A Paper Chuck is used to hold a piece of paper so that an image of the rosette's final product can be visualized. The shape of the rosette may not be readily evident about the product it will produce, plus the other variables like the rubber's shape can change what the rosette produces.
A paper chuck is sometimes called a Tympan Chuck, especially in historical documents. A tympan is a tightly stretched sheet or membrane, as on the head of a drum. In this case though, the tympan is a piece of paper held by the chuck. Typically, the ones which are more nicely done are called Tympan Chucks. Frank Dorion's article shows a very professional design (see below).
A typical paper chuck is designed to hold an index card (e.g., 4" x 6"), and Lindow Machine Works makes a very nice one. Other sizes of paper can be used as shown in the home made paper chuck to the right.
Note: the traditional paper chuck can only be used to show the effects of rocking motion, not pumping motion. There have been some who have made a cylinder (e.g., using a plastic tube) and affixed paper to that. Such a device can indeed show pumping motion. There are some examples below
Additional pictures of this device
Paper Chuck using an Acrylic Cylinder
Sources for buying one
- The Design and Use of a Tympan Chuck by Frank Dorion. Ornamental Turners International Newsletter, Volume 29, No. 2 - December, 2022, pg. 25
- Making a Tympan Chuck by Ian Lane. The Society of Ornamental Turners Bulletin 142, Spring, 2020, pg. 23
- If you choose to make one
- MDF Rose Engine Lathe : # 2 - Paper Chuck by Rich Colvin. YouTube Video
- Rose engine lathe paper chuck by Wes Pilley. YouTube Video
Disclaimer: eMail comments to me at OTBookOfKnowledge @ Gmail.com. The process of woodturning involves the use of tools, machinery and materials which could cause injury or be a health hazard unless proper precautions are taken, including the wearing of appropriate protective equipment.