User:1sfoerster/enes100/fall2013/p0Inkjet-503

Problem Statement
Science, Technology, Engineering and Math need to be displayed. An Inkjet printer might be converted into a robotic base. The resulting robots might be operated around the school to highlight the engineering program.

Conceive
Market/Customer Needs Producing mobile printers that move around CL-158, CL-159 and CL-160 bring awareness of engineering class to students who are walking past the engineering hallway. The printers will display a vision that reflect engineering, brand HCC as an engineering school and are memorable enough to attract visitors. Also, it looks cool to see robotic thing moving around the campus.

Initial target goals Mount wheels that are attached to paper feeding motor from the inkjet so that it can move forward and backward depending on how they are wired.

System performance metrics Building and grounds can maintain floors, walls and ceiling infrastructure. Fire and safety codes are not violated. Sharp protruding objects can not be accidentally run into.

Project cost and schedule Cost of a used working inkjet, a simple gear and mounting hardware could exceed $30.

Estimation and allocation of resources Resources can all come from engineering department, donated inkjet printers and existing disposable resources in the engineering room should cover most other needs.

Alternatives This conceive focuses on the "science on display" finished vision of this project. Other conceives could be written based upon:
 * Inkjet printer is modified to drive an RC car that is moves when the printer is turned on.
 * Inkjet printer is mounted on existing RC car and dribbles sand on the floor in patterns.
 * Inkjet printer is programmed so that it can be remotely control.
 * A webcam camera can be mounted on a moving inkjet printer so that a person who controls it can move around the campus for FUN!

Design

 * Reverse Engineering:


 * A quick rundown of how inkjet printers work was found here - http://www.youtube.com/watch?v=tcc69NPBc2M
 * A car inspiration here- http://www.youtube.com/watch?v=HozfWhXd0xk
 * And something that just looked cool and suggested future uses for that printer head as part of our robot -http://www.youtube.com/watch?v=gLdUbcay44E
 * We dismantled one printer - a bit too far as it turned out, and it was no longer operational as a printer. Its motors were removed, and its power supply had an accident with electricity. It gave us a firmer idea of what was in the printer that we were working with. This became our test printer to explore ideas on and use for parts on a second printer. The second printer's inner workings were exposed more carefully. Here's a picture of the second printer with the more dismantled printer in the background Inkjet printer, no case, backside.JPG


 * The Design Process
 * We initially pursued an idea of making the printer a sort of car, perhaps by mounting it on a platform with wheels on axles and driven by the print head motor. This headed more in a direction of being less a printer and more using the printer motor to make a car. We refocused on retaining the basic printer elements or having a working print head, and using the printer as its own platform.
 * We moved on to an idea of mounting the printer on wheels and using the paper feed motor to drive it. We were stuck in figuring out how to drive an axle with the paper feed motor.
 * Stymied there, we pursued an idea of using caster type wheels fixed to the bottom of the printer and having the paper feed motor pull the car, maybe on a string. Inket with caster wheel 2.JPG This led to a concept of using the rollers themselves as a sort of driver by threading a string or band through them and around the front caster wheel in order to turn it. We removed the extra parts around the rollers. This had good movement potential, but creating a closed loop that did not catch and had sufficient tension was a roadblock. We thought maybe a tensioner pulley could create the tension, but failed to find a way to create a closed loop. Running band around paper rollers of inkjet.JPG A belt might have been used, but it would require the paper rollers to be taken apart in order to put in on, so we explored a different route.
 * We thought perhaps we could use the gears already driven by the paper feed motor in some way. A paper roller from another printer used as a set of front wheels for our printer has a gear naturally as the end. The challenge would be to mount the roller and line up the gears.
 * Prototype Building
 * Gearing: We initially thought we may be able to line up the gear on the added roller directly to the gears driven by the paper feed motor, but it turned out that the printer roller wouldn't extend far enough to roll on in that case. It had to be placed further out. So we decided to place a third gear in between the two. This was set in place on the printer with a bolt and a nut. Inkjet wheel gearing.JPG It was difficult to keep in place - the rotation of the gear would keep loosening the bolt. When it would loosen, the gear would fall out of place. We used loctite on the threads of the nut and that seemed to secure it pretty well. It seemed to change position at one point, and rubbed against the metal case. The case was bent away from the gear, but the very slight wear on the gear made it even more difficult to mesh it with the others.
 * Wheels: To use the roller for wheels, we needed more space in which to mount the roller, so we cut away a large part of the steel casing on the bottom of the printer. About every other roller wheel had a rubber grip around it. We took additional rubber rings from another roller to put on each of the wheels on our roller-as-wheels hoping it would grip the surface it was rolling on better and more evenly.
 * Mounting Wheels: We had some bracket-like odds and ends we sorted through in developing an idea for attaching our roller. We settled on part of a curtain rod bracket that we trimmed down for the non geared side, but a sort of squared off unidentified hardware bit with a round hole in it for the rod on the geared side to fit through. The brackets were secured with bolts and mainly held on by tightening them down with nuts. We tried bending the bracket to secure it, but this subtly changed the position of the rod which brought it out of alignment with the gear in each of several attempts. The bracketing is somewhat unstable, and movement in the position of the brackets takes the gearing out of alignment. When we initially placed the printer down on it new wheels, the bracketing just folded. We tried reinforcing them with a couple more bolts, which helped, but did not entirely solve the problem. Improved stability in the bracketing would help in keeping the gearing aligned for operation.Inkjet on its paper roller-as-wheels.JPG
 * Power: To power the motor through the regular printer power supply, the printer's control board would need reprogrammed or bypassed in some way. We choose to power the motor directly in our focus on achieving a moving platform. A switch was wired up the motor to let us turn it on and off. A more complex switch that allowed us to switch the positive and negative would have allowed us to change the printer's direction with the switch too, but we changed the position of the wires to do this. We tested it using the classroom power supply, and got some movement at 5 volts, and good movement near 9 volts of power. This led us to try on-board power using 9 volt batteries. This worked well, but drained the batteries quickly. We tried a 9.6 volt rechargeable battery, and this worked, but seemed like perhaps more power than needed and may have contributed to some problems with keeping the gearing secured. For video of power testing - Testing our Printer with the classroom power supply
 * Materials
 * Inkjet printer
 * Spare gears and roller from another inkjet printer
 * Dremel tool
 * Bracket type things
 * Appropriately sized bolts with nuts
 * Loctite threadlocker

Implementation
defined how we were going to make the printer into a car we then made the design we originally wanted but ran into to many issues redesigned built again then tested multiple times added a switch presented it to the class in seminar

Operation
Tighten nut that holds gear connecting to the wheels in place.

Power with battery or power supply.

Next Steps

 * Stabilizing gears and getting the mounting secure
 * Developing steering
 * Refining on board power
 * Programming control panel to control paper feed motor
 * Finding uses for the print head and programming for control over them
 * Developing remote control over printer functions