My brother bought this vs. 61, the owner said it's an old D-Technik import. It's marker TGI Knox TN. It was advertised as being threaded, and it is in 1/2x28, but there's no shoulder to the barrel. The new Checkpoint guns use thicker barrels so it leaves a good shoulder but this threading is the same diameter as the rest of the barrel.
My brother also bought a Rugged Obsidian for this gun, not knowing Rugged says it needs a solid 90 degree shoulder to mount.
Is he fucked? What's the deal with this threading, is this how they used to come from D-Technik? Is there anything he can do to mount the Obsidian on this thing?
That's pretty shitty. If the thread is the same diameter as the rest of the stock piece, you're supposed to make an undercut at the end.
Joshua Martin
>What's the deal with this threading, is this how they used to come from D-Technik?
I have no idea about what's standard for D-Technik, but as a machinist I can tell you those threads are awfully done.
>>undercut at the end That depends on how the threads are cut. Usually you'd leave clearance for the threading tool back in the days before CNC machinery. A modern CNC lathe can cut threads single-point without the need for a relief cut. Also, making threads via the rolling process doesn't need a relief cut either.
Those threads look like they were rolled, and they weren't properly done either. That's shitty manufacturing for sure.
Jeremiah Bailey
I still wouldn't want to do a threading cycle without an undercut. It does this little angular motion at the end of the canned cycle which can be dangerous if you don't clear the path for it, first. I only studied CNC when it comes to machining, so maybe the controllers you use are a little different. Threading already makes me pucker, so I see no reason to make that worse.
Anyway, OP, you could just get a little clamp that gives you a shoulder. Or shrink-fit a ring at the right place.
Thomas Torres
"Threading."
Carson Bennett
This. Shit's like a rolled 30% thread 0/10 would not bang.
Thomas Moore
I'd throw the barrel out at that point and get a new one
Henry Cruz
Some controllers do that extra motion and some don't. I normally design my parts with the relief because it usually avoids a bad stress concentration in the part itself, and I agree it makes sense to err on the safe side, but the point is that it isn't strictly necessary for manufacturing, and it certainly isn't needed for rolled threads.
>>Anyway, OP, you could just get a little clamp that gives you a shoulder. Or shrink-fit a ring at the right place. Zoom in on those theads, man! They're obviously shit, shoulder or no shoulder.
Caleb Green
that threadform is fucking terrible... jesus
no thread relief, no shoulder -- looks like a dumbass bubba tried to NPT that shit
I'm no machinist or specialist or anything, but those threads don't look very good at all. What even screws onto it?
Nicholas Roberts
That looks like a home threading job, none of the vz61 importers or modders would leave that as is, it's unusable by anything. Looks like somebody tried to start a 1/2x28 thread without measuring the OD of the barrel first, which is far too thin for 1/2x28. It looks tapered too lol, the threads just kind of fade off.
That's absolutely unusable as-is, however you might contact Tornado Technologies with your picture and see if they can salvage it. They do a vz61 threading package wherein they thread the barrel for 0.475x32 and include a 1/2x28 adapter. Pic related. It's not cheap though, sorry.
>It looks tapered too lol, the threads just kind of fade off.
It's a bad rolling job. That is why you see the taper and also the odd shape where the crest of the threadform should be. This was not done at home, this was done in a factory with a thread roller. And it was done poorly.
Rolling is possible yeah. You can still get burred threads or rolled edges on a lathe with incorrect feed rate or dull or chipped bits as the workpiece metal just gets shoved out of the way instead of cut.
If it were rolled, why didn't the operator see it through or reset his jig?
Poor is an understatement.
Connor Diaz
If you haven't done it, don't talk about it please.
Just because you studied CNC doesn't mean you know how it works in the real world.
As a guy who ran CNC work.
While I don't have pictures or video of the threading this machine does, when I threaded this barrel for the muzzle device I made it required zero relief and since I set up the tooling I knew I could get the thread to the shoulder without issue and no undercut.
Also, does have have a nut to make sure it threads on? As said, it looks like they barely cut them. Those are some big flats on that barrel.
Good news if they don't thread on but is the right thread pitch, you can at least chase it easier with a die.
Andrew Evans
>Anyway, OP, you could just get a little clamp that gives you a shoulder Again, I'm no machinist, but looking at it, this doesn't look like it would help. Those threads just look really bad and shallow.
Pic related is how I expect a threaded muzzle to look like.
He needs to fix the threads, but if the can needs a shoulder, then he still has an issue. Are you familiar with the term "MMC"? Maximum Material Condition. If that actually is the correct major thread diameter, then there is no material there for him to cut and make a proper shoulder.
Robert Miller
First time I see the term. Honestly I'm thinking to outright just cut the barrel off to remove the shitty threads and then start over further down the barrel.
Ian Scott
>threads terminating at increasingly shallower depth some bubba did that with a fucking die, no way it's concentric with the bore t. machinistfag
Landon Cook
That is so skeezy i didn't even think about it, you're absolutely right. It's from a die. lol
Kayden Torres
Czechpoint does sell just threaded uppers. Relatively cheap and factory made
His best option is to get a threaded upper from czechpoint. Mine was like $280, they come in stock fairly regularly. Sign up for the notification and grab one when they come back. It's awesome to shoot suppressed, but no fucking way I would risk my can on those threads.
