Mods are trying to keep the 3D2A sub alive while under the Reddit censorship microscope. Reddit isn't interested in keeping the sub compliant, they're trying to find any excuse to kill it. Reddit is psychotic about encouraging people to use other platforms. That predates the current rule 7 crusade and goes back to the API lockdown.
So Reddit doesn't want us there but also doesn't want us to tell people to leave. The only way to win is not to play.
Printable TPU is much too hard and doesn't have much heat resistance.
Never a waste when you learn something in the process.
I'm sure. With that spacer sleeve you couldn't install the cups if you tried. The spring would be fully compressed before the end reaches the spot on the firing pin that retains the cups.
Normally the cups are there so when you pull back on the firing pin, the cups (which are locked to the firing pin) cause the spring to compress. As a result the firing pin is held almost all the way forward (it free-floats with no spring pressure the last few mm of forward travel).
The Franken9 works "backwards". You want the spring applying rearward, not forward, force on the firing pin. So the channel liner, not the cups, becomes the forward spring stop and spring compression holds the firing pin all the way to the rear. It's a really clever design in how it reuses the firing pin and spring in a completely different way.
Drill the grip screw hole all the way through then press in a heat-set 5mm threaded insert from the receiver end. You may need a longer M5 bolt trimmed to the exact length so it doesn't protrude and hit the receiver, but if you do it right you'll get a nice solid grip.
Temp tower, flow rate, and pressure advance (in that order). Then I run a 100mm 3-axis cal print with my 3D2A settings to check quality and calibrate shrinkage. If you plan to anneal, anneal the cal print before taking shrinkage measurements. If you know your starting point for settings is close, you really just need to fine-tuning stuff that is filament/printer dependent.
I've never gotten Sunlu PA6-CF to print as clean as Polymaker. Seems like no matter how clean the print is, there are always a few random defects in the extrusion. I suspect it's impurities resulting from less rigorous process QC (they have to take out cost somewhere to undercut Polymaker). No issues with mechanical performance.
My only other issue with the Sunlu is the plastic spool can't handle 100°C drying. Have to bundle the filament using some fine wire, then carefully pop off the plastic spool halves leaving just the filament on the cardboard core. That hassle alone is enough to make be pay the premium for Polymaker in the future.
Control numbers for my two submissions around 0900 zulu were 20 minutes and 141 control numbers apart. That's 7/min for those who can't math. I was actually pleasantly surprised that the system was still working and responsive. I figured you animals would have brought it to its knees by the time I jumped on :)
You are correct. Remove the firing pin spring cups, remove the spring, remove the stock plastic spacer. Put the printed sleeve over the firing pin and push it all the way to the rear. Put the spring over the firing pin (no cups) and insert the assembly into the slide channel (make sure you already have the stock channel liner installed in your slide). Lastly, put the M3 through the printed donut and put that into the channel head first behind the firing pin. Install backplate (don't forget the extractor spring assembly) and you're good to go.
AR22 barrels will not work for the DB9-22. I looked into redesigning the conversion to accommodate them and convinced myself that it couldn't be done without also changing the lower. At that point it makes more sense to just build a DeAR 22 instead.
Are you by chance running something other than a mil-spec hammer? I had a DB9 build with a light strike problem and it turned out to be the face of the non-mil-spec hammer catching on the front wall of the FCG pocket.
BTW, thanks for all the work you've put into this! I really like this style for a PDW and your improvements are really clever. I've wanted to do a Recession Ruger for some time, but I prefer to shoot suppressed and threaded Ruger barrels are completely impractical. Being able to do a similar build with Glock parts is awesome since it opens a boatload of aftermarket options.
I just built up my Franken9 frame and have a very similar problem. The root cause is the recoil spring stop in front of the slide lock. The back of the recoil spring guide rod is supposed to butt up against this:
In the Franken9, this is V-notched for some reason.
That lets the guide rod pass through the stop and butt up against the slide lock. Depending on your parts, the barrel may then bind on the guide rod when it's trying to drop into the locking block. Even if it doesn't, this isn't the way you want to run the gun since the slide lock isn't designed to do double duty as a guide rod stop.
It's possible to get the current frame working correctly by cutting an appropriately sized steel washer in half and epoxying one half to the front of the guide rod stop.
Definitely a typo. SP00308 is the part number for a two-pin G17 locking block. The spring bearing LCI should be part number SP02714, and there should be only one. Actually, most of these Glock parts appear to have incorrect part numbers (several of which don't even show up on the Glock Armorer's Parts List):
Depressor Plunger - SP00337 (should be SP00112) Extractor - SP01903 (should be SP01895) Firing Pin (Striker) - SP01193 (should be SP00063) Locking Block - SP04361 (should be SP07894-1) Locking Block Pin - SP04368 (correct) Slide Lock - SP02919 / 2912-3 (should be SP00301) Spring-Loaded Bearing - SP00308 (should be SP02714) Spring-Loaded Bearing - SP00308 (should be Depressor Plunger Spring SP33522) Trigger Pin - SP00408 (should be SP00420) Firing Pin Spring - SP00063 (missing from BOM)
It's one of my favorite builds. You still need the side plates, but printed ones work fine for 22LR. I'll try to post a pic of mine tomorrow.
I suspect a lot of folks are in "wait and see" mode. Needs a couple of successful builds posted to get momentum. I finished the slide assembly today. I just followed the picture in the docs and it seemed pretty straightforward. I'll probably print the lower tomorrow, but won't receive FCG parts until next week.
I do not have a reddit or X account
Confirms my belief that you're a lot smarter than the rest of us :)
Wild guess (best I can offer with limited info) is slide hanging up on the ejector. Easy to test -- remove the ejector and see if the problem persists.
Correct. Large diameter "bull" barrels may contact the forend, but not standard carbine barrels.
There are a dozen different sizes of 10/22 barrels so most chassis designs "free float" the barrel. The receiver should be a snug fit into the chassis so that when you tighten the bolt in front of the magwell, there is no movement. If that's not the case, you may want to check the dimensional accuracy of your print.
I tell anyone who asks that my stuff is 3D printed. It's completely legal where I live and I figure if people see someone using 3D printed firearms responsibly, it helps counter the media stereotype of "ghost guns are for criminals". It's to the point now that when I arrive at the range, the first thing the ROs ask is if I have any cool new printed guns to show them :)