Motion-Controlled Razor Crest: An ILM Inspired Project

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HackinSpock

Active Member
It's been a while!

To bring you guys up to speed, I am going to go back a couple of weeks. I decided to make this project an independent study at my college so I would have more time to work on it, and as such, I made a bulk purchase of nearly every single part I would need to assemble each rig as per the CAD. The one issue that needed to be squared away was the 80-20. I spent a good couple of hours searching for cheap 80-20 and stumbled upon a site called Misumi. After compiling my cart, I decided to reach out to the company and see if they provided college sponsorships. To my luck, they were, and offered to cover all of my 80-20! I also reached out to the company Igus that manufactures the quarter moon rails I need for the miniature rig and also scored a sponsorship with them. Thank you Misumi & Igus!

More recently, I have received all of my parts including the 80-20 & quarter moon rails & started assembling it all! Of course, I ran into some small problems, that being the 80/20 I purchased doesn't have any inside threading on the faces, so I had to quickly CAD a profile with an M5 hole to sit flush against the inside. Otherwise, here are some images of my progress!

PXL_20211103_161033054.jpg
PXL_20211107_141634236.jpg


The linear rail is 3 meters in order to have enough room for longer camera shots. The miniature rig is taking a bit longer since a large portion of it requires 3D printed parts. Here is an image of the quarter moons!

PXL_20211107_143044276.jpg


On the electronic and coding side of things, I've made great progress on the Jog box, which is the numpad & joystick that will handle moving the rigs and a blender simulation at the same time. The real rig will move so I can actually see where it is going, while the blender simulation is there for me to program keyframes and revise the movement curves. Once all the revisions are done, I can export that scene in blender as a gcode file using a nifty python script I found online.
PXL_20211107_143426340.jpg


Now I am just waiting for more 3D printed parts. But in the meantime, I might install the linear rail belt and see if I can create a small test of the camera rig filming a shot of the razorcrest.

See you guys soon!
-Matthew Winchell
www.matthewwinchell.com
 

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HackinSpock

Active Member
Just another quick update. I was able to position the internal clamping rig on my razor rest miniature, so now I can position it on the roll rod. I do have to slightly sand off the side walls to allow side clamping, but I should be fine.

The miniature rig works surprisingly well. There is a bit off wobble happening, which is primarily due to the parts being 3D printed instead of being machined out of aluminum. I'm thinking to string up some weights on either side of the quarter rails to ease the wobble.
PXL_20211123_010417887.jpg
PXL_20211123_010404701.jpg


Happy Thanksgiving Everyone!
 

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Bjorn

Active Member
I was curious why the motion in the Yaw axis became so coarse when you reduced the jog speed to 1. I was expecting to see it to get get slower but stay relatively smooth.

For a moment I thought you had directly mounted the motor to the Yaw axis, but I realised you have a reduction belt drive like the other axis.

Understanding its a work in progress. And seriously that aside, well done.

Absolutely great work!
 

HackinSpock

Active Member
I was curious why the motion in the Yaw axis became so coarse when you reduced the jog speed to 1. I was expecting to see it to get get slower but stay relatively smooth.

For a moment I thought you had directly mounted the motor to the Yaw axis, but I realised you have a reduction belt drive like the other axis.

Understanding its a work in progress. And seriously that aside, well done.

Absolutely great work!
Good eye! So the coarseness of the yaw motor moving at 1 is not an error, as it is primarily the nature of jogging. The use of jogging for this rig is purely to position the axis and set keyframes. The actual motion will be programmed through standard gcode, so the movements will appear much smoother.
-Matthew
 

StevenBills

Sr Member
RPF PREMIUM MEMBER
Not sure about the software that you're using, but I am familiar with keyframing in After Effects. Are you able to adjust the curve so that you can ease into and out of a specific keyframe?
 

HackinSpock

Active Member
Not sure about the software that you're using, but I am familiar with keyframing in After Effects. Are you able to adjust the curve so that you can ease into and out of a specific keyframe?
That's the idea! However, I am still trying to figure out what program to use. Ideally, I want to simultaneously jog the rig in realtime and jog a virtual rig to keyframe. Blender is the current candidate I am working on, but I am finding it extremely difficult to program shortcuts to move a virtual camera and set keyframes. Not only that, once I set keyframes on the timeline and smooth out the curves, I need to output that timeline to proper gcode. I'm not sure After Effects has that capability. Do you have another program in mind that can do all this?
 

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StevenBills

Sr Member
RPF PREMIUM MEMBER
That's the idea! However, I am still trying to figure out what program to use. Ideally, I want to simultaneously jog the rig in realtime and jog a virtual rig to keyframe. Blender is the current candidate I am working on, but I am finding it extremely difficult to program shortcuts to move a virtual camera and set keyframes. Not only that, once I set keyframes on the timeline and smooth out the curves, I need to output that timeline to proper gcode. I'm not sure After Effects has that capability. Do you have another program in mind that can do all this?
Yeah I honestly have no idea which software would be best for your application, sorry. I know that there are off-the-shelf motion control units (by companies like Kessler and Rhino) that use an app to control the keyframing. But that doesn't really help you, sorry.

SB
 

HackinSpock

Active Member
No worries! I appreciate it nonetheless.
Yeah I honestly have no idea which software would be best for your application, sorry. I know that there are off-the-shelf motion control units (by companies like Kessler and Rhino) that use an app to control the keyframing. But that doesn't really help you, sorry.

SB
 

MangyDog

Sr Member
Amazing work...
Seeing youre also working on a camera rig too... Im actually going to be doing the same thing a bit later (maybe in a year or so) Ill be making a custom camera control rig. Using a 3d printer board as a base. But ill have to make a custom animation program to send gcode commands to the rig. I might also write the program as a plugin for 3dsmax so the camera rig will be directly tracked and controlled within the digital 3D space.

But also going to make it stop motion too, so ill need to write a program to control my camera as well to take photos... This means i can run my camera at 5k raw rather than HD compressed in motion mode.

I did notice some wobble and backlash on your camera rig though when you were testing it. My only suggestion I can make there is, go large. Make your lasysue bearings or needle ring bearings as wide a diameter as possible. It increases ther... umm... solidness! Yeah thats the word :D

You might also want to consider gearing down the stepper motors for the camera rig as well... And make sure you got 0.9' steppers as well, to get the best smooth motion. Unless speed is your goal. With stop motion filming speed isnt important, accuracy is.
 

HackinSpock

Active Member
Amazing work...
Seeing youre also working on a camera rig too... Im actually going to be doing the same thing a bit later (maybe in a year or so) Ill be making a custom camera control rig. Using a 3d printer board as a base. But ill have to make a custom animation program to send gcode commands to the rig. I might also write the program as a plugin for 3dsmax so the camera rig will be directly tracked and controlled within the digital 3D space.

But also going to make it stop motion too, so ill need to write a program to control my camera as well to take photos... This means i can run my camera at 5k raw rather than HD compressed in motion mode.

I did notice some wobble and backlash on your camera rig though when you were testing it. My only suggestion I can make there is, go large. Make your lasysue bearings or needle ring bearings as wide a diameter as possible. It increases ther... umm... solidness! Yeah thats the word :D

You might also want to consider gearing down the stepper motors for the camera rig as well... And make sure you got 0.9' steppers as well, to get the best smooth motion. Unless speed is your goal. With stop motion filming speed isnt important, accuracy is.
That sounds awesome! Please keep me updated on your progress when you start your build. In terms of the stepper motors, I can't really change them at this current stage, but I will let you know I am using the exact same ones that John Knoll used in his rig, so I'm pretty confident with their smoothness. The wobble/backlash you mention does in fact need to be addressed. The main cause of that is the 3D printed brackets. Because there is some inherent flex, some parts are cantilevering some of my mechanisms. My current way to reduce this issue is to use zip ties, but I think I might have to machine some of the brackets in aluminum to eliminate the flexing. There's also an inherent issue with the o-drive (the linear motion of the camera). Because the linear rail is 3 meters, I have to extend a belt that long, which is a pain since you need to make sure it's ultra-tight. Unfortunately, I'm definitely going to need to re-tension the belt, but I'm not sure what solution to use to make it permanent and super-taut. Another slight issue is the roll mount where the camera is positioned. Because the camera is a bit heavy, it's tilting the roll rod ever so slightly. But I took a look at John Knoll's rig used in the show and observed some similar leaning. The current rod is 3D printed, so I am planning on replacing it with an aluminum one, but I doubt it will make a difference.

If you have some solutions to the things I listed above, I am all ears :)

-Matthew
 

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