Espresso! My Espresso! "HOW TO" Pages
by Randy Glass - Copyright 2006 - All rights reserved
E-mail me at frcn@cncnet.com

DISCLAIMER-As with any such modification, do not attempt to do this unless you accept all responsibility for the procedure and its consequences. By following these instructions and reading any further you accept full responsibility. I present these instructions only to document what I have done to my Hottop to allow me to monitor the roast temperature more precisely.

10- Adding Temperature Monitoring to the Hottop Coffee Roaster
      There are lots of ways to judge roast level- sound, color, smell, temperature, and even smoke level, and certainly combinations of those. For those of you who want to add precise temperature measurements of the beans, here are some directions to assist you in adding that to the Hottop.

      Although the KN-8828D roaster has a temperature readout, there are more accurate ways to measure the temperature. If you already have a digital temperature meter you are half way there. If not, here is an inexpensive one to play with. If you want something a bit more sophisticated, try one of these from Omega (I use the HH506RA). Add the KTSS-HH probe (listed on the page of the last link) from Omega or check eBay for one. I like the probe because it can be located right in the bean mass and away from the heating element and walls of the roaster.

      Here is an image of how I inserted a probe through the bean loading chute cover of the Hottop Coffee roaster. I used the 6" stainless grounded K probe as mentioned above.

      Here you can see the probe and how it extends into the roasting chamber, close to the drum. Be sure that the probe cannot be touched by the stirring fins, the drum itself, or the rear drum support arms or the probe or the drum motor can be damaged.

Here are some measurements to assist with hole placement. Use these measurements for reference purposes only. Measure twice, cut once :
RED: 35mm
BLUE: 41mm
GREEN: 4mm
GREEN: 10mm
BLUE: 12mm
The lower hole (the one in the "flap") is oval shaped to accommodate the angle of the probe. The upper one is somewhat ovalized.

      Here are the measurements to assist you in location the holes for the probe:

      I started by looking at the angle I needed by inserting the probe into the opening with the cover removed. I wanted to be sure that the probe cleared the rear drum support arms yet went deep enough to be immersed in the bean mass. I used a 1/8" Whitney punch to create that hole. After punching the starting hole in the top I used the 1/8" drill bit to run through that punched hole and leaned it over to create the angled opening. I then used that to "scratch" the location of the hole on the flap. Once that position was located I used the punch to create a series of holes along a line to make the oval shaped hole. A bit of clean up with a file and rotary tool finished the job. The probe is held in place by the tension of the slight misalignment of the holes- sometimes it pays to be slightly inaccurate.

      Use caution- If the probe is at the wrong angle or is inserted too far while the machine is running it can bend the heck out of the probe and stop the drum from rotating! Use a scratch awl to make a mark on the probe to indicate maximum safe penetration. If necessary, make some sort of clamping arrangement to assure that the probe cannot be moved from its safe depth of insertion.