Page 2 of 3 FirstFirst 1 2 3 LastLast
Results 11 to 20 of 21

Thread: Changes to scratch built lower design.

  1. #11
    Gunco Member joezx10r's Avatar
    Join Date
    Jan 2009
    Location
    Kentucky
    Posts
    255
    Feedback Score
    0

    Default

    Quote Originally Posted by TRX View Post
    WHOA! Someone who understands dimensioning!

    You need to do the bolt carrier next. <grin>

    Well, seriously, the carrier is one of the most expensive parts of an AR.
    Started drawing it last night. Ill try to get it done this weekend.

  2. #12
    TRX
    TRX is online now
    Gunco Irregular TRX's Avatar
    Join Date
    Aug 2008
    Location
    Central Arkansas
    Posts
    2,665
    Feedback Score
    3 (100%)

    Default

    Quote Originally Posted by joezx10r View Post
    Started drawing it last night. Ill try to get it done this weekend.
    Keep this up and I might have to build an AR!

  3. #13
    Gunco Member joezx10r's Avatar
    Join Date
    Jan 2009
    Location
    Kentucky
    Posts
    255
    Feedback Score
    0

    Default

    Just finished the bolt now I need to double check the dimensions of the holes with some gauge pins at work and go over it again then I can make some prints.

  4. #14
    Thunderbolt Armory LLC A-Rok's Avatar
    Join Date
    Oct 2009
    Location
    Seattle, WA
    Posts
    40
    Feedback Score
    0

    Default

    This is AWESOME!

    What kind of tolerances should I expect to be within when milling all the parts of the receiver?

  5. #15
    Gunco Member joezx10r's Avatar
    Join Date
    Jan 2009
    Location
    Kentucky
    Posts
    255
    Feedback Score
    0

    Default

    Quote Originally Posted by A-Rok View Post
    This is AWESOME!

    What kind of tolerances should I expect to be within when milling all the parts of the receiver?
    Well it depends if your going to use flat head screws or buttons. When I built mine from the original prints I changed it to flats with countersinked holes and tried to keep them as tight as possible but had some fitment issues during assembly with the rear mag block and fire control side plates binding when the screws are tight. Clearance the shoulders back a few thousands under sized and all is good. The hole diameters where it bolts to the upper and the fire control dimensions should be kept within original AR print specs but other than that its up to you.

  6. #16
    TRX
    TRX is online now
    Gunco Irregular TRX's Avatar
    Join Date
    Aug 2008
    Location
    Central Arkansas
    Posts
    2,665
    Feedback Score
    3 (100%)

    Default

    There are guys who can center-punch and drill a hole to within .005". The damned drill bits always fail to cooperate with me, though.

    The old bench-work method is to only lay out and drill one fastener hole. Use that to bolt the pieces together - you can use superglue to help keep them from slipping - and then lay out, drill, and tap the other holes. Use acetone to dissolve the superglue, then open up the holes on the top part so the screws will go through, countersink or counterbore as needed, done.

    The other trick is, if you're trying to get a bunch of bolted-together bits to all line up neatly, is to leave a bit of extra stock on the edges. You can then mill, belt-sand, or spindle sand the stack so everything looks neat. Those reciprocating spindle sanders can do amazing jobs on internal curved surfaces.

    Of course, if you're using CNC you don't have to worry about that sort of thing...

  7. #17
    TRX
    TRX is online now
    Gunco Irregular TRX's Avatar
    Join Date
    Aug 2008
    Location
    Central Arkansas
    Posts
    2,665
    Feedback Score
    3 (100%)

    Default

    Probably an artefact of kpdf or something, but when I printed the drawings the numbers showed up fine, but not the lines on the dimensions.

  8. #18
    Gunco Member joezx10r's Avatar
    Join Date
    Jan 2009
    Location
    Kentucky
    Posts
    255
    Feedback Score
    0

    Default

    Quote Originally Posted by TRX View Post
    Probably an artefact of kpdf or something, but when I printed the drawings the numbers showed up fine, but not the lines on the dimensions.
    Hmmmm. Well I think I put the line color as red maybe that has something to do with it.

  9. #19
    TRX
    TRX is online now
    Gunco Irregular TRX's Avatar
    Join Date
    Aug 2008
    Location
    Central Arkansas
    Posts
    2,665
    Feedback Score
    3 (100%)

    Default

    Quote Originally Posted by joezx10r View Post
    Hmmmm. Well I think I put the line color as red maybe that has something to do with it.
    It's a plain old black printer, but the driver usually grayscales colors. Hmm.

  10. #20
    TRX
    TRX is online now
    Gunco Irregular TRX's Avatar
    Join Date
    Aug 2008
    Location
    Central Arkansas
    Posts
    2,665
    Feedback Score
    3 (100%)

    Default Rivets!

    It just occurred to me that, with a few modifications to your design, you could use sheet steel for the side pieces, a few machined bulkhead pieces, and rivets to hold it all together.

    Perhaps I need to change my medication. The Voices are getting strange lately...

Page 2 of 3 FirstFirst 1 2 3 LastLast

Search tags for this page

There are currently no search engine referrals.
Click on a term to search our site for related topics.

Posting Permissions

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