|NOTE: This is a basic version of the Drum Alignment instructions which covers just the basics. The full alignment procedure is available HERE.
DRUM CLEARANCE VERIFICATION
Assemble the machine (install the drum and the bearing plate) but leave the front cover off.
• Examine the distance between the drum and the rear wall of the roast chamber. It should be around 1 millimeter and no more than about 1.5mm (it must be less than than 2 millimeters) from the rear wall of the roast chamber when that drum is fully inserted into the drive coupling (this is approximately 0.05"). Be aware that this measurement is critical. To describe this less specifically, it should be as reasonably close as possible to, but not touching the rear wall.
A gap this small is difficult to see so we have a page on our website that guides you, step by step, on how to make a simple gap checking tool.
In this simplified illustration you can see the correct use of the tool.
To use the tools you just made:
• Leave the front cover off during these adjustments.
• Remove the bean loading chute cover.
• Slide the "thicker" tool tool down into the chute and insert it into the roast chamber
• Slide the end of the tool upwards so that it is inserted between the drum and the rear wall of the roast chamber.
It may take a bit of practice to get it into place. Looking into the roast chamber with a flashlight the first few times will help you find and "feel" the correct location. Once the tool is in place gently move it about and slide it up and down a few millimeters to get the feel of how to judge the gap. Now do the same with the "thinner" tool you made. Rotate the drum 1/4 turn and repeat the same checks. Repeat until a full revolution of the drum has been checked in that manner.
Ideally, the thick tool should be somewhat difficult or impossible to slide in, but the thinner tool should fit just fine with little or no effort. If both of those conditions exist then the drum is in good alignment. If not:
If the thick tool fits too easily with excessive space left it means the drum is too far from the rear wall and you need to adjust the drum clearance.
If the thin tool cannot be inserted it means that the drum is too close to the rear wall and you need to adjust the drum clearance.
DRUM CLEARANCE ADJUSTMENT
If the drum is either too close or too far from the roast chamber's rear wall in the above positioning tests, the axle can be adjusted slightly following the Roasting Drum AXLE ADJUSTMENT instructions.
If an adjustment was necessary and the drum is now properly located in the roast chamber, you may need to use the tools to recheck the spacing every two or three roasts for a while. This is because the heating and cooling cycles the roaster experiences may allow the metal to "relax" and cause the drum to return towards its original, incorrect alignment.
THE GOLD KNOB
The Gold Knob should not have to be tightened more than just seated enough against the front cover to hold the front cover in place on the machine. That is the Gold Knob's only job. If there are still scraping noises then there is a problem that needs to be addressed. If the noise is from the front of the machine then try a tiny dab of food safe lubricant on the end of the axle where it is held in the dimple of the bearing plate. If scraping sounds are still heard, follow the Roasting Drum AXLE ADJUSTMENT again.
Whenever a drum adjustment has been made you must run an "Empty Roast Test." That is a full roast cycle but do not add beans. Stay with the roaster throughout the roast, and if any scraping sounds are heard, immediately hit the eject button. Allow the roaster to cool and readjust the drum as necessary.
This page is an abbreviated version of the drum alignment process.
A more detailed, full alignment procedure is available HERE.
If you are unable to adjust the drum, if scraping sounds are still heard, please contact Hottop USA.
If we cannot solve the problem the machine will need to be returned to us for examination and repair.