9815/9825 Capstan

[vassilisprevelakis]

(09-09-2017 08:25 PM)Craig Bladow Wrote:  Is the capstan removed from the motor? Width and length of tape, how many layers of tape? Final diameter? How much, if any, of the overlap is trimmed off?

I have never needed to remove the capstan from the motor.

I did have to remove the motor itself and unsoldered the two tiny wires from the tacho sensor

I vaguely recall that you have to be sure not to cross them when you reassemble the motor, I could be wrong though, since its been some time since I repaired a capstan.

Having said that I have repaired about ten tape drives with the tape method and they are all working OK even after 8+ years

The overlap is important ! You have to smooth it out. Its very easy you wait 8-10 hours for the tape to firm up and then you run the motor (anything between 9V and 12V should be OK) holding a file against the wheel. Worst thing that can happen is that you file the tape away and you have to do it all over again.

After reassembling, you can test your repair by retentioning a scratch tape (the command on the HP-85 is called CTAPE). If it works you know the capstan can move the tape without slipping.

**vp