Doug White writes:

They are less fragile than the ceramic ones, and tend to be a bit smaller
for a given rating. Several vendors make them, and they are available
surplus from time to time. Be careful with the power ratings, however.
They assume a certain level of air flow & heat sinking for continuous
duty. For the 200W braking resistor, you could probably get away with a
200 W rating without heroics because the load is transient.

Put them in a can full of transformer oil of some type.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"Bill Noble" writes:

another good source is Ford Electronics in Fullerton CA - they used to have
a reasonable selection of large surplus resistors


Echo Halted. Also try a query to Mendelson's -- meci.com &
electronicsurplus.com in Mentor OH. They will have items not in their
catalogs. There are other places too; maybe Skyline in Orlando.

Figure on some choices you can use series/parallel. IOW, if you need 10
Ohms, you can buy not just two 5 ohm resistors, but three 30 Ohms, etc.






--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

A standard cook top element runs 35 to 40 ohms, about 1500 watts each. I
get them for $1 each at the appliance recycling place. 2 in series would
be perfect, would max out at 3000 watts dissipation.

GeoLane at PTD dot NET wrote:
My Teco VFD specifies a 70 Ohm, 200 Watt braking resistor. I did
some quick looking on eBay and Mouser. It looks like the least
expensive ones are the open tube ones - BUT at around $33 and up. Is
there a less expensive place to buy these or a different way to search
either site that would bring up the less expensive alternatives?


RWL

On Tue, 22 Dec 2009 20:48:55 -0800, Carla Fong
wrote:



Bill McKee wrote:

"Gunner Asch" wrote in message
...
On Tue, 22 Dec 2009 16:08:09 -0800, "Bill Noble"
wrote:

another good source is Ford Electronics in Fullerton CA - they used to
have
a reasonable selection of large surplus resistors
They are about 5 minutes from my shop in Fullerton. Ive driven by there
a number of times in the past month. Ill have to stop in and see what
they have.

Gunner

"Bill McKee" wrote in message
m...
"Doug White" wrote in message
...
"Martin H. Eastburn" wrote in
:

The large open end ones with ribbon wire - are called 'corn cob' power
resistors.

I have two smooth sided resistors - each 8 ohm (nice speaker loads)
but must be 1000 watt. I'd have to look. I also have a 1/2 ohm IIRC
corn cob. Nice to measure current flow in a circuit - voltage drop.

$33 isn't bad for that - I'm surprised myself.

If you get one, look for mounting hardware. It helps. Or you make
some.
I like the ones in aluminum housings, like these:

http://www.token.com.tw/resistor-pd/...esistor-ah.htm

They are less fragile than the ceramic ones, and tend to be a bit
smaller
for a given rating. Several vendors make them, and they are available
surplus from time to time. Be careful with the power ratings, however.
They assume a certain level of air flow & heat sinking for continuous
duty. For the 200W braking resistor, you could probably get away with
a
200 W rating without heroics because the load is transient.

Doug White
Give a call to http://www.halted.com/ large surplus dealer in Sunnyvale.



Big light bulbs. Resistance may be wrong, but they absorb a lot of energy.
We used a bank of light bulbs as a dummy load on a TACAN unit. Absorbing
3000 watts.


We've had good luck using ordinary hardware store kitchen range heater
elements (tradename Calrod). Cheap, low resistance, high power dissipation.

Indeed. Should work quite well as long as the ohms range is within what
the VFD is expecting.

I did some mods to the VFD running my Gorton MasterMill..and the Yaskawa
MP3 Vfd really diddnt like resistors below or above the range specified
in the manuals.

Gunner


Carla

Next time you're stopped, just jump out and DEMAND proof of probable
cause. Don't forget to call him PIG! and JACKBOOTED THUG! Ask for his
badge number. Tell him you pay his salary. They like that.


"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

On Wed, 23 Dec 2009 00:08:19 -0600, RoyJ wrote:

A standard cook top element runs 35 to 40 ohms, about 1500 watts each. I
get them for $1 each at the appliance recycling place. 2 in series would
be perfect, would max out at 3000 watts dissipation.

GeoLane at PTD dot NET wrote:
My Teco VFD specifies a 70 Ohm, 200 Watt braking resistor. I did
some quick looking on eBay and Mouser. It looks like the least
expensive ones are the open tube ones - BUT at around $33 and up. Is
there a less expensive place to buy these or a different way to search
either site that would bring up the less expensive alternatives?


RWL

Excellent!! Thanks!!!

Gunner


"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

Calrod heater elements can be bought at Lowe's and sockets
for them as well. Mounting is a little tricky - but they
don't get very hot so almost anything goes. Since the rod is
ceramic you can't short it out except at the connection end.

Martin

Gunner Asch wrote:
On Tue, 22 Dec 2009 20:48:55 -0800, Carla Fong
wrote:

snip

We've had good luck using ordinary hardware store kitchen range heater
elements (tradename Calrod). Cheap, low resistance, high power dissipation.

Indeed. Should work quite well as long as the ohms range is within what
the VFD is expecting.

I did some mods to the VFD running my Gorton MasterMill..and the Yaskawa
MP3 Vfd really diddnt like resistors below or above the range specified
in the manuals.

Gunner

Peanut oil is high temp. You can tell when it starts
to smoke - smells of peanuts.

Caution - old - read that old transformer oil can give you cancer.
Power line transformers are time-bombs and most have over the last 50
years been replaced.

Just know what you use.

Oil can be a good heat sink assistant. e.g. put the resistor in a 5 gallon
can or 25 - what ever it takes - and add oil. the whole can absorbs.
It might be a tank attached to the legs of a machine that has oil -
something like the coolant oil. A sheet metal box.

Martin

David Lesher wrote:
Doug White writes:

They are less fragile than the ceramic ones, and tend to be a bit smaller
for a given rating. Several vendors make them, and they are available
surplus from time to time. Be careful with the power ratings, however.
They assume a certain level of air flow & heat sinking for continuous
duty. For the 200W braking resistor, you could probably get away with a
200 W rating without heroics because the load is transient.

Put them in a can full of transformer oil of some type.

beware of peanut oil if anyone nearby, or who might be nearby, or who might
possibly be nearby or passing by is allergic to peanuts - it is a common
allergy now, and those who have it can go into shock from the vapor from
peanut oil -

"Martin H. Eastburn" wrote in message
...
Peanut oil is high temp. You can tell when it starts
to smoke - smells of peanuts.

Caution - old - read that old transformer oil can give you cancer.
Power line transformers are time-bombs and most have over the last 50
years been replaced.

Just know what you use.

Oil can be a good heat sink assistant. e.g. put the resistor in a 5
gallon
can or 25 - what ever it takes - and add oil. the whole can absorbs.
It might be a tank attached to the legs of a machine that has oil -
something like the coolant oil. A sheet metal box.

Martin

David Lesher wrote:
Doug White writes:

They are less fragile than the ceramic ones, and tend to be a bit
smaller for a given rating. Several vendors make them, and they are
available surplus from time to time. Be careful with the power ratings,
however. They assume a certain level of air flow & heat sinking for
continuous duty. For the 200W braking resistor, you could probably get
away with a 200 W rating without heroics because the load is transient.

Put them in a can full of transformer oil of some type.

"Martin H. Eastburn" wrote in message
...
Peanut oil is high temp. You can tell when it starts
to smoke - smells of peanuts.

Caution - old - read that old transformer oil can give you cancer.
Power line transformers are time-bombs and most have over the last 50
years been replaced.

Just know what you use.

Oil can be a good heat sink assistant. e.g. put the resistor in a 5
gallon
can or 25 - what ever it takes - and add oil. the whole can absorbs.
It might be a tank attached to the legs of a machine that has oil -
something like the coolant oil. A sheet metal box.

Martin

David Lesher wrote:
Doug White writes:

They are less fragile than the ceramic ones, and tend to be a bit
smaller for a given rating. Several vendors make them, and they are
available surplus from time to time. Be careful with the power ratings,
however. They assume a certain level of air flow & heat sinking for
continuous duty. For the 200W braking resistor, you could probably get
away with a 200 W rating without heroics because the load is transient.

Put them in a can full of transformer oil of some type.

The old transformers had PCB oil. When one blows up, makes a hazardous
waste site for awhile.

I do like the idea of Calrod or similar stove elements. If you can
find the correct resistance, great. They are sturdy and high wattage.

Immersing them in oil is better.

Caution - old - read that old transformer oil can give you cancer.
Power line transformers are time-bombs and most have over the last 50
years been replaced.

No one will give/sell you PCB oil, unless they want to die filling out
EPA reports. Any transformer oil you can buy today won't be that. I
believe mineral oil will work but not as well.

"Bill Noble" writes:

beware of peanut oil if anyone nearby, or who might be nearby, or who might
possibly be nearby or passing by is allergic to peanuts - it is a common
allergy now, and those who have it can go into shock from the vapor from
peanut oil -

I have a peanut allergy, and was told by an allegist that when they make
the oil, they remove the part that causes the reactions. I know various
fastfood places use it for chicken, and I've never had a reaction.


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

Gunner Asch wrote:

On Sun, 20 Dec 2009 23:53:58 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


My Teco VFD specifies a 70 Ohm, 200 Watt braking resistor. I did
some quick looking on eBay and Mouser. It looks like the least
expensive ones are the open tube ones - BUT at around $33 and up. Is
there a less expensive place to buy these or a different way to search
either site that would bring up the less expensive alternatives?


RWL

One can get away with a 100 watt tubular or solid resistor if you are
simply operating it HSM and not doing rapid starts and stops ie CNC.

Surplus houses often have similar resistors btw....google is your
friend.

Such as this page....time to find it less than 1 minute...

http://www.surplussales.com/resistor.../WW70-110.html


https://www.fairradio.com/catalog.ph...ategoryid=4230

RS-200 - 200 ohm, 100 watt Resistor, $2.00 each

RS-113 - 200 ohm, 113 watt Resistor, $2.25 each


Use three in parallel for 66.6 ohms at 300 or 339 watts. If one ever
fails, you still have a 100 ohm 200 or 226 watt load.


--
Offworld checks no longer accepted!

"Lloyd E. Sponenburgh" wrote:

On Sun, 20 Dec 2009 23:53:58 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


My Teco VFD specifies a 70 Ohm, 200 Watt braking resistor. I did
some quick looking on eBay and Mouser. It looks like the least
expensive ones are the open tube ones - BUT at around $33 and up. Is
there a less expensive place to buy these or a different way to search
either site that would bring up the less expensive alternatives?


A couple of 250W incandescent bulbs in series will work, having a cold
resistance of about 10ohms, and a hot resistance of about 100 ohms.
They'll heat up to incandescence almost instantly (in just a couple of
cycles).

OTOH, there'll be a 100ms or so of very dramatic braking before the
filaments heat; maybe more than the VFD's output transistors can take --
dunno. Most will handle it just fine, but might trip on overcurrent.

$33/resistor isn't all that expensive, if you need more braking than the
VFD will provide without them.


Light bulbs aren't reliable.


--
Offworld checks no longer accepted!

On Thu, 24 Dec 2009 13:37:26 -0500, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

On Sun, 20 Dec 2009 23:53:58 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


My Teco VFD specifies a 70 Ohm, 200 Watt braking resistor. I did
some quick looking on eBay and Mouser. It looks like the least
expensive ones are the open tube ones - BUT at around $33 and up. Is
there a less expensive place to buy these or a different way to search
either site that would bring up the less expensive alternatives?


RWL

One can get away with a 100 watt tubular or solid resistor if you are
simply operating it HSM and not doing rapid starts and stops ie CNC.

Surplus houses often have similar resistors btw....google is your
friend.

Such as this page....time to find it less than 1 minute...

http://www.surplussales.com/resistor.../WW70-110.html


https://www.fairradio.com/catalog.ph...ategoryid=4230

RS-200 - 200 ohm, 100 watt Resistor, $2.00 each

RS-113 - 200 ohm, 113 watt Resistor, $2.25 each


Use three in parallel for 66.6 ohms at 300 or 339 watts. If one ever
fails, you still have a 100 ohm 200 or 226 watt load.

For those using lower value VFD braking resistors...

RS-35 - 35 ohm 200 watt Resistor,
$4.00 each

Fascinating! Bookmarked!!!

Thanks!!!

Gunner


"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

Gunner Asch wrote:

On Thu, 24 Dec 2009 13:37:26 -0500, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

On Sun, 20 Dec 2009 23:53:58 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


My Teco VFD specifies a 70 Ohm, 200 Watt braking resistor. I did
some quick looking on eBay and Mouser. It looks like the least
expensive ones are the open tube ones - BUT at around $33 and up. Is
there a less expensive place to buy these or a different way to search
either site that would bring up the less expensive alternatives?


RWL

One can get away with a 100 watt tubular or solid resistor if you are
simply operating it HSM and not doing rapid starts and stops ie CNC.

Surplus houses often have similar resistors btw....google is your
friend.

Such as this page....time to find it less than 1 minute...

http://www.surplussales.com/resistor.../WW70-110.html


https://www.fairradio.com/catalog.ph...ategoryid=4230

RS-200 - 200 ohm, 100 watt Resistor, $2.00 each

RS-113 - 200 ohm, 113 watt Resistor, $2.25 each


Use three in parallel for 66.6 ohms at 300 or 339 watts. If one ever
fails, you still have a 100 ohm 200 or 226 watt load.

For those using lower value VFD braking resistors...

RS-35 - 35 ohm 200 watt Resistor,
$4.00 each

Fascinating! Bookmarked!!!

Thanks!!!


You're welcome. Fair Radio was always one of my favorite surplus
stores. It was easy to spend the entire day digging through the stuff
they don't catalog.


--
Offworld checks no longer accepted!

On Thu, 24 Dec 2009 13:37:26 -0500, "Michael A. Terrell"
wrote:




https://www.fairradio.com/catalog.ph...ategoryid=4230

RS-200 - 200 ohm, 100 watt Resistor, $2.00 each

RS-113 - 200 ohm, 113 watt Resistor, $2.25 each


Use three in parallel for 66.6 ohms at 300 or 339 watts. If one ever
fails, you still have a 100 ohm 200 or 226 watt load.

Now those are good prices.
I spotted another one that would work well also - 35 Ohms / 200W.
String two of them in series to get the 70 Ohms.

After posting my query to the group, I emailed Factorymation the day
before Christmas asking what the Teco would tolerate without any
braking resistor. I'm awaiting a reply at this point.

As cheap as those ones from Fair Radio though, it might be worth
adding them as an inexpensive insurance policy.

RWL

GeoLane at PTD dot NET wrote:

On Thu, 24 Dec 2009 13:37:26 -0500, "Michael A. Terrell"
wrote:



https://www.fairradio.com/catalog.ph...ategoryid=4230

RS-200 - 200 ohm, 100 watt Resistor, $2.00 each

RS-113 - 200 ohm, 113 watt Resistor, $2.25 each


Use three in parallel for 66.6 ohms at 300 or 339 watts. If one ever
fails, you still have a 100 ohm 200 or 226 watt load.

Now those are good prices.
I spotted another one that would work well also - 35 Ohms / 200W.
String two of them in series to get the 70 Ohms.

After posting my query to the group, I emailed Factorymation the day
before Christmas asking what the Teco would tolerate without any
braking resistor. I'm awaiting a reply at this point.

As cheap as those ones from Fair Radio though, it might be worth
adding them as an inexpensive insurance policy.


Definately. Better to have them and not need them, than have the tool
die becasue you didn't.


--
Greed is the root of all eBay.

My Powermatic 1200 has a reversing switch. It seems to work very
nicely for me.

http://igor.chudov.com/projects/Powe...-5845.jpg.html

i

On Sun, 27 Dec 2009 00:39:14 -0600, Ignoramus9012
wrote:

My Powermatic 1200 has a reversing switch. It seems to work very
nicely for me.

http://igor.chudov.com/projects/Powe...-5845.jpg.html

i


That drum switch is NOT a proper "Big Red Panic Button" that you can
mash if things go very wrong, and we both know it. Install one, NOW.
Better yet install two, one high and one low. It doesn't have to be
beautiful, it just has to work.

Do you really want 100 of your best buds all yelling "I Told You
So!!" as you learn to type while short a digit or two for the rest of
your life? Or worse, the whole arm?

Oh, and that drum switch better be connected as a signal-level input
to the VFD, and not be line voltage between the VFD and the motor.
Most VFD's do NOT like it when you open the motor leads under load,
the Magic Smoke tends to escape from the transistors.

-- Bruce --

On 2009-12-28, Bruce L Bergman wrote:
On Sun, 27 Dec 2009 00:39:14 -0600, Ignoramus9012
wrote:

My Powermatic 1200 has a reversing switch. It seems to work very
nicely for me.

http://igor.chudov.com/projects/Powe...-5845.jpg.html

i


That drum switch is NOT a proper "Big Red Panic Button" that you can
mash if things go very wrong, and we both know it. Install one, NOW.
Better yet install two, one high and one low. It doesn't have to be
beautiful, it just has to work.

Do you really want 100 of your best buds all yelling "I Told You
So!!" as you learn to type while short a digit or two for the rest of
your life? Or worse, the whole arm?

I definitely do not. OTOH, I have never seen a drill press with such a
button, either.

Oh, and that drum switch better be connected as a signal-level input
to the VFD, and not be line voltage between the VFD and the motor.
Most VFD's do NOT like it when you open the motor leads under load,
the Magic Smoke tends to escape from the transistors.

Yes, 10v signal level input.

On Sun, 27 Dec 2009 22:02:46 -0800, Bruce L. Bergman
wrote:

On Sun, 27 Dec 2009 00:39:14 -0600, Ignoramus9012
wrote:

My Powermatic 1200 has a reversing switch. It seems to work very
nicely for me.

http://igor.chudov.com/projects/Powe...-5845.jpg.html

i


That drum switch is NOT a proper "Big Red Panic Button" that you can
mash if things go very wrong, and we both know it. Install one, NOW.
Better yet install two, one high and one low. It doesn't have to be
beautiful, it just has to work.

Do you really want 100 of your best buds all yelling "I Told You
So!!" as you learn to type while short a digit or two for the rest of
your life? Or worse, the whole arm?

Oh, and that drum switch better be connected as a signal-level input
to the VFD, and not be line voltage between the VFD and the motor.
Most VFD's do NOT like it when you open the motor leads under load,
the Magic Smoke tends to escape from the transistors.

-- Bruce --


Damned straight. And not!!! switching the motor leads under VFD is
something Ive mentioned time and again here.

Gunner

"I am for doing good to the poor, but I differ in opinion of the
means. I think the best way of doing good to the poor, is not
making them easy in poverty, but leading or driving them out of
it. In my youth I travelled much, and I observed in different
countries, that the more public provisions were made for the
poor the less they provided for themselves, and of course became
poorer. And, on the contrary, the less was done for them, the
more they did for themselves, and became richer." -- Benjamin
Franklin, /The Encouragement of Idleness/, 1766

On Mon, 28 Dec 2009 01:17:42 -0600, Ignoramus27446 wrote:
On 2009-12-28, Bruce L Bergman wrote:
On Sun, 27 Dec 2009 00:39:14 -0600, Ignoramus9012 wrote:

My Powermatic 1200 has a reversing switch. It seems to work very
nicely for me.

http://igor.chudov.com/projects/Powe...-5845.jpg.html

That drum switch is NOT a proper "Big Red Panic Button" that you can
mash if things go very wrong, and we both know it. Install one, NOW.
Better yet install two, one high and one low. It doesn't have to be
beautiful, it just has to work.

Do you really want 100 of your best buds all yelling "I Told You
So!!" as you learn to type while short a digit or two for the rest of
your life? Or worse, the whole arm?

I definitely do not. OTOH, I have never seen a drill press with such a
button, either.

Then you haven't been looking very hard, Iggy. Or you simply choose
not to see...

The vast majority of the power switches on newer drill presses and
saws and such (unless they are imported from Elbonia) are right out in
front, and are a hybrid Push-Pull Toggle hinged at the top. Pull out
from the bottom to turn on, mash in to turn off.

The fancy ones on stationary tools have a Key Pin you have to insert
to turn it on, and if there are kids in the house you can take the
plastic key out and hide it. Keeps the under six set from losing an
arm.

The "keys" I've seen are easy to defeat with a sliver of wood and a
little whittling, but if the kid is old enough to defeat the lock he
should also be old enough to realize the tool can be dangerous.

Oh, and that drum switch better be connected as a signal-level input
to the VFD, and not be line voltage between the VFD and the motor.
Most VFD's do NOT like it when you open the motor leads under load,
the Magic Smoke tends to escape from the transistors.

Yes, 10v signal level input.

Good. And you used a hunk of CAT-5 cable (4-pair) between the VFD
and the switch, right? Should have taken two pair tops. So take a
spare pair and hook the NC contacts on a mushroom head Panic Button to
the E-Stop contacts on the VFD.

And the second remote switch down low or a few feet away can't hurt
- if there's a large piece of work spinning around on the chuck, you
might not get close enough to hit the button on the machine...

If I was running a CNC Shop where I wanted to start the machine and
let it do it's thing as I wander away to do something else, like
paperwork...

I'd have a video camera on each machine and a monitor on my desk -
with a remoted Little Yellow button for a regular machine stop (to go
out and replace a broken tool without losing the zero and the program)
and a Big Red Button for E-stop if you see (and/or hear) a full-on
crash happening.

Remember our r.c.m motto: Safety Third.

-- Bruce --