Things to be improved still
We are
very social people, so we think about the people that will have to do a
project after us.
We'd like to give all of you a start already if you should choose for this
project too in the future.
First maybe a few tips.
Don't take anything for granted. The law of Murphy is your enemy. If it can go wrong, it WILL go wrong in mechatronics. Just don't ever give up. Work as much as possible with printboards. It will safe you lots of troubles.
Test everything!!! Our motors weren't strong enough and suffered much from friction. So we had to redesign a lot in the last 2 weeks of the project. STRESS STRESS!!!
Don't be afraid to try new things or buy exotic chips, they help.
And of course, we'd like to give some possible improvements. Much of what follows has been suggested by JP Schepens.
To
make a system of multiple axis over the guitar. These axis can be moved
up or down with the help of a relais. After they have been moved down
you block them. Then you pull the guitar up so the axis presses on the
strings.
Then you move the axis up again and make the next one that you need go
down.
A lot of work, but we're certain it'll give a nice result.
Instead of using a motor to make the plectrum move, you could use a relais to give it a linear movement. That way you could have 6 plectrums, one for each string. That saves you two motors, the motor for the bridge and the motor for the turning of the plectrum. That's already 30€ you save on components for the motor control. (every motor uses two chips a L297 and a L298, each costs about 7€)
If you'd choose to keep our mechanical design, we'd suggest you find a new stepper motor for the movement of the roll. It isn't strong enough. If we would have had a stronger motor for that movement we could have improved the speed with about 50% or more.
For the
rest...
GOOD LUCK !!