The International Hobby Metal Casting ezine.
Brought To You By:
Col Croucher, administrator of: www.myhomefoundry.com
Australia.
Volume:05. Number: 57
I hope the past month has been productive for you and the projects you have been slaving away on have finally come to fruition, I know how hard it is at times to get things to work out the way you want them to, even though you follow the correct rules & methods, disaster still happens, and then you have to take a break and try to work out why... unfortunately that is all part of the deal with hobby foundry work.
For the rank beginner, it is all a bit daunting at first, but with experience and some small success you soon gain the confidence to enable you to just go out into the shed and put a project together without any frustrating problems, once that happens you know you are well past the rookie stage, the thing is not to be too ambitious when first starting out, take it slowly, learn the basics, build on it step-by-step. Apprenticeship is ideal, but in this day and age where you can watch video tutorials on the internet, tips and tricks of this skill can be found in alternative mediums as well.”
Just lately on SBS TV here in Australia a three-part series documentary called The Passionate Apprentices" was shown, each episode covered an old traditional skill, the first being Knife making, the second collecting & producing a special honey from the wilds of Tasmania, and the third, baking bread using a traditional wood fired oven, a rare thing today when most bread baking ovens are either fired by gas or electricity.
The knife maker was the one that appealed to me as the most interesting, only because he was dealing with metal, and also the fact that he used a charcoal forge to heat and work the metal, with which he produced his knives, knife making is no doubt more to do with blacksmith and forge work than it is to do with casting metal, but extremely interesting none the less, especially when he explains that some of his knives have hundreds of layers of steel, all forged with the utmost care... just think how fine the layers of steel must be, enthusiasts of antique damascus twist gun barrels would understand the methods well.
The apprenticeship slant on the story become evident when a couple of young fellows arrived at the knife maker's workshop one day and they asked him to teach them the art of knife making, then the story continued about the young passionate apprentices learning the art of knife making, the place in question is way down south in Tasmania deep in the Huon Valley, I’ve been there, and you would not be wrong if you called it Gods own country, such is it's beauty, and the Huon Valley area probably has the most pure air on the planet.
The people live "a back to basics", lifestyle which is the envy of many a stressed out city person if the feed back on the web site blog is anything to go by. But the whole point about this SBS TV series is that no matter how fantastic the worlds technology becomes, there is still a great need for basic knowledge, knowledge that has been around for hundreds of years, but unfortunately if it wasn’t for the knife maker, the bee keeper or the traditional wood fired baker, and every person reading this ezine who enjoys the challenge of basic metal casting technology, all of this beautiful old world stuff would just simply die out, so while you are doing something for your self in your hobby foundry you are also making sure that the small scale metal founding skills will be handed onto someone else, e.g, a brother, nephew, friend, perhaps even the boy next door. To read more about this interesting SBS series, click here: http://tinyurl.com/5afkam
When you arrive at the page don't forget to scroll down to read the comments left by many of the viewers, it seems that people cant get enough of this kind of stuff.
Now, with this issue we are also going to announce the winner of The Show And Tell Metal Casting Comp, to say we have been blown away by the quality of the entries would be an understatement, there is some truly talented people around who are creating some wonderful metal casting projects in the humble back shed, the variation of the many different things that on shown will astound you.
A big thank you to all who took part and submitted project work, I am sure that many people will be impressed with your submissions. And newbie metal casters.... take note of the following projects, there is a ton of knowledge here.
But there is another problem, we are unable to show all of the entries here in the July ezine all at once as there are just too many images and support articles to print, so what we will do is to feature the entries that we consider to be the most creative and most interesting. This will also show the people who are only just thinking about taking up the metal casting challenge, the possibilities of metal casting.
We will be putting the other entries into the next ezine, which we will begin putting together as soon as this issue has been published. I hope you enjoy this months ezine, it is probably the biggest issue we have put together yet. Yes, a lot of time goes into putting it all together, but I think it is worth it.
So are you ready for a lengthy read? Grab a nice cup of coffee and settle in here for some great reading courtesy of your fellow hobby casters from around the globe.
Col.
Yes, I know you have been waiting anxiously to see who & what was entered, and who gets the moolah ($50.00), and who gets the runner up prizes. As we stated in the initial news release about the hot metal ezine show and tell metal casting comp, we said we would pick a winner, plus a second & third for the runner up prizes, but as you could imagine, it was a hard job to choose three runner up entries, because every entry has something special & unique about them, so to be fair, we will award a first prize, but then we thought we would select two for equal second, two for equal third and decided to add an equal fourth place too, yes, we are probably getting a little carried away, but we want to reward the effort put into the projects, but please don't think we are being unfair to you if you have missed out on a prize, to be honest everyone deserves a prize for the effort they have put in, and the response to the comp was truly overwhelming, and a big thank you to all who have contributed to this fun competition. And if you were a bit slow of the mark, or you were unable to have something ready, and several people did express their interest to submit a project but couldn’t enter a project due to time constraints... so to the people who missed out, please keep working on your projects, because we may well run another competition in the future. We were not able to show all of the projects in this issue, it is late in the month, and we will be preparing the August issue straight after this one, we will show the rest in August issue.
And now as they say in show business "It's On With The Show."
You Can Do It.
Do What?
Cast Metal In Your Own Backyard.
How?
By Learning & Applying The Knowledge.
Click Here
To Grab Your July Special.
First Place
Awarded To: Trevor Desecke; Home Built Dividing
Head. (See Story Below Photo's)
Image 02. Hand
Made Patterns.
Image: 03
Image: 04.
Image 06: Home built dividing
head.
Image 08:
The Simple Home Built Furnace.
Image 11: A
Table Of Foundry Patterns.
The Show & Tell Hobby Casting Competition.
Most Innovative Project and application of workshop skills with limited resources.
(See Photos Above)
The Story Behind The Entry Submission.
Pyro Trev’s Metal Casting Adventures.
I am a 40-year-old man that has a desire to create most things myself from scratch. I come from a background of jack-of-all-trades and master of none. My venture into the world of home metal casting started from the need for extra equipment and tools for a small Chinese lathe that I purchased.
Not having the spare money to just go out and buy them, I looked to the Internet for the answer. Being an Aussie, Col’s page of books and info came up in the search engine listing first page. I purchased a few of them and with some other info from the web, off I went to melt some metal and create all the workshop gear I needed. Big pipe dreams and wishes where soon to be wetted down with failures and frustration.
A steep learning curve began.
I eventually got the right type of green sand, learnt not to melt the metal till the cows come home and make it hotter than hell, ram the moulds hard enough, and why the venting wire was invented. I used steel crucibles with a clay wash to stop iron contamination. After making crude shapes of Aluminium that where to my satisfaction, they were ready to be transformed into my desired projects; I started to make real pieces of equipment that I could actually use in my workshop. Gingery books have a good deal of instruction for the beginner and frugal caster.
I need a dividing head to make the cutters I needed to make other tools and gears.
Here is the pile of patterns I used to pour the aluminium parts to make my own dividing head. (Picture02)
To finish coat the patterns I made a coating of paint thinners and Styrofoam with a little marking dye to cover the patterns. It works quite well at smoothing the pattern edges and stopped sand from being broken away when the patterns were pulled from the moulds after ramming.
Here are some of the results from the pour. (Picture03)
I had to learn to handle brass as well as Aluminium.
Being frugal and broke, I tried using fired 22 cartridges from my local gun club. It is a 70/30-brass mix and casts ok and machines fairly easy as well. The worm wheel is cast in that 70/30 brass. (Picture04)
Pictured also is the home made threading tap I made from a high tensile 1 inch 12 tpi bolt I found at the local recycling centre. I used the tap making jig pictured later to make it. I used another bolt as the worm.
Drilling the dividing plates was a whole new world to me. That thing called dimensions I found out is really needed if you want things to fit with other parts. (Picture05) Not Shown)
All the parts partly dissasembled are shown in Picture06.
I make tools & things as I need them and when I can, I scrounge the parts for little cost as can be seen from the pictures.
My furnace. An old drum lined with local clay and mixed with local silica sand and a talc/clay wash for the hot face. (Picture08)
The pile of reclaimed metals. Aluminium, brass, lead, cast iron. I construct all of my own home made burners. The newer versions are based on Mike Porters design. They are very stable at low pressures. Here are some of my other attempts at casting some useful equipment. All of my Patterns Picture11)
I have also constructed moulds for home made crucibles and some of the crucibles, I have constructed a pattern and cast a new head for sanding machine, a tang for Black Powder Rifle, Bullet Mould for 45 Cal Black Powder Rifle + Cherry.
I hope this inspires others to follow their dreams and realise that given time and a little basic know how, almost anyone can make metal equipment for themselve’s.
Trevor Dasecke.
Australia.
Note From Editor: Unfortunately we are unable to use all of the project pictures sent in by Trevor, but we will endeavor to show them as well those sent in by several other people in the next ezine issue.
Dale Hampshire: Equal Second.
Calgary. Alberta, Canada.
For teaching new basic foundry technology to the Islanders in Vanuatu to enable them to press & process their own coconut oil. See Dale's Pictures below his article.
Colin, I do have a project that might be interesting to people, and would like to enter my story & project into the contest.
After returning from living in Vanuatu (1987-1995) I began working on finding a way for villagers to make their own coconut oil at the household level. One of the most difficult parts of making oil efficiently is pressing the coconut. Although you can squeeze the cream out by twisting the shredded coconut in a cloth, the process only yields about 10% of the oil. Commercially available presses start at $1,500 (not including shipping from India or China) and replacement parts are impossible to get. At first I had some success using modified meat grinders and fruit presses but I needed to design a press that would cost about $80 or less and that could be manufactured at the village level. That led me to backyard casting.
In October of 2006, I began by casting aluminum using a small, charcoal furnace and green sand. I struggled for a couple of months trying to make molds and mixing sand that resulted in good castings - the hollow, press barrel was especially difficult. Then I found some information about lost foam casting on the Internet.
Lost foam casting sounded like my answer and I tried a couple of simple shapes - they came out as gross deformities. I puzzled over this problem for several weeks until I realized that the painted coating on the Styrofoam mold was not simply to make the surface of the casting smooth, it was to delay the sand from rushing in until the metal flowed down into the mold. After a few experiments with various coatings, and drying times, my castings started turning out perfectly.
Finally, at the end of January 2007 I was able to successfully cast all the press parts, including the hollow barrel. With some filing and sanding of the surfaces (I use only hand tools in order to keep the manufacturing process simple), I was able to make the working press shown in the picture (photo 'Coconut Press'). It can make 1-2 liters of oil an hour and is 80% efficient. With imported materials and local labour it should sell at the village for about $80. Broken or worn out parts can be replaced by the local (small scale) village caster. I have made several presses now and the parts can be made very roughly to size and still work effectively (the specs have a high tolerance for variation which of course is necessary when only non-electric hand tools
are used to make the molds and finish the parts).
The press has eight parts, five are cast; the barrel, the base, the auger, the bushing and the handle (photo 'Parts of Press'). These were all cast in dry sand (photo 'Lost Foam Casting'). They look rough on the outside because lost foam casting faithfully copies every detail of the styrofoam mold (every scratch, every chip). The barrel mold is shown in the photo 'Foam Mold'. The masking tape hides particularly rough areas of the surface and the lines where two pieces of foam have been glued together and makes for a smoother surface in the casting.
As I have mentioned, I used a small (5 gallon pail), charcoal furnace. As far as supplies, I use the common blue styrofoam available in hardware stores (not the white foam - although it casts well, it is hard to work into a mold because the foam is composed of larger pieces and they tend to chip off easily). I use liquid rubber glue to join parts of the mold together (a little bit spread on both surfaces does it, too much melts the foam - I don't use a hot glue gun to join pieces, although hot glue can be useful for filling in small holes and imperfections in the foam mold).
I find that styrofoam can be drilled, cut, and sanded easily (and if you make a slip, it's cheap and easy to start over). I tried cutting styrofoam by melting it with a hot wire but found the melting could not be controlled and contained as well as cutting with a razor knife or drilling. I use a 50:50 water to latex paint mix to coat the molds (I use dark green paint because it is easy to see uncoated areas). I coat once, by dipping, and then let it dry for a few hours then recoat. I let the molds dry for 2-3 days (any moisture left in the coating will boil when the hot metal comes near and ruin the casting surface). I use Sil 1 sand (I sieve the used sand through a fine screen and reuse it). For sprues, I use the same foam usually cut 3-4 inches long (1/2"x1/2" 'square-ish') and glue a couple to one end of the mold before applying the paint coating. I try to judge whether the metal will flow easily to all the areas of the mold through the sprues and I may add more sprues to a large or complex mold. To cast the barrel for example, I used about 6 sprues of different lengths glued to various parts.
Just a note, I recently tried casting cast iron using dry sand and a lost foam mold. The cast was a little deformed at one end because I did not make the sprue long enough but otherwise it was good. I used Colin Peck's oil-fuelled furnace design to melt the iron. The casting was a 4-pound iron auger.
I have found that lost foam casting gives me the ability to prepare and cast complex shapes easily. This is very important as I work through a series of 'experimental models' that may or may not be used in the final design.
Anyway, that's my casting project. To find out more about my project in Vanuatu go to there's even a video of some natives using lost foam casting to cast an aluminum 'A' (A for their island Ambae) using a coconut oil burning furnace made from a one gallon paint can.
Learn More Here: http://www.villagesfirst.com
Cheers - Dale Hampshire.
Calgary. Alberta, Canada.
Dale Hampshire Metal Castings: Photos Of Hand Operated Coconut Screw Press.
 Coconut Press. |
 Foam Foundry Pattern |
 Casting Foam pattern In Dry Sand. |
 Coconut Press Parts. |
Ray Brandes. Equal Second.
Builder of a very intricate Woodson Engine.
This is my story;
When I was young, probably pre-teens, in the late '50's and early '60's, dad would bring home Popular Science magazines from work. He worked at Bell Laboratories in Murray Hill, New Jersey. This is where they invented the transistor, the laser and built Telstar, the first communications satellite. Dad worked on Telstar.
Anyway, every once in a while, the Popular Science magazine would have an article on a little steam engine. Photos showed it whirling around. I wanted to build one! "Dad can you help me build this?" Dad's reply was that we needed a metal lathe to build one. "Well, we have a metal lathe!" Dad told me our lathe was for wood turning. "But it is made out of metal!!!!!" I just didn't understand.
Eventually I did understand, and took metal shop in high school. After high school, I entered a tool & die maker four-year apprenticeship. After that I worked in many shops and I spent years cutting metal, but it wasn't until after my 60th birthday on April 8, 2008 that I started build a "real" steam engine in earnest.
The engine I built is from four issues of Popular Science from 1947, a year before I was born. It had the Stephenson reversing gear and this presented me with a challenge. Since about 1990, I have been casting metal. The Internet is better than any class you could take. I have learned more from other casters on the forums than I could have from any book.
Building something like this tends to over power me. But, if I try to make one or two parts a day, eventually I get it done. I find I look to make the next bit in between my regular work, which is mostly servicing the CNC machines. I'll put some stock in the Haas and while it is cutting I have a minute or two where I can do a little engine work in the manual lathe or mill.
Being familiar with lost foam casting, I thought this project would be a good application of the technique. Many parts were cast or made from stock that was cast. The standard gave me trouble though. You will notice the first foam model has cutouts in the legs. This is the one that failed. The second foam model had solid legs (and a little thicker too) and it turned out OK.
When all the parts were made, they still had to be fitted. As precise as I made the different parts, there was still quite a bit of shaving, polishing and lapping before the engine turned as smooth as I wanted. Now it runs nice and slowly on about 5psi. You can see it in action at: http://www.youtube.com/watch?v=5x82mEiH7_k
Following is my web page regarding my 1947 Woodson steam engine:
http://www.foundry.ray-vin.com/woodson/47/woodson.htm
Regards, Ray Brandes, Marianna, Florida. USA.
Ray Brandes. A Beautifull Woodson Model Engine Cast In Bronze.
 Woodson Model Engine. |
 Cast Bronze Parts. |
 Foam Foundry Patterns. |
 Woodson Top End Machined Engine Parts. Ray is an exceptional engineer and has done an incredible job on this Woodson engine, if this comp was just about model engines we would have awarded a first prize. Check his video at youtube. |
Roly Border. Equal Third.
Queensland Australia.
For Imaginative Self Designed Aluminium Parts for A Stirling Engine - Cast In Green Sand.
The castings shown in the pictures are for a Stirling Engine being built to my own design. The project was started about 8 months ago and I hope to have it completed later this year. I have included a photo of the patterns used for green sand moulding plus a group photo of the castings. The additional photos are included to give you a choice of what to use, if I'm lucky enough to be in the running.
I have an LPG fired furnace but when using this for aluminium got many reject castings. The problem thought to be oxide plus hydrogen absorption from the products of combustion. I have not been able to source a supplier in Brisbane of flux in small quantities.
Melting is now done in a crucible with a kanthal element wound round it, insulated with ceramic fibre and powered by my stick welder, the low voltage making it intrinsically safe. Using clean scrap, skin drying the mould and melting in this manner has eliminated most of my problems.
A photo of my small crucible is included which has about 0.6 Kg capacity.My large one holds 3.5 Kg. Have recently adapted another crucible, again using kanthal wire for melting brass and bronze. Only two melts to date.
Regards Roly Border.
Roly Border Stirling Engine Castings.
 Assembly of cast engine parts. |
 |
 Stirling Engine Crankcase |
 Electric Furnace Constructed Around A Crucible. |
Simon Milner: Equal Third. From Melbourne Victoria Australia.
A Passionate & Highly Enthusiastic Aussie Metal Caster.
As a mechanical engineer, my grandfather had been involved in casting aluminium adaptor plates for converting Holden 6 cylinder motor’s into Land Rover’s back in the late 70’s and early 80’s, and some of his old tooling was still to be found in my fathers engineering workshop.
I have always been interested in metal casting, and decided to make an attempt to create my own casting equipment when I took over my fathers engineering workshop in 1994.
Back then I had no Internet for research, and no books to look into for details on set-up and casting methods. My first attempt at casting was extremely agricultural, using a 44 gal drum cut in half, and the top of it cut thinly to slide across the top to adjust the amount of heat escape. For a burner, I found my grandfathers original kerosene jet burner, which used a drum of kero with a tap to stop the flow and a flow adjuster built into the burner unit. The airflow was supplied by a reverse blowing vacuum cleaner, and the burner had a depth adjustable head to control the main orifice distance to the burner tube. To light the burner I used the oxy torch to create a source of constant ignition until the kero flow was matched to the airflow and it would sustain flame itself. This flame was fired into some house bricks shaped to catch the flame and a cast iron cooking pot sat on top of them, spanning the gap, which I melted the alloy in.
Well as you can imagine, this was a pretty dangerous method of setting up a furnace, and the results were extremely slow, with over ½ hr required to melt a relatively small amount of alloy, approx 2.5 kg. The alloy was poured into split cylinders to make solid ingot bar for machining, and the quality left much to be desired with air bubbles evident throughout the alloy.
I did make some useful equipment from the small amount cast, but the effort that went into the melting procedure far outweighed the end product, especially not knowing anything about sand casting moulds.
Many years later, after selling my engineering business, and changing careers a couple of times, I found my grandfathers tools in my shed at home and got some enthusiasm about learning about casting again, only this time I was determined to learn properly, and take no short cuts!
With the Internet commonplace, I soon found Col’s web site, purchased the e books, and set about finding the materials required to accomplish the job. I pulled apart my grandfathers kero burner and utilised only the housing that had a built in butterfly for air flow control, then fabricated an internal gas jet complete with venturi to extract the gas under negative pressure while the forced induction air flow was flowing through the venturi. Then I welded some plates into the end of the burner pipe the same as I have seen in jet engines from when I worked on aircraft, with the intention of swirling the airflow to create a more complete burn of the gas.
After a couple of test runs of the burner mounted in a stand, I sent some pictures to Col for some input as to whether it would work. He was very happy with the design, so I got stuck into the furnace itself. Following his spec’s I built the housing inside a 60lt drum, and filled it exactly to the requirements in the e book with refractory, and mounted the burner as specified as well.
I built all of the additional tooling such as lifting tongs, pouring frame and even bought a small cement mixer to mix the green sand. Everything was running to plan, and even had Col put my equipment as a main story in one of the ezine articles last year.
I was feeling pretty proud of myself up to this point, and broke out the newly purchased Petro Bond, the brand new foundry quality sand, along with the $120 worth of special oil required to mix the Petro Bond, as this was the bees knees of casting sand, according to an article supplied with one of the ebooks. I was absolutely adamant of doing everything to the highest standard, so this was the sand to use.
Well after mixing up 20kg of sand measured and mixed precisely to the instructions, I started to ram together my very first mould, carefully following the instructions step by step. When I parted the rammed sand for the first time, my excitement turned to frustration, when it tore a huge chunk of sand leaving it mostly sticking to the pattern. Once again I rammed together another mould ensuring copious parting dust, including brush dusting the contact surfaces of the pattern. Once again a huge tear!
I started messing around with different quantities of Petro Bond, Sand, and Oil and even went to the extent of mixing the whole 20kg of sand in my wife’s blender, totally destroying the mixing blades by the end. The result was the same, time after time; it just would not hold shape in the moulding box.
Well this went on for several weeks with me looking into buying some green sand, but I kept getting the run around from foundry supply stores. Even the Bentonite, the crucial ingredient needed to make green sand, seemed to be a mystery to obtain when putting the word into a yellow pages search.
In the end, I gave up; put it all away as I had some much needed house renovation to complete that was getting neglected while I was concentrating on this project.
Earlier this year after completing the house, I pulled all of the foundry tools out, dusted them off and started where I left off. I did only one ram together with the Petro Bond, which predictably tore, then as not to get discouraged I turned my attention on researching the Bentonite, which I found could be purchased quite cheaply at any pottery supply store.
I came home and using Col’s recipe, mixed up some common green sand, which immediately, when squeezed in the hand, held shape, more firmly than the Petro Bond. Getting pretty exited at this stage I quickly rammed a mould together using a prop hub from a hovercraft as a pattern, quite a bit more complex in shape than anything I had attempted before, then when it came to opening the moulding box, the result blew me away. It was amazing; all of the detail was as on the original pattern. Well I was not going to leave it at that, I raced inside, 7:20PM at night, and asked my wife to put a hold on my dinner, fired up the furnace for it’s first ever run of fury, and proceeded to melt my first lot of alloy in 14 years.
In less than 10 minutes I had over 2kg of alloy melted and ready for pouring. I could not believe how quickly the alloy melted and how fiercely the furnace was operating. I made the pour, shut everything down and went inside for a clean up and dinner. After an hour I went out to the shed to break out the casting. The finished product blew me away. Although a couple of small floors were evident, the quality of the alloy was amazing, and the casting detail better than I could have ever expected after the persistent problems I had with the initial sand issue.
Since then I have been busy buying books, learning methods and recently purchased an oven off eBay to make sand cores. With overcoming this initial failure and seeing what can be achieved, the sky is the limit.
Col, Thank you for everything you have done. Every month you must sit in front of the computer trying to think of what to write about this time. While you are doing that, the people you are helping, are working at, and learning your very teachings, which bring a level of satisfaction that you will probably never really get to truly appreciate. That is why I have just written you about this very long-winded journey.
You might have just helped another guy to melt and cast alloy, but you have also given me the knowledge that I was never able to find out about from my Grandfather, and achieved something that I feel I was destined to learn, as it gives me a closer appreciation to what my grandfather used to accomplish.
Thank you.
Regards.
Simon Milner. Victoria Australia.
Simon Milner Foundry Gear & Castings.
 The LPG Furnace Burner In Action. |
 The Burner Venturi. |
 First Ever Castings: Centre. Hovercraft prop hub.Small test projects, Alloy sinker moulds. |
 An Antique Bronze Kerosine Burner, belonged to Simon's Grandfather. |
Daniel C. Postellon. Equal Fourth.
Imaginative Grey Iron Art Casting.
Digital Armillary.
Material: Cast Iron.
20 X 25 X 25 centimeters (8 X 12 X 12 inches)
7 kilograms (15 pounds).
This is a post-apocalyptic cargo cult object. If that doesn't make sense to you, think of it as what the children in 'Mad Max Beyond Thunderdome' would have made if they had a cast iron foundry!
(Ed Note: Mad max was filmed in outback Australia.)
Armillary spheres are analogue representations of all of time and space, and are inherently NOT digital. This was cast in 2007 at Ox-Bow, a school of art and artists' residency, affiliated with the School of the Art Institute of Chicago, as part of a "metal casting for sculpture" class. This was a resin set sand mold, filled with a two-man ladle from a cupola furnace operated by the class.
The pattern for the base was hand-carved from expanded polystyrene packing foam, a circuit board from a disposable insulin pump was glued on for the digital effect, and the base divided in two (split pattern). The pattern for the sphere was a commercial foam sphere, also divided. A mold was made with the right half of the base and sphere in position, and then turned over. The left halves of the pattern were registered to the right halves with toothpicks, and the left side of the mold was cast on top of the right half. The two pieces were separated, and the Styrofoam half-spheres were removed, and replaced by cast-in place resin-set sand half spheres.
These were removed for future use as a core. The rings, axis, pillar piece connecting the base to the sphere, signature, date, sprue and vents were all hand carved into the mold or core, and the foam base pattern was removed. The core was replaced, the mold banded with steel bands, and cast upside down, with the sprue feeding the middle of the base of the sculpture.
There was quite a bit of flash in the inside of the sphere, removed by drilling and by a hand grinder with rotary stones.
Cast iron is fairly brittle, and the piece fell out of the vise when the sprue was being removed. The sculpture was now in two pieces, the base and the sphere. I drilled a hole though center of the base, continuing into the supporting pillar, threaded it with a hand tap, and screwed the two pieces back together with a threaded bolt. This was then cut off flush with the base.
Although it is not really a working sundial/armillary, the angles and spacings are approximately accurate for the 43 degrees North latitude, where it was cast. This project was accepted for a local juried show, the 22nd Annual West Michigan Art Competition.
Daniel C. Postellon.
Michigan USA.
 Digital Armillary: Rear View. |
 Rear Side View. |
 Front View. |
 Name Inscription. |
Equal Fourth Place Also To:
Carl Wilson. USA. For Intricate Pattern Making.
Col:
Below is a set of photos of the patterns for the latest project: a vacuum (flame licker) engine. This is a joint venture with Dennis to produce an engine to our design of an engine by Jan Ridders published in Model Engineer recently. Patterns were machined from acrylic plastic; the base will be aluminium and the flywheel brass. I have some thought of eventually making both from cast iron, which will be a new material for me to pour.
Following are photos of patterns done in the last few years. Some of the castings are not available for photographs, so I used the patterns instead.
0080: (vertical) back plate for Jubilee Clock, designed by Edgar T. Westbury and serialized in Model Engineer in front of back plate,
from right:
>> Pendulum support pattern.
>> Support casting.
>> Flat belt sheave casting for small dynamo.
>> Follower for flat belt sheave pattern done in plaster
>> Flat belt pattern in MDF
Front:
latex mould of original way wiper support from Monarch 10EE lathe (slightly green colour)
Urethane pattern cast in latex mold (white)
pair of patterns on board (blue)
Two connecting rods for small internal combustion engine:
These were melded from a one-piece pattern carved by a friend in the 1940's
Carl Wilson.
 0080: Selection of Patterns. |
 Base Pattern. |
 Flywheel Pattern. |
 Patterns Assembled. |
Once Again, congratulations to:
Trevor Dasecke.
Dale Hampshire & Ray Brandes.
Simon Milner & Roly Border.
Daniel Postellon & Carl Wilson.
If you submitted your work but it has not been featured in this months ezine please be patient, we will feature your work in next months issue which is only a bit over two weeks away.
Thanks to all who submitted casting photographs and articles, each and every submission make for very interesting reading & learning, I'm sure it will allow others to understand & learn more about what can be achieved with: skill - determination - passion, and good old persistence. To anyone who has been holding off thinking they might like to have ago at metal casting sometime soon, now might just be the time to get stuck into it.
There's more to come in next months issue.
Enjoy.
Col.