Melting pot (building your own) [Archive]

pick

03-10-2009, 10:01 PM

Hello to All,

This is a great site. I have lurked here on and off for many years. To get to the point of this post; I have reloaded for over 30 years now. In the last 3 to 4 years I have been thinking of starting to cast my own. Well just this last saturday I did my first casting of some 350g .460 dia bullets for my 45-70. This was my test to see if I really wanted to invest and set up casting for myself. Well the answer is a resounding Yes !!!

Given that I have now decided to take the plunge I am working on drawing up my equipment list. This site has been great in helping me sort the wheat from the chaff so to speak without wasting time and money. I am sure that I will waste some of both before I am done, just not as much

I got a good handle on what I want to start with and can find everything that I am desiring through normal channels with ONE exception. That is the melting pot. I really want a PID controlled pot with bottom pour. I have read several of the threads here about retrofitting existing ones, which work fine, but since I have an electrical engineering background along with a full fledged machine shop I was thinking that I could build my own and be much happier in the end.

My thoughts for this smelting pot are as follows :

1. I will be casting for 44 Mag and 45-70 mostly and I shoot both a LOT just for fun. Therefore the 20lbs seem ok but I was thinking if I was to do one for myself that around 30lbs at the 80% level would be better.

2. The PID would be built in from the start and would include on/off, ramp up and cool down.

3. This will be bottom pour and I was thinking of giving 5 to 6 inches of clearance underneath.

4. The diameter at the top I am thinking about is 5 inches across and about 4.75 inches at the bottom (a mild tapper). Also I am thinking about a 4 to 8 degree slope on the bottom of the pot to the 'drain' spout.

5. Since I tend to be wanting the best value for my dollar I thought that if pull this off there may be some interest from others here on the site.

Given all of the above I would like to open this thread up on your thoughts and experiences about making an excellent melting pot at a reasonable cost. Something that we would all be proud to call our own.

I already have a question or two to start off ....

1. For the pot I could use either stainless steel or cast iron. I am leaning toward stainless steel. All experiences welcome along with opinions

2. The thickness of the pot. I am leaning towards not real thick since you want the BTUs in the melt not the pot. I want just enough thermal mass in the pot that it is not prone to warping and no more.

3. Since I personally do not have much history casting my own I would like to know what bells and whistles are great to have and which are really of little value.

4. What do you feel the max temperature should be. Should it go to say 1400 F so someone who wanted to use for alloys other then lead based ones could?

I hope to start working on this the week of the 23rd of March, so I am hoping to see GREAT suggestions and insights. At the conclusion ending up with an EXCELLENT smelting pot.

... pick ...

felix

03-10-2009, 10:19 PM

Another engineer! Way goody, goody.

Only suggestion I have is to put a limiter into the controller, assuming you are going to build one almost from scratch. Desired would be an external, single throw, toggle such that the ON direction would indicate 900 degrees max input, OFF unlimited to the gadget's max. If going to use a stock controller without mods, then insert the 900 degree limiter into the pot itself, or as a stage between the pot and the controller, such that the limiter can be bypassed for when melting silver, etc. Any lead alloy will expel dangerous stuff above 900 (they say 1100, but be conservative because who really knows what's in the pot). ... felix

Second thought, and important. Build the sensor into the pot's spout! That is where you REALLY want the temp measured. The caution there would require shielding so the controller won't go bananas with excessive use of it's differential feedback algorithm to maintain serenity. ... felix

hedgehorn

03-10-2009, 10:29 PM

There is a great post on this somewhere if someone can post a link.

pick

03-10-2009, 10:48 PM

Felix,

I have seen in some of the posts here that people are casting with the melt temperature as high as 975 F. Am I missing something? It is not that much trouble to make it a 'dual' mode machine ... One for lead with limit plus another for unrestricted control. I am not all that much up on other 'low' temperature metals and alloys so the question is what would be a 'reasonable' upper limit on the temperature ??? Anyone ???

I was planning on getting the temp senor as close to the pour spout and possible since this it really the temperature of the alloy you will be placing in your mold.

Only suggestion I have is to put a limiter into the controller, assuming you are going to build one almost from scratch. Desired would be an external, single throw, toggle such that the ON direction would indicate 900 degrees max input, OFF unlimited to the gadget's max. If going to use a stock controller without mods, then insert the 900 degree limiter into the pot itself, or as a stage between the pot and the controller, such that the limiter can be bypassed for when melting silver, etc. Any lead alloy will expel dangerous stuff above 900 (they say 1100, but be conservative because who really knows what's in the pot). ... felix

Second thought, and important. Build the sensor into the pot's spout! That is where you REALLY want the temp measured. The caution there would require shielding so the controller won't go bananas with excessive use of it's differential feedback algorithm to maintain serenity. ... felix

felix

03-10-2009, 11:27 PM

Yeah, Pick, you can go to 1000F with no problem, especially at the spout. Perhaps that would be better, because I like to use copper alloys sometimes which require more heat at the drop location. ... felix

Bret4207

03-11-2009, 07:21 AM

When I switched from a cast pot to a stainless my dross dropped by 60-75% at least. I'm sure most of the dross was from the cast iron pot.

Whatever you come up with, leave enough room at the top to ladle cast. Some moulds just want a ladle and if you limit yourself you'll regret it later.

klcarroll

03-11-2009, 09:26 AM

Pick;

Please post pictures, schematics, and electronic part lists as the job progresses!!!

…….Leave the light “ON” for those who wish to follow in your footsteps!!:drinks:

Kent

HeavyMetal

03-11-2009, 09:52 AM

Pick:
I think stainless steel a much better pot material than cast iron, provided you can get the right alloy, and thickness, to withstand the temp changes without cracking from "age". Designing it with an easily replaceable "pot" might be a good idea as well.

As for temp limits I think a top of 1000 degree's is good. Sounds like your planning a pretty accurate temp system to reduce the "bouncing" of alloy temp we see in some pots. This is a good idea, my suggestion would be a remote adjustment with a digital readout. Easier to see and more important the control knob might not get to hot to touch as my old Lyman does when it's on.

Opening on the pot itself: 5 to 5 1/2 inches should be plenty wide enough. Try to get the bottom feed set up as close to the pot wall as you can. This will help with those who have molds that must be ladle poured and will also make it a bit easier for the larger sized ingots I've seen being made on this site.

Capacity: 30 to 35 lbs is about right more than that might require a 220 system and some won't have access to that type of power outlet in older homes.

For additional capacity you might make it a "stackable" design and figure on connected linkage. This can be a great time saver with the top pot melting fresh ingots while the bottom pot continues to cast.

Ask anybody with a pair of Lee 6 bangers or H&G 6 or more cavity molds what they think of that idea.

One last idea: a platform to set the molds on to preheat. this should be large enought to balance a lee 6 banger on and some type of "post" or "lip" to let the handles prop up against will keep them from falling during preheat.

Good luck

monadnock#5

03-11-2009, 10:17 AM

There was a chapter on cast iron in my heat treat certification course. It was obvious from reading that chapter that a whole book (the size of The Rise And Fall of The Roman Empire) could be written on the subject. There are many, many types of cast iron. My smelting pot is cast. The cast iron has pores in it that trap dross particles and lead which form a soldered layer of crud on the bottom of the pot. I cleaned it down to bare metal last spring, but after one day of rendering range scrap, was right back where I started.

Now if it was a choice between stainless and the same type of cast iron as my pot is made of, stainless would be the only choice. I suspect though that there is a grade of cast iron out there, either as cast or machined that would equal or better the qualities of stainless. You would have to talk to a real metallurgist with lots of years of real world experience to get a handle on the cost effectiveness of each.

My first take on your pot geometry is, I don't like it. The slanted bottom would concentrate the dross as the pot got low, and invite sucking a spoutful of gunk. I would prefer a flat bottom with a radius between bottom and wall so as to make routine cleaning with wire brushs that much easier.

I hope that you are successful in this endeavor. My Lyman pot has reached an age where one of these days....:cry: I've been thinking about a Lee pot as an emergency backup, but what you're talking about sound a whole lot better.

One last thing. The threads I've read discussing PID's have made me wonder why one of the big guys (LEE, LYMAN, RCBS) hasn't put a kit together with a PID with all the accessories along with simple instructions for we booliteers. I think (we're in dangerous territory here) that the entrepreneur who put a kit such as this up as a group buy would be not only astounded by the response, but buried in orders. Buried for how long I don't know. No long term market analysts at this address. :coffee:

WickedGoodOutdoors

03-11-2009, 11:18 AM

Let me know what you come up with for cast .44 mag

I have an Oil Fired Hot Water Heater that would make one hell of a Smelting pot if your in the Maine Area. Let me know. Ill disconect it as it is working in my house right now and I bought a new Electric water heater to replace it.

Springfield

03-11-2009, 11:56 AM

Here's my 2 cents worth. I started with a LEE 10 lb'er, quickly went to 2 LEE 20 lb'er's, then an RCBS 20 lber, and finally I am now using a Magma 40 lb'er. If you are going to be doing any kind of volume, meaning you are going to empty the pot at least once during the casting session, then anything less then 40 is too small. But more important than size is wattage. The Lee's and RCBS were 6-700 watts, and it just didn't allow for adding ingots to the pot while casting without commonly freezing up the spout. The Magma is 1500 watts and it never freezes. It is also 110 volts, and it seems to work fine on my regular circuit. 220 would be a nice option, though. My RCBS is 220. Didin't seem to heat any faster, just easier on the house wiring. Another feature of the Magma I like is the 2 pour spouts. At first I didn't like it but later I found it sped things up quite a bit. Most of us use molds with at least 2 cavities. The Magma is actually easily converted from 1 to 2 with just 2 screws, which can even be done with hot lead in the pot. This system also makes it easier to clean the spigot without draining the pot. I also agree with the idea of NOT making the bottom tapered, it just makes all the dross head right for the spigot. Flat would be better. An on-off switch would be nice. My RCBS had one, the Magna does not. I asked them about that ands they felt it was much better to unplug it than to turn it off to prevent accidentally leaving the pot on. I feel an bright light on an off switch would be better, it is easy to forget and leave it plugged in. And whatever system you use for the spigot, make sure the lever is spring loaded to prevent dripping. I cast a few thousand bullets a week and these are my thoughts on the subject.

Willbird

03-11-2009, 11:58 AM

I have devoted some thought to the subject of pot level. I have often wondered if you could use a piece of EDM graphite that would be pushed into the melt to allow the pot level to remain more constant from full to empty.

I agree a slope down to the pour spout is probably not a good idea. Putting the pour spout up near the front of the pot is a good thing IMHO.

Putting the temp sensor in the spout itself might SOUND like a good idea, but the spout temperature will change when metal flows through it I would think ? Until you start to pour the spout temp is determined by heat conducting into it from the pot itself, and the spout is a heat sink because it hangs out in the air. Then you start to run alloy through it and it assumes the temperature of the alloy, or pretty close.

There are some benefits to a thicker pot because it acts as a heat sink, and prevents hot spots where the heating element is closer to it, if the pot is insulated the heat is in no way wasted by having a thicker pot. I would think you would want a seamless draw formed pot so it seems the whole mess will have to be designed around a pot that is already available.

Autopsy or exploratory surgery of the common pots on the market would probably be worthwhile to begin with, stand on the shoulders of giants so to speak :-).

http://www.magmaengr.com/images/drawings/bmpot.gif

It looks like Magma uses (5) 750w cartridge heaters in one of their pots

in another pot they make they use (3) cartridge heaters
http://www.magmaengr.com/images/drawings/cmpot.gif

In yet another one they are using some kind of band heater that clamps on the pot.
http://www.magmaengr.com/images/drawings/mcpot.gif

runfiverun

03-11-2009, 12:20 PM

pick

03-11-2009, 01:37 PM

Thanks to all inputing at this point. I have learned (the hard way) no matter how well something is made if it DOES NOT have what the end user is happy with it will fail. I am not planning on over engineering this thing. I am hopping to make it in a price range that most could afford.

My overall goals are

Great ease of use and function
Easy to afford and maintain
Users are happy to have and use it.

So from the feed back so far it looks like,
1. stainless steel for the pot
2. flat bottom in the pot
3. 40 lbs is better then the 30 I was thinking of
4. place the pour spout near the interior wall of the pot
5. make sure you can easily use a ladle if you so choose
6. Clear power on light and a big and easy to see power on / off switch
7. The temperature sensor 'near' not on the pour spout.
8. adjustable mould support / guide
9. make sure the d*** spout does not drip !!!!!

Add these to my requirement of
1. PID temperature control with digital temperature read out

Now for the options (nice to have but not required)
1. a mould heat (warming) plate
2. two instead of one spout at the bottom of the pot.

So far I am doing basic searching for items and materials. There is one area that i could use everyones collective help on. I need to locate a manufacture and/or supplier of those heating elements you see on electric stove tops. I am going to need to find away to have an element formed to fit the pot. I am having trouble tracking this aspect down. So far I found out that all the ones I am able to locate are made in either Mexico or China, but they are all made as replacements for the stove tops and I can not find the supplier or manufacture to get the specs on them for electrical or mechanical properties.

Also I will be dusting off the digital camera so I can post a new thread once I start to build the thing.

Keep the comments coming

... pick ...

Willbird

03-11-2009, 01:38 PM

i was going to suggest what springfield said.
as i have just done the same thing i am still working on a mold guide for mine and setting the height ,so i don't have to stoop a bit to see under the pot.
two holes and a 4 cavity, the boolits fly out and you can keep the thing [mold] hot.
an on/off switch with an indicator light would be nice too.
i have gone to pre alloying in my lee 20 lb'er and pouring it into the 40 lber when i need a break.
i am going to build a stand that will allow direct feeding,but 40 lbs of boolits will wear you out if you have to hold the mold all the time.

Here is something to think about, what about a "lead measure" and 4-6 pour spouts ?? A sliding piece of EDM graphite with cavities drilled in it large enough to pour a bullet and leave a decent sprue....would work just like a powder measure, just pull the handle and drop 1, 2, 3(rarely), 4, or 6 charges of lead right into each sprue hole. if it were well insulated and heated I think it would work slick.

Bill

Dale53

03-12-2009, 01:18 AM

The suggestion to have an "on/off" switch is necessary, in my view. Before I became a Major Case Insurance Adjuster for thirty years, I made my living working on appliances (auto clothes washers, dryers, refrigerators, electric heaters, toasters, irons, etc). In those days EVERYTHING was repaired when it failed. MUCH cheaper than replacing. At any rate, I observed that every time you unplugged a heating appliance you got an arc at the plug. Before long, the plug and socket were "burnt" causing a high resistance connection which increased the heat at the socket and eventually led to premature failure. Switches are DESIGNED to handle current and last MUCH longer. So, I ALWAYS use my switch on the RCBS pots to turn them off BEFORE I unplug them as well as my hot plate. It is just a good idea for long service life (rather, a VERY good idea).

Dale53

HeavyMetal

03-12-2009, 01:43 AM

Willbirds "powder" measure Idea sure is slick but I think the lack of "weight" in the alloy flowing into the "measure" might cause huge weight fluctuations.

Without a "baffle" to keep the alloy weight the same through the whole pour cycle I don't see this idea working. Seems to me thats why I rigged up two pots on top of each other!

Once a pot gets to the half way point boolits start getting lighter! Thats why I always drop alloy into the pouring pot at the 1/4 empty point and then refill the top pot! Helps keep consistancy up!

I will agree with R5R big molds and no support can be hard on the arms. I have been toying with a "roller" mold guide but have not done a prototype yet! Don't know why I didn't mention a mold guide this morning while I was have other brainstorms?

With a 40 lb pot one would not need to have them stacked it should be enough alloy for any one guy to work with plus adding alloy as needed.

As to multiple spouts? Heck most of us can't keep one working most of the time I think six would lead to suicide!

However this leads us in another direction just slightly related to this thread.

While your looking for a supplier of the stainless steel pot how about looking for a "smelting only" pot for a plumbers type furnace or turkey fryer?

My thought would be simple and clean here. 100 Lbs, flat bottom, a "cage" that can be lifted out to remove WW clips and other non melted trash ( this idea has been posted on this site I will not take credit for anothers idea) and maybe a temp guage or a permanant location for a temp guage. big enough for a decent size rowell ladle to get in and pour ingots in the triangeluar 3 lb weight range.

Stainless steel here as well, we've all heard the story of cracked cast iron when someone struck it while hot!

What do you think?

pick

03-12-2009, 08:20 AM

One project at a time here (by me). Let me do this one well and then if this is still out there will see.

No promises.

... pick ...

However this leads us in another direction just slightly related to this thread.

While your looking for a supplier of the stainless steel pot how about looking for a "smelting only" pot for a plumbers type furnace or turkey fryer?

My thought would be simple and clean here. 100 Lbs, flat bottom, a "cage" that can be lifted out to remove WW clips and other non melted trash ( this idea has been posted on this site I will not take credit for anothers idea) and maybe a temp guage or a permanant location for a temp guage. big enough for a decent size rowell ladle to get in and pour ingots in the triangeluar 3 lb weight range.

Stainless steel here as well, we've all heard the story of cracked cast iron when someone struck it while hot!

What do you think?

badgeredd

03-12-2009, 09:07 AM

So far I am doing basic searching for items and materials. There is one area that i could use everyones collective help on. I need to locate a manufacture and/or supplier of those heating elements you see on electric stove tops. I am going to need to find away to have an element formed to fit the pot. I am having trouble tracking this aspect down. So far I found out that all the ones I am able to locate are made in either Mexico or China, but they are all made as replacements for the stove tops and I can not find the supplier or manufacture to get the specs on them for electrical or mechanical properties.

Keep the comments coming

... pick ...

Pick,

You might want to check into industrial heater suppliers. There is a company in Battle Creek, Michigan that forms heaters for plastic injection mold hot manifolds. Some of the heaters are pretty intricate in shape. A company I worked for had some made up for a foreign hot manifold at a cost the was significantly cheaper than buying the replacements from the Chinese company. At the moment, the company's name escapes me but I can get the info if you are interested. IIRC, the heaters we had formed up were in the 1000 watt range. These heaters had both wire connections on one end of the heater on some and some had one wire connection on each end. Just a thought.

Edd

Willbird

03-12-2009, 09:45 AM

Willbirds "powder" measure Idea sure is slick but I think the lack of "weight" in the alloy flowing into the "measure" might cause huge weight fluctuations.

Without a "baffle" to keep the alloy weight the same through the whole pour cycle I don't see this idea working. Seems to me thats why I rigged up two pots on top of each other!

Once a pot gets to the half way point boolits start getting lighter! Thats why I always drop alloy into the pouring pot at the 1/4 empty point and then refill the top pot! Helps keep consistancy up!

Well if the sliding lead measure communicated with the pot, then was shut off before dropping it's charge the amount of lead should be pretty consistant, AND it would contain enough to pour a boolit and leave a sprue, the drain speed should remain fairly consistent no matter how much lead is in the pot :-).

The real question is if the EDM graphite(or other material such as inconel) could be made to seal up by holding it up there with some coil springs. I mention iconel because it has much the same mechanical properties at 1000f as it does at room temperature.

The principle of operation in some ways is similar to a belding and mull powder measure.

Also the option to use LP or natural gas with a PID temp controller is very interesting, to me anyway :-).

Bill

HeavyMetal

03-12-2009, 09:47 AM

Didn't mean to suggest you switch horses just that you might keep the idea in the back of you head while you were searching for components for the current project.

I think we've all stumbled over something while looking for something else!

I can also apreciate not wanting to have to many irons in the fire at one time!

Texasflyboy

03-12-2009, 10:55 AM

There is a great post on this somewhere if someone can post a link.

You mean this homemade bottom pour casting pot that uses off the shelf components?

The original Thread here on Cast Boolits (http://castboolits.gunloads.com/showthread.php?t=5126)

And my webpage devoted to the Cast Boolits Model 1 Pot (Which I need to update soon):

Cast Boolits Model 1 (http://hgmould.gunloads.com/newpot/instructions.htm)

pick

03-12-2009, 12:28 PM

Pick,

You might want to check into industrial heater suppliers. There is a company in Battle Creek, Michigan that forms heaters for plastic injection mold hot manifolds. Some of the heaters are pretty intricate in shape. A company I worked for had some made up for a foreign hot manifold at a cost the was significantly cheaper than buying the replacements from the Chinese company. At the moment, the company's name escapes me but I can get the info if you are interested. IIRC, the heaters we had formed up were in the 1000 watt range. These heaters had both wire connections on one end of the heater on some and some had one wire connection on each end. Just a thought.

Edd

Edd,

If you can come up with a name a least that would be good. Also if you were to land a telephone number and contact name the would be best of all :) This sounds exactly like what I am looking for.

I am doing as much research as possible prior to starting a 'hammering'

Thanks in advance

... pick ...

pick

03-12-2009, 12:29 PM

You mean this homemade bottom pour casting pot that uses off the shelf components?

The original Thread here on Cast Boolits (http://castboolits.gunloads.com/showthread.php?t=5126)

And my webpage devoted to the Cast Boolits Model 1 Pot (Which I need to update soon):

Cast Boolits Model 1 (http://hgmould.gunloads.com/newpot/instructions.htm)

Texasflyboy,

Thank you. I am on my way to look at those links and see what you have already blazed on this trail.

... pick ...

pick

03-13-2009, 04:22 PM

To All,

I have come to find out that this is a VERY economical bunch here [smilie=1: I have been building semi-custom and custom stuff for customers for over 20 years and consider myself pretty good at sourcing things at good prices. Well I have been put to shame so far on this project. Those that have gone before me have worked the suppliers very good and I have not been able to source anything at any substantial discount then what has already been posted on this site :)

I was hoping to get the pricing of all components under $100. Right now it looks as if I am right at the $100 mark plus or minus $5. This is saying a lot about the folks here. Seems that just about everyone really knows how to get the most for their time and money.

Still, all considered, $100 is not outrageous. I went and toured the Magma web site and they have some great stuff but the price is up there also. I am going ahead with this project mainly because I want to build my own (that is a least half the fun).

Just to let everyone know where I currently stand with the 'build' I am nailing down the components that I plan to use and the feature set of the melter. For review here is the list.

FEATURES
1. 40 to 50 lbs of lead melt capacity bottom pour
2. PID temperature control built in, up to 1000 F, set limit user defined
3. Changeable nozzles, even when loaded and at temp (if you dare)
4. Removable pot (no tools required), Stainless Steel (apx 6.5 inch opening)
5. Universal A/C power input from 90 to 265 Volts
6. A real on/off switch that totally isolates all electrical power from the machine
8. Power ON indicator (light)
7. Adjustable mold guide
Optional. Warming plate for preheating of molds with own independent temperature control

Components
1. Solid State electrical system
2. Digital temperature and set point read outs
3. Stainless steel and Aluminum construction for majority of product
4. Easy access and replacement of all major parts.

Now that I have that out of the way ... the only area I am still sourcing is those d*** heating elements..... Anyone ???

Hope to nail down the part sources this weekend and pulling all the material together next week and working on the physical layout and design. The week after that (23 March) start banging away to build it. Lets see how well my plan holds together.

Springfield

03-13-2009, 05:24 PM

I always liked the moveble mould guide on my RCBS pot, so when the Magma had a non movable one at the wrong height, I had to do something. I just flipped the Magma guide upside down to get it out of the way but still have the support, then drilled holes in both sides and ran a steel rod through it. Spring clipped the rod on the outboard ends to keep it in place and Voila! Mould guide. To adjust it you just need a set of holes at the height you want. Not as adjustable as the RCBS but I deal almost exclusively with LEE 6 bangers so it isn't a problem. Nice thing is the rod rolls and it is easy to get the spilled lead off of it, unlike the big flat plate the Magma came with. Little things can make a big difference when you use the tool quite a bit, like I do. My 40 lb Magma uses a band heater, or maybe 2, not sure, haven't been in there lately.

Springfield

03-13-2009, 05:31 PM

A band heater site. http://www.thermalcorp.com/band_heaters_mica_stand.php

waco

03-13-2009, 11:51 PM

wow!.........after that, im gonna grab 2 advill and a cold beer.......just a tick over my head....lol

lee 10# pot.......just add and cast and add and cast..........call me simple.......
waco:drinks:

HeavyMetal

03-14-2009, 01:20 AM

Pick:
Looks like your on your way!

Hopin you post pic's as you go along, not sure I'm up to this kind of challange but if you keep it second grade enough I just might stumble through one if money gets better.

Good luck!

pick

03-27-2009, 02:51 AM

Well nothing is ever as planned ... should know that by now at my age.

An update... I have parts collected and ordered and on the way. Have the rough layout and fabrication worked out. The biggest issue I am having is the power input / supply for this thing.

I really want to have an 'universal' input (86 to 265 volt ac) so you never have to worry about what type outlet you need. Just use the plug for the outlet you have and go for it.

You would thing (at least I did) in this day and age when computers are able to be plugged in no matter where you are in the world and they are mass producing them by the gazillions that working up something for this melter would be straight forward ... WELL WRONG ... I may have to go with out it. The only real trouble is that all the easy to come by and low price heating elements are made for 220 to 250 volt range and I really do not want to need 220 Volt outlet. .....

Despite all this the parts are arriving or have been found locally for free. I am going to take tomorrow (friday) and the weekend to see what I can do about this 'power supply' issue and make a decision and live with. I will be dusting off the digital camera and making sure i have good batteries for it. Hopefully the last of the items will be arriving next week and I can start building.

... pick ...

SciFiJim

03-27-2009, 09:30 AM

Charlie Sometimes

03-27-2009, 11:07 AM

Sounds like a pot that I would want for my very own!
If you get to sellin' some, let me know.

pick

03-27-2009, 07:57 PM

Your mentioning computers being universal brought up an idea. How about adapting a power supply from a computer?

Check the pricewatch.com website here (http://www.pricewatch.com/power_supply_for_case/) for power supplies.

Well that was the Idea but there is no way to tie them in with the PID which is the main point of doing this in the first place. Also the output voltage of the computer supplies would mean having a semi-custom heating element (more money and time).

You know how it goes ... solve one issue and create two others :)

On the issue of potentially offering this build to others, that is the very reason I have spent the time and research to source the parts and cost. If it all works out then I should be able to come up with a melter for casting that offers PID (fine) control and easy function at a reasonable cost.

Wish me luck you all ... as I am about to now leap with both feet [smilie=1:

... pick ...

hpdrifter

03-27-2009, 11:18 PM

I don't know how to draw it on the computer for posting, but you could put one leg of 220 thru a relay. The nuetral(N) to the N of the relay coil and jumper it to a common input of the relay and feed thru a normally closed contact. Put one leg of 220 to the hot(coil) and jumper it to a common input of the relay and fed thru a normally open contact. The other leg of 220 would feed thru to one termination of the heating element. If the second leg of the 220 is dead(110), then all you"d get is 110 with the nuetral feeding thru the normally closed contact and the first hot at the element(or switching device). Should the second leg of the wiring(220) be present the relay will be activated and the nuetral opened, and the second leg fed to the other end of another heating element thru a now closed contact.

Just make sure that if plugged into 110 the hot goes to the switching device/element and the neutral goes to relay and also jumps to the control system for a completed circuit.

Might need two cords with a common attachment port at the machine and be very careful about polarization.

Maybe more complicated than you want, but food for thought.

Heavy lead

03-27-2009, 11:24 PM

hpdrifter

03-27-2009, 11:49 PM

if rated for proper amperage, yeah.

hpdrifter

03-28-2009, 12:12 AM

hope this turns out legible.

Gerald C

03-31-2009, 10:36 AM

I use a pid controler it was a night mare to program. I had my brother help me (retired EE) and it still was a head scracher. I used a dpdt 10 amp relay with the poles tied parallel to control the pot. these controller are not cheep. (250.00) got mine used for nothing. I wish there was a controller out there with out all the bells & whisles, so a dummy like me can program them
Gerald C

thebigmac

03-31-2009, 02:09 PM

WTB=THERMOSTAT FOR AN OLD SAECO OR LYMAN CASTING POT. PM ANY INFORMATION PLEASE. THANKS, Mac

pick

04-08-2009, 05:49 AM

Well time for update #2.

Got a good cast iron pot for the same or lower price I could get for a steel pot and the manufacture is willing to work with me to get a special 'group' price if need be. That part finally came together. I have a back up pot, but it is much bigger (nearly twice the volume) but it was made and designed for the Al casting industry. The price on that is basically the same as the cast iron pot.

The controller part I have been able to source a good PID that has auto learn (self programing) so set up should not be an issue. Also this controller comes at a good price point.

Now to heating and this thing. Given that the volume is two quarts or apx 50 lbs Pb at max that takes a lot of power to get melted. So unless you wish to take one hour plus to get it liquid I am looking at a 1,400 watt or more output heating. That is doable on a 115 volt outlet, but I was hoping to avoid a separate 220 volt design. I am still looking into this whole power issue and 115 vs 220 volt issues. Call me stubborn, but I WANT to be able to plug it into either a 115 or 220 and just have it work. Also, if some one was to take it anywhere in the world it would work.

I have found some companies out there that have power supplies in the range that I am looking at but none are less then $400 USD and that just kills the budget for this project. I may have to just design and build my own power supply for this and that will take more time and testing. I have been researching this area.

This has turned it to a much bigger project then I had originally thought, but I want to come up with a design and build that is nearly a finished product not just a 'klug'. Do not get me wrong about the home solutions. They work great for those that have them. I am just looking to come up with a design that is at least a kit level and will be safe and functional no matter where it is used at.

I guess the engineer part of me got me going down this road as I just will not be happy with anything less.

... pick ...

monadnock#5

04-08-2009, 01:50 PM

You've got good instincts. Take your time and do it right on the first take. The wife's dryer runs on 220V. Should it become necessary, I could tap right into it.:)

scrapcan

04-08-2009, 03:39 PM

Watching patiently and hoping for the best to come in "kit" form.

Charlie Sometimes

04-08-2009, 09:39 PM

What Chief Dan George said in the movie Josey Wales- "Endeavor to persevere".

hpdrifter

04-08-2009, 10:31 PM

Well time for update #2.

.............................Call me stubborn, but I WANT to be able to plug it into either a 115 or 220 and just have it work. Also, if some one was to take it anywhere in the world it would work...............................

... pick ...

Ok, stubborn.....er I mean pick, most 115 volt and 220 volt receptacles are completely different. You're gonna hafta intentionally change receptacles anyway. Why not make a separate cord to fit a 15A 220 volt receptacle?

If an electrician put a 115 volt receptacle in for a 220 volt system, I'd be leary of plugging anything into it, without checking the system out.

BTW, I don't think ONE cord fits all is doable.

Charlie Sometimes

07-20-2009, 11:25 PM

Any new action or updates lately?

jmorris

08-03-2009, 04:41 PM

I really want a PID controlled pot with bottom pour. I have read several of the threads here about retrofitting existing ones, which work fine, but since I have an electrical engineering background along with a full fledged machine shop I was thinking that I could build my own and be much happier in the end.

The project below started the same way. I used a 3500 watt oven element ($9 at Sears repair center) and 3/8" steel pipe (holds over 60#), PID control, 555 timer circut for the pour and cool timers finish out the automated caster. Then sizing was a pain so I had to automate that too.

http://i121.photobucket.com/albums/o213/jmorrismetal/caster3.jpg

http://i121.photobucket.com/albums/o213/jmorrismetal/caster5.jpg

http://i121.photobucket.com/albums/o213/jmorrismetal/caster1.jpg

http://i121.photobucket.com/albums/o213/jmorrismetal/center.jpg

http://i121.photobucket.com/albums/o213/jmorrismetal/die.jpg