Rebuilding NEsco Coffee Roast ++
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Rebuilding NEsco Coffee Roast ++

by datagen24 on Fri Aug 23, 2019 10:11 am

Hi, I have a NEsco Coffee Roaster, now discontinued. this unit is nice as it includes a smoke control system that makes it so it does not have to be vented.

The issue we have is the main motor is shot and replacing the motor is proving impossible (103v DC dual ended motor, the part numbers do not search result in any find)

SO we want to replace the motor, right now the dual ended motor runs the main blower and the agitator through a belt drive) we could replace the agitator drive with another motor turns about 90 rpm
then add some sort of other blower.
I am trying to find a blower I can control with a PI that will stand up to the heat involved, ~520 Degree F. the machine uses a semi closed loop air system, vents on the side of the blower housing allow for air pressure changes.
I can easily fit an 80mm fan or 3 in the blower housing the current steel fan is about 100mm.

My Goal is to build a new control for the system, and allow me to create many different roast profiles, the original machine the the controller only turned on or off the two heating elements. temp is measured at the input to the roast chamber via a small thermistor.

I would want to measure the input and output temp, so 2 pyrometers i think would be better for the purpose.

this is very early in the sketches any input people can would / provide would be wonderful

thanks in advance

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Joined: Fri Aug 23, 2019 9:48 am

Re: Rebuilding NEsco Coffee Roast ++

by adafruit_support_bill on Fri Aug 23, 2019 10:29 am

For temperature measurements in that range, RTDs will probably give you the best accuracy. Second choice would be thermocouples.
The code in this guide is a good example of PID temperature control:
https://learn.adafruit.com/sous-vide-po ... iduino/pid

A web search for high temperature blowers is likely to turn up mostly larger industrial units. You might be able to scavenge something of an appropriate size for your project from a hot-air gun.

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Please be positive and constructive with your questions and comments.