Studio 49
Sr Member
Thanks mate! More to come shortly... and it may or may not involve Dome Arms...
Thanks man! It's been a good one to keep me sane while I wait for work to start up again thanks to Covid
I'll be getting another update posted soon!
Chopper Droid Replica WIP - Aluminium and 3D Printed
- Thread starter Studio 49
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Studio 49
Sr Member
While I was printing the first part of the dome, I decided it'd be cool if I could give Chopper functional dome arms. They're a great part of his personality so figured I may as well have a go
My main goal was for them to be sturdy enough to withstand any prying hands of kids coming to have photos with him. I explored a few ways of doing it but ultimately settled on using a linear actuator/servo. The Chopper used by Lucasfilm uses Actuators to great effect, so I drew inspiration from that and modified that concept to suit my needs.
Best part was I was able to find 3D IGES files for the linear/servo actuators I was going to purchase. Which meant I was able to modify their IGES files to make functional actuators to test in Autodesk Inventor! (You can see a video of that below, sorry for the dodgy video)
After testing that it worked in Inventor, I printed out the parts for the arm mech to do a prototype test. The actuators I ordered were Arduino compatible so I was able to hook up my Servo Tester and do a proper test! When it comes to the final version the rail at the top will be aluminium extrusions, and arms that connect to the actuary will be 3mm aluminium and the arm itself will be 3D printed.
My main goal was for them to be sturdy enough to withstand any prying hands of kids coming to have photos with him. I explored a few ways of doing it but ultimately settled on using a linear actuator/servo. The Chopper used by Lucasfilm uses Actuators to great effect, so I drew inspiration from that and modified that concept to suit my needs.
Best part was I was able to find 3D IGES files for the linear/servo actuators I was going to purchase. Which meant I was able to modify their IGES files to make functional actuators to test in Autodesk Inventor! (You can see a video of that below, sorry for the dodgy video)
After testing that it worked in Inventor, I printed out the parts for the arm mech to do a prototype test. The actuators I ordered were Arduino compatible so I was able to hook up my Servo Tester and do a proper test! When it comes to the final version the rail at the top will be aluminium extrusions, and arms that connect to the actuary will be 3mm aluminium and the arm itself will be 3D printed.
While I was printing the first part of the dome, I decided it'd be cool if I could give Chopper functional dome arms. They're a great part of his personality so figured I may as well have a go
My main goal was for them to be sturdy enough to withstand any prying hands of kids coming to have photos with him. I explored a few ways of doing it but ultimately settled on using a linear actuator/servo. The Chopper used by Lucasfilm uses Actuators to great effect, so I drew inspiration from that and modified that concept to suit my needs.
Best part was I was able to find 3D IGES files for the linear/servo actuators I was going to purchase. Which meant I was able to modify their IGES files to make functional actuators to test in Autodesk Inventor! (You can see a video of that below, sorry for the dodgy video)
After testing that it worked in Inventor, I printed out the parts for the arm mech to do a prototype test. The actuators I ordered were Arduino compatible so I was able to hook up my Servo Tester and do a proper test! When it comes to the final version the rail at the top will be aluminium extrusions, and arms that connect to the actuary will be 3mm aluminium and the arm itself will be 3D printed.
Yup thanks to the Internet you just didn’t hear me scream like a little girl..
Kal Argos
Sr Member
This is some incredible work. Chopper was a cool addition to the astromech star wars family. Very impressed by your design and execution so far. Looking forward to more updates.
I showed my kids and they say its a "real chopper".... so you have their vote too.
Just curious is the third leg/wheel an issue ... it looks like its a tight fit in the references or screen caps I've seen.
I showed my kids and they say its a "real chopper".... so you have their vote too.
Just curious is the third leg/wheel an issue ... it looks like its a tight fit in the references or screen caps I've seen.
Studio 49
Sr Member
Well I didn't hear or see anything mate haha
Thanks so much for the kind words mate
Ah yes, the infamous centre wheel! It's another one of those fun instances where it works fine in animation but not in reality.
My CAD model is accurate to the animated model, but I'll be modifying it to work for the real droid I'm building. Essentially I'll be modding a castor wheel to house a different wheel (I've been able to source a rubber wheel that's as close as I'll get to the dimensions of the real thing). The other thing that helps is mine will stay in the 3 leg position, so I don't need to worry about it being able to fit inside the body past the skirt thankfully
Long story short, I'll have to diverge from the source material a bit to get it to work which is a running theme for folks building chopper with a functional centre leg haha
NakedMoleRat
Master Member
Insane. Very well done. He will be followed around the convention hall by children and Wookiees alike!
Studio 49
Sr Member
Another aspect of the dome I've been working on is designing functioning retracting door for the dome arms.
With that said I think I finally have the design sorted! I just need to print the finalised parts for mounting the mechanism properly and then I’ll post a heap of videos/photos for any folks that would like to have a look at the setup I’ve designed.
For now, here's a quick preview of it in action from the outside
With that said I think I finally have the design sorted! I just need to print the finalised parts for mounting the mechanism properly and then I’ll post a heap of videos/photos for any folks that would like to have a look at the setup I’ve designed.
For now, here's a quick preview of it in action from the outside
NakedMoleRat
Master Member
That is just amazing. You’re going to have a fully functioning actual droid by the time you’re done. What I like best about chopper was his irascible personality.
if R2-D2 is a loyal dog, then chopper is a cat!
if R2-D2 is a loyal dog, then chopper is a cat!
Thanks for the kind words guys
Speaking of Chopper, I should hopefully have the rest of the dome printed by the end of the week!
You keeping track of how many hours?
Studio 49
Sr Member
Finally found a solution I’m happy with for the Centre foot/wheel.
I wanted it to be a functional rubber castor wheel while also getting as close as I could to the specs of the actual wheel design.
After a bunch of digging online I found that certain styles of Jockey wheels (typically used for trailers) were surprisingly close in their diameter and tread design to Choppers!
(The jockey wheel is the black wheel on right side of the images below)
With the wheel sourced I needed to find a solid castor mount that I could mount my new wheel to. After some digging on eBay I found a winner (which is the gold rimmed castor wheel you can see on the left of the images below). The specific thing I was after was a fork that was wide enough that I could fit my wheel on. It also was perfectly flat on the sides meaning I can design up some parts to glue on the sides to make it look even more like choppers Centre wheel mount (that’s a job for another day though).
And finally, I wanted to cover up the writing on the sides of the jockey wheel. I could have 3D printed something, but I had some castor wheels on hand that had curved covers (picture six). I was then able to remove them and fit them within the wheel assembly. The covers help round out the wheels shape to reflect the show and also have the grey included for the ‘rim’ seen in choppers Centre wheel.
Obviously, it’s not 100% screen accurate, but with this specific part there’s no way to get it 100% accurate without 3D printing it, and that wasn’t a route I wanted to take for something that’s going have to deal with wear and tear while rolling around.
I wanted it to be a functional rubber castor wheel while also getting as close as I could to the specs of the actual wheel design.
After a bunch of digging online I found that certain styles of Jockey wheels (typically used for trailers) were surprisingly close in their diameter and tread design to Choppers!
(The jockey wheel is the black wheel on right side of the images below)
With the wheel sourced I needed to find a solid castor mount that I could mount my new wheel to. After some digging on eBay I found a winner (which is the gold rimmed castor wheel you can see on the left of the images below). The specific thing I was after was a fork that was wide enough that I could fit my wheel on. It also was perfectly flat on the sides meaning I can design up some parts to glue on the sides to make it look even more like choppers Centre wheel mount (that’s a job for another day though).
And finally, I wanted to cover up the writing on the sides of the jockey wheel. I could have 3D printed something, but I had some castor wheels on hand that had curved covers (picture six). I was then able to remove them and fit them within the wheel assembly. The covers help round out the wheels shape to reflect the show and also have the grey included for the ‘rim’ seen in choppers Centre wheel.
Obviously, it’s not 100% screen accurate, but with this specific part there’s no way to get it 100% accurate without 3D printing it, and that wasn’t a route I wanted to take for something that’s going have to deal with wear and tear while rolling around.
Looks great!
NakedMoleRat
Master Member
Don’t stop now! Great work!
Studio 49
Sr Member
After much designing, printing and prototyping I'm excited to say that Choppers dome door mechanism works!
There were a number of design challenges with this, specifically with the dome is somewhat conical in shape. This meant I wasn't able to just insert a simple flat sliding door. For those not super familiar with these doors, they're the doors that Choppers dome arms come out of and then need to retract/slide back into the dome to allow access for the arms.
There were a number of design challenges with this, specifically with the dome is somewhat conical in shape. This meant I wasn't able to just insert a simple flat sliding door. For those not super familiar with these doors, they're the doors that Choppers dome arms come out of and then need to retract/slide back into the dome to allow access for the arms.
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Studio 49
Sr Member
Ultimately my solution was to add a slight curve to the door that matched the inner profile of the dome. With this curve I was able to have it slide in and out without the issues I would have faced with a flat door.
The next challenge was adding movement to the door. I went through a number of different solutions but ultimately decided to make my own DIY version of Linear Servos as typical linear servos wouldn't cut it (in the same way the flat doors wouldn't work too well). I designed up my own custom 'linear servos' but had it operate with a curved rail. This curved section matched the profile of the dome and would allow me to retract and extend the door easily within the confines of the dome’s geometry.
Next I needed to motorise the door mech. To do this I sourced some continuous rotation servos and then designed up a prototype that consisted of the gear (which I mounted to the servo), a curved rail with corresponding gears/teeth and a housing that that rail could slide through. After I set it up and hooked it up to my servo tester and test my prototype you can see in the video below.
While I'm at it, here's some tech drawing showing some details of the dome that I've designed which also includes the door and dome arms mechanism. You can also see in the back where the grooves are for the custom curved servo rails I designed along with embedded mounting spots for the servos.
The next challenge was adding movement to the door. I went through a number of different solutions but ultimately decided to make my own DIY version of Linear Servos as typical linear servos wouldn't cut it (in the same way the flat doors wouldn't work too well). I designed up my own custom 'linear servos' but had it operate with a curved rail. This curved section matched the profile of the dome and would allow me to retract and extend the door easily within the confines of the dome’s geometry.
Next I needed to motorise the door mech. To do this I sourced some continuous rotation servos and then designed up a prototype that consisted of the gear (which I mounted to the servo), a curved rail with corresponding gears/teeth and a housing that that rail could slide through. After I set it up and hooked it up to my servo tester and test my prototype you can see in the video below.
While I'm at it, here's some tech drawing showing some details of the dome that I've designed which also includes the door and dome arms mechanism. You can also see in the back where the grooves are for the custom curved servo rails I designed along with embedded mounting spots for the servos.
colinjreed
Member
Can I say damn on here? If so, daaaammmmnnn!
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