Week 12: Machine Production & Design

Finish

Assignment

Mechanical Design (part 1 of 2)

Group assignment:
    Design a machine that includes mechanism + actuation + automation + application
    Build the mechanical parts and operate it manually
    Document the group project

Individual assignment:
    Document your individual contribution

Machine Design (part 2 of 2)

Group assignment:
    Actuate and automate your machine
    Document the group project

Individual assignment:
    Document your individual contribution

Planning

First I sit down with my classmate Angela to make a plan. We want to make a machine called “BirdPeck”. It is made of little hammers that look like birds pecking a button to make a sound! We originally thought of having 1 head move around, but simplified it to having multiple heads; we are making a Birdband! We will also build a controller, where each button represents 1 note/bird.

We also split up the work. I will take care of the mechanical side. I will make the bird heads and the structure and striking method. She will make the controller. We will coordinate to figure out the best way to attach the motors so the heads can strike.

Prototyping

After a few hours I was able to make a mostly successful cardboard prototype of the striking motion. It is made from 4 pivot points and 2 linkagaes, including a cam to move the head up and down.

The instructor say with me and drew rough measurement’s of what I had made. This is a rough kinematics chart! The green dots are the fixed points, the pink dot and pink line represent the highest lowest motion the birds head can be, and the orange dot and line represent the highest motion.

Next I need to simulate it so I can have the correct ratios.

Simulating

I followed along with MangoJellyCat’s video FreeCAD 1.1 Beginners Friendly Modeling and Assembly (Model, Assemble, Simulate, Animate) to lean how to simulate.

![[CopyCat.png]]

I folowed this tutorial and firt copied the master sktech

![[W12Settings.png]]

Before you start, make sure your settings match mine,

![[W12Goal.png]]

the example goal is to create this shape

![[W12MakeBody.png]]

make sure you click close and switch to part design to make a new body

After you create the master sketch, right click into empty space so that you have nothing selected. then click new body

![[W12Rename.png]]

Next left click on the new body and rename it so that you can keep your parts organized

![[W12FitAll.png]]

A handy tool you can use is the “fit All” tool

![[W12Transform 2.png]]

right click on the body and left click transform

![[W12TransformOrgin.png]]

we can see the orgin point is in the cent, but we cant it to be closer to where our part is.

![[W12MoveOrgin.png]]

select move to other object and pick where you want it centered. then hit OK!

![[W12Subshape.png]]

click the master sketch and click “subshape binder”

![[W12MakeFace.png]]

click the new binder, go to data on the bottom and unselect “make face”

![[W12LineWidth.png]]

next click “view” on the button and change the line width to 4.

![[W12HideMaster.png]]

next hide the master sketch by pressing the eye

![[W12CreateSketch.png]]

make sure nothing else is selected and click create sketch

![[W12SelectPlane.png]]

select the plane you want to work on then click okay,

![[W12ExternalProjection 1.png]]

use external projection tool to select the lines for the part you are working with

![[W12ToggleConstrution.png]]

left click and drag to select everything, then click toggle construction geometery. this will make all the lines solid

![[W12HideBinder.png]]

next click close and hide the binder layer

![[W12Rotate.png]]

hold down middle mouse button and hold left click and drag to change perspective

![[W12Pad.png]]

click pad tool, then change the settings. Mode Symmetry. Length 4”. Then click close

![[W12SelectFace.png]]to create a void, select the face you want then select sketch

![[W12SideView.png]]

now we are in this side view!

create a retancle that goes past the side so that it cuts all the way trhough

close sktech

next click pocket

![[W12DigBabyDig.png]]

change mode to symmetric and type to through all, then click ok

![[W12WrongDig.png]]

oops, i wanted the cut to be on the other side

![[W12ChangeSketch.png]]

open the pocket dropdown and double click sketch

![[W12FixBox.png]]

adjust the rectangle

![[W12Goal 1.png]]

now its correct!

now repeat all the steps for any other shapes you need.

assembly

![[W12ChangeSketch 1.png]]

assembly time! switch to the asembly workbench

![[W12NewAssembly.png]]

click new assembly! it should show up below

![[W12InsertComponent.png]]

click insert component

![[W12InsertParts.png]]

if you started a seperate part for assembly or need to upload another, you can click Open file to upload the other parts!!

![[W12NoForNow.png]]

cllick no for now

![[W12MoveParts.png]]

click and hold to move your parts around, or use transform tool. click OK

![[W12FixGrounded.png]]

now you can click which part you want to be a fixed point. click toggle grounded

![[W12ZoomIn.png]]

zoom in and select the out circle of the part

![[W12OtherCircle.png]]

rotate and hold town control and select the inner circe of the linkage body. you want these two parts to be linked

![[W12Highlighted.png]]

make sure on the side there are 2 items highlighted

![[W12RvoluteJoke.png]]

click revolute joint

![[W12MoveitMove.png]]

it moved! click OK

![[W12MoveitMove 1.png]]

you can spin the part now! Yay! Hold down left click and drag

![[W12EasierMethod.png]]

if you click revolute jpint first, it will preselect joints for you! much easier to click

![[W12Beautiful.png]]

beautiful!

![[W12WrongEdge.png]]

right click to remove an edge if needed

![[W12Delete.png]]

you may also delete a part by right clicking on the parts name anc clicking delete

![[W12Mirror.png]]

use insert component to make another counter weight. we are going to mirror it with the current counter weight. double click and transform to rotate it to match

![[W12FixedJoint.png]]

fixed joint

click fixed joint and click the joint, then the other one

![[W12TheCornersCastor.png]]

you are trying to match the ver very corner of the two counterweights as shown

![[W12IsItFixed.png]]

ta da!

![[W12Offset.png]]

move the offset to position it around the bar. click okay

![[W12TogetherForever.png]]

now both counterweights will move together as a team

![[W12HatTime.png]]

‘’this time you must click the inside of the circle joints and then click revolute

![[W12HatTime 1.png]]

that doesnt look right…

![[W12HatTime 2.png]]

click the offset until its center or roughtly center

![[W12Bucket.png]]

right now the head can be dragged in any direction, we want ti level so that we can have an up and down motion.

![[W12SliderJoint.png]]

click slide joint

![[W12TopTop.png]]

click top of the head

![[W12SecretBottom.png]]

select the bottom

![[W12Beautiful!.png]]

beautiful!

TIme to start! I know I’m working with 1/4” ply and 6mm Pins

birdtime?

my rough master draftp, all circles are 6mm pins

![[W12DraftBird.png]]

my rough master draftp, all circles are 6mm pins

![[W12PadOut.png]]

and now we make body parts, making each 1/4in and linked to the mastersketch

heres the rough try

![[W12BirdUp.png]]

i need a point where the bird goes low here

![[W12BirdDown.png]]

but the tail piece seems to limit it. maybe the key isnt in changing the tail length, but some other part… and high here

LETS MAKE A MOCKUP to see if its the simulation or a problem of real life!

turn the files into SVGs

Cats!

This week was a treat! I got to play will a small friendly cat named Oliver. Shadow knocked over a bunch of cardboard and then just looked at me, unrepentant.