tag:blogger.com,1999:blog-1592992209402300549.post1565478726740852872..comments2024-03-28T08:06:43.198-04:00Comments on The Silicon Graybeard: The New Project ContinuesSiGraybeardhttp://www.blogger.com/profile/00280583031339062059noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-1592992209402300549.post-63660051777518046692010-11-03T18:52:16.404-04:002010-11-03T18:52:16.404-04:00Use your step-block hold down kit.
In my first ...Use your step-block hold down kit. <br /><br />In my first post on the AR lower, I mentioned that I needed to modify the fixture so that the hold down set from Sherline could work. It's not a big thing, I just put two 1/4-20 bolts at about 0.5 in and 0.5 up from the bottom of the fixture. <br /><br />If I had it to do over, I'd lower the one on the front side of the lower, next to the magazine well, maybe drop it 2/10, to 0.3 up and 0.5 in. It fits as is, but the hold down bar hits the mag well before the full end is over the bolt. I have an aversion to just engaging the tip of the hold down.SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-57892173764216492932010-11-03T12:49:46.018-04:002010-11-03T12:49:46.018-04:00I've got a 3/8" quick change holder and a...I've got a 3/8" quick change holder and a 1/4" collet, as well as the Jacobs chuck for our machine so I can handle just about any type of end mill or bit. My only limitation right now is that I don't know if I have a vise big enough to hold the lower and the jig. I have step-block hold downs and the little Sherline vise that opens to about 2 1/8" but anything bigger than that and I'd have to engineer a method to keep it on the axes (which could be done pretty easily now that I think about it).<br /><br />Of course, I still have to let the budget recover from the Garand that I just picked up through the CMP before I launch into the next firearms adventure. :-)Event Horizonhttps://www.blogger.com/profile/10554770386040937098noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-24171305740884365942010-11-02T22:48:33.136-04:002010-11-02T22:48:33.136-04:00It sounds to me like you could do this with no ext...It sounds to me like you could do this with no extra work. Do you have a few end mill holders? I've used 1/8 and 3/8" for most drilling, and a Jacobs chuck to hold the 5/16" drill for the trigger slot. <br /><br />This is simple to do. When it comes time to engrave the label, I'll use a program to generate the code. <br /><br />There are dimensioned drawings of the lower online. If nothing else, Colfax Tactical sends one on the CD that comes with the forging.SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-47706384951345710802010-11-02T13:49:30.776-04:002010-11-02T13:49:30.776-04:00I'm really intrigued by this operation, thanks...I'm really intrigued by this operation, thanks for posting it! I'd never thought about doing something like this before, but the more I think about it the more I think this may be something I have to try sometime. I've got quite a bit of experience hand-coding G-code programs for our Sherline machine at work, and given a dimensional drawing I could probably knock out a simple program relatively quickly. Keep us updated on the progress, it really fascinating!Event Horizonhttps://www.blogger.com/profile/10554770386040937098noreply@blogger.com