I'm new to roasting and loving my Hottop. I have a question about this big fins mod. I'm trying to understand how it works to reduce tipping. When my roasts were tipping I just added them at a lower temperature and that fixed it. I'm now adding them at 200 degrees on the screen temp. Do the fins allow you to start the roast at a higher temp without charring? What is the advantage of this? So much to learn...

It agitates the beans more keeping them in the air and not on the hot drum surface. I just charge my roaster at 280-300F ET (thermocouple in the roaster). One day I will get bored and add a couple oversized fins to the drum but it has not been that big of an issue for me which is why I have not added the fins yet.

It's been a long time since I had any charring issues; the first drum fin mod might have helped with that. I measure ET with a T/C installed in the upper part of the drum & drop the beans between 360*F-400*F ET which corresponds to 235*-270*F on the HT readout.

I went to the longer 3 fin mod as I wanted the beans falling through the hot air more then I was getting with the previous mod. With the current set up the beans are tossed from the hotter upper area of the drum & funneled away from the front window. The tiny stock HT fins are pretty hopeless & do little more then stir the beans as they slid around on the lower right side of the drum.

The half dozen City+ - FC roasts I've done with the new set up have produced the best tasting roasts of several Kenyas & Centrals that I've been roasting for a year or two so I'm happy with the mod. Today I'm relocating my BT T/C slightly & making a few other upgrades.

Here's what the HT looked like yesterday:

JohnB. wrote:It's been a long time since I had any charring issues;....

The half dozen City+ - FC roasts I've done with the new set up have produced the best tasting roasts of several Kenyas & Centrals that I've been roasting for a year or two so I'm happy with the mod.

Nice work John
I'm sure you are better able to key in on a desired taste profile with much more even heat application through the improved agitation.
With the quality of beans we use and the effort with put in a profile to isolated certain flavors, poor agitation ends up producing an unintentional melange. Improved agitation seems to narrow and strengthen the flavors of a particular level while limiting bean surface damage, yielding a cleaner/richer roast.

Is it just my early-morning eyes, or do all three long fins appear to be at the same angle that would continually throw the beans towards the rear of the roasting chamber? Is that by design? if so, what is the theory behind that?

The 3 long fins are at the same angle as the stock fins. They do funnel the beans away from the front window area with most beans getting tossed mid way & a nice rotating pile covers the bt T/C. I didn't have much time to play with the new set up before Irene knocked out our power for 5 days but I will be watching the bean flow to see if I want to add a cross fin similar to the Huky drum design.
Huky Roaster?

So far I haven't seen any problems & I don't want to interfere with the bean flow when the eject door opens.

JohnB. wrote:I don't want to interfere with the bean flow when the eject door opens.

My fins go straight forward/backwards, so slightly disrupt bean ejection. Its not a big deal at all though, I just lift the front of the machine up an inch after ejecting to clear out any strays that may be lingering too long.

If I were to do it from scratch, I'd probably remove the stock fins, and install the bigger replacements in alternating directions to drive the beans forward and backward, like John's Huky Roaster reference, but maybe not that complex. My guess is this would help with efficiency of heat transfer, and would help with self ejection to boot.

rama wrote: My guess is this would help with efficiency of heat transfer, and would help with self ejection to boot.

I agree it might help with heat transfer but I don't see how moving the beans back & forth could possibly improve the ejection process. The faster the beans flow to the rear the better for a quick ejection.

JohnB. wrote:I agree it might help with heat transfer but I don't see how moving the beans back & forth could possibly improve the ejection process. The faster the beans flow to the rear the better for a quick ejection.

I meant it would be an improvement over the 'straight' fins I've got.

With the help of folks in this great community I've finally got good BT and ET probes installed. I also got some excellent advice on how to avoid scorching and tipping but I still see some issues in that regard so the next step is to do this fin mod. It's been quite a while since the last post so I was wondering if there's been any further observations or recommendations before I get to work. Thanks!