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!

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.

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.

Nice John! I suppose we are the KZfaq 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.

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.

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

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.

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.

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

no climb cut?

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!!

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).

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

+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.

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.

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.

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

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.

I just did a similar slot in steel with HSSCo at 1400rpm@40mm/min. One rough pass 160 mm at 4 minutes no coolant.

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.

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.

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...

I've been an applications engineer for 20 years served an apprenticeship @ Rolls Royce aero in the UK got a masters degree in engineering from what I've seen your work is neat tidy and you work safe any of these. So called professional journey men master machinist are 100 a dollar as you say in America I've been in this game 25 years and by watching your videos I've learnt a few things that I didn't know so you never stop learning and don't let any body tell you different or disrespect what you have accomplished

Ive been using trochoidal milling for about 2 years, efficiency of our machineshop has dramactly improved when combined with quick change fixtures.

Totally Agree with the lack of constraints. The school of hard knocks is an excellent instructor.

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

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 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.

Looks like a job for a shaper. .

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.

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)

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.

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

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.

A few notes (secrets?): use only climb-milling for your HSM-style paths (this one is a [edit] trochoidal path), it will save your tools in the long run by throwing the chip behind the cutter aiding in evacuation and keeping a more consistent load on the cutting edge (instead of feeding the edge into the material); at 5100 RPM, due to the chip-thinning effect, you should be able to take that full-depth cut at twice the feed (40IPM, but remember: CLIMB ONLY). As to the slot width: there have to be other settings in Sprutcam for getting that closer to finish dimension. I'd leave .01" for finishing... but that's my preference.

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.

Why not take 1 full depth of cut down the center with your rougher. the use the finisher in 1 pass to clean up the walls? much simpler. T1H1M06 S6500 M03 G0 G90 G54 X-6.Y0. G43 Z1. M08 G0 Z-.5 G01 X6. F50. G0G91Z0.Y0. M09 M05

First comment is if you're only cutting .350 deep, get a tool that has 3/8" LOC. If you hold the tool with only as much as you need sticking out you'll have much better rigidity and be able to get your chip load up and therefore your volumetric material removal rate up. It looks to me like you're going from a 2 flute to either a 3 or 4 flute tool. You're always going to increase your volumetric rate of removal by using more flutes. So you're speed comparison is not simply because you're using a "high speed machining" CAM process. It's mainly because you added flutes and bumped your feeds up to keep a constant chip load. Btw, you mentioned if you just use the tip of the tool you'll wear the tip prematurely. Not necessarily true. The tip will wear whether the rest of the tool is engaged or not. It's a matter of linear cut distance and with more passes at shallower depths your linear cut distance does up. However, with your high speed machining path your cut distance is increased as well due to all of the little circular movements. I think the real lesson you learned, or should have is get the right tool and know how to maximize your volumetric rate of removal. Shortest tool possible, as many flutes as is practical, deepest cut and highest chip load as you can handle. If chip clearance is an issue, run high pressure coolant or air. Also maybe try ramping along the length to help with chip clearance. If I run a 3 flute at 16 ipm and ramp from one side to the other down to a depth of .175 I can get the roughing done in 4 passes which should be around 1.5 min, then finish takes around 30-45 sec. Shouldn't take longer than 2.5 min and shouldn't require a tool change. Another note, some controls will have trouble storing all of those lines of code when you run loads of circular interpolation. That type of tool path is very memory intensive. Oh and climb cut all the time unless your machine is sloppy.

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.

As a Fitter and Turner, seeing someone/anyone get to where you are by essentially teaching yourself makes me respect you even more. But people like you always end up with way more skill because you do it cause it interests you and its not 'just a job'. You might like to subscribe to Sandvik's KZfaq channel. Those blokes have put untold squillions into figuring out faster and better ways of doing things and they have tons of videos with very good tips.

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.

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.

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.

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!

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.

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

Also, don't think I'm condescending to you, 'cause I'm not. We've followed (and are still following) a nearly identical path into the world of machining and manufacturing. I just got started a little earlier than you did. I bought my first machine in 2001, a Rong Fu knock-off (not even a name brand junker, lol) that I and a buddy converted to CNC while I was in engineering school. Then came a very old manual Bridgeport Series I, then an ancient small-ish VMC (new 1994, 22"x16"x16", 22 tool ATC), then a brand new Sharp LMV50, and lastly (in 2007) a brand new PM1660 gap bed engine lathe. Since I had never done any kind of machine work prior to buying that Chinese mill/drill (which we referred to as "The Chimetric Wonder" because all the fasteners were neither imperial nor metric in size, but half way between both, meaning an adjustable wrench was the ONLY tool you could use on it), I was very cautious about how I did things, and tended to use the CNC for things that it really wasn't needed for. Then in ~2005 I had a stretch where the CNC was dead in the water and needed more love to fix it than I could muster. It was down for almost three months all told, which forced me to embrace my manual machine in order to get anything at all done. This hiatus from my go-to machine forced me to get comfortable with the manual mill, and once I did, I realized that a great many things are not only faster but also easier to do on a manual machine vs the CNC. This realization is what prompted the purchase of the second manual mill and the manual lathe (in late 2006 and early 2007, long after the CNC had been fixed). Keep plugging away at it and really try to embrace the manual machines. Doing so gave me the confidence in my abilities to undertake a lot of projects currently that I would not have touched back in 2005, and that sense of being able to tackle any job I might encounter has finally gotten me to the point that I don't feel like a total fraud calling myself a machinist.

This speed up of cuts is nothing but beneficial and I think you could go even faster with coolant. Thanks for sharing! :)

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.

The first way you tried it- Take it in 2 depths of cut, at 30 ipm. To start on the conservative side. And faster rpm if you can. And change it to climb milling (the second pass).

Thanks John. It is always good to see new ways to go about "common" tasks.

Always climb mill when using an HSM path. The HSM paths rely on radial chip thining to keep an even load on the cutter. conventional milling reverses the radial chip load on th cutter and it's what's causing that grinding thunking noise on that first pass and what's causing the welding build up. For depth of cuts, you can go as deep as the flutes on the cutter. Depth of cut is a factor of spindle horsepower and requires no adjustment to speeds or feeds regardless of depths (unless your cut depth exceeds your spindles HP in which case back off on the chip load). But the deeper the cut the better. Provides better tool stability in the cut and drastically increased tool life.

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.

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.

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.

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.

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

I love that shot at the end when you've got the Tormach behind you and the venerable old Bridgeport over to the side.

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.

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!

You will have much better results if you climb mill with profit milling. Our shop is just starting to get into HSM. I don't know the capabilities of your Tormach machine, but we are running 12,000rpm and approximately 300ipm with a half inch high helix 6 flute endmill.

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

Cheat on the y axis to center the roughing pass, cheat on cutter comp to widen roughing pass, delete second roughing pass, punch in finish pass by hand. Spurt cam path fixed. Its hard to find cam software that can be improved some how.

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

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.

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

Im not sure why a slot only .350" square by approximately 8" long would take 4 minutes. At a minimum of 400 sfm and a chip load of .0022" on a 3 flute endmill, you should be able to rip through that in 2 steps in about a total of 30 secs. Most endmill brands will handle those speeds and depths. I know Helical Solutions aluminum cutters will with no problem.

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.

How does the finish compare between the first tool alone, and the combination of the first and second tool? The Lakeshore Carbide tool is advertised as a finisher-rougher, but I wondered what your experience has been. Thank you.

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!

You sure have come a long way and learned a lot since this John.

Should be running that size at one finish tool climb cutting with coolant at 15k RPM and .003-.004 ipt and about 15-20% radial engagement

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.

This video points out the downfall of lower cost machines. If you took that tool path, and upped the spindle to 15k, and your feed to 350ipm, then you could call it hsm. I do agree with your premise of adopting a new approach, but if you invest in your tools, they will return ten fold.

Be interesting to see you revisit this with Fusion360 and what you know now...

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

Great for roughing out :) I started something similar in our company programmed all at the control. Trochoidal milling if I remeber correctly. Guys worked 10y on the machine and never seen this milled by new guy (me) :D Now I use SolidCam for 3 years, iMachining do this type of milling, big DOC low WOC with same engagement in cut. Works great, You can try it out for 30 days free if u have valid SolidWorks licence. Best thing for me, and belive me I tried almost everything worth mentioning. You can contact me if u have any questions, try it you will like it.

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

Climb mill with your high speed roughing toolpath. You will find little or no chip welding on your part. You should also run faster rpm. You should be maxing out your machine 7000-10000 rpm. Also you should check out Autodesk Fusion 360 CAD/CAM. It is very cheap and has some fantastic high speed toolpaths.

Is there a reason why you're conventional milling? is there a plus to this rather then climb?

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

How about to use a saw (various thickness) to do a rough cut first?

0:17 I don't think it's boring, it's slotting :P, Great video, thank you very much!

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.

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.

is there a point where the trochoidal milling makes so many extra moves that the ways or ballscrews wear out faster? I'd rather an endmill wear out over the linear bearings or whatever. Just curious if anyone has talked about this before?

333 surface feet per minute? Um... I START at 800 and go up from there. Also, .350 wide slot use .312 dia 2 flute @ Z-.165 per pass. So that's 3.82 x 800/.3125 = 9,779 RPM x .002(IPT) x 2 flutes = 40 IPM feedrate. So, 2 roughing passes 9800RPM @ 40 IPM = Z-.330, 1 finish pass to clean up, same rpm/ipm. If you don't have the spindle speed recalculate. You can probably increase IPT to .004", keeping in mind you're building tool pressure. Coating definitely helps. Lots of coolant!

i am doing slotting in steel , I quit using this technique times ago as it make me loose lot of time , I just slot with full OD and guess what , my tools are lasting longer , by the way I use TIAlN tools coating .

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 was considering buying a Tormach but if you have to do all that to mill a little slot in Alum. I think I will just buy another ProtoTrak

Good video! But why are you doing conventional milling instead of climb milling for this?

The slow-mo shots are awesome.

In my opinion better is use Roughing End Mills with 0.5mm bigger in offset with normal linear move g41 and than finishing with End Mill.

DATA FLUTE is "my" solution for better cost per part ratio. High end performance. Longer tool life and amazing customer service. Sandvik Coromant is a close second. Go "smart" or burn up tools and money. Invest wise on your tool purchase, think long term.

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.

If my CAM had HSM/trochoidal I would be all over it. It doesn't so I've had to learn to make slotting into a science. I discovered that slotting can be just fine provided you clear those chips. In fact paradoxically the most gentle and high MRR cuts I've done are slotting. I tend to run the slotting to the hairy edge of failure but the tool life is superb and it ends up being almost silent. Staying in the cut instead of constantly re-engaging definitely promotes longer tool life. You have to have decent PSI (~7-8psi) flood to clear the chips though. When doing these cuts if I move the nozzle away for an instant the tool will snap like an icicle. If you get to using flood, give full depth moderate feed slotting a try. On a Tormach 1/2" in Al would probably be ok but a 3/8" should go through it like a light saber. In steel going bigger than 3/8" ends up being a diminishing return so I would stick to 3/8" there. I don't have a lot of experience with aluminum but every time I do cut it it seems like warm butter by comparison to the steel I normally cut. I won't belabor the climb milling issue, I haven't read the other comments but I bet you're getting an ear full. LOL

WTF??? Where's the Hangsterfers water soluble? 3 flute uncoated for al alloy, forget high helix, usually use rougher and finisher (ie.- new), always use as much of the side of the tool as possible, but most importantly, forget about getting a perfect script posting from any tool path program. Even MasterCam can be quirky as hell, and the guys who developed the software ain't the guy cutting the part. I used to program on "G-Zero", an old basic program without all the "bells and whistles". I quickly learned to get the graphics doing sorta what I wanted, posting a rough script, then doing wholesale edits to get it where I wanted it. Like inserting multiple cutter comps for the same tool on different features on tight tolerance parts. G code is easy to learn, and editing in a simple word processor can be done very quickly. Cut and paste can work wonders.The graphics engine is a great number cruncher, it is really handy for stuff like developing a helical interpolation with cutter comp, or a radial step over pattern like what you were running, but I have always viewed the posted script as a starting point, not the finished program. As always, the best stuff is finished by hand... BTW, try using a shorter end mill. Helps reduce chatter, better finish, better tool life, and can be run faster. One other point; raw cycle time is no substitute for good planning. I wish more shop owners would learn that.

Hey John, Whatever happened to your Atlas horizontal mill? Seems like that would be the perfect solution to your slotting problem ;-)

Why are you programing a CNC mill in inches per minute? That is an archaic holdover from manual machines where the feed and spindle couldn't be synced. Take your chip load, multiply by number of teeth and use that in inches per rev. You can now use your speed override and maintain proper chip load.