think the fan would take much more of the heat ;)

The cost of a variac appears to be about 2x that of the Nesco so I'm unlikely to go that route. However thinking about the cat heater I am now wondering if it could be used as a pre-heater. I'll have to see how the air is drawn in for the main heater and if it can be mechanically modified to pull through the cat.

I see how you have done the temp probe. What I was thinking of was just slipping it under the chamber to measure the airflow heat - mostly to make one less thing to clean later ;)
---
Green to Brown: Nesco "Professional"
Whole to granules: Breville "Smart"
Dry to wet : Breville BES920
 
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