Hello everyone,
I am very new to this side of things and am hopeful I can be pointed in the right direction. I own an escape room company in OKC and have created some incredible special effects, but this area of expertise is not really in my wheelhouse. We are currently building our 5th escape room which will have an AI theme. I need some guidance on a particular prop that will be for the Power Core of the AI. It will be an 8" diameter solid resin sphere that needs to rotate organically in various angles. It needs to be a “set it and forget it” prop which basically means that when our manager arrives and powers up the entire game it will begin and continue throughout with constant movement until the end of the night when the facility is closed. I’ve used Chatgpt to help render some images and have a reference video, but the site is having issues with uploading. Maybe after the post I can upload. Robotshop would not spec the products necessary when I had questions and they recommended that I post my needs here. The 8" sphere will weigh approx. 14lbs max. There will be a housing that we will build to hide the mechanics which will leave about a 5" reveal around the center perimeter to be able to view the sphere. What was suggested was 3 - 100mm Omni Wheels with a shaft assembly (If the shaft assembly kit is not available I will need the appropriate bearings, blocks and couplers), 3 - 36D 12V Brushless DC Gear Motors, Motor Mounts, etc. From what I’m to understand, the motors must be mounted at a 15-20 degree angle to allow constant contact with the lower portion of the sphere. Is there an angled pivot motor mount that is available or a set angled mount? I’m looking for a little guidance here. Are there motor mounts that have a pivot point so that we don’t have to mount them at the exact angle allowing the sphere to dictate it once it rests on all three wheels? Just curious. Trying to make this as easy as I can for the build team. Any help would be greatly appreciated.
Hi @sanctuaryescape and welcome to our forum!
Please try uploading now some images and sketches that you have. It would help us understand your project better.
Thank you.
It looks nice!
I’ve did search RobotShop product pages, and here is what I have found that might suit your project:
https://www.robotshop.com/products/100mm-double-plastic-omni-wheel-central-bearing
https://www.robotshop.com/products/e-s-motor-36d-brushless-dc-planetary-gear-motor-12v-5rpm
https://www.robotshop.com/products/lynxmotion-mmt-02-motor-mounts
Now you could have a more detailed look to see if these components are compatible for start…
Thank you very much! Which hubs are needed to connect the shaft to the omni wheel?
So something like this:
I believe this one would fit:
https://www.robotshop.com/products/6mm-shaft-universal-aluminum-mounting-hub
Maybe you would need to drill out the hole in the center, if your shaft of the motor is bigger than 6mm.
Or you can design your own special hub…
To confirm, the omniwheels shown in the images above should be perpendicular to the sphere:
Yes, that was ChatGPt’s failed attempt at rendering the appropriate orientation. Is there a baseplate/chassis you’d recommend? I see your rendering has the walls already angled at the proper pitch. I was looking at a flat baseplate where the angle would be set with the motor mount. Curious to know what your thoughts are. I appreciate all the help. Again, this is new territory for us.
You’ll likely need to custom make one, and not sure adapting an existing mobile robot kit/ mechanics would be worth it. Consider learning a bif of CAD to be able to draw it yourself. At 14 pounts, the motor’s output shaft can likely support the load directly, but not sure thin aluminum will do well. What tools do you have at your disposal?
Definitely not versed in CAD, but we have a 3D Printer, CNC for wood/plastic and have a master welder who works for us. It shouldn’t be an issue to manufacture something. I just didn’t know if there was anything “off the shelf” that could be utilized that is reliable and strong enough.
It looks a bit like these Nexus omni wheel robots:
https://www.robotshop.com/products/3wd-48mm-omni-directional-triangle-mobile-robot-chassis
https://www.robotshop.com/products/3wd-100mm-omni-directional-triangle-mobile-robot-kit
https://www.robotshop.com/products/3wd-100mm-omni-wheel-mini-mobile-robot
Nor sure if this is helpful for you…
Thank you for the links. The issue is that the Omni Wheels must be mounted at a 15-20 degree angle as to be able to make full contact with the sphere. It will either be accomplished with an angled motor mount or pre-fixed chassis wall.
That is a great idea. I will show this to our metal fabricator and I’m sure he will over engineer it like we do everything and it will work perfectly. Thank you again.
Pivoting mounts sounds like the best idea. Do you have any recommendations? The motors just arrived. These are them: https://www.robotshop.com/products/e-s-motor-36d-brushless-dc-gearmotors-12v-12rpm?qd=cc0fbafac4c1cc76921a202696b8f151
Another similar idea!
Ballbot: