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Topic: The Uglyroast needs your help (22 msgs / 983 lines)
1) From: Derek Bradford
Hi All,
I've been working on the roaster for the past day or so, and I've
arrived at a bit of an impasse.  I would appreciate any pointers or
ideas you might have.
The current roaster has a motor attached at the end of a shaft, but
not attached directly to the roaster housing.  I disconnect the shaft
to dump the beans.  I would instead like to attach the motor directly
to the housing, so that when I tip the roaster to dump the beans, the
motor tips with it.  I find myself facing a couple problems.  (When I
say "directly to the housing", I actually mean connecting the motor
assembly to the same unit as the housing, unless there is a way to
overcome the heat of the housing, in which case I'd be delighted to
bolt it directly to the back of the roaster wall.  I would consider
this dream option #1.)
1: The motor itself.  It's a fan motor, and it just doesn't have the
torque to rotate the drum stably in the long run.  Put lightly, it
won't last, and since I'm in redesign, I want to fix that. 
Unfortunately, I know little about electric motors, and don't know how
to go about buying a suitable one and controlling the rpms.  This
place has been recommended to mehttp://www.surpluscenter.com/home.asp?UID=2005091410153692, but I
don't know enough to choose and buy a motor.  Specifically, I don't
know how to control rpms.  Can that be as simple as putting a dimmer
switch on the circuit and reducing the voltage?  I know a variac would
be ideal, but if it works for lights, can it work for small AC motors?
  I don't want to break the bank; I'm all for simplicity.
2: Well, I guess I covered that in point 1.  I don't know how to control rp=
ms.  
So give me your best...I'm looking to have some fun and come up with
something really good.
Thanks in advance,
--Derek
-- 
The Uglyroast 2 Coffee Roaster.  ...Now 40% less ugly!http://uglyroast.atspace.com

2) From: tom ulmer
Derek-
I don't know how accessible a rotisserie motor and spit is for you but they
work quite well and can be easily adapted. If you can find one to view, I
believe you will readily see what I mean. There are budget models available
in the states for approximately $30.

3) From: Matthew Price
On 9/14/05, Derek Bradford  wrote:
<Snip>
You have two problems which can be overcome with one solution. 
There's no reason to try to source a motor that can take the heat and
put out the kind of power that you are requesting.  You will need to
build a gearing/pulley/chain system so that the motor ends up geared
down and is also at a safe distance from heat radiation.  You could
still mount this to the roaster so that it rides along with the drum.
Also try adding the phrase "gear motor" to your scavenging vocabulary:
those are motors with a gearing house attached directly to the motor's
housing.  Usually that also means a tougher part with real specs for
what load it can take and at what RPM output.  Even with a gear motor
you will still need some sort of power transfer setup as electric
motors and heat are not friends.  Separating the two is always easier
and cheaper than getting them to play nice.
Matthew

4) From: Robert Avery
This is a multi-part message in MIME format.
Derek ... Here is what I would do ... would like to see the blog again =
to get a better picture of the drive end of that motor ... but knowing =
what I know traditionally ... the output shaft usually has a couple of =
mounting holes or screws to provide support for the motor, especially =
the drive end. Most of the time because of the low torque levels you can =
get away with a standoff bracket sort of shaped like C it would look =
like this ... I'm going to shape it out in letters because we cant send =
attachments on here .... 
                   xxxxxxxxxxxx
                   x   Motor    x 
                   xxxxxxxxxxxx
                           x
                           x
            xxxxxxxxxxxxxxxxxxxxxx
            x              x             x
            x             x x            x
            x             x x            x
XXXXXXXX             x             XXXXXXXXX
Hope this is clear ... you would have to mount the motor to the top and =
connect the shaft the bracket ...then the bracket to the outer housing. 
Later, Bob

5) From: Derek Bradford
The only rotisserie motors I've seen have been considerably more
expensive.  Can you provide a link?
On 9/15/05, tom ulmer  wrote:
<Snip>
ey
<Snip>
le
<Snip>
d
<Snip>
ribes) go tohttp://sweetmarias.com/maillistinfo.html#personalsettings<Snip>
-- 
The Uglyroast 2 Coffee Roaster.  ...Now 40% less ugly!http://uglyroast.atspace.com

6) From: Derek Bradford
Hi Bob,
Unfortunately, my host is updating their servers, and I'll be offline
for another day or so.  I didn't know they were doing that, but hey,
it's a free service.
For now, I've setup a page where you can see some photos of the motor
assembly. http://randompicsofmyroaster.blogspot.com/To be honest, I'm not quite sure what you mean with your
diagram/description.  Pardon my ignorance, but what's a standoff
bracket?  Google Images gives me many variations of them, and I'm not
sure what you're referring to.
Thanks,
--Derek
On 9/15/05, Robert Avery  wrote:
<Snip>
I
<Snip>
d.
<Snip>
ing
<Snip>
 
<Snip>
 
<Snip>
ey
<Snip>
le
<Snip>
-- 
The Uglyroast 2 Coffee Roaster.  ...Now 40% less ugly!http://uglyroast.atspace.com

7) From: tom ulmer
http://www.amazon.com/exec/obidos/tg/detail/-/B0001B509E/002-0615975-8038465?v=glance&s=garden&me
VPDKIKX0DER&vi=pictures&img#more-pictures
or, do a search on Charbroil 4584722 Premium Universal Fit Electronic
Rotisserie.

8) From: Robert Avery
This is a multi-part message in MIME format.
Ok Derek ... Now I see what I was looking for. You could use the same =
bracket but mount the motor differently. I see now where the screws =
mount .
Looking down from the top view !!! Picture a piece of metal bent 1/16 =
thick x 2 to 3 inches wide and the motor mounted the way you have it =
configured now ... I wish I could send you a cad drawing .. , Bob
               xxxxxxxxxxxxxxxxxxxxxxxx    
               x    xxxxxxxxxxxxxxx      x   
               x       x             x        x  
               x       x  Motor   x         x  
               x       x             x        x
               x       xxxxxxxxxxx         x 
<Snip>
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                  Back of Roaster
                              xx

9) From: Peter Zulkowski
Okay,
I have never tried this, but I noticed that my garage door motor has a 
lot of torque, is in the game for decades, and is really geared down.
They are all the time at thrift shops because things other than the 
motor wear out. They can be had (at least in LHC, AZ) for less than $20.00.
Seems like there may be other metal parts there to frame or mount the 
whole drum assembly. Hmmm, but you probably need a welder though..
Just some thoughts,
PeterZ
Derek Bradford wrote:
<Snip>

10) From:
Hi, Derek-
I've been watching the progress of your "UgRoaster" with a lot of respect=
 
for your ingenuity and resourcefulness.
I have one of the SurplusCenter catalogs, and there's a lot of neat stuff i=
n 
it. The gearmotors are what you should be after, I think. A gearbox output=
 
speed close to the drum rotation speed you want, with gobs of torque.
If you spin the drum directly on the motor shaft, the speed regulation will=
 
be very poor if you run the motor slow enough to give a tumbling rather tha=
n 
centrifuge effect. A DC or "universal"- AC/DC motor will be series wound,=
 
with brushes. Such a motor could be controlled with lower input voltage tha=
n 
the rated voltage, but the torque available would drop like a rock.
A motor speed control would stabilize the motor, but would boost you out of=
 
the "aconomical" category. Could you utilize a cheap VS drill motor? I was=
 
going to use one for my grinder design, but I'd hate to tie up my 1/2 inch=
 
Milwaukee.
Gearmotors are good, IMO.
Cheers -RayO, aka Opa!
One good shot deserves another
On 9/14/05, Derek Bradford  wrote:
<Snip>
 
<Snip>
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the 
Wichita WurliTzer

11) From: Michael Dhabolt
Derek,
 I will have to agree whole-heartedly:
 >Gearmotors are good, IMO.
<Snip>
How is service using eBay over there? Within the last six months I've won=
 
auctions for three different gear-motors / motors with attached reduction=
 
gears for use in different projects. Each time I found final drive speed 
well within the range I was looking for. The motors I've purchased have bee=
n 
in the 1/10th to 1/6th HP range with final drives in the 30 to 80 RPM range=
. 
The most expensive of which was $12 (of course that is without shipping 
costs). There are several varieties of speed control that are still usable=
 
to fine tune speed without moving the motors RPM substantially away from it=
s 
design speed and losing power / torque.
 Mike (just plain)

12) From: Michael Dhabolt
Derek,
 I will have to agree whole-heartedly:
 >Gearmotors are good, IMO.
<Snip>
How is service using eBay over there? Within the last six months I've won=
 
auctions for three different gear-motors / motors with attached reduction=
 
gears for use in different projects. Each time I found final drive speed 
well within the range I was looking for. The motors I've purchased have bee=
n 
in the 1/10th to 1/6th HP range with final drives in the 30 to 80 RPM range=
. 
The most expensive of which was $12 (of course that is without shipping 
costs). There are several varieties of speed control that are still usable=
 
to fine tune speed without moving the motors RPM substantially away from it=
s 
design speed and losing power / torque.
 Mike (just plain)

13) From: Michael Wascher
Garage door motors are designed to run very intermittently. It won't last=
 
unless you derated it a lot.
On 9/14/05, Peter Zulkowski  wrote:
<Snip>
 
<Snip>
-- 
"Not all things that are countable, count, and not all things that count,=
 
are countable". Albert Einstein

14) From: Michael Wascher
Derek,
Speed control depends on the type of motor. The most common AC motors are=
 
called synchronous motors because their speed is synchronized to the line=
 
frequency. It's possible to vary speed by varying frequency but the 
controllers are expensive and commonly available motors are highly optimize=
d 
to standard power line frequencies.
Universal motors, called that because they run on AC or DC, are the older=
 
style power tool motors that have brushes. Speed on these can be varied by=
 
varying voltage but slow it too much & you lose torque.
Gears, belts, pulleys ... any mechanical way to control speed is most 
workable.
On 9/14/05, Derek Bradford  wrote:
<Snip>
 
<Snip>
-- 
"Not all things that are countable, count, and not all things that count,=
 
are countable". Albert Einstein

15) From: Derek Bradford
Thanks all for your suggestions and clarifications.  The idea of a
gear motor is exciting, but before I go there, I'd like to pick your
collective brains on rotisserie motors.  Why rotisserie motors? 
Because they appear to require less work to install and support.  That
translates into fewer potential failure points.
My question is this:  Currently, my drum is rotating at 20rpm.  I'm
pretty happy with that; there don't seem to be any hot spots, and it
seems like a good speed for its overall size.  Rotisserie motors seem
to rotate at somewhere around 5-8rpm, which is quite a bit slower. 
So, I have a couple questions about this:
First, can I compensate for the slower revolutions with more vanes
inside the drum; something to agitate the beans more and keep them
from sitting around too long against the drum wall?
Second, can I run the rotisserie motor on higher-than-specified
voltage and increase the rpms?  During robotics competitions, it's
pretty common for us to run 3 volt DC motors on 12 volts to get a
great deal more speed out of them.  They always survive the
competition, but I don't know what they'd do in the long run.  For the
record, we normally do that with small servo-type motors.  The
difference here lies in that I'd be using AC, and I'm fairly certain
that pumping double the AC voltage through the motor would make it
rather unhappy with my decision.
Comments?  Suggestions?  As for gear motors, there do seem to be quite
a few that look good, and one on eBay in particular that might do the
trick:http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&rd=1&item=754593122=2&ssPageName=STRK:MEWA:IT
Unfortunately, it's kinda big and looks pretty heavy; I was hoping for
something a little lighter.  I have yet to see a geared motor that
doesn't come with plastic/vinyl cogs, so if I were to buy one of
those, I'd have to replace the bits with metal ones.  That makes
things more complicated, and expensive (multiple shipping to Korea =
lots of money).
Thanks,
--Derek  
On 9/15/05, a whole bunch of people wrote a whole bunch of stuff,
which has been snipped:
-- 
The Uglyroast 2 Coffee Roaster.  ...Now 40% less ugly!http://uglyroast.atspace.com

16) From: Johnny Kent
At 08:52 AM 9/14/2005, Derek wrote:
<Snip>
IMO, you can't beat the easy availability and price of a motor 
vehicle windscreen wiper motor. Mine cost  50 roasts. It  has 2 
speed settings by wiring different terminals that I found by trial 
and error. One about 60 rpm and the other about 120 rpm. It's 12 volt 
dc so I used an  old PC power supply 12 V rail to run it.
These are of course gear motors and they have high torque as they are 
designed to drive those wipers  about 15-18 inch out from the spindle 
and they will take continuous duty. I'll bet you can pick one up for 
a song at your local auto wreckers....
You might want to distance it from the direct heat by use of belts 
and pulleys as someone else suggested.
Mine will be converted to drive the drum of my next drum roaster 
which I'm more inspired to do after reading your story.

17) From:
"...can I run the rotisserie motor on higher-than-specified voltage and 
increase the rpms?" No! It probably has a shaded-pole induction motor, whic=
h 
means it depends much more on the line frequency than voltage. All motors=
 
run best at their rated voltage. Even variable speed tools run best when 
they're running "full-tilt."
Why not get a 3/8ths inch electric drill- that's definitely a gear motor 
that has no plastic gears to cause you any worry. It's a classic universal=
 
AC/DC motor, but the variable speed control would just be "ON-OFF" if you=
 
run it on DC. You could always rig it so the drill could be used normally=
 
when you're not roasting.
What's wrong with a "5-8 rpm rotisserie motor?" Have you tried one with bad=
 
results? If it's easier to get working, That's Your Answer! 
Lots of people roast coffee in skillets and dog bowls with no RPM at all.=
 
Who needs RPM? Punt!
Cheers, and Happy Jury Rigging -RayO, aka Opa!
Eschew Bad Grinders! One good shot deserves another- like two 18 second 
ristrettos of 14g of Panama Carmen Estates 1700-1800 Mtr. Just touched 
Second in 8:50. Whoopie- Gold ! !

18) From: Derek Bradford
On 9/15/05, raymanowen  wrote:
<Snip>
l
<Snip>
I have one I'd be happy to use.  How about some clarification on speed
control: You say DC would be on/off.  I can get a comfy 12 volts DC
from a computer power supply, or 5 volts just as easily.  Is that in
line with your suggestion?
  
<Snip>
bad
<Snip>
My old design rotated at about 6 rpm, and I think I had hot spots. 
However, I only had 2 vanes last time; this time I have 4.  It might
be enough at 5-8, especially with the 4 vanes.  However, at 20 rpm my
roasts are quite consistent in colour, and that's something I'd like
to preserve.  That said, however, it may not have anything to do with
rpm at all.
  
<Snip>
.
<Snip>
I do!  :)
--Derek  
-- 
The Uglyroast 2 Coffee Roaster.  ...Now 40% less ugly!http://uglyroast.atspace.com

19) From: Derek Bradford
I've seen these, but I think a motor that large (they are kinda hefty)
would require more stability than my roaster currently has to offer. 
I'm considering building a stronger frame for it, but I'd like to try
to avoid belts and pulleys if I can; more points for potential
failure.  Belts and pulleys always bring the cool factor way up,
though, so maybe...
On 9/15/05, Johnny Kent  wrote:
<Snip>
ribes) go tohttp://sweetmarias.com/maillistinfo.html#personalsettings<Snip>
-- 
The Uglyroast 2 Coffee Roaster.  ...Now 40% less ugly!http://uglyroast.atspace.com

20) From: Alchemist John
At 20:24 9/14/2005, you wrote:
<Snip>
That is why I like and use them.  Ease of installation and use of 
something that was designed to do what we are using it for :)
<Snip>
20 is a good speed, but 6 rpms works just fine also.  That is what I 
use. I have 6 1/3 vanes in my roaster drum.  Plenty of agitation and mixing.
<Snip>
Oh, see above.
John Nanci
AlChemist at large
Zen Roasting , Blending & Espresso pulling by Gestalthttp://www.chocolatealchemy.com/

21) From: tom ulmer
I run the rotisserie motor at its intended speed and I am quite pleased with
the results. There is something about 8-10 RPMS that is comforting to me. I
roast in the evening and see it as my time to relax. I have read posts from
those who believe 57 RPMS is the perfect speed, but I think that is more for
chaff extraction. An even roast can be accomplished by proper heat
application and bean agitation and the matrix of possibilities...
I have more vanes in my drum because it is solid and considerations were
given to agitation. Whether I got the proper proportions of drum size /
density / and rotational speed to vane size and number correct? I don't
know. It works and the results are quite tasty.
I am happy with the rotisserie motor and all of the appurtenances it came
with made it quite easy to integrate.

22) From: Robert Avery
This is a multi-part message in MIME format.
Derek ... just jumping back to another reply and agree with ... I have =
used a car wiper motor for some other projects also ... they work quite =
well. They have some good torque as well. They are also easy to mount. =
If you just use a 12 volt power supply you will find you would be in =
business. I also found that the VW type are small and are readily =
available. Also ... On that picture ... If you want I can sketch =
something and pdf file it to you ... Later, Bob


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