Dennis & Brian's Build
Posted 25 March 2014 - 04:27 PM
You guys really have it going. Very impressed with both the master and the student. Thanks for the suggestion on the sites.
Looking forward to more pics.
Have to give credit to Dennis for the posts and pictures and the great job he is doing on helping to figure out this project. Fast learner and is doing a great job machining parts and helping in the shop.
Posted 30 March 2014 - 08:36 PM
Unfortunately my wife decided she needed wallpaper taken down and painting done a week after we started this project so I had to abandon Brian for a couple of days to get things ready for the painters. Needless to say he did not sit down and eat Ponpons while waiting for me. Rather, he made large piles of chips turning big chunks of 1144sp in cam blanks, casings and cocking rings. We decided we did not like the thin, out of round brass or steel tube we purchased for the casing so he turned .250 thick wall blanks for the casing. He was kind enough to wait for me to help clean the chip pan. Sorry no pictures of that. He also ground a lathe tool to cut the first groove in the one piece cocking ring blanks on the lathe. We will finish the cocking ring blanks on a rotary table on the mill.
He also turned the fixture we will use the cut the cams.
Posted 30 March 2014 - 09:18 PM
Posted 30 March 2014 - 11:27 PM
When we cut the front cam we drilled the holes in .250 from the front of the cam or we thought we did. We haven’t figured out why but the front cam ended up .017” short. If that had happened to the rear cam it would have been a big problem but the front cam being .017 short really doesn’t matter. Just wish we knew what happened. Not knowing what happened is what’s really disrupting.
Posted 30 March 2014 - 11:43 PM
Posted 31 March 2014 - 12:01 AM
Posted 31 March 2014 - 12:31 AM
Posted 05 April 2014 - 12:21 AM
Now, for the big however, the 1144 stress proof is not totally stress proof. After we cut through the back cam and took it off of the fixture it closed up .035”. Both side curled in and closed, although the one side did curl more than the other. This means the bolt extractor will not fit in the slot and the cam is curled inward toward the bolt carrier. This caused many hours of frustration, consternation, and anxiety.
Brain decided to turn another cam blank oversized, cut the slot, turn to final size and part it off. Unfortunately it did the same thing. Next, we took a jack and spread the cam as shown but it would just spring back when we took the jack out so we will try cutting a slot opposite of the bolt extractor slot but not completely through to see if we can spread it and get it to stay.
Posted 05 April 2014 - 04:53 AM
Posted 07 April 2014 - 05:40 PM
We did think of trying to heat the cam and spread it but just wasn't sure where the part would go if we heated it with a torch. Yes, I think we should have heated it before we cut the slot but my foresight isn't a whole lot better than my hindsight. What we decided to do was to cut a slot in the bottom of the back cam and spread it and let it relax until the slot for the bolt extractor was correct. Brian made a fixture to locate and space the cams as shown. Since the back cam was tight, due to the distortion, we pressed the whole assembly into the casing using a plug cut to the correct depth. This located the whole assembly to the correct depth so we could screw it to the casing.
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