User:Mhassanu5050/ENES-100/project 2


 * probect 2: access

week 1 narative
during this week i have started working on my access project in which my goals are to recreate the results of the previous team. i started out by making all the hardware stuff. my first task was to get a motor assembly out of a inkjet printer. what i did was basically using tin snips i separated the motor and some gears that were attached to it. while doing this i made sure that i would have enough wire left over that was connected to the motor in case i needed it later on. here is a video of it http://www.youtube.com/watch?v=V5yKU8pmcDE&feature=youtu.be.
 * separating the motor

for the compression spring that is connected to the bottom of the door i had to modify the design a little bit. what ben had done was use a wire to make the hooks but all the steel wire i could find was to thick for me to follow his design. so instead i used two 2.5' nails to replace the wires. the first picture is off of bens pages and how he did it and the next is the way i did it.
 * compression spring

week 2 narrative
this week i worked on some of the other hardware stuff like making the latch that goes on the door handle to which the string is going to be attached to.

to manufacture this i used the lamination technique. first what i did was take a soda can made out of aluminum, and cut a straight piece as long as possible. the next step is to get the appoxy ready by mixing equal parts of the A and B parts. while doing this you need to make sure that you make enough appoxy that you dint run out. next put any sort of weights on the end of your aluminum strip so that it stays straight, then apply a healthy coat of appoxy on it while trying to keep it and evenly spread as possible. now quickly apply a coat of oil on the door handle of which you are trying to get the mold of. then wrap the aluminum strip around the handle tightly and clamp it down.
 * latch that goes on door handle

one requirement of the project was that there could be no holes on the door. because of this i couldn't drill a hole to anchor the string, so i made a bracket that would attach to the bottom of the door and modified it make sure it stayed there. what i did was cut three slits on one side of the bracket using tin snips and then using long nose pliers i curved them upwards creating small hooks. the hooks plus the tension created by the strings are going to be enough to keep the bracket in place.
 * door bracket

after the appoxy had set on the latch the first time around, i took it off the door handle. after examining it for a while i decided to laminate another layer of aluminum on it because it felt flimsy and i thought that it would bend under pressure. so it put some more oil on the door, put the old latch back on it, and repeating the same process as last time i layered it with another strip of aluminum. after the appoxy had set the second time, this is how the latch looked like.
 * second layer of aluminum

when the latch was done i had to find out a way to attach a piece of string to it that would be then attached to the motor so that the door handle could be pulled open. at first i thought of bending other steel and soldering it to the latch but then i changed the design a little bit. what i did was take a piece wire and bend it around the latch a couple of times, while creating a little gap in the loop on one of the occasions so that the string could go through it. i set the steel wire in place using appoxy. the first picture is f how ben did it and the rest are the pictures of it before applying the appoxy and after it.
 * finishing up the latch

the next step was to make the spool on the maker bot. for this first i took all the measurements on the motor where the spool was suppose to go on. i took the measurements in mm using the calipers. the two important measurements were 9.63mm, which was the radius of where the spool would fit, and the second was that the spool could not be bigger that 50mm in radius. then using Google sketch-up i designed the spool.one thing of note is that when choosing the template on Google sketch-up, choose the one that measures in mm. i designed it in two halves so that if i print two of the same halves they would fit together perfectly.
 * making the spool

then using the stl plugin in Google sketch-up i exported the file into maker ware. then i moved the file to the SD card so that the maker bot can print it.

week 3 narrative
at the start of this week i printed out the spool using the maker bot. and at first i thought that it was great and it look good in the blue color that i had printed it out in. then what i did was try to fit it on top of the motor mount, but it was clear that the hole of the spool was too small to fit on top of the mount. at first i tried to cut notches on the sides of the hole in the spool, what my thinking behind this was that it would make the plastic around the spool a little bit more flexible and thus i would be able to press fit the pieces in place. so after cutting the notches i tries to press fit the pieces in place but all that did was damage the spool. because of me trying to force the pieces i had bend the flanges and there were stress marks on it. so now i am going to fix my design a little bit and take into account the thickness of the plastic from the maker bot. what i am going to do is increase the diameter of the hole in the spool by about 10th of a millimeter, and hopefully that will fix the problem. this is the picture of the redesigned spool half.
 * finishing the spool

the second time i printed out the spool, it didn't come out right either. even though the hole was a little bigger this time, and the spool slid into place a little better, the flanges still got bent when i forced the spool in place. so this time when i made the spool on sketchup, i made the diameter of the hole 9.7 mm instead of 9.63 mm. then i went a step further to design some notches in the hole so it will easily bent when im trying to put it on. the notches will also help in setting the appoxy in place.
 * redoing the spool

when i separated the motor mount from the printer assembly, the edges of the metal were a little rough and even i cut myself on the sharp and rough edges even though i was being very careful. so what i did was cut the excess metal off from the piece and then i filled the edges down so that the piece was easier and safer to handle. the results are clear.
 * final touches on the motor

week 4 narrative
finishing the spool

so i printed out the final design of my spool in yellow but as usual there was something wrong with it. there was some excess PLA on the inside of it. so what i did was simply file the excess out. then after that i connected the spool to the motor shaft. because of the increased radius of the hole in the spool and the notches designed in, the spool slipped on the shaft really easily, but to make sure that it stayed in one place i eppoxied it in place.

mounting the motor on the door

first i attached the latch that i had made with the strip of aluminum and appoxy to the door and tied a piece of thread to it which was connected to the spool. then i tied a piece of thread to both ends of the motor, one side was connected to the door handle and the other was connected to the bottom of the door using the clasp and spring mechanism.

other materials used

after i has gotten all the motor mechanism on the door, the next step was to test it out. some of the other things i used was an arduino uno and a motor sheild a power source and the code i got from an open source to test the motor.

testing the motor

my design is a bit different that what ben has put on the other door. the gears of his motor have been stepped down a lot, where as my motor has been only been stepped down once. so i had to make sure that the motor was powerful enough to pull the handle. so i connected the motor shield + arduino to the motor and run the code.

what i found out was that it was not working. so at this point i compared my project to the one ben had already finished and what i figured out was that my power supply was not powerful enough. he was running the system with a 16V 4 amp power supply whereas a was using a 12V 2.5 amp power supply. so the next step i took was to change the power supply. the new one i choose was a 12V 4 amp supply.

but the problem still remained. the handle would still not open. so then i turned my focus onto what other reasons there could be because of which the door was not opening. while i was testing the handle i noticed that the handle was bit harder to push than the one that was which was in the other door. what i did next was to get a newton meter and measured how much force was required to open the door., then i went ahead a tested the same setup on the other door and tried to find out the force required to open the 2nd door. the results were clear, as there was a difference of about 12 newtons.

setting up on the other door

after the results i got from the newton meter test, i decided to put the knock knock door setup on the door that required less force to open. so i transferred everything including the new power supply to the other door and tested it out. the results were a little better but the handle still didn't open completely. to fix this problem i decided to use weights on the handle to aid the motor in opening the door. first i tested the 1 Kg wieght. but as it turned out that the weight was too much and the handle couldn't return to its initial position. then i tested out some nails as weight but they were not enough to pull the handle down enough.

Next steps
the next steps for me are to play around with the weights and finding out the perfect balance. finishing the door and the knock knock command. and finally cleaning up the looks of it.