Building a kiln controller

On Thu, 10 Feb 2005 14:39:54 -0700, nJb wrote:

My kiln with Perfect fire has 3 small relays with each 2x 25 AMP poles
, so I can swiths 6 x 25 AMP if needed.
To see my kiln and controller click on the following link ( I hope it
works )
http://pg.photos.yahoo.com/ph/hnkdej...bum?.dir=/3f87



Now say you only turned off one of the legs of the circuit. Guess what,
that element still has a potential of 110 volts relative to neutral (which
in most places is tied to earth) and is capable of putting up to 30 amps
through the shortest path between the tool in your hand and your foot on
the ground (or, if you have a wood floor, your hand on the shell of the
kiln, which is quite possibly also tied to neutral.)


I solve that problem by using a 2 pole definite purpose contactor with
all safety and overtemp devices wired in the coil circuit. It cuts both
legs before the control relay. On my small kiln I turn the manual
switches off before reaching in.

Jack

nJb wrote:

A look at your website tells me that you're good at making beads. I'm
good at building things, especially glass machines and controllers. I'm
working at getting good at building things out of glass. If my glass is
ever in such demand that I don't have time to build machines, I think I
could live with building glass only. Maybe someday.

Jack


http://pg.photos.yahoo.com/ph/xmissionbobo/my_photos

Thanks, Jack.

From the looks of your fused work, you're darn good at it. OTOH, from
the looks of your kiln, you're *really* darn good at that... I wouldn't
mind having your mechanical skills. (Like you said.... maybe someday.)
--
-Kalera
http://www.beadwife.com

Aint that the truth. One day retirement will come and I will have. Lucky for
me it gets slow at the shop I work at so I have time to futz around at work.


http://www.livejournal.com/users/warmglass/


"Kalera Stratton" wrote in message
...
I think the enjoyment of building it probably makes it worth it. I just
wanted to throw those financial considerations out there, in case it was
something that hadn't come up.

I'd like to build torches, but it's something I haven't had time to look
into. Maybe in 30 years when I "retire"...

liam potts wrote:
If I where to buy a kiln controller with the cal9500 functions I think
the
cheapest I can get is a bartlet and its $600 and some change and still
does
not store as many programs. For $350 I can get a control that holds one
program or I can build the cal9500 plus I just love building things so I
can
say I did it.

"Kalera Stratton" wrote in message
...

That's a good point, if I was in the market for a large kiln or expected
that I would be. However, I was just using my particular situation with
the kiln class to illustrate the fact that sometimes, when you take your
time for labor into consideration, it's less expensive to buy something
than it is to make it.

That's what I was wondering about this particular controller; if it
costs $350 in materials, and then there's the time spent researching,
aquiring parts, and building it, is it actually a less expensive
controller? The price is not far from many commercially-available
multi-segment controllers, and what I am wondering is whether it is
significantly superior to, say, the 30-amp multi-segment controller
available at Arrow Springs? If it is, I'd love it if someone would
explain that to me, because in that case I might be interested in it
myself. If it's not, then I'm wondering if the OP had taken under
consideration that his time might be more efficiently spent making
product to sell for the difference in cash to buy the premade
controller. That's not going to be true in all cases, and for some
people, as Javahut pointed out, it's worth it for the simple pleasure of
building something yourself. I can appreciate the joy of building
things; I am an avid do-it-yourselfer around the house, but a lot of
people overlook the fact that sometimes building something yourself is
not the most economical option.

Charles Spitzer wrote:

"Kalera Stratton" wrote in message
...


I can see your point re; the curiosity, but...


From a purely financial viewpoint, I think I would have to take a good

hard look at that $150 and ask myself whether I would be shortselling
my
time by building it myself vs. making salable product. In other words,

it

might COST me more (that I could have spent on glass) to save the $150

vs.

making salable product in the same time frame. There are a LOT of
variables involved, but it's something that self-employed people (or
people who supplement their main income with their art sales) often
fail
to take into consideration in the "make it or buy it?" equation.

For example, a fellow not long ago was encouraging me to take a day

class

at the coast (a 3-hour drive) that would teach me to build a small
kiln

in

one day. The class was only $150, and materials were included (no
controller, of course.) It was a full-day class, plus of course the

drive

there and back again, and meals... that's about a 14-hour commitment.

Plus

$150. You can buy a small fusing kiln for about $400, shipped, and,

given

14 hours, there is a strong possibility that many artisans could make

the

difference between the cost of the class (plus travel expenses) and
the
price of a kiln. If I wanted to build a lot of kilns it would be
completely worth it; I only want one right now. Maybe a few more down

the

road. Not nearly enough to make the cost/benefit ratio tip in favor of

the

class.


well, except for the fact that if you can build a small one, you can

build a

big one (the concept scales). the cost to build a big one may be 2k-3k,

to

buy a big one might be 15k-20k, making your savings be a lot more.



Javahut wrote:


"Kalera Stratton" wrote in message
...



This may not adequately address many people's financial situations,

but

if you're going to put $350 plus labor into building one, what is
the
advantage over spending the extra $150 and buying one?

My line of thought usually follows the question, "What am I good
at?"
and usually when I answer the question, I find that I end up ahead
if

I

put the time into what I'm good at, then sell my work to earn money
to
pay someone else to do what I'm not good at, in this case build a
controller. Especially since, for me, it is an endeavor I would
engage
in too seldom to ever really *become* good/fast at it.



Learning how to do something new and what do you do when your

controller

fails?

If you know how its built, it is much easier to repair it when it

breaks.

That's not an "if" it breaks, its a "when". and some of us just
can't
resist the "how do you do that" thing. It's what got me into glass
in
the
first place.
and $150 buys alot of fusible glass, right?





--
-Kalera
http://www.beadwife.com



--
-Kalera
http://www.beadwife.com




--
-Kalera
http://www.beadwife.com

Ahhh, ain't that the best... I used to love it when I had slow time at
my old job and I could do my own projects using their equipment... that
was great! Nice employers, too, who didn't mind. Guess they were smart
enough to know that a happy employee does better work than a bored,
resentful one!

liam potts wrote:
Aint that the truth. One day retirement will come and I will have. Lucky for
me it gets slow at the shop I work at so I have time to futz around at work.


http://www.livejournal.com/users/warmglass/


"Kalera Stratton" wrote in message
...

I think the enjoyment of building it probably makes it worth it. I just
wanted to throw those financial considerations out there, in case it was
something that hadn't come up.

I'd like to build torches, but it's something I haven't had time to look
into. Maybe in 30 years when I "retire"...

liam potts wrote:

If I where to buy a kiln controller with the cal9500 functions I think

the

cheapest I can get is a bartlet and its $600 and some change and still

does

not store as many programs. For $350 I can get a control that holds one
program or I can build the cal9500 plus I just love building things so I

can

say I did it.

"Kalera Stratton" wrote in message
...


That's a good point, if I was in the market for a large kiln or expected
that I would be. However, I was just using my particular situation with
the kiln class to illustrate the fact that sometimes, when you take your
time for labor into consideration, it's less expensive to buy something
than it is to make it.

That's what I was wondering about this particular controller; if it
costs $350 in materials, and then there's the time spent researching,
aquiring parts, and building it, is it actually a less expensive
controller? The price is not far from many commercially-available
multi-segment controllers, and what I am wondering is whether it is
significantly superior to, say, the 30-amp multi-segment controller
available at Arrow Springs? If it is, I'd love it if someone would
explain that to me, because in that case I might be interested in it
myself. If it's not, then I'm wondering if the OP had taken under
consideration that his time might be more efficiently spent making
product to sell for the difference in cash to buy the premade
controller. That's not going to be true in all cases, and for some
people, as Javahut pointed out, it's worth it for the simple pleasure of
building something yourself. I can appreciate the joy of building
things; I am an avid do-it-yourselfer around the house, but a lot of
people overlook the fact that sometimes building something yourself is
not the most economical option.

Charles Spitzer wrote:


"Kalera Stratton" wrote in message
...



I can see your point re; the curiosity, but...


From a purely financial viewpoint, I think I would have to take a good


hard look at that $150 and ask myself whether I would be shortselling

my

time by building it myself vs. making salable product. In other words,

it


might COST me more (that I could have spent on glass) to save the $150

vs.


making salable product in the same time frame. There are a LOT of
variables involved, but it's something that self-employed people (or
people who supplement their main income with their art sales) often

fail

to take into consideration in the "make it or buy it?" equation.

For example, a fellow not long ago was encouraging me to take a day

class


at the coast (a 3-hour drive) that would teach me to build a small

kiln

in


one day. The class was only $150, and materials were included (no
controller, of course.) It was a full-day class, plus of course the

drive


there and back again, and meals... that's about a 14-hour commitment.

Plus


$150. You can buy a small fusing kiln for about $400, shipped, and,

given


14 hours, there is a strong possibility that many artisans could make

the


difference between the cost of the class (plus travel expenses) and

the

price of a kiln. If I wanted to build a lot of kilns it would be
completely worth it; I only want one right now. Maybe a few more down

the


road. Not nearly enough to make the cost/benefit ratio tip in favor of

the


class.


well, except for the fact that if you can build a small one, you can

build a


big one (the concept scales). the cost to build a big one may be 2k-3k,

to


buy a big one might be 15k-20k, making your savings be a lot more.




Javahut wrote:



"Kalera Stratton" wrote in message
...




This may not adequately address many people's financial situations,

but


if you're going to put $350 plus labor into building one, what is

the

advantage over spending the extra $150 and buying one?

My line of thought usually follows the question, "What am I good

at?"

and usually when I answer the question, I find that I end up ahead

if

I


put the time into what I'm good at, then sell my work to earn money

to

pay someone else to do what I'm not good at, in this case build a
controller. Especially since, for me, it is an endeavor I would

engage

in too seldom to ever really *become* good/fast at it.



Learning how to do something new and what do you do when your

controller


fails?

If you know how its built, it is much easier to repair it when it

breaks.


That's not an "if" it breaks, its a "when". and some of us just

can't

resist the "how do you do that" thing. It's what got me into glass

in

the
first place.
and $150 buys alot of fusible glass, right?





--
-Kalera
http://www.beadwife.com



--
-Kalera
http://www.beadwife.com



--
-Kalera
http://www.beadwife.com




--
-Kalera
http://www.beadwife.com

What unit do you have the uses USB? I thought that would be a good way to
go.

ed

"Boner the Cat" wrote in message
. ..
that looks like it would do anything a fuser needs.

I am working on a computer based unit, I have it running now in, HOLD ON,
dos.

yes folks a dos batch file (showing my age.) I have a board that works
off
the parallel port that has 12 relays.

I have a USB unit that will ultimately run up to five kilns at once with 2
type thermocouples in each and up to 196 relays.