We often receive messages from Vinyl Recorder users asking for help because either their grooves are skipping towards the end of the disc or that the lead-out groove breaks up or disappears entirely. This is something we have experienced ourselves and luckily have a very simple fix for.
These issues are caused due to the feedscrew lifting slightly, often by 1 to 2 mm, as it travels toward the centre of the disc, meaning that the groove depth gradually becomes more shallow during a cut. The feedscrew is driven by a motor mounted inside the overhead unit, running toward the spindle. You may already know that your motor is held in place using silicone, so even a small shift when it sets can cause the motor to slightly drop and for it to sit at a slight upward angle. As the cutter head moves inward during a cut, this results in it rising slightly, making the stylus lighter on the surface, and ultimately causing a shallower groove.
Even tiny weight changes can have big effects in record cutting and this one is subtle but significant.
How to check for this issue:
1 Make sure your platter and overhead are level.
2 Lower your vacuum tube until it just touches the mat.
3 Manually wind the cutterhead and carriage inward, to where you’d normally end a cut and watch the vacuum tube.
If it lifts even slightly, it means your feedscrew is rising and that’s your problem.
Simple fix: shim the overhead
If the feedscrew is rising:
• Place a shim under the right-hand arm of the overhead.
• We used a 1 mm brass shim, and it solved the issue instantly.
This small adjustment keeps the feedscrew travel flat and your groove depth consistent from start to finish.
Below are some images:
Start Point:
Finish Point:
Shim:
