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    One more thing: machining produces much crisper parts than molding. I've seen these parts machined, excellent surface finish, no flash. They part very clean. Machining also makes parts with same height, whereas injection produces parts that are higher on one side. The difference might be on the order of .05mm measured around the ring.

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    ^ Yeah thats kinda all you have to do, but its all in the doing of that that does or does not make a successful part, the above advice from some of the more grumpier members does hold true regrettably and its all those little finer details that make or brake these kinda things. What your wanting to do is make a hard bit do to size, material and tolerance, do able yes, but its hard, you then want to automate that on argubly the simplest crudest multi fucntion lathe going, its a steep hill and only if you get it all right will you win, i do think it can be done, but its not effortless, you can't make your features with just axial plunges either, your going to have to have at least one radial plunge to do one of the chamfers + part it off.

    If your starting from moulded pipe you may do real well to look up annealing, makes a big big difference and also drying the nylon out really helps it cut too.

    One thing you need to grasp, a lathe works on cutting metal off a radius, bolts have slop, hell at these levels even close fitting pins only repeat so well hence simply bolt and unbolt won't really cut it going from one part to the next is going to involve some scrap and setup time even once your practised at it. If your 200K parts a year is actually 100 runs of 2k parts with diffrent dimensions IMHO that is the last machine type you want to look at!

    How you hold - clamp your material is also going to matter greatly, hell if the part needs to come out round and can not rely on what its fitting in to achive that even the pile in the gravity feed may prove a issue if your pips thin walled, more than a few plastics will take a set pretty fast and once machine and sat on a shelf for a while will revert back to being round or as the case may then be out of round.

    If you want truly sharp corner, your going to have serious fun making the tooling. On the plus side in nylon it will last, but its going to be hard to make, for the size part your dealing with, a simple wire cut form tool won't cut it, std wire cutting uses a circa 10 thou wire and thats just too much radius on what your doing. Equally the tool needs to look like a mirror polished right upto the cutting edges and they need to be sharp under magnification.

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    How about uploading the video to YouTube so we can take a look?

    Bill

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    Quote Originally Posted by adama View Post
    ^ Yeah thats kinda all you have to do, but its all in the doing of that that does or does not make a successful part, the above advice from some of the more grumpier members does hold true regrettably and its all those little finer details that make or brake these kinda things. What your wanting to do is make a hard bit do to size, material and tolerance, do able yes, but its hard, you then want to automate that on argubly the simplest crudest multi fucntion lathe going, its a steep hill and only if you get it all right will you win, i do think it can be done, but its not effortless, you can't make your features with just axial plunges either, your going to have to have at least one radial plunge to do one of the chamfers + part it off.

    If your starting from moulded pipe you may do real well to look up annealing, makes a big big difference and also drying the nylon out really helps it cut too.

    One thing you need to grasp, a lathe works on cutting metal off a radius, bolts have slop, hell at these levels even close fitting pins only repeat so well hence simply bolt and unbolt won't really cut it going from one part to the next is going to involve some scrap and setup time even once your practised at it. If your 200K parts a year is actually 100 runs of 2k parts with diffrent dimensions IMHO that is the last machine type you want to look at!

    How you hold - clamp your material is also going to matter greatly, hell if the part needs to come out round and can not rely on what its fitting in to achive that even the pile in the gravity feed may prove a issue if your pips thin walled, more than a few plastics will take a set pretty fast and once machine and sat on a shelf for a while will revert back to being round or as the case may then be out of round.

    If you want truly sharp corner, your going to have serious fun making the tooling. On the plus side in nylon it will last, but its going to be hard to make, for the size part your dealing with, a simple wire cut form tool won't cut it, std wire cutting uses a circa 10 thou wire and thats just too much radius on what your doing. Equally the tool needs to look like a mirror polished right upto the cutting edges and they need to be sharp under magnification.
    And if that wasn't enough, ...........there's temperature control to add to the mix, ..along with correct storage of the material regarding humidity and moisture content, .....and then machining parts like that from tube as opposed to solid bar, opens up yet another whole new ball game.

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    Quote Originally Posted by Limy Sami View Post
    And if that wasn't enough, ...........there's temperature control to add to the mix, ..along with correct storage of the material regarding humidity and moisture content, .....and then machining parts like that from tube as opposed to solid bar, opens up yet another whole new ball game.
    Limy Samy:
    You solve the problem of moisture in 2 ways:
    1. You can cook nylon in hot water for a long time to actually absorb water. You then let it sit for a week or so to let the excess moisture escape and moisture level stabilize.
    2. You can substitute other materials with similar properties that are less susceptible to moisture.
    BTW, I didn't mean to denigrate your way of doing whatever you are doing. This is not the way I want to manufacture. If I had wanted a very slow but more controllable way to do this, I would be doing it. But there are always minuses with anything. I am really not interested in doing it in a another way, the only reason for it being it is not cost effective. I am not trying to find out how you're doing it, because making 50 parts very slowly is just not the way I want to do it.But I am sure your way is more secure on the machining side. You're more than welcome doing it your way, and if that puts the bread on your table, I am glad it works for you.

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    Quote Originally Posted by Limy Sami View Post
    And if that wasn't enough, ...........there's temperature control to add to the mix, ..along with correct storage of the material regarding humidity and moisture content, .....and then machining parts like that from tube as opposed to solid bar, opens up yet another whole new ball game.
    Also, don't forget this machine is bar fed, it uses collets and during production a very small amount of material is being exposed at any time. Collet should make the pipe round even if there was deformation. Softness is a 2 edged sword. But maybe 3-4mm of unsupported material is being exposed during machining.

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    Okay, apology accepted, I was a bit short with you, we're quits.

    But I still maintain in the qty's you want, and the methods you propose, you are in for one hell of a struggle, EG just because you hold a tube in a circular collet to true it up, doesn't mean you will end up with a truly circular part or one with consistent wall thicknesses, .sounds counter intuitive, but real life practice will show otherwise.

    The tolerances on your drawing (0.02 & 0.05mm) while quite ''doable'' in almost any metal, in Nylon, and most plastics are at best - borderline to obtain, ......to give you an idea, the heat from a warmed up lathe spindle even for the short time a bar or tube of most plastics will be in there, will be enough to throw such small tolerances out the window, .........and compensating for variable heat changes as a shift progresses is one SOB.

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    Quote Originally Posted by adama View Post
    ^ Yeah thats kinda all you have to do, but its all in the doing of that that does or does not make a successful part, the above advice from some of the more grumpier members does hold true regrettably and its all those little finer details that make or brake these kinda things. What your wanting to do is make a hard bit do to size, material and tolerance, do able yes, but its hard, you then want to automate that on argubly the simplest crudest multi fucntion lathe going, its a steep hill and only if you get it all right will you win, i do think it can be done, but its not effortless, you can't make your features with just axial plunges either, your going to have to have at least one radial plunge to do one of the chamfers + part it off.

    If your starting from moulded pipe you may do real well to look up annealing, makes a big big difference and also drying the nylon out really helps it cut too.

    One thing you need to grasp, a lathe works on cutting metal off a radius, bolts have slop, hell at these levels even close fitting pins only repeat so well hence simply bolt and unbolt won't really cut it going from one part to the next is going to involve some scrap and setup time even once your practised at it. If your 200K parts a year is actually 100 runs of 2k parts with diffrent dimensions IMHO that is the last machine type you want to look at!

    How you hold - clamp your material is also going to matter greatly, hell if the part needs to come out round and can not rely on what its fitting in to achive that even the pile in the gravity feed may prove a issue if your pips thin walled, more than a few plastics will take a set pretty fast and once machine and sat on a shelf for a while will revert back to being round or as the case may then be out of round.

    If you want truly sharp corner, your going to have serious fun making the tooling. On the plus side in nylon it will last, but its going to be hard to make, for the size part your dealing with, a simple wire cut form tool won't cut it, std wire cutting uses a circa 10 thou wire and thats just too much radius on what your doing. Equally the tool needs to look like a mirror polished right upto the cutting edges and they need to be sharp under magnification.
    Everything you say is true, so the key is designing the tooling in a way that addresses these issues. If I were to look at a tool just a tool and make is as an individual tool, that is most likely not going to workout too well in a longer run because it will make swap outs for different parts time consuming. I'll ask the toolmaker to design this as a system, so setups can be fast, also make changes to machine toolholding to make tooling easily swapable.

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    Quote Originally Posted by Limy Sami View Post
    Okay, apology accepted, I was a bit short with you, we're quits.

    But I still maintain in the qty's you want, and the methods you propose, you are in for one hell of a struggle, EG just because you hold a tube in a circular collet to true it up, doesn't mean you will end up with a truly circular part or one with consistent wall thicknesses, .sounds counter intuitive, but real life practice will show otherwise.

    The tolerances on your drawing (0.02 & 0.05mm) while quite ''doable'' in almost any metal, in Nylon, and most plastics are at best - borderline to obtain, ......to give you an idea, the heat from a warmed up lathe spindle even for the short time a bar or tube of most plastics will be in there, will be enough to throw such small tolerances out the window, .........and compensating for variable heat changes as a shift progresses is one SOB.
    Please keep in mind, I am most interested in wall thickness, and height, these are measurable values. Diameters are less so, since that is an open space. Also, machined parts are soft enough to assume a form of anything you put inside it. But as long as I have the 2 values I mentioned above consistent, I am happy.And, btw, I have seen parts made by these machines, and they were good on both these counts, but where they failed is the undercut on the id. But that is, I feel, a function of correctly designed tooling.The tooling this machine needs has to cut both sides of the wall together so the amount of material is always the same. The tools are plunged into the wall of the pipe, they cut the wall of the part longitudinally, along the Z axis of the lathe. that I feel is the only way to get this right. As I said before, if you want to pm your email, I'll send you a video of the machine in action.

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    Quote Originally Posted by Limy Sami View Post
    ... and that's what I got for being polite!

    You come from New York so I'm sure you'll understand this - go fuck yourself - asshole
    Now Limy....I prefer Your native sayings....

    "Buggar off" pretty much sums it up eh ?

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    Quote Originally Posted by semionb View Post
    Please keep in mind, I am most interested in wall thickness, and height, these are measurable values. Diameters are less so, since that is an open space.
    Getting your id profile correct is just a tool shape issue, if you can make the outside correct then its just the same as doing the inside, it just takes the correct tooling (correct being it works not designed by god or approved by god or a PM memeber acting as his agent!! :-)

    Part height and the parallelism of those faces is almost a free function of turning, so log as you cut a slither of those faces that is probably the easiest thing to get spot on on any given turned part.

    Starting from a moulded tube may be your biggest issue, moulded parts the world over have lot's of internal issues, the way the plastic flows into the mold creates all kinds of defects and stresses that may well have a far greater effect than you think they should especially as you remove the outside then the inside ones. If the injection - feed point is at one end you may well find things differ as you go down the piece making your parts. the fact your molder can not mold these says little for his ability IMHO to actually make a great high quality tube blank. Your part IMHO is very very moldable in a very simple mold (you need it to do some tricks to get around your uneven part height caused by shrinkage do to temp chainge as the mold fills!!), but not something multi cavity unless your a genius and it needs the correct sized injection molder to get the high accuracy shot size parts like this need. In simple terms to mold high accuracy parts you have to sacrifice cycle speed for quality, but it also lets you use a far simpler mold and a far cheaper system of molds were your differing diamiters are simply differing inserts loaded into said mold. You need to be talking to some were doing biomedical molding not light switches or kiddy toys though! Sharp corners are again under the control of the molder, but to get great control on that the machine its run on needs to be designed around a small shot sized part like your trying to mold. You need a molder that is as good as Sami is about turning and IMHO most places are not, this is not the part to get run at most places, you need the good guys or you need to bring that inhouse and learn it your self.

    You mention increasing the humidity in the nylon, whilst yes that does improve its properties robustness and toughness wise and make it more stable, it actually makes it cut worse, most polymers turn a lot lot better in there fully dry state, but then you get to deal with the humidity induced swelling, which whilst hard to mesure on a 2mm height, may well have a hell of a effect on a diameter and especially the parts end roundness, the flow of the plastic into your "pipe mold" is not going to be even, its going to create a grain structure not dissimilar to the grain in wood and thats going to effect how the parts going to come out roundness wise once its freed from the blank in your lathe.

    Samis warnings about a collet helping but not being a free ride are worth listening too! Especially on a molded tube blank that probably won't be round to start with. Chucking pressure weather you use a collet or a humble 3 jaw adds a lovely bunch of variables to play with. At this tolerance rangne plastic is on a par with play-doh touch it and it ozes out else were.

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    HI adama:
    While what you say about molding may be right, I finally lost patience with it. I paid a consultant to design the mold, I paid for the mold, then all the changes. It is sort of like a riding on a carousel, just as you stretch your arm to catch the ring, it moves away. Each time you think you have the problem licked, something else comes. And making 2 different diameter parts on the same mold doesn't work because of the pressures in the cavity; and hydraulic injection press is not good because it is not precise enough, you need electric, etc, etc. It just wouldn't end.
    Now, please keep in mind, these are aftermarket parts, they're not my own. However, looking at the OEM parts, they're very crisp. That tells me right away they're not injected parts, since stuff coming out of the injection press, corners are always rounded. So that gives me a hint, these parts were definitely machine made.
    As far as injected pipe, if what you say is right, then I'll go for extruded pipe, unless what you say also applies to the extruded pipe. But I have some samples of the material I want to use, and can run it to test samples. If I find there are issues, I'll switch to another resin. The other resin has fewer moisture issues. Pipes I have are undersized on the ID and oversized on the OD, so there is enough material that can be removed. I even have a backup plan for the lathe, using a similar tools on a turret CNC lathe. But in general it is much less expensive making mistakes with lathes than with an injection mold. A mold is just a money pit, to finally get the mold to work right takes a lot of money and time, and knowledge. And in this case I had help, and still failed. For less than the cost of the mold I could have bought a lathe. I think getting the mold right is a question of luck, and not all the parts can be molded. What makes these difficult to mold is wall thickness. And people who have possibly the right type of machine want huge orders. Anyway, I finally gave up on the mold, was just a waste of money.

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    IMHO the problem was not the mold, the problem is you hired a consultant that did not know his trade to make a mold then someone to mold from that, your about to make the same fuck up with a lathe, by all means hire in consultants, but make there payments dependant on results of final outcome, not just shiny things, but actual final in tolerance good parts, because like Sami says, thats the hard bit. You have to make someone own the process and then pay what they desire for delivering on that results wise but only on results.

    Edges can be near sharp on molded parts, as in radiuses less than a thou, but to do that takes skill and the correct mold design and moulding cycle, that means no simple cavities, but proper shrunk together ground parts, because nearly all tooling - grinding can't make sharp internal corners, you always have a radius of the abrasive grains used to grind it! Equally all thoes corners have to be vented so the air can escape, that can be as simply as scratch orientation in the ground parts of the mould, little details matter in this stuff at these sizes - at these tolerances. Im no expert, my injection molding knowledge was the result of only a 2 week work experience stint when i was in school, but strangely enough they were moulding and designing - making the moulds for seals to go in and control spot etching on silicone wafers, the seal edge was approximately a 60 degree knife edge and that had to be pretty damn sharp, so that it formed a dead square internal corner when loaded with a certain low force against a very flat object! So the etch location could be very precisely controlled. Trust me it can be done, but almost certainly not by your average happy meal toy mould maker or typical mould shop!

    Yes a lathe may seam cheap, just understand theres a big learning curve and some not insignificant tooling costs too, the lathes going to take a couple of weeks minimum shipping, going to then have to design and make the tooling and then and only then do you start to try the process and find out how it does not work to go around and remake - modify the tooling, unless your uncanningly skilled your not going to have the lathe hit the floor on Monday and have good parts to ship that week with that style of lathe! CNC maybe you might as single point turning you can tweak the programme and try another part ever few minutes till you get it right. With form tooling and such modification is not all that much simpler than modify a mold tool. When it comes to the tooling a lot of its also what other tooling you have in house and also what you can do with it, i could not imagine trying to not make and be able to modify the tooling in house to at least a fair degree.

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    I am not looking to buy the lathe either, I want to make the tooling and run it on someone else's lathe. Can't be done without having some skin in the game.

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    Doesnt look too impossible. Like others said you will need to make a lot of specialized tooling. But a lot of it could be made adjustable too, like if you work with similar diameter material then itd be easy to make 1 adjustable tool that did the i.d. and o.d. in 1 pass, then grind hss cutters for to make chamfers on each end, and part off. For fine adjustments all youd need is a 1 inch travel indicator and magnetic base and plan on running a few scrap pieces for every setup. I used to run Warner & Swasey automatic turret/screw machines etc. that made stuff similar to what youre trying to do, except bigger and from steel. You ota try google image search screw machine tooling and look at lots of old pictures to find out how to make tools. And be ready to run a lot of scrap until you get a feel for the machine and what the tools r gona wana do when u make adjustments to them. Good luck tho. Looks fun, nice clean litle plastic parts ha.

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    Quote Originally Posted by StinkyDan View Post
    Doesnt look too impossible. Like others said you will need to make a lot of specialized tooling. But a lot of it could be made adjustable too, like if you work with similar diameter material then itd be easy to make 1 adjustable tool that did the i.d. and o.d. in 1 pass, then grind hss cutters for to make chamfers on each end, and part off. For fine adjustments all youd need is a 1 inch travel indicator and magnetic base and plan on running a few scrap pieces for every setup. I used to run Warner & Swasey automatic turret/screw machines etc. that made stuff similar to what youre trying to do, except bigger and from steel. You ota try google image search screw machine tooling and look at lots of old pictures to find out how to make tools. And be ready to run a lot of scrap until you get a feel for the machine and what the tools r gona wana do when u make adjustments to them. Good luck tho. Looks fun, nice clean litle plastic parts ha.
    Stinky Dan:
    You've read my mind. Now if you only said resharpenable, that would really top the cake. What may also be possible is to do a setup for each part, it may take some time to set up for next part. Minimize tooling setup time. And as I said before, the parts I've seen come out with great surface finish, very shiny.

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    Semion,
    Coming back a little late. But I think I understand what you meant by pinch machining. Not a term I use or very many others on this forum. I think you want to bore and turn with tool tools at the same time so you can maintain the .6 and .67mm thickness.
    I do not think any commercial tool does that, you would end up using a couple of tenth set boring bars and completely remanufacturing them to ride on the end working slide. You will be trying to control chips with a 2 or three step boring bar (Depends on whether you face with it also). Chip control will be difficult unless that PA66 machines way different than regular nylon.
    Your slides on the air actuated machine will probably need positive screw adjustable stops to hold the tolerances you are shooting for. I would guess it would take a year of designing and building and modifying to get production. To me there is an uncertainty whether the process will even work.
    Thinking about the A42 and B42 screw machines mentioned earlier, positive stops could be added the slides allowing more precision. You would still need some sort of "pinch" tool to ride the drill slide. Cams could be designed by a professional like Lester Deterbeck. I would ask for cams with a little extra overlap to give you more lee way in development. If you get it working then get another set optimized for maximum production.
    One other possibility is doing this on a gang tool CNC. You do not think carbide can turn plastic because you have not hung around this forum long enough. We use Arno high positive inserts, you can almost shave with them others have mentioned other brands that work well. With cnc you can try different approaches by just changing inserts are altering a few lines of code.
    We have 2 Omniturns and a Hardinge GT. The Hardinge instructors said the shortest practical cycle time was 20 seconds. We have run a little faster than that. There is a plastic supplier in Shiner Texas that had a Hardinge GT with the 16C collets. http://www.boedeker.com/mashop.htm Just looked at there website, they call the Hardinge a GT27 but say 1 5/8 capacity. I saw an omniturn retrofit on a 16C hardinge for sell about a year ago they were asking $4200. I should have bought it as I am still messing with this one I am trying to build. If Boedeker can build you 10,000 of these with a 20 second cycle time then you could buy a gang tool machine and be way ahead of the time curve building a air actuated screw machine or adapting a mechanical one. After thinking on it I think adapting an existing screw machine would take 1/2 the time as the camless one. If Boedeker has done something similar they could get good parts in a do or so of fussing with it otherwise it may take a week of fussing. Either way I would expect to pay for their time.
    One other I saw mentioned earlier. If your stock is not round your collet will pull it round. when that force is released with cutoff, it will spring back to that out of round condition. Just looked back Adama already mentioned that. What he said on molding sounds good to me also.
    [ATTACH=CONFIG]216600[/ATTACHdoubledrill3.jpg]
    Just for grins I attached a photo of a double drilling slide I built for my small screw machine. The slide was custom built by Milwaukee Slide and Spindle, commercial cylinder and Ace hydraulic shocks were purchased all the rest was built on borrowed milling machines and my 9C South Bend. Designing and building figure about a month and refining another month and that is just one slide. I have not used it in about 15 years but it was fast on the index from tool to tool (fraction of a second).
    Attached Thumbnails Attached Thumbnails doubledriil1.jpg  

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    Hi Fred:
    Thanks for your input on New Year's eve.
    Actually, if you look at the video carefully, they have a single piece of steel cutting both sides of the part, doing the wall. This is what I was thinking. Keep things as simple as possible. It is really not that critical that when the part is cut off it springs back, since the part is flexible enough and it goes around another part. That will impart its shape. As I said, the most important thing is maintaining the wall thickness, keeping the undercut on the part, and part height, both sides should be parallel. The roundness is not critical, I can adjust the diameter to give me critical contact between the 2 parts. When assembled, the gasket will be round. It just needs enough "meat" so that it seals. That is the wall. I am trying to keep the tooling as simple as possible. Chamfers can be done with separate tools mounted on slides.
    Anyway, for all those who commented, I want to thank you, and I wish every one a Happy New Year, all the best in the coming year. Keep those good ideas coming.

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    Can you define a bit better what needs to change on the other versions of this part, ie the height, chamfer angles - what? Haveing a lot more freedom on the diameter tolerance helps. Equally it cant be over stated how much easier that in turn makes this part. That will make the harder parts a lot lot easier to do.

    The id step, how sharp does it need to be, because it greatly simplifies the tooling if it can have some radius on both those corners, at this part size, grinding a typical "sharp" corner still leaves a fair radius Only way to get no radius is to have that as 2 parts that go together to form that dead sharp internal corner.

    Tooling very much needs to be shrpenable and adjustable for the metal that means removeing, hence you need a way of adapting it for center height. Finish wise on the tooling, you need thoes cutting edges lapped to a good mirror level of polish. Same for the clearance angles on the tooling, they need to have a bloody good finish, a typical ground finish wont cut it!

    Other thing is spindle speed, dont know what that things good for, but you don't want silly high speeds, you want a 1k of rpm tops to start with and you may well find you get better results going slower. Feed needs to be very smooth, though possibly not as slow as it seams. Nylon likes to be cut, but it does not like heat, heats a direct function of speed hence lower speed can actually work in your favour. Hss in mild steel whilst praphs conservative aint normally a bad starting point for typical nylon 66, if your polymer is gummier like nylon 6 its going to be a lot lot harder to do.

    You still have not made it clear your expected run sizes of a given size, cant be stressed enough, if there not in thousands this sorta lathe and tooling won't pay off and you would be a lot better off going to a far more flexible single tool turning on something like a tormach or better. Were for a given diffrent part assuming out of the same size stock its mear secounds to call a diffrent programme to be run, if tool ofsets are good you could be doing runs of 10 of's each size all day long. hell get creative with the programming and you can be queuing them up and automatically running a varied list of a days production - sales! Yes the base machine would cost you about double the cost of the above, but no stock to hold but raw material and constant flexability in part design should see that pay back fast.

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    Quote Originally Posted by adama View Post
    Can you define a bit better what needs to change on the other versions of this part, ie the height, chamfer angles - what? Haveing a lot more freedom on the diameter tolerance helps. Equally it cant be over stated how much easier that in turn makes this part. That will make the harder parts a lot lot easier to do.

    The id step, how sharp does it need to be, because it greatly simplifies the tooling if it can have some radius on both those corners, at this part size, grinding a typical "sharp" corner still leaves a fair radius Only way to get no radius is to have that as 2 parts that go together to form that dead sharp internal corner.

    Tooling very much needs to be shrpenable and adjustable for the metal that means removeing, hence you need a way of adapting it for center height. Finish wise on the tooling, you need thoes cutting edges lapped to a good mirror level of polish. Same for the clearance angles on the tooling, they need to have a bloody good finish, a typical ground finish wont cut it!

    Other thing is spindle speed, dont know what that things good for, but you don't want silly high speeds, you want a 1k of rpm tops to start with and you may well find you get better results going slower. Feed needs to be very smooth, though possibly not as slow as it seams. Nylon likes to be cut, but it does not like heat, heats a direct function of speed hence lower speed can actually work in your favour. Hss in mild steel whilst praphs conservative aint normally a bad starting point for typical nylon 66, if your polymer is gummier like nylon 6 its going to be a lot lot harder to do.

    You still have not made it clear your expected run sizes of a given size, cant be stressed enough, if there not in thousands this sorta lathe and tooling won't pay off and you would be a lot better off going to a far more flexible single tool turning on something like a tormach or better. Were for a given diffrent part assuming out of the same size stock its mear secounds to call a diffrent programme to be run, if tool ofsets are good you could be doing runs of 10 of's each size all day long. hell get creative with the programming and you can be queuing them up and automatically running a varied list of a days production - sales! Yes the base machine would cost you about double the cost of the above, but no stock to hold but raw material and constant flexability in part design should see that pay back fast.
    Adama:
    My other parts will have different heights, different wall thicknesses, some parts have different profiles. The inside corner needs to be sharp, I mean 90 deg. sharp, as it has to be inside another part, they need to mate well. But I don't see 1 tool being able to do the entire profile, just the ID and OD. The chamfers will be made by separate tools.
    As far as speed of the lathe, it is more a function of the material, so for nylon 66 surface speed is about 185m/min. This means larger parts will be turned slower and smaller parts faster. The part in the drawing should be turned at about 2000 rpm. These speeds are recommended by DuPont and other resin manufacturers. But everyone seems to have their own speeds.
    As far as defining quantities, the part in the drawing will be about 50,000/year, and maybe more. I have another smaller part, that would be about same. Other parts 5-10K/year. Total of about 7 different parts.
    But I don't think a single point tooling will be able to produce these parts successfully, unless there is some sort of support on the opposite side of the cutting tool. I tried it, it didn't work too well, but then the machinist probably was a problem too.
    But at the end of the day, the only thing that matters is cost for a correctly made part.


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