My NXT Scanner/Photocopier/Plotter V2

Sorry it's been a while since I posted on here, I have had so much school work i've struggled to find time to play with lego, let alone update the blog.

About this time last week I completed V2 of the All-in-One Scanner thing, which now thinking about it really needs a better name, so i'll call it the Sco-Cop-Ter from now on just to make it easier. The construction of V2 actually went very well and the final model was considerably stronger than the previous model, and also looked a lot better in my opinion.

However because it was stronger and better looking didn't mean it was functional, and that's where the problems began to start. The problems I had with the V2 are first I simply could not attach sensors where I needed them so I would not be able to tell where the robot or be able to reset it.

Here on the right you can see the design of this model. As you can see I had the motors placed vertically to try and minimise the lengths of the module and it worked fairly well, but unfortunately when programming I had no way of knowing whether the pen was up or down and no way to reset it because it was so difficult to attach any sensors. An ideal solution would be to have pneumatics/a linear actuator that could lower and raise the pen directly which also means I would not need to was space on the module with the awkwardly shaped motors.

Another problem I had with this model is that it really struggled to keep paper straight when it was fed through and it always crinkled. Below you can see the rear end of the paper feeder, and as you can see I have used the ultrasonic sensor to sense when paper is placed there and it will start turning the wheels to feed the paper.
Above each wheel is one of the angled beams which are pivoted and are held firmly against the wheels by rubber bands to keep the friction enough to keep the paper moving.

You can also see in this photo how I kept the pen module running perfectly straight across the width of the ScoCopTer. I used two 11 beams locked parallel to each other which successfully allowed the module to move back and forth nicely. But what I did not foresee is the beams catching on the 90 degree angle beams.

So this V2 version, although considerably better than V1 is still not really suitable for programming quite yet as there are still quite a few construction details that need to be ironed out first.

As this post has actually taken me so long to post I have in fact already built the base of the V3 module and all the sensors are already implemented and it is able to feed paper properly. But more details about that should, hopefully, be up over the weekend depending on the homework situation.