300g in a Hottop

[yoma]

Re: 400g in a Hottop!

... try 400g of Indian Tiger Mountain, which is an A size bean, so nothing like a Peaberry!

Whats the power rating of the newer hottop models?

My old hacked D-model is marked 700W (Ill confirm this with a power meter next roast).

Ive always wondered about running a more powerful heater element / power board to increase roast capacity.

I roast 225 to 230g.  I can get to FC in about 9 minutes when desired and theres head-room to ramp up in the later stages.

[beanflying]

Re: 300g in a Hottop

For additional info. Hottop Model d

Just finished running 3 back to back 300g roasts in my Hottop without any problems. Indian Tiger A 20.30 a few under roasted beans and not all that even (I think a longer warm up might be needed?). PNG Wahgi 22.00 nice even roast. PNG Jikawa Peaberry dumped at 21.30 nice even roast.

Baens very cool after the standard cooling cycle around 40 degrees.

[gregpullman]

Re: 400g in a Hottop!

... try 400g of Indian Tiger Mountain, which is an A size bean, so nothing like a Peaberry!

Whats the power rating of the newer hottop models?

My old hacked D-model is marked 700W (Ill confirm this with a power meter next roast).

Ive always wondered about running a more powerful heater element / power board to increase roast capacity.

I roast 225 to 230g.  I can get to FC in about 9 minutes when desired and theres head-room to ramp up in the later stages.

My factory B is rated at 740W but I believe the heater elements are unchanged. Its likely the newer motherboard is a bit more power-hungry. The heating elements are plenty powerful enough anyway - in the D the element doesnt run at full power for all that long, and as I mentioned even in this 400g roast on the B it was only running 60% power for most of the roast. Since you dont have a cyclone of air to combat like you do on the Gene, you dont lose anywhere near as much heat so you dont have to put as much power in to get the same amount of heat in the drum.

BF: The D and the P *potentially* give slightly less even results than the B because they control the heat by switching the heating power on and off (as the Gene does) so beans can be exposed to much higher temperatures as they pass the element than the drum will ever get to. By contrast the B provides analogue heater control where the output power is actually reduced rather than just changing the on/off duty cycle. So with the D and P a range of (comparatively) very hot and very cold temperatures average out to produce a smooth curve, whereas the B provides continual heat and simply varies how much power is applies to the element to achieve that. The image below is a collection of screenshots of a CRO attached to the heating element of my Hottop B where the power was taken through a full sweep.

I should say that Ive done many roasts with the P controller installed and cant say Ive noticed any marked uneveness, so I dont think the different heating methods necessarily has a great effect on the eveness of the roast, but all other things being equal the B should provide a more even result.

Greg

[beanflying]

Re: 300g in a Hottop

Hi Greg,

Time to get on to my little USB project . The board and SSR arrived last week but I havnt had a chance to have a play yet.

I had only been running 250g Green for roasts up to tonight but it seems that 300g is OK so I will stick to it for a while.

[yoma]

Re: 400g in a Hottop!

BF: The D and the P *potentially* give slightly less even results than the B because they control the heat by switching the heating power on and off (as the Gene does) so beans can be exposed to much higher temperatures as they pass the element than the drum will ever get to. By contrast the B provides analogue heater control where the output power is actually reduced rather than just changing the on/off duty cycle. So with the D and P a range of (comparatively) very hot and very cold temperatures average out to produce a smooth curve, whereas the B provides continual heat and simply varies how much power is applies to the element to achieve that. The image below is a collection of screenshots of a CRO attached to the heating element of my Hottop B where the power was taken through a full sweep.

I should say that Ive done many roasts with the P controller installed and cant say Ive noticed any marked uneveness, so I dont think the different heating methods necessarily has a great effect on the eveness of the roast, but all other things being equal the B should provide a more even result.

Interesting output - so it chops up the AC cycle (Ill have to research thats done).
So theres no relay on board (no clicking sounds as it switches the heat on/off on my D model).

I use 2 TCs in my hottop.
One is closer to the centre of the drum (just in the bean mass), the other closer to the drum (deeper in the bean mass).

With no coffee in the roaster the one in the center is a few C hotter.
With coffee, they soon converge and remain within 1C.

I wonder what proportion of the heat comes from:
 - the heated drum surface
 - the focused heat along the drum axis
 - heat from the element through the drum

I suspect the combination of the above has an leveling effect to keep the roast even.
When I drop the duty cycle down, I dont see any increase in difference b/w the TCs.

Anyhow - it does a great roast.

[beanflying]

Re: 300g in a Hottop

Hi Yoma,

the D will be electronically switched so you still wont hear a click even with the quiet clinking of the beans going on

[yoma]

Re: 300g in a Hottop

the D will be electronically switched so you still wont hear a click even with the quiet clinking of the beans going on

Hi beanflying,

My D-model does "click" - the controller board does the electronic switching - of the main power board.  Actually its my own controller board which provides manual roast controls - http://coffeesnobs.com.au/YaBB.pl?num=1172066309/4

Your USB project sounds interesting.

Ive got a Velleman K8055 USB controller sitting around which Ive been planning to wire in to the Hottop.  I initially built the simple controller first to get a feel for controlling the roaster directly.  But it worked so well providing great results - Im still using it 200 roasts later.

Actually I did wire up my notebook to the vellman and a 4 channel temperature logger, but I found it a bit clumsy to use as well as taking up too much bench space and wires everywhere - cant beat a couple of simple old fashioned dials.  In fact I made a note to look at using motorised POTs in my next version.

However with the arrival of the iTouch/iPhone apps, I have been tempted to move the project onto the next stage and use the iTouch/iPhone to monitor/log roasts (and even provide supplementary controls).  I can hide all the controller stuff and wifi with  the iTouch/iPhone.

[beanflying]

Re: 300g in a Hottop

I hadnt seen your mods in my searching Got to love a nice 555 project.

Drifting a little OT but I looked at the Velleman board as well but I found this one http://www.thesiliconhorizon.com/reflow.htm I had origionally planned to use a toaster oven but picked up a S/hand Hottop instead to save the metal work.

I will start a thread when I find a little time to start playing.