Page 3 of 3 FirstFirst 123
Results 21 to 25 of 25

Thread: TAP Plastics/Acme Plastics experience?

  1. #21

    Join Date
    Sep 2014
    Location
    Montreal, Canada
    Posts
    934

    Re: TAP Plastics/Acme Plastics experience?

    The gears are a confusing rathole. McMaster was where I first looked. They have nylon and acetal. If you look up chemical compatibility charts for acetal/Delrin, photographic solutions are explicitly indicated to be bad (although exposure tests are typically 24-48 hour immersion). There are many types of nylon. A common type for gears seems to be MC901 (Nylon 6). Chemical compatibility is indicated as good for photographic solutions, however these types of nylon do absorb water, which could be problematic over time. Not sure. They seem to generally be recommended for dry applications.

    Stainless seems to predominantly be 303 because it’s much easier to machine gears out of it than 316. Perhaps 303 is resistant enough for this application. I don’t know.

    PTFE (Teflon) would be best but I can’t seem to find suppliers.

    Sourcing this stuff isn’t easy. Gears for hobbies are simple to find in general (brass, etc.) but not chemical-resistant plastic gears.

    I suspect I’ll have to just try either nylon or 303 stainless and see what happens.

    Quote Originally Posted by Drew Wiley View Post
    Any skilled small cabinet maker could be hired to do this very precisely, especially if you offered to buy the appropriate circular plastics blade for him, which don't come cheap. But exact dimension isn't as important as sheer consistency of dimension, which Tap should be able to provide once they lock down their settings. Just communicate well in advance and don't be in a rush, so that they can give the project due attention.

    Gearing : there are specialty suppliers for this very kind of thing. Do a web search, or try McMaster first. No, you don't want ABS; nobody is likely to make gears out of that anyway unless its some toyish application. You want machinable solvent-resistant Delrin or durable HMW (high molecular weight) nylon, Acetal, or perhaps 316 stainless steel (noisier). At the heading of each catalog section, including their online catalog, McMaster gives good specification comparisons on the various materials. Then you can home in on more thorough solvent resistant specifications of potential candidates looking elsewhere.

  2. #22

    Join Date
    Dec 2018
    Posts
    547

    Re: TAP Plastics/Acme Plastics experience?

    Maybe a Colex/Colenta rep or service tech can let you know what type of plastic they use(d) for their gears?

  3. #23
    Drew Wiley
    Join Date
    Sep 2008
    Location
    SF Bay area, CA
    Posts
    16,006

    Re: TAP Plastics/Acme Plastics experience?

    Searching for an Ivory Billed Woodpecker, eh?

  4. #24

    Join Date
    Dec 2018
    Posts
    547

    Re: TAP Plastics/Acme Plastics experience?

    And that comment was helpful how, Drew?

  5. #25

    Join Date
    Sep 2014
    Location
    Montreal, Canada
    Posts
    934

    Re: TAP Plastics/Acme Plastics experience?

    Quote Originally Posted by Dugan View Post
    And that comment was helpful how, Drew?
    As an aside, a quick google of Colex-Colenta turned up this place I was not aware of

    http://www.footprintsequipment.com/I...a&P=Processors

    Not directly related to my current project but might be an interesting potential resource for people.

    I’ve reached out to a few people to see what they’d recommend.

    It may be that I’m over-complicating/over-engineering. “Photographic chemicals” covers a lot of different things, but for my purposes the range is considerably narrowed. Photographic solutions are also typically fairly dilute, which helps. Still, what I might start out with are some MC901 (Nylon 6) gears, which are fairly standard, and just soak them for a while in water, and some photographic solutions, to see how they do. If I can find a source for gears made of more resistant plastic (ideally PTFE/Teflon, or perhaps HDPE) that would be better.

Similar Threads

  1. Plastics question for film developing
    By Michael R in forum LF DIY (Do It Yourself)
    Replies: 25
    Last Post: 23-Sep-2021, 05:02
  2. Acme 4 wierdness
    By swmcl in forum Lenses & Lens Accessories
    Replies: 5
    Last Post: 31-Aug-2011, 07:35
  3. Sources for Plastics and Hardware
    By Alan Rabe in forum Resources
    Replies: 3
    Last Post: 26-Sep-2006, 13:37

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
  •