Free 173 Best Homemade Tools eBook:  
Become a founding member: 500+ tool plans, full site access, and more.

User Tag List

Results 1 to 2 of 2

Thread: Casting a giant propellor GIF

  1. #1
    Jon
    Jon is online now Jon has agreed the Seller's Terms of Service
    Administrator
    Supporting Member
    Jon's Avatar
    Join Date
    Jan 2012
    Location
    Colorado, USA
    Posts
    20,883
    Thanks
    6,302
    Thanked 29,730 Times in 8,207 Posts

    Casting a giant propellor GIF

    Casting a giant propellor GIF. What is the alloy? Some sort of Aluminum bronze?



    Original source video:



    Previously:

    Lead sheet casting

    173 Best Homemade Tools eBook
    Last edited by Jon; Sep 8, 2020 at 11:32 AM.

  2. The Following 2 Users Say Thank You to Jon For This Useful Post:

    Miloslav (Nov 6, 2019), Seedtick (Jul 31, 2017)

  3. #2
    Supporting Member Toolmaker51's Avatar
    Join Date
    Feb 2016
    Location
    Midwest USA
    Posts
    3,373
    Thanks
    5,308
    Thanked 2,209 Times in 1,363 Posts

    Toolmaker51's Tools
    Propellers have come a long way. The first experimental forms tried to emulate the Archimedes' screw and how a wood screw works. Observation said this was logical hypothesis but disappointed inventors only found awful results. They didn't factor tubing that made Archimedes' screw function. Quite some time passed before the shape and educated guesses of bird flight visualized the foil; opposing flat and concave surface. Josef Ressel is recorded first with a successful device.

    Pardon what will seem to ramble;
    I believe this form of milling is called 'scarfing'.
    At 0:43 [among others] of the 1:09 GIF, the face mill is intentionally canted to the surface, compared to how we normally perceive milling. There isn't any flat surface on a prop, some straight lines, but no flats. Though it rotates, essentially works same as an airfoil - an aircraft's wing. Canting develops the profile, made up of these successive, equal, ~ parallel and shallow 'grooves', lacking a better term. Being multi-axis, a single cutter removes cast layer into solid material, over much of the surface using different angles, delivering intended profile[s] at the same time. Also, the inserts probably aren't cornered; looking at chips, feed rate and finish tells one they carry a decent radius, or completely round. Later will be dressed, removing about a third of the crest between.

    Not long ago, a thread about fly-cutting mentioned 'flat'. In actuality that is rare, a very large radius is more common; difficult to see or measure due to part width.
    I commented some machine tables use this effect intentionally to reduce friction under large parts; against near impossible feat removing every speck from a large surface like a radial drill. Those shallow grooves are usually about 1"-1.25" and the land [crest] maybe 1/16 to .090 width.

    A photocopy used to circulate, diagramming long form mathematics to solve for angle and cutter diameter to produce intended depths and radius. When I say Long Form, I mean it; covered the entire sheet.
    There has been a great deal of math-prowess displayed here of late. Would be very happy, if a member should write and share a program for this process. I think his username is mklotz. . .

    So after writing I finished the longer video. Better than how-it's-made topic, but typical verbal hype. Like a tungsten cutter "grinding away", or "painting" the finish [varnish or lacquer surely] to keep from "rusting". AL-bronze, Si-bronze, High Copper, Beryllium? Really?
    Last edited by Toolmaker51; May 6, 2019 at 06:04 PM.
    Sincerely,
    Toolmaker51
    ...we'll learn more by wandering than searching...

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •