David
OOPS I should have read your description more closely before replying.
Jim
________________________________
From: Jim Holligan <jtholligan@sbcglobal.net>
To: gingery_machines@yahoogroups.com
Sent: Mon, September 12, 2011 9:01:41 PM
Subject: Re: [gingery_machines] Re: Electric furnace parts update
David
Power = Current * Voltage
Power is directly porportional to voltage.
Jim
________________________________
From: David Frantz <websterindustro@mac.com>
To: "gingery_machines@yahoogroups.com" <gingery_machines@yahoogroups.com>
Cc: "gingery_machines@yahoogroups.com" <gingery_machines@yahoogroups.com>
Sent: Mon, September 12, 2011 8:23:15 PM
Subject: Re: [gingery_machines] Re: Electric furnace parts update
One thing to keep in mind is that power varies with the square of the voltage.
If your line voltage is lower than the design voltage you will not get the
expected power out.
In any event it looks like you are on the right track looking for air leaks.
Sent from my iPad
On Sep 12, 2011, at 10:20 PM, confed2001 <confed2001@yahoo.com> wrote:
> Ron,
> The Elements you use are the same thing I had. (I say had `cause my pot had a
>blowout on my last melt, and shorted out the element!) Anyway, the controller is
>
>homemade and uses 2 SCRs that are rated at 600V / 70amp. This is tied into a
>Lutron dimmer switch. The switch comes with a very low rated triac so that was
>replaced with one rated for 400v.
>
> After thinking it over I really don't think it's the controller so much as I am
>
>just losing heat from the seams between the base, body, & lid. Most likely it is
>
>between the body & lid. I've ordered a new heating element & should have it in
>by the end of the week. I plan on installing it this weekend, and running it at
>night. Kill the lights out side the shop & see what I can see.
>
> As for the refractory we once had a foundry here in Louisiana (that was knocked
>
>out by Katrina). I got two 5 gal tubs of high temp cement from them for nothing,
>
>and used that for the base & lid. The body has an inner wall of fire bricks that
>
>have been notched for the heating element, and between that & the outer metal
>shell it was packed with more refractory. Short of making another lid I was
>considering using that ceramic blanket you showed in your post to help seal the
>gap between the lid & body like a gasket. I've also been considering building
>the Gingery charcoal foundry with the remaining refractory I have….but than
>again….
>
> Anyway, thanks for all the help
> Brian
>
>
> --- In gingery_machines@yahoogroups.com, Ron Thompson <ron@...> wrote:
>>
>> On 9/11/2011 10:50 PM, confed2001 wrote:
>>> Am I to understand that you are using this to control the temperature
>>> of an electric foundry such as the Gingery "Little Bertha"? I got a
>>> set of plans for an electric foundry from this site:
>>>
>>>http://www.dansworkshop.com/aluminum-foundry/homebuilt-electric-melting-furnace.htm
>>>
>>>m
>>>
>>> It works & I have been using it for several years, but despite what
>>> the plans say it does not get hot enough to melt copper much less
>>> brass. I constructed the controller as described in the plans, and am
>>> using the heating elements stated, but aluminum is the best I can get
>>> out of it. If this controller will raise the temp of a small electric
>>> foundry than I need to get one.
>>>
>>> Brian
>> The controller will not raise the temperature of a foundry. It will
>> regulate it and help the elements live longer due to the Pulse Width
>> Modulation (PWM). This is easier on the elements.
>> I bought Dan's plans years ago, but have lost them. What kind of element
>> wire and controller does it use?
>> One thought is your elements may be too long. Do they glow bright orange
>> under full power?
>>
>> Another thought is the refractory. Maybe it isn't insulating enough and
>> loosing too much heat. Is the outside of the furnace hot to the touch?
>>
>> I am using 2 Kanthal elements from here:
>><http://www.ebay.com/itm/170641989014?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649>
>>
>>>
>>
>> This will be for 220V operation.
>>
>> I intend to use this ceramic blanket refractory:
>> <http://www.axner.com/superwoolfiber-1thicksoldpersqft.aspx>
>>
>> Axner is local to me, but they do ship. I am going today to pick it up.
>>
>> I still need some heater duct for the shell and for the solid state
>> relays to arrive from China.
>>
>> Oh and I need some small ceramic insulators to hold the elements in place.
>>
>> --
>>
>>
>> Ron Thompson
>> On the Beautiful Florida Space Coast, right beside the Kennedy Space Center,
>>USA
>>
>> There are two kinds of posts on newsgroups.
>> 1. This is what I have done...
>> 2. This is what I think...
>> Be aware of the difference!
>>
>> http://www.ourcadguy.com/
>>
>> http://www.plansandprojects.com My hobby pages are here:
>> http://www.plansandprojects.com/My%20Machines/
>>
>> Visit the castinghobby FAQ:
>> http://castinghobbyfaq.bareboogerhost.com/
>>
>
>
>
>
> ------------------------------------
>
>
>
>
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
http://groups.yahoo.com/group/gingery_machines/app/peoplemap/view/map
No comments:
Post a Comment