Making a rope knurl

A rope knurl is just a knurl made with a concave knurl so that a series of raised ridges wrap around a half round (or less) hump. This photo shows how it should be done (taken from a SawMill Creek article by Leigh Betsch, well worth reading but requires a log in to view the images). Flat and convex knurls are easy to come by but rope ones are not and this one was home made. I haven’t advanced that far and use a flat knurl and rotate it around the hump to make the rope, sometimes holding the tool by hand (brass is pretty easy to knurl, titanium is difficult).
Here is a knurl holder similar to what I use, with two flat, angled knurls; the angles are opposing to form a cross hatch. The holder is mounted on the cross slide and jammed into the work and the knurls form (and cut) the pattern. I use a one arm of the holder and one of the knurls to make my ropes, rotating the holder to get all sides of the hump. I usually have to reverse the work to get at all sides. Not quick and takes a bit of finesse to make sure I get the grooves lined up (otherwise you can get ghosting or double grooves).

I now use a different knurling tool that works much better than a push tool, see it here.

Here is a nice video of making a rope knurl use a shop built hob:

This entry was posted in Tools. Bookmark the permalink.

2 Responses to Making a rope knurl

  1. Phil Lang says:

    ZK Project Notebook:

    Thanks for the additional information. I appreciate the link to using a tap to help make the initial knurling tool.

    Keep up the good work.

    Phil Lang

  2. Pingback: Making cap screws | ZK Project Notebook

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s