On 14/03/2016 17:27, legg wrote:
On Mon, 14 Mar 2016 07:04:19 -0700 (PDT), "
wrote:
On Saturday, March 12, 2016 at 11:16:48 AM UTC-5, DaveC wrote:
wrote:
The capstan is a passive device. The motor pulley diameter via the *pinch
roller* determines the tape speed. The capstan wheel can be any size at all.
By my mind that is backward: the pinch roller is passive (not being driven).
The capstan shaft (~2mm diam) is driven by capstan flywheel/belt/motor
pulley.
No?
Thanks.
(op)
THE *MOTOR PULLEY* DIAMETER..... Not the pinch roller.
Peter Wieck
Melrose Park, PA
Question was re flywheel diameter differences. Motor pulley drives
both. Same belt on two different dia flywheels, yet obtains same
spindle rotation at their separate pinch rollers.
Identical belt speed should drive a smaller dia flywheel faster. Motor
speed does not account for this physical difference, as it is uniform
for both functions.
Supposition is that the difference in flywheel dia is related to belt
thickness, as one flywheel is inside, and other is outside the drive
belt loop.
RL
That would be lead to a much closer pair of pulley diameters.
But then although you have a free range of pulley sizes, as cast and
machined, the sintered metal bearings come in only discrete sizes of * x
0.1mm , so you have to increase/decrease the pulley diameter ratio to
then be compatible to 2 available bearing diameters and hence spindle
diameters.
That is the reason i'd go for