Re: [CAD_CAM_EDM_DRO] Re: Timing belts

Hi Dave,

I still have an old board I've kept, probably for sentimental reasons as I
doubt I'll ever use it again.

The end pulleys are about 5" in diameter and are grooved so that the wire
winds across as the square goes up and down. The wire is wrapped around
three times. If you wanted to wrap it ten times you would need enough width
to allow for the movement of the gantry. It would be no good running out of
pulley before getting to the end of the travel.

Regards,

Terry


| > Hi Chris,
| >
| > As an old school draughtsman trained in the early 70's I can give you my
| > experience of using this type of drawing board for the odd hour or two.
| >
| > If you move the square from one end quickly the motion goes out
| regardless
| > of how much tension is one the wires. This was avoided by gripping the
| > square at the centre. There for if you had more back preessure on
| one end of
| > your gantry the wires will slip and cause the motion to go kak.
| >
| > Regards,
| >
| > Terry
|
|
| ah.... things to be overcome by creative thinking....
|
| using a dual wire and screw will keep both sides in alignment.
|
| wrapping the wires around the screw 10 times would eleminate the wire
| slipping.
|
| One would need to have the screw/wire in place geometrically for this
| method and one could run the screw thru nuts so the screw moved back
| and forth, but the wire would not change geometery.
|
| the longer the table, the longer the screw. the longer the screw, the
| fatter it needs to be.
|
| very interesting
|
| Dave