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I have seen Sprutcam generate good simulated "cl data" tool paths and then generate g code that had errored tool paths as mentioned above. I don't see it as much these days. Tormach use to say always air cut to test tool paths. But you can't always see it at mill in air. With a true g code simulator it would be easy to spot such silly moves. Sprutcam has one now but pp is not supported yet.
I still have this particular operation saved in my CAM software so after I get the rest of it done I'll be going back and looking at my G-Code line by line in the area where I experienced the tool path error. I want to see if the numbers are in sharp contrast to those of the previous four little center flutes the end mill had already cut perfectly before that second to the last one when it decided to go off the rails.Quote:
Originally Posted by mountaindew
This is the first time I'd experienced a problem like this. I suspect that in the end the fault will lay in me ASSUMING to much. Like I mentioned; I went back and added a flute and subtracted some flutes from my model. I then cut air to test those tool paths on the spiral fluted sections of this project but I didn't do any air-cutting tests on these small center flutes. I just ASSUMED that if the spiral flutes turned out good then those short smaller flutes would also turn out just as good; and they did, UNTIL I got to that second to that last flute.
OH WELL; live and learn.
MetalShavings
Here are the photos I mentioned earlier. I tried to get a clear close up of the bad cut made by my wondering end mill. The accompanying photo didn't come out as clear as I'd hoped. I chalk that up to being in to much of a darn hurry all the time.
For the most part the spirals came out as I'd hoped. It's just that one 4th-Axis snafu that still leaves me scratching my head trying to figure out what happened. Oh well. I should have did my air cutting tests on all the flutes instead of some of them and then assuming they were all good.
Now for the worst part of all my milling projects. Now I have to clean my mill. I hate that part. I also should mention; in the photos I mistakenly wrote that this was a Tikka T3 Hunter rifle that this rebarreling project was going on. My mistake. I rebarreled my Tikka Hunter previously and it turned out better than I'd hoped. That's what spurred me on to do this particular rebarreling project. Sorry about that. I chalk it up to being in to much of a hurry again.
MetalShavings.
Since it was cutting the straight flutes at that time, it looks like it didn't retract before indexing to the next straight flute, or not enough. Since that is at the end of the program, and straight flute cuts, it should be easy to spot any issues in the program.
Did you manually reset the A axis zero before you started, or did the program zero it out?
The barrel will look nice in any case!
Nice job on the barrel. I'm sure you'll figure the boo-boo out.
By the way, those thread protectors are nice. Don't lose them - they'll be useful for the next barrel job. Another dead-useful fixture is to make some brass chamber & muzzle inserts with 60 degree centers in them for lathe work.
I know it looks that way from the photo but that second-to-the-last flute that my end mill veer of course out of had not yet been cut to full depth before it made that left hand turn. Another thing was, I mentioned that like an idiot I stood their without pressing the "E-Stop" which allowed my end mill to make a second bad pass. What I mean is that the first time my end mill decided to cut to the left it did so till it reached the top center as shown in the photo. Because I failed to stop it, it retracted and came back to that second-to-the-last little flute, made one more pass within that flute and then veered to the left again stopping where it stopped before, retracting and then heading back to the previous flute again. Hope that makes sense. What I mean is that my end mill did the identical moves twice. This tells me that it wasn't an insufficient retraction before moving to the next and last flute to be milled. It hadn't yet reached the full depth of the flute it veered off course from. It was really crazy.Quote:
Originally Posted by Tbkahuna
I do agree that since it all happened near the end of all the tool paths, It may be easier to get a fix on exactly what happened once I get that far along. I did manually zero or index my barrel at the center of the barrel itself, (center of the barel in the X,Y and Z) with the top dead center as my X and Y Zero. Since my model's coordinate was in the center of the barrel In the Z-axis I touched off my end mill on the surface of the barrel and set my Z height at .5". I don't think this 4th-Axis anomaly had anything to do with where I zeroed my Axis'.
I may never know why this error happened other than whatever amount of blame rests on me for not fully test/air cutting each and every flute before doing any actual milling. I'll just have to wait and see what I find when I go over that G-Code. For now, I'm just glad to have gotten this far without anything worse happening. I'll be back after I've finished the project. I still have to repair that bit of damage and then inlet the stock and I'll be able to assemble it for testing.
MetalShavings
I was thinking of making those brass inserts like you've mentioned earlier when I was figuring out how I was going to patch up that gash where my end mill veered off course. I was thinking that whatever I use may need to be lathe turned again to give me a surface finish that perfectly matches the rest of the barrel's surface.Quote:
Originally Posted by spumco
I don't want to take the chance of ruining the crown at the muzzle or the mouth of the chamber so If I find that I'm not able to get a surface finish that I like I may chuck it up on the lathe again and turn the barrel at the same angle that I did to cut the taper of my barrel blank. I'll have to wait and see. If I do this I'll make the insert. I actually made one out of aluminum when I originally tapered the barrel. I used it on the tail stock end but I found that it had broken off inside the bore. I hadn't yet cut the chamber so the .224" diameter shank of that aluminum insert was to thin to hold up whether it was made of brass or aluminum.
I'm also a bullet caster so I'm thinking of making a slight undercut or small indents with the tip of a 1/16" drill bit on the walls of that gash and filling it with lead; same as the old-school body and paint guys used to use. It should be a relatively easy fix but then again I though that milling these flutes would be easy too.
We shall see.
MetalShavings
It's taken a while to finish up this project and I'm still not completely finished but, I'm far enough along to where I can confidently see the light at the end of the tunnel; so to speak. I had a few snafus along the way so I had to divert my attention and resources toward getting those things taken care of. I learned a few things that I didn't know before and if I were to do another similar project I know I'd go into it with alot more confidence.
I want to give a shout out to Eldar G. over at HSM Advisor for his help in figuring out some good feeds and speeds for the type of metal my barrel blank was made of. Also thanks to you guys for the interest you showed as I muttled along with this project. As pictured in the included images, this rifle project is wearing some of the cheapest peripherals that money can buy. I don't intend on investing any more money into it until I find out if she's going to shoot good for me. If it shoots only half as good as my last Tikka rebarreling project I'll be a happy camper.
MetalShavings
The thread protector is sweet. Nice job.
Next: Form 1 and use the 4th axis to engrave the can...
The suppressor in the pic is already engraved it's just hard to see. I have dreamed of going the "Form 1" route and making my own suppressor. If I did so I'd most likely just clone the design of this present Lane-Suppressor. I like that I can take it apart to thoroughly clean it; especially after shooting cast lead bullets through it. What I don't like is that it's a bit on the heavy side.Quote:
Originally Posted by spumco
It's a combination of titanium and stainless steel. I would have liked to have bought the all-titanium version but that was a bit to expensive for my budget at the time of purchase. I've dreamed of making an all titanium clone to lighten it up a little.
MetalShavings
I figured that particular one was already engraved. I was mostly prompting you - unnecessarily it seems - to go down the roll your-own rabbit hole. For Form 1 stuff, I have this 80/20 philosophy:
If it is about 80% as effective as a decent commercial dingus, and weighs 20% more I'm happy. I don't spend weeks or months and squillions of dollars chasing the last dB in a lab environment, and it generally costs me about 10-20% of the store-bought thing.
End cap for an all titanium .22 can. Works a treat.
And if you do eventually make one, stick with 17-4 for the blast baffle. Titanium blast baffles don't live long in high-pressure chamberings.
https://www.cnczone.com/forums/attac...d=420860&stc=1
Interesting. I've never milled anything harder than the 4150 metal that this barrel project entailed. Have you or anyone else milled titanium on their Tormach 770? It would be interesting to know what feeds and speeds and cutting tools they were working with. I don't know enough about titanium to be able to choose the correct one for a suppressor baffle stack or mono-core. I suppose I could ask over on the suppressor forums but I'm reluctant to do that because for some reason, when such an inquiry is made there are always those who reply as if I was asking them for permission to do my project. Another group of responders will inevitably respond in the form of a long winded lecture and still others who consider themselves experts on the subject will chime in with replies that just exuding arrogance; even though they've never made anything for themselves in their lives. All they did was buy a suppressor. It's a form of self-assigned "Expertise-By-Osmosis." And all I wanted to know was which kinds of titanium to use for this application. I mean, which would be best for the end caps, the baffle stack or mono core baffles and the body or enclosure; that kind of stuff.Quote:
Originally Posted by spumco
I'd have to learn alot more about titanium before I took any major steps into making my own suppressor out of this stuff. It would be cool though.
MetalShavings
I did TI-6-4 on my 440! I made a small magnet/clip/hanger for my glasses to attach to my shirt. Pressed a magnet in, put a thin steel shim inside the shirt for it to latch on to. It's about 1.5"x5/8"x3/8" overall dimension, made out of round stock held in a vise.
I used 3/16" and 1/8" end mills, and I spun/fed them at about 1/4 of "standard" feeds/speeds for aluminum and took cuts that had 1/2 the depth. (I used the low-RPM belt setting, too.)
Note: "standard" for 1/8" end mills is 16,000 rpm feeding 15 in/min with a 3-flute, which means 4000 rpm feeding 3.75 in/min for Titanium. Of course I can't get 16krpm on the 440, so when I cut aluminum, I have to run it slower than I want to.
I knew that milling titanium was possible with a tormach. I just have never done it myself and not having done it, I really have no idea of what the proper speeds and feeds might be or if a special end mill type might be required or optimal. I do have the HSM Advisor software I can use to punch the numbers in with but, I've found that with just about all the calculated feeds and speeds I've gotten out of this software I've had to dial everything back by about one third or so.Quote:
Originally Posted by jwatte
Most likely I'd have to do the same if I were to set up a titanium project on my 770. If worse came to worse I could ask Edlar, the guy who developed the HSM Advisor software for some assistance. He's pretty good about helping out like that. I don't often ask his help cause on most metals I've worked with (Steel, Stainless and aluminum) I can figure it out for myself; and because I don't want to wear out my welcome. With something like titanium it may take someone with a bit more expertise to help me figure out what works best.
My previous post had more to do with finding out which specific type of titanium would work best for each component of a given suppressor. This is all new to me but, I've heard that there is more than one kind of titanium just like there are different types of aluminum, steel and stainless steel. I don't have a clue as to which one would be used for the various components of a suppressor project. At this point it doesn't really matter cause I'd have to save up for a while to come up with the expendable income to pursue such a project.
MetalShavings
I'm not an expert, but so far Ti for supressors has been pretty straight forward for me.
Grade 9 for the tube, Grade 5 for the baffles. Other grades of titanium are either commercially pure and soft/gummy, or are rare(ish) alloys intended for specific applications.
High-positive rake tools, flood coolant. I find that the polished carbide tools for aluminum work beautifully in titanium. I keep speeds about 100-150SFM and try not to take less than a .001" chip to avoid work hardening.
For threading I use HSS inserted tools, honed razor sharp. SFM slowed down, and coolant mist instead of oil for heat management.
Tapping just sucks, unless you get specialized titanium-specific taps with lots of back clearance. The titanium springs away from the cutting edge if it's even a little dull - then work-hardens, grabs and then it snaps the tap.
You can pick up a 1/2-28 tap, but you're probably better off single-pointing in the lathe (or thread milling).
Don't assume any tubes you buy are actually round. Buy thicker than you need so you can true up the bore and still have wall thickness left for threads. If it weighs too much you can always take some off the outside.
An alternative for the blast baffle or whatever feature takes the initial flame front is 416 stainless. Turns beautifully and, like 17-4ss, can be hardened.
Quote:
Originally Posted by spumco
Yea; out of curiosity; after my last post I went online in search of some information about titanium. I found basically the same info that you just listed. I do most of my threading of anything larger than 1/2" inside diameters on the lathe whenever I can. The lathe brings up another set of feeds and speeds for that Grade-5 and 9 titanium. I'm sure that information can also be gathered up with a simple online search as well.
I did notice that even though I suck at math that the price of materials alone will be about two-hundred and fifty buck or so. That doesn't count any new cutting tools I may need. The Form-1 tax stamp is another two hundred bucks. That's still about half the price or less than buying an all titanium suppressor from a retailer; which on this particular brand of suppressor is close to a thousand bucks. I'm sure if I were to shop around for better prices on the titanium stock I may be able to drop that price a bit more but, as I stated in a previous post, I'd have to save up for a while in order to make it all happen; and then a longer while still for the Form-1 paper work to get OK'd.
I was wondering about the way suppressor are assembled last night. I wondered if suppressors were like firearms in that on some firearms like ARs or semi-auto handguns the frame of the gun is the part that one has to register, mainly cause that's the part that the serial number is etched on. On a Suppressor like mine that's able to be disassembled completely; is the core of my suppressor the registerable part or is the outside tube that has the serial number on it the registered part?
I ask because if the baffle core, which is now stainless steel (and very heavy) is the part that is not considered the registerable part of the suppressor, I may be able to either just make an all titanium baffle core and forego the purchase or the building of an entirely new suppressor. If it were possible to just buy only the all titanium mono-core baffle to replace the stainless one, that would do just as well and the price may be a bit more in my budget range.
MetalShavings.
You're now asking legality questions. I'll answer them to the best of my ability, but I am not a lawyer and this is just an internet forum. And I/we may be so off the machining topic that other Tormach machinists may get annoyed at this tangent...Quote:
Originally Posted by MetalShavings
All parts of a supressor are considered by the BATFE to be a 'supressor' or surpressor parts.The tube is typically the component which is engraved by the maker (Form 1) or manufacturer (FFL Type 7). Other parts of the supressor can be engraved instead of the tube, but the BATFE has very specific regulations on font size, depth and other details.
Legalese note - FFL Type 7 is a license to manufacturer firearms including NFA items, but not including destructive devices (think artillery).
Legalese note 2 - the term is 'made' when a can is built by a private person via a Form 1 - thus, you would be the 'maker''. The term is 'manufactured' when it's done by an FFL-07.
Short answer is that once a suppressor is manufactured (OEM) or made (you, via Form 1) it is done. You cannot make new parts for it, you cannot make it larger. You cannot decide a different baffle design would be better and make new baffles. You cannot decide that it's too loud and replace the tube and add a couple more baffles or a longer blast chamber.
Supressors are not like firearms. There is no 'registered part' like the frame of a firearm. Even in the case of a machine gun you can have most of the parts as long as you don't have the registered part as well (frame, sear, whatever it is on that particular model). This is not the case with a supressor.
If you get a baffle strike and make a new baffle - you now have an unregistered supressor component and are in violation of the regulations. About the only thing I THINK you can do yourself is to repair the existing parts - as long as you aren't adding anything. Think repairing the threads or a skim cut on the end cap if it gets dinged. Or reaming out the bore if a burr develops.
If you would like to repair, upgrade, or otherwise alter a supressor, the OEM or another FFL-Type 7 can do so. They can open it up and re-core it and do other things, but you cannot - not even to one you built yourself. There are some 07's who will 'fix' Form 1 supressors but I've only heard of a couple and never contacted them personally.
As for the math, it's pretty favorable if you plan to make more than one. The $200 tax stamp is the same for a Form 1 or a commercial transfer - so that's a wash. And $250 will get you enough Ti tube and barstock in different diameters to make 2 or 3 cans
Check with your supressor manufacturer and see if they offer an upgrade service - I suspect they do. There is no $200 transfer between you and the manufacturer or back, but there are some special handling/shipping requirements; they should be able to advise you how to proceed.
Hope this helps.
Back to machining - HSM Advisor has a lathe setting as well as milling. Check the "machine" drop-down in the upper right and you can set up a new machine as a lathe. The tool and materials fields then change appropriately and you get your turning RPM and feed/rev based on the type of turning you're doing. Very handy - and as you've found you should drop the F&S by half or a third to start with on smaller machines. I think Eldar is brilliant, but he's got a pretty aggressive baseline for most of the cuts I've fiddled with.