SC/TO Profiles / Q&A / Tips & Tricks

[milowebailey]

Nicely Done Ramzy

You'll be graduating from the air popper and moving into a whole new experience.  I'm guessing you'll be pleased you did.

[sea330]

I found if you position the bean cooling system close and at the right height makes it easy to dump with a permanently installed thermocouples, I use a k type 20 gauge thermocouple wire. This gauge wire seem to hold position better then fine wire thermocouples. Setting the thermocouple about mid way from center to outside of the pan works best. Temperatures run a little hotter on the Extreme out side of the pan. A tiny compression fitting mounted on the spacer to pass the thermocouple wire threw works, TC stays in position very well, tried mounting TC on the bottom of pan didn’t work out for me. There are surface mount thermocouples but there kind expensive for what we do with these things

[RamzyB]

Hi, I made a chaff collector and a bean vacuum to save having to dump the SC.  Please follow this link to view the pictures:


http://imgur.com/a/CIGFE

The TO and temperature sensor arrived today and I will be able to roast once the silicone adhesive is cured (see pictures to see why I used adhesive).

thanks,
Ramzy

[milowebailey]

Ramzy

How do you plan to cool the beans?  I don't think the trip through the PVC pipe will be enough to cool them, they will continue to roast (unevenly) for quite a while in a glass jar.   You'll need air blowing through the beans for 3 - 10 minutes to cool them.

[RamzyB]

The glass jar is not for holding hot beans.  It is only to catch them for transfer into the cooling system I made and have been using for the hot air popcorn poppers.  The two mesh strainers in the picture let me do double batches of coffee in the hot air poppers, but will serve pretty well for cooling the larger batches from the SC/TO.
thanks,
Ramzy

[milowebailey]

The glass jar is not for holding hot beans.  It is only to catch them for transfer into the cooling system I made and have been using for the hot air popcorn poppers.  The two mesh strainers in the picture let me do double batches of coffee in the hot air poppers, but will serve pretty well for cooling the larger batches from the SC/TO.
thanks,
Ramzy

Now I know the rest of the story.

[Aromajunkie]

Ramzy, the bean vac accessory is genius. I'll be making one of those. I like your "keyhole" latch for the spacer ring too. Thanks for the pics.

AJ

[sea330]

What a great idea, bean vac system to remove the beans, I will be implementing that method on my system, stroke of genius on your part. Thanks for going to the trouble of documenting with great picks and a most excellent job of tech writing on your build.

Rich 

[peter]

Ramzy, I can appreciate the work and creativity going into this project.  Great fun, isn't it?

Was there something specific that was keeping you from dumping the SC?  The vacuum is very slick, but can't see the advantage in it, and believe dumping would've been quicker and easier.

I like the keyhole ejector locking mechanism too.  I was thinking of something along those lines until the lazy gene forced me to just use a stick.

This isn't directed at you per se, but every time I see a shaft mod or a new shaft design, even one as slick as yours, I'm left scratching my head thinking a 79cent hanger bolt screwed into the stock shaft will work for years and years, and leave all the stock geometry intact for the hole in the pan and the arms.

[sea330]

Im with ramsy on this one, temps at 440 deg F+ will take it's toll on plastic, it will outgas even if it don't look like it. I have inspected after several roast and there is heat damage. We all spend allot of money on brewing equipment that dosn't have plastic in it, why wouldn't we feel the same about roasters. Anyhow nice job ramsy,

[peter]

I'm not saying anyone's wrong for making metal shafts, just that there's a whole lot more work going on that in turn creates other obstacles.  I know that work in designing and creating is fun, but isn't all that necessary when it comes to the SC shaft.

[RamzyB]

Peter, you're correct that what I did was not necessary (both the metal shaft and the bean vacuum).  However, it was indeed, fun.   I am a tinkerer and can't help messing with stuff.

So, I wanted to vacuum up the beans because the metal shaft doesn't fit all that tightly in the SC, so I think it would likely fall out if I dumped the beans.  Instead of  fixing the loose fit, I opted to try the vacuum idea, just because it is cool.

I think the jury is still out on the all metal shaft.  I don't know how well heat will travel down the shaft.  It could very well be that it damages the nylon square drive on the motor.  If so, I will report back so others don't make the same mistakes as me.  Since I still have the original plastic shaft, I can always implement the hanger bolt design if the metal shaft turns out to be a bad idea, and assuming it doesn't actually ruin the motor.  BTW, the motor is identical to the motors used in microwave ovens to scatter the RF waves.  These are typically installed in the top of the microwave.  If anyone has a failed microwave handy, salvage that motor.

Cheers,
Ramzy

[sea330]

Peter, you are the guru when it comes to stir crazys mods,  you can throw together a hanger bolt shaft assembly in a few minutes. I have been playing with an idea of  taking a 3” ¼” drive  extension,heating it up to remove the hardness and running threads on one end. Using a brass bushing  11/16 od 5/16" id, locking it down with nuts on both sides of the bushing, a brass washer bigger then the passthrew hole in the pan just to keep it from flopping out, then fab a stir arm. May not work but it’s worth a try. I have been using a metal shaft going on 6 months, haven't had a problem yet, However I use this roasting method maybe once or twice a month just for sampling, and only 1 to 3 batches in a row at the most. I think you will be good if you don't plan on making this a heavy use production roaster. Off course over the holidays roasting for family and freinds gifts can push things. If anybody needs drive motors for these things I have a bunch of them, maybe 12 or more

Rich

[peter]

When I first read Ramzy's shaft mod, I was wondering if a really cheap China-made extension, like something from HF would still have the hardness problem.  I think your idea of turning some threads further down on the extension would safe a few steps.  From there, I'd think about using a nylon spacer where the shaft goes through the SC bed.  Maybe even something 1/4" thick with a step so that part of it can peek through the hole.  Know what I mean?

The little spring that rests inside the shaft where the motor drives it, can be an important part of the whole setup, to keep pressure on the flange of the shaft against the bottom of the SC bed.  I know that when I remember to use that instead of lose that, things work better.

I still don't think heat transfer down a metal shaft to the motor, even over prolonged roasting sessions is that much to worry about.  I doubt that they chose that motor in the stock units to be rated for use in high heat, but that whole bottom unit gets purdy durned hot even with the plastic shaft and the motors don't seem to mind.  So I don't think there's all that much more heat getting down there with a metal shaft.

[RamzyB]

Hi, I made my first batch in the SC/TO.  I used 1 and 2/3 cups of Kenya Thunguri.  I tried to follow the roasting profile given early in the SC/TO thread, but the thermometer probe seemed to be measuring more of the air temperature and not so much the coffee temperature.  Total roast time was 17 minutes and it went into first crack at around 11 minutes and it was truly slow.  I initially set the TO at 300 to preheat, then 400 to roast.  After first crack began, I reduced the oven to 350.  The end roast was darker than I like (but I never detected any second crack activity), so I will try roasting at lower temperatures.  I chewed a couple of beans and got a nice fruity/wine aftertaste, so have great hopes.  Why have I not heard of anyone chewing the beans like that?  Am I an uncultured cretin?

The stir arms kept reversing direction as someone had warned they might.  That doesn't seem to hurt anything as long as they keep moving, but it seems like I am at the upper limit of how many beans I can put in, and it would be nice to put more in so the temperature probe is buried in the beans.  I'd like to find out more about a more powerful motor that someone had mentioned.

The chaff collector worked great, didn't lose any beans through the chute and had a nice pile of chaff right outside the opening.

There was hardly any smoke compared to the hot air poppers.

The vacuum pickup worked really well until it clogged and I had to turn it off and shake it to move the beans and chaff off the metal screen,  Then it finished up OK.  There was some chaff on the metal screen in the vacuum pickup and I just cleared it with compressed air.  I think the vacuum will have trouble if it is used to pick up too much coffee with chaff in it.  I will try a more gradual pickup of beans to see if I sucked up too many all at once.

thanks,
Ramzy