Therming

Therming is a technique used by woodturners to simultaneously create multiple copies of spindles and table legs.[1] Often described as off-center spindle turning, therming is also known as drum turning and barrel turning.[1] Therming allows a woodturner to make exact duplicates of three, four or however many spindles a therming rig can hold. Figure 1 shows multiple identical, partially completed spindles mounted on a therming rig. Note that all outer surfaces of the items being turned are curved. By rotating each spindle in the therming rig, all of the sides can be turned to individual contours to create unique shapes. For a four-sided turning, each side would be rotated 90 degrees after completing a side. Each spindle must be rotated the same amount in the rig to maintain similarity. Shapes with three, four and five sides are typical. Historically, the technique was used to produce table legs and balusters, usually with four sides.[1] Therming dates back to the 18th century and is mentioned in a letter to Thomas Jefferson from Nathaniel Colley, dated 22 January 1791 on the delivery of tables from London with therm’d legs.[2]

Therming rigs can be made with a center shaft or just with end plates as shown in Figures 2 and 3. A therming rig includes individual turning blanks separated by gaps when mounted between end plates. These gaps result in a process called ‘turning air’, as shown in Figure 4, where the cutting action occurs intermittently as the turning blanks rotate past the cutting tool. Production therming rigs often hold 20 or more spindles at a time. An article on 'Angular Turning on the Lathe', published in the Summer of 1998 in 'American Woodturner' magazine, provides descriptions of the techniques used for turning multiple spindles.[3][4]

Description of the Therming technique for making a therming rig and creating a three-legged stool

  • Figure 1 Therming Rig with Multiple Spindles
    Figure 1 Therming Rig with Multiple Spindles
  • Figure 2. Therming Rig with End Plates and Central Shaft
    Figure 2. Therming Rig with End Plates and Central Shaft
  • Figure 3. Therming Rig with End Plates only
    Figure 3. Therming Rig with End Plates only
  • Figure 4. Therming Rig in Motion on Lathe
    Figure 4. Therming Rig in Motion on Lathe

References

  1. ^ a b c Art, Liestman (April 2010). "Beyond Round, Therming" (PDF). American Woodturner: 48–52. ISSN 0895-9005. Retrieved 20 January 2021.
  2. ^ Jefferson, Thomas (1971). "To Thomas Jefferson from Nathaniel Colley". In Boyd, Julian P. (ed.). The papers of Thomas Jefferson. Vol. 18. Founders Online, National Archives: Princeton University Press (published 24 January 1791). pp. 591–592. ISBN 9780691045825. OCLC 491499558. Retrieved 20 January 2021.
  3. ^ Angerer, Sigi (1998). Lacer, Alan (ed.). "Angular Turning on the Lathe". American Woodturner: 10–13.
  4. ^ Findley, Richard (2017). "Therming or Square Turning". Woodturner (305): 25–30. ISSN 0958-9457.

Content Disclaimer

Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.

  1. The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
  2. There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
  3. It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
  4. Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
  5. Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.