The Ashford scotch tension knob is available in two styles. The most common one is one piece with a tapered wooden shaft.
On the older Ashford wheels the knob is a wooden ball with a dowel inserted.
Please pick the right knob for your wheel. If the hole on your mother of all is 1/2″, you need the new knob. If it is closer to 3/8″, then you need the old knob.
Full Scotch Tension Knob Kit available here.
Choose your option from the drop down list.
To help identify parts needed, you can find Ashford assembly manuals here: Ashford Assembly Guides