Just came home with a complete 4x5 RH8 found buried in a pile of junk on a flea-market. After a well-deserved cleaning and a check of moving parts I put a roll inside following instructions found here ( my first RH, so… ) and discovered the film flatly refuses to move when I turn the knob. Some escapement inside makes cliclicliclicliclic, the counter works, the automatic stop works too, but the film stays where I put it. Seems the torque needed to advance it is higher than the torque needed to actuate the escapement. The blade on which to engage the roll turns freely but it is easy to stop it with a finger. Looking deeper, I discovered remains of glue on the lower side of the knob near the bronze thread. So apparently something went wrong someday and was fixed with DIY genious. Did I buy a nice paperweight ?

I'm guessing here. If I understand correctly, the threaded shaft is slipping at the winding knob end. Can you epoxy the shaft-into-knob area where you discovered the glue job? This should hold any slippage. As for the key (that's the little wing-shaped part that fits into the slot on the end of the take-up spool), keep in mind that it is a left-hand thread! I.e., it unscrews clockwise (looking at it dead-on from the bottom of the insert). Sometimes this key gets balky and binds up. Underneath the key is a brass washer; removing this washer solved the bind-up problem on my RapidVance RH10 holder. The absence of the washer doesn't seem to adversely affect the operation of the mechanism. HTH.