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Martytoof posted:Sounds like some weird resonance in one of the axes but nothing terrible. The vacuum pump is much more annoying Yea but that thing costs $1000 and you cost way more than that. One could buy several of them for the cost of a year of you.
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Sep 10, 2013 23:46
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echinopsis posted:we used to find that there was a world of difference between like 8001 and 8005 Ali [or whatever it was], the cheaper stuff that was great for folding bending etc was substantially worse for machining.. maybe it doesn't matter but I guess it's worth knowing that the marine grade was so much easier to cut so if you are having trouble with it cutting clean just something to be aware of. maybe preaching to the choir but I'm risking it As a person who's job it is to understand aluminum machining chat and metallurgy chat this makes no sense.
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Oct 21, 2013 23:24
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Sneaking Mission posted:What Is The Best Metal? It is steel. Alloys of steel can basically do everything they just do it heavier but from super alloys to corrosion resistance to very high strength to great machinability steel pretty much owns. echinopsis posted:it's cool dude I mean I worked 6.5 years machining alu but to be fair neither I not anyone I worked with had any real engineering or manufacturing experience. we found the softer grades of alu chewed up and harder ones machined nicely. idk if I was really trying to say anything but get an avatar or something jesus Oh then yea that is true in precip hardenable aluminum alloys, when the matrix itself is harder it is generally more machinable. Hence why machining stuff as cast suck rear end.
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Oct 22, 2013 03:48
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rotor posted:i didnt know Cut up cast aluminum wheels. They'll be high silicon and suck rear end to machine afterward without aging, but you can prob age them in your home oven. I forget what the againg time and temps would be and can look them up tomorrow if you really want. P.S. moisture in castings is a very dangerous problem that also causes inclusions. Make sure your scrap is dry. EDIT: Nevermind you said no home melting what a wuss/nice neighbor EDIT2: Call metal suppliers. Ask who sells drops. Go to their retail store where they sell drops. Be in home machinist heaven. EDIT3: Dont use a steel crucible by the way its super stupid cause with few exceptions Iron causes really brittle and makes lovely precipitates in aluminum and how lovely it is is a large part of why manganese is added to alloys. CarForumPoster fucked around with this message at 04:37 on Oct 22, 2013 |
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Oct 22, 2013 04:16
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Zhentar posted:Incorrect (partially). You can mix in more magnesium, or more virgin aluminum, and end up with something that's suitable for the sides or lid. It's not very convenient, but refining aluminum from ore is very energy intensive, so it ends up being worth it anyway. Hes correct in that you shouldnt try to melt your own aluminum cans. No one was suggesting that one should. Melting aluminum cans at home though has all of the problems. 100% of possible problems.
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Oct 22, 2013 18:21
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Agree with most of what is above adding to it, 10-30% step over since you probably have no spindle power. Carbide endmills can be fed around 1% of diameter per tooth.
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Oct 28, 2013 04:03
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echinopsis posted:As a person whose job it was to cut alloy for over 6 years this makes no sense I shall explain it then. 1% of cutter diameter per tooth is a good rule-of-thumb starting feed rate for milling aluminum. Power consumption is essentially a function of MRR and the way to decrease your cutter load effectively is to use constant cutter engagement angles. You don't want to run the cutter on center line nor do you want to slot if you can avoid it so your "good" cutter step over ranges tend to be 10-35%, 65-85% with the ideal being 70%. With <50% you get chip thinning effects and should increase feed but on your baby mill at 1% cutter/tooth (e.g. a 1/4" cutter would be fed at .0025/tooth or for a 2 flute .005/rev) you'll be ok staying in the 10-30% step over range even if your effective cutting thickness isn't the full 1%.
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Oct 28, 2013 20:19
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You are welcome.
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Oct 29, 2013 17:38
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ante posted:I'm planning on spending almost no money on this if I can help it. This seems like it has a lot of extra parts, why not just make the table follow the square tubing and the lead screw pass through the cross members?
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Nov 2, 2013 06:40
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Unless you're ordering ground rods, which might be a good idea theyre not too much more expensive, theyre basically extruded in the same way. Dont expect your straightness per foot to be great with rod either. If you could get thick walled tubing (or just solid, this is the base of a machine) weld it all together and then just square it up on a bridgeport you'll find massive improvements in all these regards. Keep in mind weldings not going to leave anything square so unless you line bore the holes for the control rods after welding they'll be pretty far off as well. This is why eliminating them and machining a control surface is probably the best idea. Do you know anyone with a mill?
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Nov 3, 2013 17:38
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ante posted:I've got a bunch of rods salvaged from printers and scanners and no access to a welder or mill. Good news is if the rods have ends that are mounted together to make a continuous rail theyre likely pretty good tolerance wise. I.E. if its all one assembly, hooray.
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Nov 4, 2013 06:33
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My concerns weren't of rigidity, they were of accuracy and eliminating parts.
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Nov 4, 2013 18:57
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Cakefool posted:I don't know if this is the best place to ask but my brother wants to build a wood mill for his little cabinetry business. He needs a 1500x500x100mm envelope, Any suggestions on where to start? he'll need to cut all types of wood but nothing harder. Id start with googling and ebaying a CNC router kit. I bet china makes one and someone imports it. Since tolerances are non existent for wood a lot of corners can be cut that cant be for aluminum. Id assume there are formulas for calculating the horse power you need for a spindle for milling wood similar to aluminum/steel/etc. Add a decent fudge factor to that because router bits are not ground to the same quality nor are they replaced as often as metal cutting bits.
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Nov 6, 2013 03:40
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Sagebrush posted:No, no, corner cutting depends on the tool radius.  
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Nov 6, 2013 08:18
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bung posted:Just saw this today. A desktop 5-axis mill with a projected price of $3000. This person did a neat thing, knows jack poo poo about machining quality or machine tool building.
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Nov 25, 2013 00:13
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oxbrain posted:Vacuum chucks are a pain in the rear end. A couple strips with the profile milled in will make good enough parallels to clamp down on. I strongly disagree with the vacuum chucks are a pain sentiment. Vacmagic is the poo poo. Cant tell you how its made from that pic. I also disagree on blasting being a good way to cover tool marks/chatter on aluminum unless you don't mind it being uneven or introducing a fair amount of cold work into the blasted surface. (Blasting the gently caress out of it) Especially when the next step is a Type II ano process. CarForumPoster fucked around with this message at 02:51 on Aug 15, 2014 |
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Aug 15, 2014 02:46
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rawrr posted:According to the site (http://www.kleptography.com/rf/), "All of Richard's grips are individually precision-machined from high-grade aluminum alloy, and then glass-bead blasted and black anodized for durability. " Translation: Commerical 6061, sprayed in a manual blast cabinet, Type III ano'd. I am guessing between machining and blast there's a fair amount of 120 grit sanding. I doubt they're stamped in the quantity he must sell them in. I am guessing a cheapy 3 axis or 4 axis mill like a Tormach and then sanded after to remove scallops and that $35 is just a v cheap price he doesn't make a lot of money on.
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Aug 17, 2014 01:14
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Audiot posted:I'm currently using D2NC (http://www.d2nc.com/) for generating gcode. It works pretty great to convert dxf's as well as having some handy wizards for quickly setting up bolt hole patterns and surfacing operations. I'm in the process of CADing up a turbine print I've been working on building forever and I can see 3D would make my life a lot easier. I keep coming back to MeshCAM. Does any one have any experience? Im a pretty big fan of Mastercam and it seems to be one of the most popular in industry for machinists to use.
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Oct 5, 2014 07:26
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Cakefool posted:Regarding building my own cnc table, I'm seeing a lot of 4 axis stepper and power board kits on eBay, are 4 axis used when you need to drive both sides of a wide Y-travel carriage? You should never ever cut through the table. Put a fixture plate or vise on the top.
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Oct 7, 2014 01:51
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Ambrose Burnside posted:1 AM thoughts: reading about how working with really low feed rates can cause cutters to burnish work instead of making chips is making me wonder: does non-subtractive tooling for conventionally-subtractive machine tools exist, beyond measurement tools like edge-finders? I don't think people do much burnishing any more, but I wouldnt call it non subtractive but clapped out CNC mills are used for polishing and sanding all the time.
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Mar 11, 2016 05:14
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rawrr posted:So it's a bit mindblowing to me that http://www.shapertools.com/ is actually a real, working thing. It's a handheld router that can display a path for you to follow (stock shapes or paths on a USB drive), then auto corrects as you go along. I used this in silicon valley ~2 years ago at maker faire 2014 and follow them on Youtube. It actually for real works and has for two years. I am very annoyed they dont sell it yet.
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Apr 14, 2016 03:27
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Bad Munki posted:Is there an expected price point? Because drat. They asked me what would I pay so they didnt have one at the time.
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Apr 14, 2016 04:32
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rawrr posted:How is the quality of the cut compared to traditional routers? I'm not really the person to answer that because my back ground is CNC machining (particularly milling) of aluminum and Mech E and 0 routing of wood save for a few times on a table. That said, the setup at the time was basically a dewalt plunge router on a portable stage IIRC so I'd expect that it was the same as a dewalt plunge router with that tool. It was quite easy to use they had a DXF file they loaded in, showed you how to use it and in 30 seconds you could have a little cut out of America from ~1/4" plywood.
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Apr 15, 2016 04:34
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Hu Fa Ted posted:IN TYOOL 2016 what would be the best CNC option for home milling semi intricate 2.5D parts, say about the size of an AR-15 lower receiver in aluminum? How much do you want to spend? 80% lowers are way cheaper than mills. A tormach is a good option
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Apr 21, 2016 03:24
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Ambrose Burnside posted:Good to know- wouldn't actually know how to set it up because it's more complicated than "plug some cables into clearly-labelled ports", but I'm starting to grasp what this "ports" and "pins" n so on business is, so maybe I'll be comfortable with that down the road. I'd strongly prefer a more physical solution like they had on the bandsaw at the blacksmith's shop- a forged arm shaped to physically flip the off switch once the saw had almost fully dropped- but the e-stop ain't positioned right Seems like you could use this: https://www.youtube.com/watch?v=hZWCX9tdkk8
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Aug 18, 2016 03:58
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(actually I could 100% make a physical arm to at least shut the spindle off if the headstock drops past some pretermined point, the switch is mounted to the vertical column so it'd be easy, hmmmm...)
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polyfractal posted:Just starting to research hobby CNC machines. Before I get too deep in the weeds, any recommendations for a machine/setup that emphasizes precision over speed/size? I think I'll mainly use it for machining small plastic (acetal) gears and mechanisms, or to make master molds for resin casting. The OtherMill might be up to the task for the small plastic gears. If you ever do consider a wood CNC, check out the Shaper Origin, it won't ship until later this year but man do I want one.
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Jan 16, 2017 04:32
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Brekelefuw posted:
Lathes can be confusing like that, especially in very old times. How old is the lathe youre using this one, which Fanuc control? A 1980s vintage Fanuc 6 series will have different positioning methods than a much newer one.
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Mar 24, 2017 03:35
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Brekelefuw posted:It's a Sherline running a UC-100 smooth stepper with 4 KL-4030 stepper drivers (so I can run my 4 axis mill as well as the lathe) and a C10 breakout board. In that case I have no idea.
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Mar 24, 2017 13:57
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Not my area of expertise but I think youre tempting the magic pixie gods with the total lack of EMI control.
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May 12, 2017 02:42
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Brekelefuw posted:Speaking of that....whats a good way to deal with EMI? Pimblor posted:The best ways to deal with common mode current EFI are chokes. Otherwise you'll basically need to build a RFI/EFI shield like a faraday cage. This but I'll translate into a few design features: -Metal box with an electrically bonded metal lid. If you remove the lid a bunch, easiest way to do the bonding IMO is with an EMI gasket. -Very good grounding including for your cable shielding. Remember you can't bond through paint or anodizing. (Except type 1 ano) -Shielded cabling (poor/lazy mans shielded cabling = Aluminum foil with copper tape on the seems) -Shorter cable runs, I've heard the rule of thumb is 4 feet. -Those blocky cable warts are ferrite chokes, use those. (https://www.amazon.com/Device-Cable-Dual-Ferrite-Chokes/dp/B004ZXN7B2) -Dont put unshielded power cables next to data cables or just use shielding -Careful about putting high power stuff like welders on the same ground/power lines. I've actually seen a control fried that we are pretty sure died from that. One more thought: Unless you know where your sources and victims are, some of the above advice can make the design worse. If both your source and victim are in the same box, going from a plastic-> metal box will probably make it worse. Same thing if you have one fat wire loom (like how cables run in planes or cars) for your cables with a big overbraid on it. If your source/victim are under that same overbraid unshielded, you will get cross talk. Lastly, not my area of expertise (I'm a mech e) but sorta tangential to it. CarForumPoster fucked around with this message at 12:28 on May 13, 2017 |
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May 13, 2017 12:12
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Brekelefuw posted:I'm going to buy a bunch of clip on Ferrite beads on Monday. Most of the 18/4 "stepper motor wire" I have seen has been shielded and I assume twisted pair. EDIT: This may help: https://www.servo2go.com/information.php?menu=TS&page=10031
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May 13, 2017 21:13
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DethMarine21 posted:I used a website called Bhiner for all the Taobao stuff. They're known as an "agent" and act as a middle-man for a small fee. I used them mainly because they accept PayPal for payment and send you photographs of your items so you can verify that everything is correct before it gets shipped internationally. Post is neat but this is especially helpful. Also I've always wondered why those little lovely import bench power supplies are so expensive. $72 for 600W, 48V? If I could live with A computer PSU (12V) I can get 74A @ 12V (~900W) for that and its got cooling figured out for me. EDIT: Hilariously bad power factor too if I did my math right. Rated input 12A@115VAC (1380VA)...rated output of 600W. EDIT2: Though it described the efficiency for that model as 88% so maybe I'm off base here...seems like if true the input rating should be like 6A @ 115VAC. CarForumPoster fucked around with this message at 22:25 on Jul 4, 2017 |
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Jul 4, 2017 22:19
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rawrr posted:Meanwell is by no means lovely FYI; they're extremely well designed, specced, and built. One of the larger power supply manufacturers that you're able to buy in hobby quantities. Oh, good to know.
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Jul 4, 2017 22:53
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Sagebrush posted:Many (most?) CNC machines are open-loop and count steps of the motors to keep track of their location. If the motors slip, well, then you're hosed. That's why you keep an eye on your spindle load and axis loads, which high-end machines will continuously measure and report. Maybe for home gamers. Most industrial machines are servos with encoders in the late digital age, resolvers in the 1980s.
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Oct 6, 2017 13:08
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Ambihelical Hexnut posted:Working on an aluminum sign. I can see now that fixing the mill finish on sheet stock is gonna be a real pain in my rear end. I used to be a mfg engineer and part of that was CNC sanding in clapped out milltaps for a tech giant. If you have any questions let me know. Long story short, 120->240->600 with a handheld RO will hide all blemishes well enough for a machined surface. Maybe starting with 80 from mill scale is a good idea. Also, I hope you clearcoated or type II/II ano'd your sign because regular ol' humidity will cause pitting corrosion in alodined or bare aluminum surfaces.
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Dec 10, 2017 23:09
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Ambrose Burnside posted:What sort of program are you in and how long do you actually spend screwing with writing programs from scratch? I'm curious how American CNC training stacks up to what I'm doing up here in Canada. TBH I'm disappointed by how superficial it is given that it's a two-year program, especially compared to how rigorous tool/die programs used to be at my institution, but I suppose it does also reflect the realities of the relevant jobs as they exist. I was an R&D manufacturing engineer at a huge tech company, did undergrad CNC research and worked as a CNC machinist through college. I also went to trade school for CNC machining before college. Once in industry I made literally every program more than ~15 lines in MasterCAM or some other cam program. The only exception might be some probing routines but even that I tended to prefer making points in MasterCAM using my part geometry and what not. As far as training for my tech degree, I was trained on CamWorks for Solidworks with a little bit of Gcode and conversational thrown in. The CAM part was the useful part, knowing Gcode by heart was a waste of time.
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Dec 16, 2017 01:34
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Ambrose Burnside posted:Oh I know, but knowing enough to troubleshoot your own generated gcode seems like a reasonable basic expectation, and in our case even that's generally not there. Just a heads up you will spend your life saying you have an engineering tech degree when people ask if youre an engineer/what you studied and other engineers will ask. If its not much extra time I highly recommend a regular ol' mech eng degree. Not industrial. Not manufacturing. Mechanical. Or Electrical if youre feeling more ambitious and want to really go in to automation. As for on machine inspection and finish machining with adjusted values, I could do that on a Fanuc robodrill with a probe, a sub $100k machine all in. The tools were set by an optical tool setter that could also spit out 2D drawings of new/custom tools. That said, you'll find environmental conditions like vibration and coolant limit some of your on machine inspection options in mass production. I think Neural networks of ____ measurement and offset on the machine (which is networked) to a CMM measurement of that feature are a trivially easy next step that could both be high tech and increase precision. CarForumPoster fucked around with this message at 14:27 on Dec 19, 2017 |
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Dec 19, 2017 14:20
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ante posted:As an electrical engineering technologist, this is exactly right. Don't do what I did. I almost did the exact same thing until someone gave me the advice you and I just gave. Engineers and the people that hire them are a snooty bunch, even the nice ones. Their view: the effort you put into your training =the effort you will put in once youre there. There is a hierarchy of degrees that no one quite agrees on but goes roughly like: Business Degrees = Web Developers/"Coders" < Industrial/Manufacturing Engineers < Mech/Elect Engineer Techs < Civil Engineers = Environmental Engineers < B.S. Physics < Mechanical = Aerospace < Electrical = Computer Science < Optics < Chemical < Nuclear Also the average pay scale roughly follows this as well.
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Dec 19, 2017 18:53
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Ambrose Burnside posted:There’ll always be commercially-viable toeholds for manual machining, given the right requirements. Those toeholds are just gonna end up real small. Ya know I was thinking the other day how portable 3D printers could be really useful for the military to fix poo poo around camp/FOB that breaks. Blacksmithing for 2017. Could also do things like printing small drone bodies and shipping in a crate the electronics and motors to be installed on site.
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Dec 23, 2017 05:24
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Pimblor posted:What would be the best/easiest way to cut this shape out on a small CNC machine? Easy answer: it doesnt matter, yea a wasteboard would be fine. Actually the following info is missing: 4 mil...as in .004 inches? Or do you mean 4 mm? Out of what material? How much to do you care if the sidewalls are straight? How much do you care about the surface finish of the sidewalls? Do you care if there is a HAZ around the part (e.g. is it okay to laser or plasma cut it?) What are your tolerances on the size of the part.
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Jun 10, 2019 02:11
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