Transcript
00:02
In this lesson, we’ll be going over the product for our course.
00:07
After completing this lesson, you'll be able to: review a problem statement, identify possible design configurations,
00:14
identify design restrictions and manufacturing options and discuss product lifecycle management.
00:22
First we need to talk about the problem statement and we'll be designing a gear reduction housing in this course.
00:29
So as we take a look at this, the first bit of information we want to know is what the gear ratio is.
00:36
For our design, we're going to be using a 3:1 ratio and we're going to be reducing our output speed.
00:43
When we talk about changing the gear ratio of a design, when we reduce the speed, we increase the torque.
00:49
So if we input 30 rpm for example, we're going to be outputting 10 rpm but we will be increasing the torque.
00:58
We also need to make sure our design has concentric input and output shafts.
01:03
We're going with this design decision because it makes a more complicated challenge.
01:09
We're going to make sure that our input and output shafts are 10 mm in diameter.
01:14
And we're going to set a 150 mm diameter max size for the entire device.
01:20
This helps drive the size of the large gear and ultimately helps us pick the size of the drive gear and any idler gears in the design.
01:30
We're going to be inputting 12 lbft of torque and we need to make sure that the gears can support that.
01:37
We're also going to be looking at this from the standpoint of function over cost.
01:42
Now, this is not generally the case has cost as a very important driving factor of design decisions.
01:48
But looking at function over the cost of a design allows us to explore some freedoms.
01:54
Then we can maybe change or make different design decisions based on what we found out.
01:58
So in our case, we're looking mainly at the function and not so much about cost.
02:03
Things that this effect will be for example, using off the shelf gears or designing our own gears.
02:09
Potentially making different design decisions to use more expensive components such as bearings,
02:14
where as a cost driven model might change the bearing that we use and ultimately change the overall lifecycle of the design.
02:23
And last we want to make sure that we have a factor of safety of at least four or greater.
02:29
So I have it set to factor of safety greater than four,
02:33
and this is telling us that if we input four times the input torque, the design will still not fail.
02:42
Next we want to talk about the different housing orientation options.
02:46
We already know that we're going to be going with an input and output shaft that is along the same axis.
02:51
But even with that said, we do have the option to have a reversed direction.
02:56
The direction is going to be important and driven by the number of intermediate gears we have in our gear train.
03:02
But in addition to this, there is also the option to have the input and the output shaft’s offset.
03:08
This is probably the easiest design challenge,
03:10
as we can generally take the input and the output gear and simply set them next to each other and directly drive.
03:18
We could also have the input and the output at some angle.
03:21
In most cases, you'll see this at 90 degrees using a ring and pinion, but that's not strictly fixed.
03:27
But in each of these cases we can have a situation where the input and output are the same direction or reversed.
03:35
Our design is going to focus on input and output being in the same axis and rotating in the same direction.
03:41
So this is going to give us the most unique design challenge.
03:46
Next we want to talk about the internal gear configuration.
03:50
Now we already identified that the input and the output need to be along the same axis.
03:56
We also know that the input and the output shaft need to turn in the same direction.
04:00
So this means that we need to understand that any idle gears that we have in between these,
04:05
is going to change the direction each time we interact with the new gear.
04:09
So moving from left to right, our drive gear is at the center and our first idle gear is reversing the direction.
04:18
Then we're going back to counter clockwise and finally our last idle gear is rotating clockwise which will reverse the direction of our driven gear.
04:27
Let's take a look at this on the final gears.
04:30
So here we can see that we're inputting on this purple shaft,
04:34
and then we're moving through the two red idle gears to the green idle gear that's going to drive the design.
04:41
Now, we want to talk about product lifecycle management.
04:45
Now this is a big term and it ultimately boils down to what the product needs to stand up to in terms of its longevity and how it's made.
04:54
A couple of the main bullet points that we want to talk about first are assembly and maintenance access.
05:00
These are going to be topics such as ease of assembly,
05:03
the longer it takes something to be assembled or the complexity involved generally increases the cost.
05:09
While that's not directly associated with the manufacturing cost, it is a cost that needs to be factored in into the retail price of the design.
05:17
We also want to make sure that we can rebuild or repair it if needed.
05:22
Next there is the topic of sustainability and there are many different things here and we'll focus more on sustainability in just a moment.
05:30
But at the core of it, we can talk about things like material choices and maybe design choices that we make and how it affects the sustainability.
05:38
Manufacturing specifications can mean things like surface finish or tolerances, things that could ultimately again affect the product's lifecycle.
05:48
There are many products that you might have around your house, where the surface finishes degrading,
05:52
whether it means plastic is fading to another color or decals or surface finishes are wearing off.
05:59
These are things that ultimately affect the product's lifecycle,
06:02
even if it's still working properly, the degradation of the outside appearance of something could ultimately affect that.
06:10
And the last bullet point I really want to touch here is lifecycle specifications.
06:15
These are things like how long something is intended to last.
06:19
When we talk about things in your house, such as door knobs or light switches, these are generally tested to a specific number of uses.
06:27
And oftentimes to find those values, they go through destructive testing.
06:31
So this means accelerated testing of a real world product.
06:36
Let's focus more on sustainability as that's a great topic for us to expand on.
06:42
First we want to see if any of the parts can be reused or recycled.
06:46
This means various different things.
06:48
First off, it could mean whether or not the housing material or the components can actually be recycled after the housing,
06:56
or in this case, our design has reached its end of life.
06:60
But it can also mean whether or not certain components are re buildable.
07:03
Can we replace the bearings?
07:05
If the gears wear, can we replace them with other gears?
07:08
At the end of the lifecycle, can we reuse the outside housing to build another gear set?
07:14
We also have to talk about the materials and if they're responsibly made.
07:19
Are we using raw materials that are new, are they from recycled materials?
07:25
If they're new or recycled, are they made in an eco-responsible manner?
07:30
Meaning are their emissions or the energy output, does it meet what we need to have in our design?
07:36
And speaking of energy and emissions, that can also mean how our design performs.
07:41
We can make design decisions that ultimately affect the amount of energy lost through the device.
07:47
Since we're talking about power transmission, we're inputting a certain amount of power.
07:51
To make the most of the design, we want to design our gears so that we don't have a mechanical energy loss or ultimately we minimize that.
08:00
The next topic is lightweighting,
08:02
and this is a big term that's thrown around because we have the advent of things like Generative Design and part optimization.
08:09
When we're talking about lightweighting, it really comes into play when we talk about manufacturing methods that are dependent on raw materials,
08:17
such as 3D printing or additive manufacturing or even injection molding.
08:22
If you can design a product that uses less of those raw materials, ultimately less is used in the fabrication or production of that part.
08:31
But when we talk about lightweighting, that doesn't always apply to everything.
08:35
If we have a part that is intended to be manufactured through CNC machining, for example,
08:41
the material removed oftentimes is just discarded as waste depending on what material it is or it could be recycled into something else.
08:50
For example, if our housing is a machine from aluminum, the aluminum chips can be reclaimed if they were created or used without the use of coolant.
08:58
So that reclaiming of the aluminum can be good for recycling downstream, but that is another source of energy.
09:05
So when we're talking about manufacturing a machined part,
09:09
oftentimes having a heavier part and reducing the material that we're removing can be more beneficial than to actually make the housing lighter.
09:19
We can also talk about the use of components in this case, things like self-lubricating plastics for gears,
09:25
because the choice of material is ultimately going to affect the overall design.
09:30
We can also use things like sealed bearings.
09:33
So the two together, self-lubricating plastic gears and sealed bearings means that,
09:37
we don't have to have a housing that is soaked in oil in order for it to have longevity.
09:43
We can also talk about things like reducing the overall volume or reducing the amount of material.
09:49
Now, while this comes into things like lightweighting and manufacturing for less waste,
09:53
there are other design decisions or design paths that we could go down to specifically talk to each one of these points.
10:01
Now that we've talked a bit about Product Lifecycle Management or PLM, let's get down to cost.
10:08
Our design is going to focus on function over cost,
10:11
but we still want to understand the different areas that are going to influence the cost of our design, first of which is the material.
10:19
Now this doesn't just mean the raw material that goes into manufacturing the part.
10:23
It also means where that material is coming from, how it's transported if it's a renewable source,
10:29
and there are a whole lot of factors that we need to understand that go into our material choices.
10:34
For example, if we're talking about self-lubricating plastics,
10:38
while that will reduce the need to have oil or an oil bath inside of our housing, is the process of creating those environmentally friendly?
10:47
How far do they need to be transported,
10:49
and what is the offset of the environmental impact by using that material and not using a petroleum oil inside the housing?
10:57
We also have to talk about the manufacturing process.
10:60
If we're talking about casting or injection molding or machining, all of these have byproducts,
11:06
whether it's some sort of material waste in additive manufacturing, if it is some sort of energy usage for CNC machining.
11:16
There are many other factors that we need to think about when we talk about manufacturing.
11:21
We also want to talk about quantity because in general when we start producing more parts, the cost per part is reduced.
11:28
But that's not entirely true because we have costs associated with things like assembly.
11:33
So if a component needs to be assembled manually, the increase in quantity doesn't generally decrease that cost.
11:40
However, if parts are assembled through the means of a robotic assembly,
11:45
then that cost might be able to be reduced as we speed up or as we increase the number we're making.
11:52
And lastly is time.
11:54
Now time is money and ultimately we need to understand how long it takes to manufacture our parts,
12:00
and if we need to reduce that time that generally is going to increase the cost.
12:05
So there are many factors here and each factor has many different subsets that we need to think about.
12:11
And while this course isn't designed to cover all of those,
12:13
it is important that we identify those and at least talk about them at the surface level as we get into learning Fusion 360 in creating our design.
12:24
As we figure out the design process, we also want to mention things like Gantt charts.
12:29
If you're working in an engineering industry, you've likely seen one of these before.
12:33
They are often used to track a project schedule and there are many different ways and many different formats that these can go into.
12:40
But at a very basic level, it's going to track the tasks, the categories, things like whether or not it's in progress,
12:48
if something has a high priority, who it’s been assigned to, the progress of that task, the start date and the duration.
12:56
And these types of charts help us identify any dependencies for tasks.
13:00
For example, if a static simulation can't start until a concept design is complete.
13:07
While those things can't happen at the same time, stacking them back to back is going to affect the overall timeline of a project.
13:14
So while we won't be using a Gantt chart inside of our course,
13:17
it is important that we understand the whole host of things that go into the engineering process, not just the CAD aspect of it.
00:02
In this lesson, we’ll be going over the product for our course.
00:07
After completing this lesson, you'll be able to: review a problem statement, identify possible design configurations,
00:14
identify design restrictions and manufacturing options and discuss product lifecycle management.
00:22
First we need to talk about the problem statement and we'll be designing a gear reduction housing in this course.
00:29
So as we take a look at this, the first bit of information we want to know is what the gear ratio is.
00:36
For our design, we're going to be using a 3:1 ratio and we're going to be reducing our output speed.
00:43
When we talk about changing the gear ratio of a design, when we reduce the speed, we increase the torque.
00:49
So if we input 30 rpm for example, we're going to be outputting 10 rpm but we will be increasing the torque.
00:58
We also need to make sure our design has concentric input and output shafts.
01:03
We're going with this design decision because it makes a more complicated challenge.
01:09
We're going to make sure that our input and output shafts are 10 mm in diameter.
01:14
And we're going to set a 150 mm diameter max size for the entire device.
01:20
This helps drive the size of the large gear and ultimately helps us pick the size of the drive gear and any idler gears in the design.
01:30
We're going to be inputting 12 lbft of torque and we need to make sure that the gears can support that.
01:37
We're also going to be looking at this from the standpoint of function over cost.
01:42
Now, this is not generally the case has cost as a very important driving factor of design decisions.
01:48
But looking at function over the cost of a design allows us to explore some freedoms.
01:54
Then we can maybe change or make different design decisions based on what we found out.
01:58
So in our case, we're looking mainly at the function and not so much about cost.
02:03
Things that this effect will be for example, using off the shelf gears or designing our own gears.
02:09
Potentially making different design decisions to use more expensive components such as bearings,
02:14
where as a cost driven model might change the bearing that we use and ultimately change the overall lifecycle of the design.
02:23
And last we want to make sure that we have a factor of safety of at least four or greater.
02:29
So I have it set to factor of safety greater than four,
02:33
and this is telling us that if we input four times the input torque, the design will still not fail.
02:42
Next we want to talk about the different housing orientation options.
02:46
We already know that we're going to be going with an input and output shaft that is along the same axis.
02:51
But even with that said, we do have the option to have a reversed direction.
02:56
The direction is going to be important and driven by the number of intermediate gears we have in our gear train.
03:02
But in addition to this, there is also the option to have the input and the output shaft’s offset.
03:08
This is probably the easiest design challenge,
03:10
as we can generally take the input and the output gear and simply set them next to each other and directly drive.
03:18
We could also have the input and the output at some angle.
03:21
In most cases, you'll see this at 90 degrees using a ring and pinion, but that's not strictly fixed.
03:27
But in each of these cases we can have a situation where the input and output are the same direction or reversed.
03:35
Our design is going to focus on input and output being in the same axis and rotating in the same direction.
03:41
So this is going to give us the most unique design challenge.
03:46
Next we want to talk about the internal gear configuration.
03:50
Now we already identified that the input and the output need to be along the same axis.
03:56
We also know that the input and the output shaft need to turn in the same direction.
04:00
So this means that we need to understand that any idle gears that we have in between these,
04:05
is going to change the direction each time we interact with the new gear.
04:09
So moving from left to right, our drive gear is at the center and our first idle gear is reversing the direction.
04:18
Then we're going back to counter clockwise and finally our last idle gear is rotating clockwise which will reverse the direction of our driven gear.
04:27
Let's take a look at this on the final gears.
04:30
So here we can see that we're inputting on this purple shaft,
04:34
and then we're moving through the two red idle gears to the green idle gear that's going to drive the design.
04:41
Now, we want to talk about product lifecycle management.
04:45
Now this is a big term and it ultimately boils down to what the product needs to stand up to in terms of its longevity and how it's made.
04:54
A couple of the main bullet points that we want to talk about first are assembly and maintenance access.
05:00
These are going to be topics such as ease of assembly,
05:03
the longer it takes something to be assembled or the complexity involved generally increases the cost.
05:09
While that's not directly associated with the manufacturing cost, it is a cost that needs to be factored in into the retail price of the design.
05:17
We also want to make sure that we can rebuild or repair it if needed.
05:22
Next there is the topic of sustainability and there are many different things here and we'll focus more on sustainability in just a moment.
05:30
But at the core of it, we can talk about things like material choices and maybe design choices that we make and how it affects the sustainability.
05:38
Manufacturing specifications can mean things like surface finish or tolerances, things that could ultimately again affect the product's lifecycle.
05:48
There are many products that you might have around your house, where the surface finishes degrading,
05:52
whether it means plastic is fading to another color or decals or surface finishes are wearing off.
05:59
These are things that ultimately affect the product's lifecycle,
06:02
even if it's still working properly, the degradation of the outside appearance of something could ultimately affect that.
06:10
And the last bullet point I really want to touch here is lifecycle specifications.
06:15
These are things like how long something is intended to last.
06:19
When we talk about things in your house, such as door knobs or light switches, these are generally tested to a specific number of uses.
06:27
And oftentimes to find those values, they go through destructive testing.
06:31
So this means accelerated testing of a real world product.
06:36
Let's focus more on sustainability as that's a great topic for us to expand on.
06:42
First we want to see if any of the parts can be reused or recycled.
06:46
This means various different things.
06:48
First off, it could mean whether or not the housing material or the components can actually be recycled after the housing,
06:56
or in this case, our design has reached its end of life.
06:60
But it can also mean whether or not certain components are re buildable.
07:03
Can we replace the bearings?
07:05
If the gears wear, can we replace them with other gears?
07:08
At the end of the lifecycle, can we reuse the outside housing to build another gear set?
07:14
We also have to talk about the materials and if they're responsibly made.
07:19
Are we using raw materials that are new, are they from recycled materials?
07:25
If they're new or recycled, are they made in an eco-responsible manner?
07:30
Meaning are their emissions or the energy output, does it meet what we need to have in our design?
07:36
And speaking of energy and emissions, that can also mean how our design performs.
07:41
We can make design decisions that ultimately affect the amount of energy lost through the device.
07:47
Since we're talking about power transmission, we're inputting a certain amount of power.
07:51
To make the most of the design, we want to design our gears so that we don't have a mechanical energy loss or ultimately we minimize that.
08:00
The next topic is lightweighting,
08:02
and this is a big term that's thrown around because we have the advent of things like Generative Design and part optimization.
08:09
When we're talking about lightweighting, it really comes into play when we talk about manufacturing methods that are dependent on raw materials,
08:17
such as 3D printing or additive manufacturing or even injection molding.
08:22
If you can design a product that uses less of those raw materials, ultimately less is used in the fabrication or production of that part.
08:31
But when we talk about lightweighting, that doesn't always apply to everything.
08:35
If we have a part that is intended to be manufactured through CNC machining, for example,
08:41
the material removed oftentimes is just discarded as waste depending on what material it is or it could be recycled into something else.
08:50
For example, if our housing is a machine from aluminum, the aluminum chips can be reclaimed if they were created or used without the use of coolant.
08:58
So that reclaiming of the aluminum can be good for recycling downstream, but that is another source of energy.
09:05
So when we're talking about manufacturing a machined part,
09:09
oftentimes having a heavier part and reducing the material that we're removing can be more beneficial than to actually make the housing lighter.
09:19
We can also talk about the use of components in this case, things like self-lubricating plastics for gears,
09:25
because the choice of material is ultimately going to affect the overall design.
09:30
We can also use things like sealed bearings.
09:33
So the two together, self-lubricating plastic gears and sealed bearings means that,
09:37
we don't have to have a housing that is soaked in oil in order for it to have longevity.
09:43
We can also talk about things like reducing the overall volume or reducing the amount of material.
09:49
Now, while this comes into things like lightweighting and manufacturing for less waste,
09:53
there are other design decisions or design paths that we could go down to specifically talk to each one of these points.
10:01
Now that we've talked a bit about Product Lifecycle Management or PLM, let's get down to cost.
10:08
Our design is going to focus on function over cost,
10:11
but we still want to understand the different areas that are going to influence the cost of our design, first of which is the material.
10:19
Now this doesn't just mean the raw material that goes into manufacturing the part.
10:23
It also means where that material is coming from, how it's transported if it's a renewable source,
10:29
and there are a whole lot of factors that we need to understand that go into our material choices.
10:34
For example, if we're talking about self-lubricating plastics,
10:38
while that will reduce the need to have oil or an oil bath inside of our housing, is the process of creating those environmentally friendly?
10:47
How far do they need to be transported,
10:49
and what is the offset of the environmental impact by using that material and not using a petroleum oil inside the housing?
10:57
We also have to talk about the manufacturing process.
10:60
If we're talking about casting or injection molding or machining, all of these have byproducts,
11:06
whether it's some sort of material waste in additive manufacturing, if it is some sort of energy usage for CNC machining.
11:16
There are many other factors that we need to think about when we talk about manufacturing.
11:21
We also want to talk about quantity because in general when we start producing more parts, the cost per part is reduced.
11:28
But that's not entirely true because we have costs associated with things like assembly.
11:33
So if a component needs to be assembled manually, the increase in quantity doesn't generally decrease that cost.
11:40
However, if parts are assembled through the means of a robotic assembly,
11:45
then that cost might be able to be reduced as we speed up or as we increase the number we're making.
11:52
And lastly is time.
11:54
Now time is money and ultimately we need to understand how long it takes to manufacture our parts,
12:00
and if we need to reduce that time that generally is going to increase the cost.
12:05
So there are many factors here and each factor has many different subsets that we need to think about.
12:11
And while this course isn't designed to cover all of those,
12:13
it is important that we identify those and at least talk about them at the surface level as we get into learning Fusion 360 in creating our design.
12:24
As we figure out the design process, we also want to mention things like Gantt charts.
12:29
If you're working in an engineering industry, you've likely seen one of these before.
12:33
They are often used to track a project schedule and there are many different ways and many different formats that these can go into.
12:40
But at a very basic level, it's going to track the tasks, the categories, things like whether or not it's in progress,
12:48
if something has a high priority, who it’s been assigned to, the progress of that task, the start date and the duration.
12:56
And these types of charts help us identify any dependencies for tasks.
13:00
For example, if a static simulation can't start until a concept design is complete.
13:07
While those things can't happen at the same time, stacking them back to back is going to affect the overall timeline of a project.
13:14
So while we won't be using a Gantt chart inside of our course,
13:17
it is important that we understand the whole host of things that go into the engineering process, not just the CAD aspect of it.
