If the rotational resistance is low then a rubber wheel might work as well.
A rubber friction drive was the suggestion I made in the earlier posts. The rotation resistance is very low since the table is just attached to a shaft that is in a sleeve in the support arm.If the rotational resistance is low then a rubber wheel might work as well.
True. If the rubber cam wheel will drive the table....that is the way to go. A counter wheel on top or the other side (underside) might help the friction between the cam wheel and the tube. Very soft (sticky) rubber might help as well. The top and bottom wheels could form a pinching action on the table that will insure a good steady drive force.I am well aware of all of your efforts on this project. I have been following this thread for some time and watching the ideas build and develop and in watching the motor driven turntable and translation travel develop there was just this little bug in the back of my mind that something basic was not being discussed; and, when I returned to the thread earlier today, I finally I realized what that something was.
If necessary to insure the grip of a rubber wheel the a yoke with the driving wheel on the bottom of the rotating table and a an idler wheel above it on the top of the table might be used.
I am concerned that adding the necessary programmed motor systems to do what this simple system can do will much more complicated to develop and more expensive as well.
That would be ideal but, I don’t think the OP has the where-with-all to pull that off. Right now he is somewhat MIA.I'm seeing this get more and more complicated. I agree that either the feed rate or the RPM of the disc would need to change as the spiral grows (remember our old records - the speed of the stylus through the final was much greater at the outside edge of the record than those inner groves). This is basic trigonometry.
At this point, I think it would be far simpler, and far more flexible to build/buy an x-y table. That could be programmed to adjust the speed to match the (presumed) constant feed rate, and could be easily reprogrammed for different shapes and sizes. And if you change dough recipes, or anything else in the feeder, you could adjust the programming of the x-y table to match. You won't be constricted by purpose-built hardware. The dough might even change batch-batch or with temperature, you could have a program ask for a feed rate.
This looks pretty cool, I really think that once you get it working, you will want to make different shapes/sizes. Keep us up to date on your progress! I'm getting tempted to make one myself now.
The OP has not provided any details on this, other than his image above.I'm also curious about the "12V actuator" for the dough. Is this a solenoid providing pressure, or a positive displacement type device? I really think you want something that provides a positive displacement, so you drive a set volume of dough per unit time. A motor/stepper-motor and threaded rod or lead screw would do it.
The batter is still enough to flow by gravity, but it won't fall like a straight line since it has some the star design around it. I guess it can go around the tube without breaking in to pieces. I will try adding a straw to test it out.Is the batter stiff enough not to flow by gravity? If it is very stiff, the supply container can be placed overhead. If it flows, due to gravity, it will need to be at table level or below and allow the pressure to move it through the tube, and out the nozzle. I would think it needs to be stiff so it does not flatten out too much on the table after being extruded and prior to being fried.
Hi NTL2009,I'm also curious about the "12V actuator" for the dough. Is this a solenoid providing pressure, or a positive displacement type device? I really think you want something that provides a positive displacement, so you drive a set volume of dough per unit time. A motor/stepper-motor and threaded rod or lead screw would do it.
junasiv: Can you tell us how automated you would like the operation to be. Will someone be operating and monitoring this system at all times while in use? How many hours per day do you expect the system will be in operation? Do you have any special operational or regulatory requirements. How about cleaning requirements? Any material restrictions or code requirements?
Thanks for your ideas!
Sure I will keep you guys up to date on my progress. I am checking on the x-y table too, also thinking of adding arduino to sync the speed. Looks like acutator internally has the threaded screw. I will find out more on this.
If you can meet the expense of a X-Y table, that is the way to go; as it will illuminate the need for a lot of mechanical design/build effort.