Path: ...!news.misty.com!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Snag Newsgroups: rec.crafts.metalworking Subject: An answer ... Date: Tue, 22 Apr 2025 15:41:34 -0500 Organization: A noiseless patient Spider Lines: 23 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 22 Apr 2025 22:41:36 +0200 (CEST) Injection-Info: dont-email.me; posting-host="0148ea9f6b8055138af30e1fc01f1538"; logging-data="1463173"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/zbnWt8uRknyte/PGuci3XFWIzCSGlRxU=" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 Cancel-Lock: sha1:fkiwNmKoHJKhKcZQFTN3KSAhYXI= X-Antivirus: Avast (VPS 250422-4, 4/22/2025), Outbound message Content-Language: en-US X-Antivirus-Status: Clean X-Mozilla-News-Host: news://reader80.eternal-september.org:119 Bytes: 2541 And now I know that the leadscrew is indeed Acme . I mentioned in the other thread about making a mold of the threads using a lead ball and a c-clamp. Well there ain't enough room under there for a clamp , but there is room for a pair of vise grips . And now I have a perfect impression of an unworn section of the threads . You can't tell from looking at the screw what the profile is . But after forming the lead then cutting it with a utility knife blade to see the cross section it's definitely acme . I shall be setting up a fixture* to hold a cutter at precisely 14.5° on the mill and grinding the profile with my grinding disc I bought for the end mill sharpening fixture . I'll need to hold the small screwless vise in the mill vise to get a relief angle on the cutters . I'll be recutting another piece of stock - with the proper angle and dimensions - as a fit check . Clare Snyder and Joe Gwinn were both instrumental in my decision to make the lead impression ... Thanks Guys ! * I'll need to grind both a 3/16" cutter for the boring bar and a 1/4" for the OD thread . This project needs more precision than I can manage freehand . And I'll probably end up making one for the Y axis too . -- Snag We live in a time where intelligent people are being silenced so that stupid people won't be offended.