Thanks for your kind answers.
Here I let some comments about them.
You need a pulley at each end of your instrument.
So you need two pulleys.
Yes, of course, I'm only concerned about the type of the pulley, so
I would buy two of them.
However this instrument looks like it may have XL pitch.
I thought that it would lighten the system, so the motor would have
to move less weight.
What do you think?
Would the MXL resist all the movement required or better switch to XL.
The belt you mention (A 6Z16-C025) is 'open ended'.
That means it is not a loop.
You need a loop so that you can wrap it around the two pulleys.
Actually, the one used in Lemur's GuitarBot is open ended, but it's
attached to the slider(you can zoom in the picture to note it). That's
a big advantage because I can buy one large open ended belt and
adjust it to my design and even make mistakes(as, obviously, gonna
You have not mentioned the motor or the encoder shafts.
The 'bore' on the motor's pulley must match the motor shaft diameter.
The 'bore' on the encoder's pulley must match the encoder shaft
Of course the motor will need to be strong enough to move your
load fast enough to play the music you want to play.
That is a complex calculation.
The motor's bore are about 2~3 mm = 0.07~0.11 inches (I don't have
them with me right now to give you more precise data)
I've picked the smaller pulley's bore from the MXL series, 0.125 inches,
I'll have to do some adjustment.
The motors are recycled from a printer and I don't have enough knowledge
to predict if they're gonna work or not, so I'll be doing a lot of trial/error.
Is there a way to extend the motor shaft so it could be attached to a wider
The pulley you mentioned has no set screw or pinning hole.
This pulley (A 6T16-036DF2508) is about that diameter has a .25" bore in an
"Aluminum "T"-Insert". The T insert has a set screw in it for mounting to a
Does the T-Insert refer to the protrusion in the middle of the pulley with holes
I thought about using set screws, but am not sure how, since my motor's shafts
Do you have access to a machine shop?
Do you talk about the place where to make parts? Yes, I have one. What I would
have to go there for?
Set screws will work but work loose.
Pins are better.
Could you tell me more about pins? How to buy or make them?
When and why use them?
Thanks for your awesome answer.