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#1 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
 

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#2 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
Can't wait to see more, thanks for sharing.
 

Attachments

#3 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
This should be interesting
 

Attachments

#4 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
Will be impatiently waiting for the next episode. Thank you for the tutorial.
 

Attachments

#5 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
Awesome idea for blog. I'll look forward to more!
 

Attachments

#6 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
Part 2

A quick disclaimer here…I thought to just throw the pictures up and leave it at that. However, the more I visited this site, the more I realized the level of knowledge and talent of its inhabitants, was pretty dam high.

I have to give the subject the attention and respect that it deserves. That's going to take me some time.

On to the story…
Castings are made by pouring metal into a closed hollow mold made of sand. The hollow shape inside the mold is made by the pattern. Patterns are very accurate wooden replicas of the casting. But, they are more than replicas, patterns are a collection of precise shapes that are engineered to obey the rules of good foundry practice.

good practice means the pattern has the draft needed to mold, that the parting plane is properly located, and that parting lines are smooth and natural, with no abrupt changes of direction.

Draft is the amount of angle, or taper, that is added or subtracted from all vertical surfaces of a pattern.
A pattern must have some amount of draft, or it cannot be removed from a mold without damaging the mold.

The parting plane is the plane that splits a pattern into two. Pattern are not always split in half, nor is the parting necessarily flat.

Partings that are not flat, or planar, are called "offset partings" and are defined by their parting line.

Remember the sand mold?..it must be opened so the pattern can be removed. Ideally, the parting line follows completely around the shape of the pattern. Think of a sphere…the parting line is a flat plane that will always pass through the center.

Now, think about an automotive manifold…where do you split a complex shape like that?
the answer is, at the parting line. In this case, the parting line follows the natural parting line of each feature of the manifold.

All this rambling about partings and lines is for a good reason, because the pattern being made has an interesting parting line. The correct parting line was maintained by the method of construction used to build the pattern. .

After understanding the blueprint well enough to build the pattern in your head…The next step is to make a layout that captures full size views of critical features or dimensions of the pattern. Good layouts are vital to accurate pattern construction.

That is where I'll start.

Wood Wood stain Flooring Hardwood Rectangle


I'll be back to describe what we are looking at.
 

Attachments

#7 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
Wood Wood stain Flooring Hardwood Rectangle


I zoomed the picture a little, hoping to show the layout lines.

Rectangle Wood Wood stain Hardwood Flooring


A layout should be full size, and in this case, its the side view of the fingered ribs.
8 ribs and 48 fingers will be assembled on top of the layout.

You can see wooden stops been glued to the layout on lines that form 3 edges, or faces, of the layout.
You can also see smaller wood stops for locating each finger on the rib.
Rib and finger material will be planed to a precise thickness that accounts for draft that will be applied later in construction.

This method of assembly is accurate and consistent.

There is the mindful zen feeling I get into when i'm focused on something like cutting, sanding, and fitting 56 different pieces of material together.
 

Attachments

#8 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
Unfortunately, I didn't capture every step of pattern construction and have no image of a rib assembly, resting on the layout.

This view shows the assembled ribs with details such as fillets and radii being added to specific areas of the fingers. The side edges are left untouched at this point.

Also, the only draft accounted for on each piece is found on the faces matching the stops on the layout.

The parting plane for the rib is defined by the line that run along the bottom of the fingers.
The fingers will mold in one direction, and the rib will mold in the opposite direction.

You can see from the layout which faces "draw" up from the parting, and those that "draw" down. The foundry terms are "cope" for up, and "drag" for down.

Draft will be applied to the sides of the ribs, but for now, they must remain parallel for the next step of construction.

Wood Rectangle Flooring Hardwood Wood stain
 

Attachments

#9 ·
A mahogany foundry pattern

A picture story about building a pattern.

10 years ago, I was the CAD/CAM guy for a pattern shop. We also had a plaster molding shop and an aluminum foundry, where we pressure cast aluminum match plates.

10 years before that, I was on the bench, building the wood master patterns that went on to become match plates.

20 years before that, I was serving a Pattern maker's apprenticeship in an iron foundry. The master I learned from once ran General Motors, "Tech Center" where the workforce was made up of 400 highly skilled craftsmen from the technical trades, toolmakers, model makers, pattern makers, designers, and engineers.

Anyway,
One day my boss walks in my office, shows me a drawing and asks me if I could machine the pattern out of a piece of aluminum billet. After a few seconds of study, I looked up and said to him, "Yes, I can make it, but WHY would we want to do that?" The amount of money in labor and machine time would be far more than if we just made the pattern "the old fashioned way". That is, Have a pattern maker make it out of wood and use it to cast a match plate for it.

I think he was just testing me and had already made that decision. I decided to document an example of this "Dying trade" called patternmaking.

The pattern maker in the photos is Gerry Koenig. Jerry is a first class mechanic, trained by a well respected master by the name of Dick Boehm, outside of Reading, Pa.

I'll start with some images of what Gerry will make.

Slope Font Rectangle Parallel Diagram


Rectangle Schematic Slope Font Parallel


Next up, "making the pieces."
So many memories of trades gone by, please keep up the great work.
 

Attachments

#10 ·
Making use of a layout

Part 2

A quick disclaimer here…I originally thought I'd just throw the pictures up and leave it at that. However, the more I visit this site, the more I realize the level of knowledge and talent of its inhabitants is pretty dam high.

I have to give the subject the attention and respect that it deserves. That's going to take me some time.

On to the story…

Castings are made by pouring metal into a closed hollow mold made of sand. The hollow shape inside the mold is made by the pattern. Patterns are very accurate wooden replicas of the casting. But, they are more than replicas, patterns are a collection of precise shapes that are engineered to obey the rules of good foundry practice.

Good foundry practice for pattern making means the pattern will have the draft needed to mold, that the parting plane is properly located, and that parting lines are smooth and natural, with no abrupt changes of direction.

Draft is the amount of angle, or taper, on all vertical surfaces of a pattern. Draft can be added, or subtracted, from a pattern. Patterns must have some amount of draft, or they cannot be removed from a mold without damaging the mold.

The parting plane is the plane that splits a pattern into two. Pattern are not always split in half, nor is the parting necessarily flat.

Partings that are not flat, or planar, are called "offset partings". Offset partings are usually non-planar, free form shapes that are defined by a parting line. Think of the edges of a potato chip.

Remember the sand mold?..it has to be opened up to remove the pattern. Molds are separated at the parting.

Ideally, partings are flat. Think of a sphere…its parting is a flat plane that will always pass through its center. Its parting line travels smoothly around the perimeter.

Remember the potato chip, it is definitely not flat. There is no plane that can split it either.
Where can the chip be parted? The answer is, at the parting line that runs around the perimeter of the chip.
All geometric shapes have a parting line somewhere. It is the lines, arcs, or splines that travel around the perimeter, separating each face of a shape into the up direction, or the down direction.

All this rambling about partings and lines is important to understand how draft was built into this pattern.

The pattern maker's first step is to understand his blueprint well enough to virtually "build" the pattern in his head.

The next step is a full size layout with accurate views of critical features or dimensions of the pattern. Layouts are crucial to accurate pattern construction.

That is where I'll start.
Wood Wood stain Flooring Hardwood Rectangle


Wood Wood stain Flooring Hardwood Rectangle


The pattern maker chose the side view of the fingered ribs for his initial construction layout.
8 ribs and 48 fingers will be assembled on top of the layout.

Wood stops have been glued to the layout. Their edges located on the layout lines that form 3 edges, or faces, of the layout.
Smaller wood stops for locating each finger on the rib are also glued to the layout. Rib and finger material will be planed to a precise thickness that accounts for draft that will be applied later in construction.

Each piece is fit onto the layout. This method of assembly is accurate, precise, and repeatable.

One thing I noticed in the shop is how easy it is to fall into a mindful zen feeling when one is focused on cutting, sanding, and fitting 56 different pieces of material together.
 

Attachments

#11 ·
the pieces become a sub assembly

Unfortunately, I didn't capture every step of pattern construction and have no image of a rib assembly resting on the layout.

This view shows the assembled ribs with some details like fillets and radii being added to specific areas of the fingers. The side edges are left untouched at this point.

Also, the only draft so far is what is on the faces matching the stops on the layout.

The parting plane of the rib is defined by a line that run along the bottom of the fingers.
The fingers will mold in one direction, and the rib will mold in the opposite direction.

You can see from the layout which faces "draw" up from the parting, and those that "draw" down. The foundry terms are "cope" for up, and "drag" for down.

Draft will be applied to the sides of the ribs, but for now, they must remain parallel for the next step of construction.

Wood Hardwood Flooring Art Lumber


Wood Rectangle Flooring Hardwood Wood stain
 

Attachments

#12 ·
the pieces become a sub assembly

Unfortunately, I didn't capture every step of pattern construction and have no image of a rib assembly resting on the layout.

This view shows the assembled ribs with some details like fillets and radii being added to specific areas of the fingers. The side edges are left untouched at this point.

Also, the only draft so far is what is on the faces matching the stops on the layout.

The parting plane of the rib is defined by a line that run along the bottom of the fingers.
The fingers will mold in one direction, and the rib will mold in the opposite direction.

You can see from the layout which faces "draw" up from the parting, and those that "draw" down. The foundry terms are "cope" for up, and "drag" for down.

Draft will be applied to the sides of the ribs, but for now, they must remain parallel for the next step of construction.

Wood Hardwood Flooring Art Lumber


Wood Rectangle Flooring Hardwood Wood stain
I'm a classically trained Mechanical Engineer, so this blog really intrigues me. I learned CAD on the same machines they drew the Saturn IV rockets on at NASA. I love all things wood and metal. This is the perfect marriage of the two.
 

Attachments

#13 ·
Rib and finger sub-assembly is finished

Here are the completed rib and finger assemblies ready, for the next step..

Wood Office equipment Office supplies Art Font


You can see the sides of the ribs have draft and the edges have been radius-ed.
Regrettably, i didn't get any photographs of the method used to apply the draft.

I am going to try illustrating it in the next entry because it is a critical operation.

I also need to make an Editor's note here: I made a mistake in describing the parting line of the ribs.

Hopefully, the images will clarify the correct parting location.

Rectangle Font Parallel Logo Slope


I would also like to say that if anything I type is not clear to you, if you have a question, or think I am full of bull, I welcome all comments or questions.
 

Attachments

#14 ·
Rib and finger sub-assembly is finished

Here are the completed rib and finger assemblies ready, for the next step..

Wood Office equipment Office supplies Art Font


You can see the sides of the ribs have draft and the edges have been radius-ed.
Regrettably, i didn't get any photographs of the method used to apply the draft.

I am going to try illustrating it in the next entry because it is a critical operation.

I also need to make an Editor's note here: I made a mistake in describing the parting line of the ribs.

Hopefully, the images will clarify the correct parting location.

Rectangle Font Parallel Logo Slope


I would also like to say that if anything I type is not clear to you, if you have a question, or think I am full of bull, I welcome all comments or questions.
A most Interesting article.

just couldnt resist!!... all in humour of course
Sleeve Font Gesture Automotive decal Emblem
 

Attachments

#21 ·
Putting draft where it's needed

Part 5

Material is removed to put draft on the rib side faces.

Wood Rectangle Slope Font Hardwood


Brown Rectangle Sleeve Wood Font


Wood Rectangle Slope Wood stain Hardwood


Slope Rectangle Wood Font Parallel


Wood Rectangle Wood stain Slope Hardwood


Hand Wood Wood stain Handwriting Hardwood
Looks good. Thanks for taking the time to put this together.
 

Attachments

#23 ·
Next step: good setup ensures accurate positioning

Part 6

After draft is applied and edge radii are added, the rib pieces are ready to be fit together.

Wood Office equipment Office supplies Art Font


Spacer blocks are sanded to precise width with a draft angle that is opposite of the ribs. This type of draft is known as "back draft". The spacers will maintain accurate dimensions between the ribs and to keep the vertical axis of each rib vertical, maintaining uniform draft on both sides.

Hand Wood Wood stain Handwriting Hardwood


Wood Rectangle Hardwood Composite material Lumber


Unfortunately, I do not have an image of the next step, but I'll describe it and the next image may help clarify the procedure.

The next phase of construction requires the use of a "follow block". A follow block can be described as "the underlying shape required to orient an object in 3 dimensional space." In this case, the underlying shape is a trapezoid, where the bottom face is horizontal, sides are vertical, and the top is an angled plane that matches the bottom of the ribs.

Remember the sand mold…and the fact that the cope has to draw up, and the drag has to draw down?
Between these two directions is the horizontal plane. The parting line around a pattern may not be flat at the pattern, but the perimeter of the mold will be.

If a pattern is not flat, or cannot be laid down horizontally in a mold, a follow block is the way to achieve that orientation.

The follow block can be seen here, supporting the ribs. The board itself is parallel, but is fastened to angled battens.

Wood Recreation Brick Indoor games and sports Wooden block
 

Attachments

#24 ·
The pattern is assembled on the follow block

Part 7 Assembly

Wood Recreation Brick Indoor games and sports Wooden block


You cannot tell from the picture, but each rib has been pinned to the block. Pinning the ribs in position allows the spacer blocks to be removed for the next step, which is to fit pieces of material between the ribs. The material, shaped with a large radius will form the "webs" that will tie the ribs together.

This illustration shows some views of the follow block with the completed pattern in position.

Wood Font Line Musical instrument Rectangle


Here is another view of the block and pattern, after the ribs have been tied together.

Wood Hat Tradesman Engineering Sleeve


Remaining details are added and the pattern is ready for a coat of lacquer.

Wood Hardwood Flooring Gas Engineering


Wood Hardwood Engineering Lumber Flooring


Wood Hardwood Wood stain Gas Composite material


Wood Rectangle Brick Hardwood Wood stain


Wood Wood stain Hardwood Natural material Varnish


I always hated the last step, which is painting a beautiful piece of mahogany…GRAY!

Rectangle Wood Gas Composite material Automotive design


The pattern was used to cast an aluminum match plate because a wood pattern like this would never survive a day in the foundry.
Match plates are the high production version of a pattern. Technically, they are precision castings, made from a plaster mold of the pattern it is duplicating. Plaster is used because of its ability to transfer detail, its consistent shrinkage rate, and its cost.
Match plates are pretty much what the name suggests, a flat plate cast with the cope side of a pattern on one side, and the drag side of the pattern on the other, where both sides "match" at the parting.

This casting went on to be part of a large mail sorting machine. It was designed to move back and forth against a pile of mail, "combing" the mail into position to be fed to the next step.

I hope this all made sense.
(I might just stick to pictures if I ever share the story about building the Ark of the Covenant:)
 

Attachments

#25 ·
The pattern is assembled on the follow block

Part 7 Assembly

Wood Recreation Brick Indoor games and sports Wooden block


You cannot tell from the picture, but each rib has been pinned to the block. Pinning the ribs in position allows the spacer blocks to be removed for the next step, which is to fit pieces of material between the ribs. The material, shaped with a large radius will form the "webs" that will tie the ribs together.

This illustration shows some views of the follow block with the completed pattern in position.

Wood Font Line Musical instrument Rectangle


Here is another view of the block and pattern, after the ribs have been tied together.

Wood Hat Tradesman Engineering Sleeve


Remaining details are added and the pattern is ready for a coat of lacquer.

Wood Hardwood Flooring Gas Engineering


Wood Hardwood Engineering Lumber Flooring


Wood Hardwood Wood stain Gas Composite material


Wood Rectangle Brick Hardwood Wood stain


Wood Wood stain Hardwood Natural material Varnish


I always hated the last step, which is painting a beautiful piece of mahogany…GRAY!

Rectangle Wood Gas Composite material Automotive design


The pattern was used to cast an aluminum match plate because a wood pattern like this would never survive a day in the foundry.
Match plates are the high production version of a pattern. Technically, they are precision castings, made from a plaster mold of the pattern it is duplicating. Plaster is used because of its ability to transfer detail, its consistent shrinkage rate, and its cost.
Match plates are pretty much what the name suggests, a flat plate cast with the cope side of a pattern on one side, and the drag side of the pattern on the other, where both sides "match" at the parting.

This casting went on to be part of a large mail sorting machine. It was designed to move back and forth against a pile of mail, "combing" the mail into position to be fed to the next step.

I hope this all made sense.
(I might just stick to pictures if I ever share the story about building the Ark of the Covenant:)
That is so cool. Thanks so much for sharing this series of posts. Very informative.

We used to use bees wax to create "draft" in out patterns. Often times we would get the wax preformed in the shape of a fillet or radius. Is that still in use?

Do you add the sprues, gates, and risers as well?
 

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