This video is about different things you can do with my
gear template generator program.
The program is for designing gears and then printing accurate
paper templates so you can then stick them on a piece of
plywood and cut them out on the bandsaw.
The program automatically updates the gears on the screen
if you change any of the parameters
such as the number of teeth.
Or, for instance, we can change the pressure angle of the
gears, which will substantially change their shape.
Or, for instance, we can change how long the various
gear teeth are.
So, there's a lot of options that we can play around with
on these gears.
Now, what's important is that the gears actually
mesh successfully. Especially if you intend to make some of these
gears out of metal. So, let's zoom in
on the area where we're meshing. And let's show the line
of contact. Which is the line along which the gears
contact. And let's turn off the animation.
Just so we can see. So the way involute gears actually work
is, imagine that we have
a string being unwound from this wheel and wound onto
that gear. And the angle at which it's unwound is actually
the contact angle here. So as we change that, you could
see that changes this angle.
So the gears are always pushing along that line.
And we want to make sure the the next gear tooth
is engaged before the previous one disengages.
So, let's rotate this gear manually.
And, now watching here we can see we're getting
to the end of the engagement.
Right about here. And the next one
is already, just barely, engaging. So, these gears will
stay fully engaged. They won't wiggle.
If you were actually building a real machine, like
a car transmission. You'd want to have at least two engaged.
But, if you're making wooden gears. This is actually quite
sufficient. If we change the pressure angle
we can also change that engagement too.
Although, sometimes it makes it worse.
You can go more extreme with a small number of teeth.
But the smaller the number of teeth
it really becomes difficult to engage. So, if we look here
although these will continue to run.
They'll be a little bit rattly because hey don't fully engage.
Now, if we go to a lantern type gearing. So, we select Pin here.
We can actually go fairly extreme.
Now, let's make that pin diameter
smaller. And we'll make the
shaft hole in the middle a bit bigger, because that's
shortening our teeth a little bit.
And now if we rotate that through here.
You can see this here continues to stay engaged
up until about here but at that point
the next pin is fully engaged.
So, we can have fully engaged with just four pins on here.
Now, if I change that to three.
Three gear teeth on the lantern.
And, let's get rid of that shaft hole.
So, I have to set that to zero.
And, now if we rotate through here.
If we see here that becomes disengaged here
while the next one is not quite fully engaged yet.
So, those gears will work but they'll be a little bit rattly.
Now, one of the coolest things this program can do
is it will calculate the gear tooth undercut.
So, you notice a round thing in here.
That's because the... Let's rotate that.
That's basically... The round in here is making space
for the other gear to, kind of get in here.
This is new to... I added that in version 2.
Although the previous video didn't cover that.
As the gear teeth become
more square.
That undercut becomes extreme.
So, this would be a very rattly set of gears.
But let's see. That would kind of barely work.
Because this would push it far enough on here.
And it would, kind of, catch the next one.
Let's make that four.
And, this can get quite extreme if I make the gear teeth a
bit longer, in terms of undercut.
So, this is a very funky looking
very fragile gear.
But, for a do nothing machine
that could be, still, kind of a fun thing to do.
The undercut is most sever with small gears.
If I make that a bit bigger. See, that becomes
much thicker already.
Another cool feature of the gear program.
Is, let's zoom out a bit here.
Is the ability to put spokes on the gear. So, if we
go into spokes, we can select how many spokes we
have on a gear. Now, a gear does need
a minimum number of teeth for the spokes to show.
So, if they have too few teeth on there, there's just
not enough room for spokes inside.
And, the detail level of the spokes...
is determined by the size of the gear teeth.
So, the more gear teeth we have the more room
we can do for spokes. Essentially these...
the spokes thickness is determined by the
tooth size. So, if we make that tooth size a bit smaller
you notice the spokes become thinner.
And, now for larger gears, you probably want to have more
spokes.
Quite a few. You can also
change the size of the shaft hole.
Let's make it a bit bigger.
The shaft hole, depending on whether you want it in there
or not. If you set zero, that makes it disappear.
But, you can specify the size. And in here
if we make it big enough the hub also needs to expand
a little bit. Now if you're cutting these gears out on
a bandsaw. You don't, so much want to
use a circle to cut it out.
You'd much rather just have a mark in the middle
for where it goes, so... If we click on Show Center
that turns that on. And there's other annotations
for instance we can show the pitch diameter
of the gear, which is the whole thing with the line
line of contact.
And the other things. We can draw the lines
a little bit thicker. That's been a requested feature by
some people because the lines can be quite thin sometimes
or faint, depending on your printer.
So, it helps to make them a little bit thicker.
Just to help with cutting it out on the saw.
Other things we can do is we can add a little bit of slop.
If you're making the gears on a C & C machine.
You can't really compensate that well so now let's
add a little bit of slop so this is essentially...
Let's zoom in on here. That's adding a minimum
amount of spacing between the teeth so this is a rather
extreme amount of slop.
Personally, I just rely on the width of the line and
I cut right to the line and that works out nicely.
But, if you find your gears are a little bit too tight
you can use that parameter to control the slop.
The program can also do Ring Gears.
And, you'd use that for planetary type gears.
So, for instance, if we make that middle one a bit smaller
and that'll look better with a better angle.
So, we could have a gear in here a gear here
and another gear here.
As the gears have very close to the number of teeth to
each other. That starts to get a little bit funky.
So, let's make that one smaller. And we can run into issues
to where we have a little bit of interference here.
The program doesn't check for that so, if you have
very close to each other gears. That can be a bit of a problem.
Although, if we do the cycloid, lantern type gears
then you don't have that issue because the program fully
calculates that. And that gets very funky. As the
number of teeth has the very close number as the other one.
Especially as the number of teeth becomes much smaller.
So that can make for some very funky gearing.
And if you look on here, the...
the pins of the lantern are fully
engaging all the way around.
So, there's no slop in here at all.
Now another cool feature of the program is it can
calculate block chains and roller chains.
But, I'll cover that in a separate video.
Now, next thing is, we can save the parameters.
Not very exciting. For printing...
Let's do a print preview on here. So, here we have
our gear thingy here.
Typically, if you want to cut the gears out with a
scroll saw, or a band saw.
You don't really want to show both of them.
Because, that's just messy, so...
Let's turn off the display of that one and turn off
animation. And let's also make that one a bit bigger.
And we'll make the pins a bit bigger. And more teeth.
So, if we want to... Let's do that print preview
on that one again. It still fits on a page.
Let's zoom out here. And let's make that...
thirty. Print preview.
Now you see, if it doesn't fit on a page.
It will split it automatically across two pages.
And the grids really help to align it.
But what's really helpful with the grids is...
there is a grid diagonal feature.
And let's make that grid
a little bit coarser. And let's do a print preview again.
And two pages.
So, when you print both of these pages out.
All you have to do is make sure these lines become straight.
And you know you've got exactly the right spacing
between them. And so you can go across many pages.
There's really no limit to how many pages you can go across.
So, let's make the gear even bigger.
Still fits on... Let's make the teeth a bit bigger.
And now it's across four pages.
And, again we can use...
the grid diagonals to line everything up and...
we can go across as many pages as you want to.
The biggest limit, really, is how much paper do you
want to use.
Now, next thing is, the units. We can work in inches...
centimeters or millimeters. I personally prefer working
in centimeters. It doesn't really change
much how the program functions. It more changes...
how the output is scaled. So if we change this gear to
inches now. And we do a print preview again.
That will go across quite a lot of pages.
Unfortunately, I can't show
that many pages, all at once in the print preview here but
you can see here. Now, I've had pretty good success...
just cutting gears out on the bandsaw but some people prefer
to use the gear program with C & C machines or with
laser cutters. And this is where the export menu...
becomes very useful. So we have DXF export with Poly lines.
Which is slightly more advanced than the earlier DXF export
that I've had. But, some CAD programs have difficulty with it
because DXF is, kind of, a horrible format.
And I may have not done it quite right. So, if you have
problems with the poly line just use the basic DXF export.
You can also export it as DAE files. Which the free version
of Sketch-Up can import.
You can export it to HPGL, which some programs like Corel Draw
can import. You can export it as CSV. That's basically just
comma separated values. If you want to do something with
the numbers yourself. Or you can export it as
an image. Or as a PDF. Which is intended mostly for using with
laser cutters. So you can then take that file
and on some laser cutters you can just use the PDF straight.
But, let's export this as an image.
And we'll do it at, say fifty pixels per centimeter.
So let's export that.
And, let's have a look at that image.
And the lines are one pixel wide. Sometimes you...
might want to have thicker lines.
So, if we turn on, draw thicker lines. And let's...
export that again as a image.
Again, fifty pixels.
And we'll call that gear 2.
And now look at that image. And we can see the...
lines are actually much thicker.
Now, next thing is there's help. Help is included with...
the program but there's also online help
that you can check out without actually buying the program.
The program is, unfortunately not free. You do have to buy it.
But the eval version can do pretty much everything
that I've just shown you here. The only difference
with the eval version is, is it has wobbly mode turned on.
The idea with wobbly mode was I wanted to have the
eval version to have pretty much everything enabled.
But I still had to give you a compelling reason to buy Th
program, so... The eval version
essentially distorts space but...
other than that it's fully
functional. So you can still use the eval for doing things
like checking whether a certain pair of gears will mesh nicely
and will work. But it's as though everything is
looked at through a swimming pool. So, if you printed these
gears out, they would not mesh successfully.
So, one major feature of the program that I haven't covered
is chain mode. And I'll make a separate video covering that.