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What breaks on a Hottop?
MichaelRpdx
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Posted on 01/03/2014 7:46 AM
A management accountant has completed 1000 roasts with his Hottop and described all the costs, including parts he had to replace after fires. My Hottop, according to UPS, will arrive on Monday. It is used, so whatever wears out and breaks is part way there. To avoid unpleasant surprise I'd like to know what does wear out or break on a Hottop.

The fan filters are obvious. What else? Please share.

(As the owner of a 1989 VW Westy maintenance and repair are not strangers.)
Portland, Oregon roasting with Popper to start; Behmor 2007 - 2013; Hottop 2014 - now,
What to do with TC4 parts now that I have Hottop 2k+ ??
 
ginny
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Posted on 01/03/2014 8:46 AM
Michael:

the list was:

Main Fan
Cooling Tray Base
Bean Ejection Solenoid
Panel under Chaff Tray (Minor little fire)
Bean Ejection Chute (twice)
Fusible Link
Heating Element
Temperature Sensor

I am on my 4th Hot Top, each has been sold when I purchased a new one. To date I have NEVER replaced any of the items that are mentioned on the list from your buyer. I have never replaced anything but the two filters.

Cleaning the machine after every few roasts is one key piece of advise for keeping your roaster alive.

I would be interested in knowing what items other Hot Top users have had to replace.

ginny

greenman


I have never had more then sparks from chaff. Using my small shop vac and sucking out any chaff in drum after EVERY roast, also using it on the outside of the fan has eliminated larger fires I believe.
 
ginny
Top  #3 Print Post
Posted on 01/03/2014 8:53 AM
It appears that he has perhaps used his Hot Top in a commercial environment. Clearly that should be considered much higher use of the equipment.


-g
 
MichaelRpdx
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Posted on 01/03/2014 8:55 AM
Ginny - quick correction (and I'm sorry about the ambiguity) I don't know the 1000 roast post guy. He didn't buy my, and I didn't buy his, Hottop. It was an interesting post I found through the SM forums.

I was surprised to see the guy had replaced the heating element. Those don't really have wear points, aside from the connectors.

All - it will be helpful if you include some indication of how much you roast and if you've had special events like fires and power disruptions.
Portland, Oregon roasting with Popper to start; Behmor 2007 - 2013; Hottop 2014 - now,
What to do with TC4 parts now that I have Hottop 2k+ ??
 
ginny
Top  #5 Print Post
Posted on 01/03/2014 9:45 AM
Michael:

I sold my KN-8828P a few months ago for $550 if I remember correctly.

I have never had problems with my Hot Tops. I have had multiple roasters from Fresh Roast, Fresh Roast 8 to Rosto (hated that stupid machine,) to Behmor (did not care for it too much,) and I have always had a Hot Top along with the "other" machine I may have purchased to try. My first roaster was an original Fresh Roast that I fondly refer to as the Christmas Gift From Hell.

The machines I use now are the Hot Top KN-8828B-2K and my Quest 3. I love them both and if I still had my small Pub/Wine Bar/Cafe I would have a small commercial roaster.

There is not a lot that will go wrong with your Hot Top unless you abuse it. Sure things break but I have discovered over my years with Hot Tops that they are a workhorse of a machine and are fixable if you need to fix them, parts are not an issue.

I roast about a pound a week for personal use. Sometimes it is all in the Hot Top sometimes it is split across both of my machines.

I believe you will enjoy the Hot Top because it will roast from light to Spanish without an issue.


ginny

One of my Hot Tops that I do not count when speaking of the number I have had is one the burnt up. It caught fire and burnt. It was an electrical issue inside and it was replaced by Hot Top USA. Simply one of those things that happens. I do not mention it often because I do not want to spoil a Hot Top for anyone. They are great machines and it was simply one of those things that happens.


party
Edited by ginny on 01/03/2014 9:51 AM
 
RAG
Top  #6 Print Post
Posted on 01/03/2014 10:58 AM
I have had no parts failure in 6 months of Hotop use. If you us it as intended, clean regularly, replace filters often, I believe it will last for years without failure.

The Hottop is often modified so I think before anyone answers this question directly , besides the obvious frequency question, you need to know if the machine was modified. I love the Hottop with all the information, support, and parts availability. It is a great product. For once a week home use, with a monthly cleaning (remove back cover), I think i is a good unit. More frequency of course brings more issues.

I have had mine for about 6 months and from my experience the hottop needed modification to avoid potential damage from a major design flaw. (See the RAF mod from Ciel). The electronics long term heat and debris exposure could cause issues IMHO especially in a back to back roast situation.

I have also looked at the circuitry some, and believe driving both fans with a ULN2003 is a poor choice as well. I had an unmodified unit reset at bean drop because of system power spike. This is a potential fire situation (heat element still hot no fan or motor rotation, beans at drop level). I think this was caused from a poorly designed fan circuit with too high of load, and no balast.

Caution needs to be observed that the front cover is loosely connected to avoid excessive drag on motor as the bean drum is pinched in place (no bearing).

Many people add controllers to the hottop circuit. The Hotop is not designed to support the additional current load.

All this is just my opinion of course on what I see as potential failure points in my limited use and exposure to the Hottop
 
Randy G
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Posted on 01/03/2014 11:59 AM
As far as I know, I have been using Hottops longer than anyone in the US, but not the same Hottop. I have owned one of every mode and still possess the first one ever shipped off the assembly line to the US before they were even for sale. The current KN-8818B-2K I am using has been disassembled so many time I have lost count. It may have started life as a KN-8828B but I can't remember. I have upgraded it a few times and added thermocouples and the TC4C+HTC boards, and currently Tom's RL-HTC boards. keeping in mind that I have actually washed the main motor and rear fan under running water in the sink, here are the parts I have replaced:

Main Motor - from gear box failure. The motor still ran fine.

Main Fans - One I broke from hitting the blade iirc. The plastic gets brittle with age and heat exposure over time. These can be replaced on the B with a 120mm computer fan because of the fan speed control of the B models allows you to compensate.

Other than those two I have never had a problem with the electronics being exposed to the heat.

Heating Elements - One I changed because the ceramic at the connection had broken and since it was apart anyway I changed it. The other was a but warped but also still working.

K-thermocouple - The conductors of the thermocouples are solid and VERY easily broken at the control panel end. Use caution when connection and disconnecting these!

Some of RAG's comments I will address:

I run the machine to an indicated 300+ before dropping the beans and leave the fan off until the machines recovers to around an indicated 275 or so. This has not been a problem. If the beans are dropped and the unit stops completely, there is some other problem going on. That has never happened to me. But even so, and with a hot element, the green beans would take some time before a hazardous condition existed. With a "-2" model you could just pull the emergency eject knob and shake out the beans, or restart and hit the eject button on the control panel.

The front cover may need to be left loose on SOME machines. Tightening the gold screw actually may relieve drum drag on other machines.
Adding the control boards places little or no additional load on the circuitry as the boards that I have used are driven by the USB. If that is not the case, the load is minimal and has not caused a problem. I have over 40 roasts on Tom's boards and did far more than that with Jim's setup on my main machine.

Be aware that any modification to a Hottop, including the addition of other boards or even the use of a different rear filter (I use a computer stainless steel filter screen) may create a hazard, but also can void the warranty. In any case, NEVER LEAVE A RUNNING ROASTER UNATTENDED and always have fire suppression on hand.

Life's too short to drink bad coffee.
 
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RAG
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Posted on 01/03/2014 1:52 PM

Quote

Randy G wrote:

...
Some of RAG's comments I will address:

I run the machine to an indicated 300+ before dropping the beans and leave the fan off until the machines recovers to around an indicated 275 or so. This has not been a problem. If the beans are dropped and the unit stops completely, there is some other problem going on. That has never happened to me. But even so, and with a hot element, the green beans would take some time before a hazardous condition existed. With a "-2" model you could just pull the emergency eject knob and shake out the beans, or restart and hit the eject button on the control panel.
.......


The beans are roasted at this point and not green. It does not take long for the beans at this stage to burn up. You must rapidly decide to pull the shoot if you model has the option, and shake, as the machine would not recycle to fan and turning drum. Also remember the machine is extremely hot at this point, and will probably fail again when retrying the dump. I can now reproduce this problem at anytime by increasing the load on the 12v. supply my adding a 5v arduino. The main fan load is.5a at start and that is not measuring inrush current, or the second fan load all powered by a uln2003. I reiterate that further loading the supply is a bad idea. But Randy has years of experience to the contrary, so your mileage may vary.
 
snwcmpr
Top  #9 Print Post
Posted on 01/03/2014 3:29 PM
I only used a HT a little more than 2 years, so I don't know long term problems.
The machine I sold had no mods except for a BT probe through a home made chute, per the directions Randy G has posted (somewhere).
I replaced a fan, but found that the problem was the way it was installed. I don't remember the details, but seems when I did a cleaning, I put some screws at tilt and the fan rubbed.
When I replaced it, it rubbed, so I looked further, and it was the way I put it in.
Some screws, removed during cleaning, seem like they COULD strip, so I was really careful when I cleaned it.

Ken in NC
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
Randy G
Top  #10 Print Post
Posted on 01/03/2014 3:56 PM
The two screws which are the easiest to strip are the ones that hold the rear two abs on the top stainless steel cover at the rear of the machine (the only two which hold the top cover in place). Having a second pair of hands to assist in replacing it will help a lot. The older the machine the more difficult to replace those as the many heat cool cycles will cause changes in the metal parts and they do not align quite as perfectly as when new. It is not a lot, but just enough to offer a bit of a challenge. One way to make that easier is to loosen all the screws on the front bezel (the ones the manual tells you not to remove). if you loosen them one at a time until they are free then turn each in about 1 to 1? turns, it allows the bezel to move forward just enough to give a bit more room to position the top cover. And with all screws, turning them COUNTERCLOCKWISE until they set into place and then turning them clockwise to tighten will help avoid stripped screws.

The other screws are the four that secure the main motor, particularly the two which mount to the frame (not the two which go into the rear wall of the roast chamber).

And the thermocouple mod article is HERE:
http://www.frcndigital.com/coffee/HowToHottopTemp.html

Life's too short to drink bad coffee.
 
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