Stop Slotting the Stupid Way! Use High Speed Machining! Widget26
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- čas přidán 2. 02. 2015
- I used to cut slots the stupid way. Until very recently. I decided enough was enough - I need to start being a "smarter" machinist! So instead of using one tool and an 8 minute cycle time, let's use high speed machining toolpaths, a LakeShore Carbide roughing end mill and a high-helix finishing end mill to make a BETTER part with LONGER tool life and a ~3 minute cycle time!
Watch along as we create the SprutCAM toolpaths and then use the Tormach PCNC to machine!
HD Slow Motion Camera we used: amzn.to/1CXxhzz
LakeShore Carbide End Mill: bit.ly/16venEu
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Just one thing. There is no reason to conventional cut with cnc on metal. Climb milling is advantageous on all metals when you have near zero backlash. Some plastics like things a certain way, but climb milling keeps the sharp edge boring through the worked material or into fresh material and bigger oversteps are best, the more overstep the closer to perpendicular the motion of the edge vs the surface of the material. Conventional milling puts that blade almost tangent to the last flute.
The circular path you are using helps chip removal. If you can get the circles counter clockwise and kill the extra path I think you can get the ipm up to 30-80ipm in one pass depending on coolant and how many rpm the spindle can handle.
Nice John! I suppose we are the CZcams self-taught new generation of do it yourselfers. We are learning from each other at twice the speed though. All we need is for someone to share good content, and folks like yourself are serving this community well. I thank you.
If only slotting was the only thing I did "the stupid way." :)
A few thoughts, in no particular order:
1) That tool path is call Trochoidal Milling, just FYI. Using the proper name instead of HSM style will keep the nomenclature nazis off your back for a while. ;-)
2) You're getting chip welding almost certainly because you are conventional milling that tool path. Switch to climb milling and maybe up the % lube in your air and that problem will very likely go away.
3) You own a manual Bridgeport Series I milling machine, yes? If so, you ought to be running a job like this on that thing so that the CNC can spend it's spindle time earning the top shelf bank. (IE put the longer cycle time and/or higher paying jobs on the CNC and let it eat while you bang out simple stuff like that slotted piece on your manual mill). Excluding setup time (which will be near identical on either machine), you should be able to rough and clean up that slot to size in that part in less than two minutes on your manual machine. I know I could do that, which means you can too.
You're where I was back in ~2005 in that you still use your CNC to do work that is more profitably done on a cheaper/simpler manual machine, because you doubt your abilities with the manual machine tools.
Don't doubt yourself, embrace the manual machines. They are the key to increasing your shop's throughput without adding any new spindles. The trick is to keep the CNC running long cycle time programs by either gang fixturing simple-ish parts or saving the CNC for the parts with more complex geometry. Then you can load the CNC, hit the GO button and let it work unattended while you do the simpler work on a manual machine.
There's no reason to spend the time to make two or three programs and change tools around in the CNC to make a few rectangular parts with a slot down the middle and three or four holes in one side. That's something that can easily be done manually on your Bridgeport while the CNC is running a more complex (and therefore more expensive) part.
The more you use your manual machines, the more useful and time efficient you'll find them, and the more profitable you'll find your shop.
->1 : he is a self trained worker.... What do you expect
Why would he waste his time doing that on a manual machine The whole point of this video is to show how much faster it is with the CNC and how it saves tools.
@@caploader111 Because it's NOT faster, that's the point. On simple parts like this, the time savings of the CNC toolpath is more than eaten up in the extra setup required to use the CNC in the first place, especially on small quantity runs. Now, if he's doing two hundred instead of ten or twenty, that changes the calculus.
Also, "saving tools" while spending half again as long making the cut is not saving money in any working shop. If you're a hobbyist in your garage, maybe you can justify taking twice as long to save some wear on a $45 tool, but that math just don't work in a commercial shop.
CNC is not a panacea, it's a tool to get the job done like any other. Sometimes it's not the best tool in your arsenal. Knowing this and knowing which machine can do the job more efficiently in any particular circumstance is part of what separates professionals from hobbyists.
Nothing wrong with being a hobbyist, you just have to realize that the economics of a thing are wildly different from that situation to a professional commercial one.
@@LogicIndustries I couldn’t agree more or faster. Then saw how he was cutting it as far as conventional or climb and why is he using carbide to cut alum? My feeling was he could have squared up a chunk, slotted it and been on to the next operation or job in the time it took to draw it up run tool path fix problems or adjust program send to machine set the datum, set the tools probably dry run it then finally run the part. Ridiculous to think it’s faster on a cnc and not a Bridgeport. Why would you use carbide also when h.s.s. Is better on aluminum?
Seven years later, here I am desperately trying to remember the term I needed: Trochoidal Milling THANK YOU
Thanks John. It is always good to see new ways to go about "common" tasks.
I usually enjoy your videos, but I'd like to make my own observation on this one. Lets analyze your tool path. One.... the approach pass, 50% of your tool motion is wasted movement. You're not producing chips. Two...On the return trip, at least 80% of your tool motion is not producing chips. This would also be much better as a climb cut since this small diameter cutter may dig in and exceed the channel boundary under load. A single pass would be a huge step in the right direction too. Possibly you have a corner radius defined on this tool in your tool definition, and thats why the second pass showed up. All totaled, I bet your table actually moved farther using all those circular movements than if you would have just run up and back a few times. I like your channel, skill and material, but I would never use this technique.
This is a little behind the release date but still relevant:
I migrated from cam-operated screw machines to CNC lathes and much of the methodology and techniques worked well for me. There was a very big eye opening job however that changed the way I looked at the CNC world.
The simple job involved turning, drilling and cutting-off of 1 inch round 304 stainless steel. In the screw machine world cutting off is a slow feed operation. When I attempted the technique on the CNC lathe the cut-off (a coated carbide insert) tool would only last 8 parts. I was running, IIRC, about 1000 rpms and feeding about .002 IPR….
A call to the tool company solved the problem. They recommended 3200 rpm @ .006 to .010 IPR. Okay… whatever you say… I was prepared for flames and molten steel. Well SOB!! It worked! And it worked *very* well. Tool life went up to 300 pcs per insert from 8, the surface finish was amazingly good, burrs went away and dimensional consistency never was a problem again.
The moral of the story is that you can run too slow. Running slow causes all kinds of problems.
BTW… 5100 rpm on a 1/4 inch carbide end mill is too slow….if your mill has 10,000 rpms you should be there. That's only 650 fpm. Remember, your cutting aluminum. Go fast!
John-
I have been a CNC Machinist and Programmer for almost 25 years and have worked at many different shops, in short the biggest thing that happens when you work in a bunch of shops is that your horizons expand and you learn what is possible.
I love that shot at the end when you've got the Tormach behind you and the venerable old Bridgeport over to the side.
sadly manual machineing is lost to younger crowd i have to do it for orhers.they cant even start up a lathe
Well done John,.. Keep us up to date with it.. I always have terrible moments when i have to slot the first pass in pockets for every height in it.. the tool noise and the vibration is so scary.
with that tool path you should climbmill it will allow the chips to clear better and wont have cutter deflection into the walls. great video! we climbmill all tricoidal movements
You sure have come a long way and learned a lot since this John.
The slow-mo shots are awesome.
man you are awesome, thank you for sharing your content, im going to start a CNC course next week and i had my doubts about it, since im "stepping down" from a more "lucrative" job ( pharmacy ) but im doing it for pure passion for creating stuff, you are such an inspiration and again thank you for sharing
NYC CNC well im from israel , gunna be taking the class in haifa , so far all i know about the class that we use solidworks and solidcam ( its funded by the ministry of labor so im not to worried about tiny specifics but i saw that these softwares are pretty decent ) and thats its probably not going to be any multiaxis
im also thinking to make youtube videos of my process as i go in arabic but ill have to see how that works with my time
Great job experimenting and learning something new!
It's cool to see the evolution in your processes, I'm glad it works for you. In our shop we would have done it different. But then again we have Fadals. Often we try every method until we find the fastest. Keep up the good work with the videos I love seeing your lathe work. Having run a hyundai for years I'd love to get one of the tormac models for my home shop. Also as far as machinist go you could ask 10 different people and get 10 different answers. It's whatever works best for you at the time.
+NYC CNC Yep, The lathe I am. The mill I'm iffy on, it's pretty light weight for what I want but then again I won't be running it but maybe 1-2 hours a day and I can probably get away with it. My biggest fear is with a used haas or fadal, the amount I run it I'm afraid it will break down. If we don't run ours daily they always break down. It cost us a fortune to get anything repaired on our fadals. Just for travel it's around $300 for one visit let alone every board is 1k and just about anything is 1k+. My theory is with the tormac I'm sacrificing speed and hp but I will be my own service man and I'm pretty good with the stepper systems the tormac is based on. I went to the open house and actually saw you there. I feel they have a good deal of support for their product and I like that. I'm thinking in February of picking up a lathe and PCNC1100. Then add on the tool changers over time. If I ever get a killer job I have access to a fadal mill but I would consider picking up a used fadal or haas if that ever happened.
This video is a game changer for me, I have a homebuilt CNC router using a zipsaw and I can cut 1/2" deep through hardwood using the HSM pattern in a single pass! It took me a bit to find that option in my cam program, but I can't believe how well it works. I love the idea that it's working the whole tool instead of just wearing out the tip. Great videos!!
+2008AlleyCat hi alley did you work this way with HSM??? i cant find the option please litle help:) thanks
+1 on climb milling. I never conventional mill on my CNC. Only time you conventional mill is on the Bridgeport so the workpiece doesn't get jerked around due to backlash.
Awesome. Perfect timing. I need to make some soft jaws for cutting down some little machine screws, and need to make a slot that's just under 1/8". I needed to get some 1/16" end mills for another project, maybe I'lll do that and try out some high speed machining!
Hey great video. Like many have said climb milling is the best but without having machine shop knowledge you are doing really good. Problem we have her in a Florida is that most machinist are old school and stick with the traditional slot milling tool paths will Cobalt slow roughers. When I show them HSM they flip out when they read my feed rates and often I see the machines running at 20 to 40 % because they don't know better. but as soon as they walk away I turn it up to 100% and when I show them that it works they are amazed... they still don't beleive in it but little by little I'm turning believers into non believers.
Technology is turning this world around and Im glad your showing the world what technology can do. Now change that federate to 350 IPM and really be amazed.
Hi John,
In conventional, we do a move that I call rocking the Y axis, a little like the circular motion you give your machine, really makes a difference on chip load and speed.
I know I'm still and probably will die conventional... lol
Thanks for time you spend doing this,
Pierre
Yep...Manual machine.
Just by alternately moving the Y handle about .050" it makes the path wider and reduces the chip load on the cutter, haven't made a video about this but it could be one that I could get done soon enough....
I'll let you know if it comes out...
Hi Pierre. Conventional will always have it's place, albeit a small one. I work in a foundry, and we cast and machine stainless exhaust manifolds, and turbo housings. I am the only tool and die maker/manual machinist that we have. I can't count the times that one of the CNC "techs" have come to me to get them out of a bind. Nobody appreciates us anymore.
ok, lemme give you a few bits of wisdom that i did pick up in a machine shop:
1: anyone who tells you you need separate finishers for aluminum is just trying to get you to spend more money... any chinese non-coated 3-fluter will cut that shit like nothing. its carbide vs aluminum, thats like steel vs peanut butter... ive gotten
This is cool. I was doing it the old way. Great channel!
its vids like this that make me want to convert my mill to cnc. great vid
Lots of comments about climb cutting vs. conventional. What actually is happening with a conventional cut
is that you are cutting into the material as you feed toward it, so the cutter has to push the chip into the metal that is going to be removed (more heat and load on everything).
With climb cutting you are hooking the material away from the mass and ejecting it in to the void you have just made (that's why the tool seems to pull into the cut - use caution on a manual machine by snugging up the table clamps).
Awesome John. Glad to see you using trochoidal milling. Its fun once you get that feedrate cranked up plowing through material. That aluminum galling is from too much heat in chips from to slow feed rate or re cutting of chips that aren't evacuated. Good deal though man as always even with your level of knowledge. These guys that are crabbing about their old places of work n such saying your lucky just had stroke of bad luck at those places. Your doing good man keep it up and always remember that the best experience comes from experimentation.
Not trying to be critical just trying to help always climb cut you will have a better finish and you will have dramatically increased tool life and if cutting steel with this type of tool path run dry just keep air on it
he was climb cutting on the finish pass???
+snakeskinner2 what I was saying is always climb mill roughing and finishing
+Matthew Genton i agree in principal on climbing, there would have to be a unique situation
Not to mention that if you climb cut, most of the cutting forces tend to push the tool away, ensuring that you have extra material on the part, and reducing chances of gouging from high speed roughing. Combining all of the benefits you mentioned, and better chances of a good 1st part, you would think more climb cutting would be used.
Matthew Genton would climb for roughing mean more time? Just curious.
This speed up of cuts is nothing but beneficial and I think you could go even faster with coolant.
Thanks for sharing! :)
Nice job. Thank you for sharing.
Good video! Hope there are more just like this. This is the type of info that is sometimes hard to come by unless you learn it by trial and error.
NYC CNC The cost of few end mill tools and a few hours of your time is cheap compared to the $10K+ for the formal classroom time to learn the same thing.
Don't get me wrong, formal education has its benefits, but real world OJT problem solving is in my opinion more useful, it teaches how to formulate tomorrow's solutions unrestrained by yesterdays conventions.
Unfortunately, most formal education in my area of the US today seems more interested in teaching how to pass an exam than how to analyze, research, problem solve, think on your feet, think outside of conventions and continue to learn.
NYC CNC I hear you.
Wear it proudly like a badge of honor.
Surface finish, too late to go back and check now but tool runout, it's a lot more obvious at higher feed rates, I have also heard it said that for every 0.01mm runout you can expect roughly 3% less tool life, and with a closer look you can often see/measure more wear on one side of the cutter. Food for thought, I'm enjoying your videos! Keep up the good work.
hey man ive watched your channel for quite a while now and love it. fair play man you have came a long way to be honest. i just wanted to mention ive been in aerospace machining for 7 years now and recently we started to use cutters that were chatter free. in my opinion the best finishing tools ive ever used....just a thought for you incase you have not heard of them before.
Totally Agree with the lack of constraints. The school of hard knocks is an excellent instructor.
I just did a similar slot in steel with HSSCo at 1400rpm@40mm/min. One rough pass 160 mm at 4 minutes no coolant.
Fantastic vid John, as always. I've never tried those endmills for aluminum. Well wait, I did try one but crashed it right away and never got around to trying another haha.
no climb cut?
Great video man. Cool to see that a totally different approach can have such drastic results. Smarter is def better.
Thanks! Building my first CNC with help from channels like yours!
Peel milling is the way to go. Full flute cuts. I use this tool strategy every chance I get. HSM has a very nice option to do so. Your going to find out you'll save sooo much time. And let's face it, it looks pretty bad ass when running. Awesome video. I see more high speed machining in your future...... :)
Phil
Way to go. Don't be afraid of cranking up your feeds and speeds with a tool path like that at is doesn't load the spindle by very much. When I was making a spanner wrench out of 6061 for my lathe to remove the chuck, I used mastercam x7 with their 2d HSM tool path to be machined on a Hass Mini Mill. My initial speeds and feeds were 70 ipm at 4200 with at 1/2 2 flute HSS endmill at a 6% step-over and full depth of cut (.750). By the sound of the machine, I knew I could bump it way up. By the time I was finished tuning, I maxed out the spindle at 6K RPM and ran the feeds at 200 IPM. The spindle load didn't go above 25%. Absolutely no chatter and it only took 13 minutes with a finish pass to machine. I know that tormach is capable of more, don't be afraid to take advantage of what it has to offer. cnccookbook has some great info on HSM and stepover.
What your looking to do here is trocodial milling the trick is to have the tool constantly engaged onto the job works a treat as long as the machine has the power and the ball screws are up to it any backlash and it's impossible
Small mills and trochoidal tool path strategies are wonderful for increasing speed. As mentioned, climb mill, figure out how to maximize the circular path to one pass with a contouring clean up, and with a 1/4" 3-flute aluminum rougher at 5100rpm and a 25% step over in trochoidal, you should be easily able to run around 35-40ipm (on your Tormach) for that operation. Get your FLOOD running, and add a flood wash down handle (I use coil garden hose and an adjustable gun type hose nozzle). You will wonder how you managed without.
I can spray my enclosure/mill down and all the chips end up in an easy to remove pile, then airblast any puddled coolant off the mill/enclosure, takes 5 minutes at the end of the day and the next morning its clean and chip free for the next set of jobs or fixtures.
Really liked the slow motion, would love to see a similar slow motion of it climb milling at the more appropriate higher feed rate, you will notice a nice stream of chips in one direction which will let you know your dialed in
Keep up the great work!
Chris
PS... I run an even smaller G0704 mill so if it works on my 350lb lightweight, be assured it will work even better on your Big (to me) Tormach.... Hahaha
I don't know if this has been mentioned yet regarding your second pass issue, but I believe if you changed setting from conventional to both this would be eliminated. The second pass back I believe is to keep the cut conventional but by enabling climbing as well it should cut full width in one pass. Hope this suggestion helps :) I've never used CNC or even a DRO for that matter, I have a Cincinnati no2 mill and a 20s vintage Rockford lathe
Thanks John for the awesome video. I've never seen that method of cutting a slot before.
When I was taking my machining course we did an experiment to see what methods we could come up with to make a slot faster. Trochoidal was not one of them unfortunately. However we tried the convention way (your old method) and plunge milling (centre cutting end mill used). Plunge won hands down including clean up cuts. However tool life I believe would certainly loose big time. Trochoidal would be a win win.
One of the great things about having your own shop is the ability to test new ideas and experiment at will. When you work for others, the chances are you can't do that.
If you find the solution to the second pass issue, will you post it please? I'd be interested for sure!
What many people forget with trochodial milling, is that it puts a HUGE load on your machine when you have a moving table. Especially with me, we have a machine with anx axis of 1600mm travell, if i go trochodial, its gonna wear the machine down realy fast.
That was a cool video. I liked the slow motion.
As did I, it gave it a really scientific aspect or techno-aesthetic feel to the video, now if I just had a mill, LOL!!!
Well done on figuring out modern methods to enhance your Machining capabilities. if you ever need any help or any Machining tips , feel free to give us a call. manufacturing knowledge should be shared.
Looks like a job for a shaper.
.
I was noticing just how little oil is spat out of the MQL nozzle during one of the slow-mo clips. Pretty cool. ...unless I'm being fooled and that was air-only with just some residual oil in the tubing. And hey, big step up for my shop: I purchased a Bridgeport Boss 8 already retrofitted with Mach3 in absolutely amazing condition last weekend. Thanks for the vids as always, man. You're a huge help.
Hey nyc cnc I always look for speed and feed slider charts from tooling companies my favorite go to slider right now is a niagara one. today I ran a 3/16 swift carb 4 flute at 8000 rpm in some 303 ss I forget the feed rate but it was pretty efficient and definitely hsm worthy speeds and feeds with no damage to tool. maybe check out niagara I've used it on lots of different end mills - works great and it's free.
I am learning like you and sometimes when you work in places with old tools and machines you are learning tricks you can use in future for fast machining. Well adaptive clearing is good thing, but I think you do not need software to machine that slot. You can program one pass and use it as a local subprogram and just repeat it. You just calculate the number of repeats and after that you will do that finish paths and you are done at least that how I see it and the full program for that will be done if just few minutes.
Thanks for the great content. You make this look deceptively easy. I worked in job shops for a few years and know it’s not, even though it should be, but that’s another subject for another time. I like the slotting technique. In keeping the “out of the box” thinking I thought I’d share another nifty trick, this one for the manual lathe, that I thought you might find it interesting. I found it on You-Tube and regrettably, I can’t locate it again to give credit. There are times when one needs to be able to control the cross slide to fractions of a thousandth of an inch. The resolution however typically only goes to .001. The solution is to turn the compound (the thing the tool post bolts to) to 7.5 deg. With that done, the compound dial will move in the Y axis in a 1/10 ratio with the Z, i.e. for every .001in you turn the dial you will get .0001in on the Y axis (don’t forget that Z movement if you have critical Z features)
Idomake I have little experience with manual machines and I love this kinds of "tricks" that show how clever and resourcesful machinists can be.
Myself I only use the cross slides for a rough approximation then I use an indicator with a magnetic base, or use de DRO if it is available... then lazyness sets in :)
Idomake This trick is often shared with the angle being mentioned as 7.5 degrees, but actually the angle has to be set to 5.7 degrees to get the correct 1:10 ratio. ( sin(5.7°)~0.1 )
great tips again mate. Ive been looking to try this for a while, and finally today gave it a shot on some aluminium plate. Results: A slot that used to take my little 6040 about 20min now took about 8 - and went from a .5mm doc and sounding nasty to a 3mm doc, with 1.5x the feed rate (1000mm/m), sounding like it could take 4mm+ - and thats with dry milling on a cheapo 6mm endmill.
+NYC CNC Is this kind of toolpath for slotting only available for sprutcam? is there a specific kind of name for this kind of slotting?
+Dana Ng Found it, it is called Trochoidal Milling.
I know this video is4 years old now and youve probably learned allot, but a couple things I noticed. first you were wondering how to eliminate the last pass on the side. the easy fix is a looped sub program. look at one level of the code and make that a sub. then loop that sub.
I'm an Iscar Rep from New England and I see this kind of thing all the time. create the path using incremental and after the circular interpolation, create your incremental X move to position the next arch. make that a sub. get to your start point and start the sub using a loop. loop it how ever many times it takes to get across the part. this is not only way faster but the entire op only takes a few lines of code compared to probably thousands or at very least hundreds. lastly, climb mill and determine your radial chip thinning or thickening. use that to determine your actual feed per tooth and apply that to the recommended sfm.
in this case you would have chip thickening so if your normal feed and speed for a 4 flute 1/4 inch end mill was 1200 sfm and .004 per tooth, your normal feed would be 293 ipm. but due to chip thickening, a .0011 fpt would give you a chip thickness of .004 so your adjusted feed would be 84 ipm. all this doesn't even take into consideration with HSM, Dmilling, Tricordial milling your able to elevate your sfm 2-3 times the norm as the tool is always coming out of the cut and cooling down. unfortunately most folks don't have 40k spindles to take advantage of those abilities.
Be interesting to see you revisit this with Fusion360 and what you know now...
As others have said, climb milling the high speed toolpath will yield better results. You can leave less material without risking gouging the part. Also, think of the feed in terms of chip load. We typically run 1/4" tools at 150% axial depth (3/8" depth) and 25% at 150+ IPM at 12k rpm. Depending on your spindle power the tools you are using could feed at 60+ IPM without risking breakage. Try it out, you will be surprised and you will really see the benefits of high speed machining. The tools will take a lot more than you think and if you are machining parts for $$$ you will come out way ahead by pushing the tools, wearing them out, and replacing them rather than trying to make them last. For similar slots that are 2-3X deep my preferred roughing a slot like that is plunge roughing with a 25% step over.
Ive been using trochoidal milling for about 2 years, efficiency of our machineshop has dramactly improved when combined with quick change fixtures.
We use mastercam at work. We also use alot of tooling from iscar that are material specific ie tooling made for cutting aluminium and tooling designed for cutting stainless steel. Cutting stainless this way was the biggest surprise to me. Dry as well!
Yeah the thermal shock from using coolant rapidly cools the tool forming micro cracks that lower tool life. I try and cut all steels dry if I can. Just use air blast. I've found that I increase tool life 2-3 times.
You would have to travel to Australia lol. Its not my shop, I work for a company and im the main cam programmer for the macnineshop.
I would use climb cutting for this type of machining, your tools will last longer (due to less rubbing). I don't use SprutCAM, But I think that the reason your waterline roughing isn't machining to full slot width is part of the machining strategy that SprutCAM uses. When cutting a waterline cam programs use clockwise circles (when conventional milling) (climb-milling would use counter clockwise circles) however each time that Sprutcam finishes a circle it makes a linear move to the next circle. so at the end of one pass one side of the slot will have a smooth finish(left side on conventional and right side on climb) while the other side will be wavy (which Sprutcam thinks it needs to fix). the only way to remove that effect would be to use both climbing and conventional-milling. Like I said I don't use SprutCAM so I may be wrong. But This would typically be the cause In Mastercam or Gibbscam
So Try switching milling type to "Both" and tell me how that goes :-) That should remove the need for a return pass..
However to be completely honest, I would run It with climbmilling (to increase tool life) and delete the rest of the code after the first pass.
By the way. The "Expert Machinists" rarely have any real secrets, almost anything that is taught as "Professional" you can find by looking on the internet. and most of the time The difference is professional machinists have some different techniques for machining that just aren't adaptable to the "small shop machinists", "hobbyist" and "learn at home guy", Just due to the fact that we have access equipment that is simply not affordable to the typical hobby machinist.
BTW, I have been watching your videos from the sidelines for a long time Though I never really, took the time to comment much before. I just want to say That I love all the little projects you do, It is a lot of fun watching you over the years.
-Morgan
I thought it was a good video. I'm just a machine operator and don't know allot of things besides how to operate and setup a bunch of different brands of machines and styles (fanuc/convo/horizontal/vertical/3&4 axis/ multi-pallet cells) . But I always find your videos educational even when it's something I've done before because another perspective is nice and you explain things for the laypeople. I didn't go to school or really have training, I was kinda just thrown into machining when that department needed people and it's been a trial by fire since. Hopefully I can have a small work shop like you someday with just a couple manual machines and try to make my own stuff.
We had a job a lot like this, 0.25" 3FL carbide, 24000RPM, 0.5" depth of cut, trochoidal climb milling 375 inches per minute. Made a super quick "ZRZRZRZRZRZRZR" sound and we did an 8" slot fast enough you'd miss it if you yawned. Fanuc Robodrill can really make chips fly!
Experimentation like this is great fun. I have spent quite a bit of time doing this even with manual machining as well as other engineering projects. Btw, if the tooling from McMaster is not marked, call or email them and ask who makes it, they will most likely tell you. They can also special order just about any brand name you are looking for in anything, this is good for companies who have limited purchasing options outside of certain vendors even though they will often pay more.
McMasters tooling is usually as good as it gets. We get the same life as we would with Niagra cutters. They are far from Chinese junk.
Once I learned about HSM techniques, I have a hard time going back to the old way of machining. I find it helps small machines act like bigger ones. My little X3 mill does things I never thought possible with HSM techniques. I wonder what "herbie" could have done!
NYC CNC HSM for me is: MUCH better tool life, and less stress on the machine. I used to have to adjust the gibs pretty often. I've found that I need to do it far less now due to smoother cut profiles. I don't think I'm getting better MRR, but I'm just a hobbyist and don't really pay attention to that much.
if you do a lot of slotting horizontal milling is the way to go, I've seen a lot of your videos and I'm sure the shop has room for a cheap old bridgeport dedicated for horizontal milling. just a thought.
Running a 3rd axis milling machine with a 16 tool carousel, with a production spindle speed of 8,000rpm, I run 1/4 inch carbide end mills going 25-35 ipm, taking 50 thousands at time with a 5 thou, wall clean up. With a run time of 2 minutes.
To get it cutting in one pass, change the stock to be left offset to something larger, and take the extra off with a straight pass
That tool path is called trochoidal. For high speed machining you should be climb milling. The theory behind it is called chip thinning. By having a smaller radial engagement, usually you want 10% or less you can utilize the full cutter length while increasing the speeds and feeds. When you figure a chip load, that is based on center engagement. The further you get from the center the thinner the chip gets, but you have to be climb milling. Most manufacture tool charts I've found for 10% engagement or less call for about 2x's the RPM and as much as 3 times the chip load.
Interesting! Good video! Woo Buddy!
Have you considered using 4 fluted solId carbide end mill for finishing? In aluminium you should be able to double your feed rate. They are reasonably cheap and last for ever. You could even use one tool for cutting & finishing, saving yourself even more time. Have a look at Sumitomo Electric carbide tooling or Sandvik Coromant, they are fantastic tools.
Thank for the video!
With my giant manual boring mill I shove it all the way through than go one step to each side. Do it even faster than that. But I have a lot more rigidity as well
if you have a rpm of 5100 you should be feeding at like 35ipm if you use that dynamic milling. and climb cutting will eliminate that chip weld.
I've never used a vertical mill, let alone a CNC machine, though I have run a K&T 2H and a Colchester Mastiff engine lathe out of my workshop for quite a few years now, well, when I could anyway. But as everyone seems in a sharing mood... I'd use a .350 stagger tooth cutter on an arbour to mill this slot, as it would eliminate (nearly) the problems with chip evacuation, leave a good finish, and the tool would last practically for ever. However, you do this for a living, so my advice would be to trust your own judgement every time. If you disagree with something someone else says, don't just write of your own thoughts because they sound like an expert. Sorry I ranted on a bit there...
Funny how one shows stuff mostly on aluminum ....which in most shops it's not the usual material.
And..if your'e in high production, the fasted and best bang for your bucks for this job would be a side milling cutter, one cut only...also in steel.
Awesome video! I've actually just started playing with this technique as well. Have you tried it any using an indexable endmill? Should be able to absolutely crank up the feed rate with that and lower tool cost for inserts over a standard endmill
Hey John, I've been enjoying hsm paths lately myself. I don't have that odd hsm return you're experiencing. In SPRUTCAM I use the third option 'pocket step' I think it is whereas you appear to be using the 'pocket step and clean up' (or something to that effect - the fourth option). Try the third option and let me know if that is what you're after.
Regards, bk
I was hoping he would make a joke out of the line "some think it's boring". it's not boring, it's slotting.
and about the tool path, it's nice, but I can't hand crank that fast, haha!
Your speeds and feeds definitely could improve to get your cycle times down. I was going through 4140 this week with a half inch at 5615 rpm, 56ipm for an .015" finish pass. That was however only a side finish, I wasn't cleaning up the bottom. I like the spiral idea for the slot. Next time I need to create a keyway grove in a rod ill have to try it. I like watching your channel for all the tips, thanks a lot I'm like you i didn't go to school for this stuff basically learned from whoever would teach, or from trail and error.
I just watched you for the first time. I am a retired machinist and ran CNC machines most of my carreer. I have some observations and questions. Why a .250 endmill? First rule of machining is hold the work peice as firmly as possible, use the bigest tool that will fit, and extend the tool as little as you can. Basicly ridgidity rules the day. It seems you are programming with a remote device using "canned" programs. That's old school but works pretty well if you are willing to edit your programs. That slot should be done in 3 passes if you are looking for a nice finish. That milling process you used wasted time only because you used a small endmill. Even though you are using carbide in aluminum coolant should be used. Coolant would stop the chip welding, keep everything cool, increase tool life, etc. I would use a 3 flute .312 end mill to rough and finish. Leave .010 or less on the bottom, and climb mill on the return finish passes. I would start at 650 SFM and depending on your machine strength I would in crease from there. Pushing the feed up without increasing spindle speed is usually counter productive. I think you are doing a fine job. Hopefully more experienced machinists give their advise. That way you don't have to reinvent the wheel.
Most of my machining is done the "stupid way" as none of my machines are newer than 1970, many being older and 4 of them flat belt driven. I've managed like this for over 40 years and produced a very wide variety of items of excellent quality.I acknowledge and admire your "skill" on a CNC machine. I doubt I could operate one as I'm pretty much computer illiterate, but on the other hand I doubt you could operate a "proper" machine either. Nice video though. Regards, Ian.
Is there a reason why you're conventional milling? is there a plus to this rather then climb?
There is a disadvantage to this. I like the small Ap's and large feeds because I can just sharpen the endmill's end, instead of grinding the flutes, wich is a pain. It is a bit slower for a production enviroment, but for single pieces like I do, the programming time is much longer then the machine time anyways.
Sander Vercammen depends on the software. Mastercam is a breeze and it avoids redundant moves even if there is a window in the middle of your cut area. Use high speed to finish and you get much flatter parts. Looks ugly but measure it.
I just started a knew job running a milling machine. My question is what's the best way to find the center of a shaft to make a keyway? Thanks
Try 3 flute mills. Very usable
How about to use a saw (various thickness) to do a rough cut first?
I slot at full depth up to 3xD. More than that one hen I trochodial or if my roughing took is too small then I use trochodial cuts at full depth and at least 45-70% engament
Hey NYC CNC, I really like your videos. I just recently discovered your channel. I work as a CNC programmer and have been in the business 11 years. It's fun to watch someone learning different techniques of machining and doing testing. After watching this video I had a question. Was there a reason you ran the roughing tool path conventional cut vs running it climb cut?
really enjoy your vids. wish I could use fusion like you use it. can you work with a 3D dwg wire frame? if so I may have some work for you.
I'm not sure what your max spindle speed is but you should be able to max it out with a carbide endmill. 1200-1600 for your cutting speed and .002~.004 chip/tooth. 5%-10% stepover and definitely try to climb mill. Try checking into radial chip thinning formulas and you should be able to get your feed rates over 100 ipm for roughing your slot and your normal feedrate for finishing.
Hey first like your channel. Second is there a way in your CAM to up your step over to get it done in one pass? Otherwise just add stock to leave and do 2 contour passes thus would get a better surface finish and hopefully get rise if the "ripple" effect
Run your feeds and speeds higher. I worked in a shop for two years where we typically maxed the spindle on aluminum. Finish passes ~40 IPM and roughing ~80 IPM on faces. Don't remember what feeds we used in pockets like that, sorry, but using high speed machining the tooling goes FAST.
Thanks for video.
Did you find the error for the extra stock?
Hi John I'm Brian. Been watching you weekly episodes for a while now and they're the biggest reason I bought a Tormach 1100 and started making my own parts. Love this video and I've been playing with this type of tool path myself trying to slot through 1/2 thick 304L plate. I haven't had much success. When climb milling the beginning of the cutting arc it screeches real bad then the carbide tool chips from all the chatter. When conventional milling the start of the arc cuts good but the end chatters. Weird!!! Anyway I'm using HSMXpress which is free with Solidworks. Using the Adaptive Clearing on a slot will generate a trochoidial tool path with this CAM. However tool diameter vs. slot diameter is important in HSMXpress and may be with Sprut as well. I had trouble at first trying to generate a tool path if the bit was to big compared to the slot. You might want to try a few different tool diameters to see if you can get rid of that pesky second pass.
NYC CNC I've had the tormach for a few months now. Yes almost exclusively machine 304L as I custom make exhaust systems for Nissan GTRs and now design and machine my own flanges (thanks to your awesome and inspirational videos).Have had excellent results with HSS CCC endmills (Cheap China Crap) but the machining time is just way to long. Well over an hour per piece. I'm now using Cobalt with pretty good results and acceptable machining time of about 30min per part. Have had zero luck with carbide as they seem to screech then shatter as soon as they touch the work piece. Have used several types and brands of rougher and variable flute EMs with every feed and speed that Gwizard and HSMadvisor spits out with the same shattering results. Hopefully when I figure out the recipe for carbide and can use a trochoidial tool path I can cut machining time down to 15min.
I'm not sure if you have tried this ..but wd-40 loves aluminum spray your cutting tool and part before and while your running..the aluminum will not stick to your tool at all , this also works to clean you flat stones spray some on them rub with your finger and whip off....also great for files spray before you file any burrs then blow the file off...clean....with aluminum you don't need a rougher up the rpms and spray it down......works great
I know this a bit of an older video, so OK great use this type of slotting operation to make a first operation slot for a t-slot. But any thoughts on advantages or disadvantages of using that type of tool path as a second operation with a t-slot cutter?
just open your gcode file in a text editor and delete all the code after the line where the end mill finishes the cut after the first pass. But keep the end of the code that tells the machine to go back to home etc.
I'd love to sit down for a beer with this guy. he seems very book smart and knows what he's talking about but I'd love to show him a few tips and tricks. Really get those tormachs humming.
JOHN I wonder if you still belive this is the best way to make a slot i think yes its a good way for using a square endmill but if you have the options a solid carbide feed mill slightly smaller diam is much faster way of doing this the finish the side walls and bottom with square endmill
I have no idea what I'm watching but this was cool. Thanks.
If your going to experiment how fast you can go as far as speed with aluminum, I can assure you that much faster is possible. I have cut aluminum at 10,000 rpm with up to a 1" carbide end mill with flood and up to 60,000 rpm with a 5/16 low helix single flute end mill and denatured alcohol mist. I'm not sure what the Tormach tops out at. I don't remember the feed rates off hand either but I'm sure you could formulate that.
Did you ever figure out the spacing issue in the cam? I don't have sprutcam, but with mastercam you can tell it how big the "Toroidal circle paths" are, I also think its called peel milling...
;)
A horizontal mill will cut even faster. It can take the entire slot out in one pass and still move at 15-16 IPM.
david
A 1,5 million $ / 35,000 RPM / 115 HP milling machine would cut this 6" long slot full depth in 1 pass at 200 IPM, 2 passes at 300 IPM on finishing, giving a cycle time of 4.2 seconds.
A Tormach PCNC IS NOT this kind of machine.
;)