Cutting Steel on a Desktop CNC

[@Jrez]

Get a Machinist's Handbook and look up the proper feeds and speeds

[@NithinJune]

this is old i think, i’m pretty sure this dude is like a machining expert by now

[@NithinJune]

i think he literally has a 5 axis machine

[@Jrez]

@DarthNithin Fair enough, it just came up in my #shorts feed and it takes an extra click or two to reach the video description so I check things like that very little compared to normal videos. Still, the comment is also for other potential viewers who are new to making/fabricating/machining or w/e.

[@hydroxide5507]

formerly chucks

[@court2379]

That isn't the issue. It's the design of the machine and that he is climb cutting. Switch that and then evaluate the speeds and feeds. But know, the values it states are the ideal numbers. They assume a rigid setup, good chip evacuation, good cooling, and enough power. In the real world you often need to run 1/2-1/4 the ideal speeds due to deficiencies in the above. Cooling usually being the biggest problem unless flooded.

[@brionthomsen7479]

you are feeding the wrong direction--always feed left to right---the chattering is caused by the bit trying to climb the wall

[@frp1276]

If only things were that simple.

[@ferrumignis]

Climb milling is perfectly fine provided your machine is rigid enough for the depth of cut and doesn't have a ton of backlash.

[@-8_8-]

Probably correct as this is a desktop mill and probably has the gibs of a knee mill. But on a CNC you typically climb mill.

[@joshuakuehn]

​@@ferrumignisyeah if his machine was more rigid climb milling would work but if it's a home gamer system it's probably not that rigid

[@DaveBlais]

Ferrum Ingnis is right. If the machine isn't really rigid, conventional milling is the best and climb milling is best avoided. Also, tired endmills should be used on softer materials. A coral end mill for your roughing might help?

[@MorRobots]

Don't climb mill on a desktop CNC at low spindle speeds and aggressive feeds. Tune feeds and speeds with conventional milling and your spindle absolutely ripping fast. Then step the feed up as you drop the spindle speeds. You will find a sweet spot where the two meet and you get perfect chips. Then find the relationship between that point and how much you can decrease speed and increase steps while maintaining similar performance. Then convert to linear speed and your overall tool engagement. Congratulations, you now have your default starting point for all new tooling in that material while doing conventional milling.

[@jeremyjohnston9120]

dude he is machining steel not aluminum, you want lower spindle speed, not "absolutely ripping fast"

[@charmzee8749]

This is the proper way .

[@charmzee8749]

⁠@@jeremyjohnston9120Um…not really depends on the factors. For a strong machine you are right but for a puny desktop one or a conventional cnc…f no you will burn tools faster . You need to find the sweet spot and you can find that by having a fixed feed let’s say 1000 mm/min and a 2400 rpm , start cycle at around 50-100 and gradually increase it until the chips fly nicely then you make the ratio . This method prevents you from having stuck plastic/Aluminium chips from sticking to the tool, prevents early wear in steel, prevents breaking pieces in cast iron , prevents premature axis wear and so much more.

[@jeremyjohnston9120]

@@charmzee8749 no. Machinery handbook

[@lonewolftech]

@@jeremyjohnston9120it’s a weak ass machine… less feed more speed.. they aren’t even designed for steel.. nothing in it is even steel accept the collet and end mill..

[@justsomeguyoverthere8002]

It looks like you're feeding it the wrong way. You need to feed in the opposite direction of rotation. From the clip of the first pas you need to go from left to right, not right to left. Your bit is pulling itself along and that's what's causing your chatter. This is called climb cutting which is only really useful for finishing passes when very little material is being removed. The reason the hole cut has less chatter is due to it being a traditional cut instead of a climb cut.

[@zechbaker6970]

No climbing millings is the recommended industry stand for cnc Milling, and the the pocket he does is also a climb milling path

[@paudan1284]

​@@zechbaker6970 yeah but this machine obviously can't handle it. either too much backlash w/ no eliminator or it's just weak.

[@maxmaynard1596]

​@@zechbaker6970 Yeah, industry standard. If you'll forgive a bit of wordplay, I don't think they make imdustrial desktop mills.

[@jamescrud]

It won't make much difference. All the chatter is mostly because his frame is simply not rigid enough. They entire spindle and frame is bouncing around because of the forces involved.

[@mastmec]

Looks like your cutting the wrong direction.

[@bryceg5709]

1st step is check your spindle run out. Such endmills need as close to no run out as possible.

[@bobelkiniii1461]

That ER tool holder will spin super true as long as he has the right collet

[@bryceg5709]

@@bobelkiniii1461 right if it's a good tool holder a good collet everything snuggled up etc. Still good practice then to check run out. I've had some where you needed to clock the collet just right and some end mills are crooked. But the smaller the end mill the less tolerant to run out. You could have several thousands on a half inch but if your running little tiny end mills they need to be darned near 0.

[@briankelly7738]

RPM and feed direction. That should help a ton.

[@peglegjim57]

I’m old, and don’t know if it’s still done this way, but “back in the day”, my co-worker (from Switzerland) said he had to hand file every type of metal(s) in their machine shop for TWO YEARS before he was allowed to run a machine. It was the standard apprentice training process of the entire region. “We have an intimate knowledge of the properties and personalities of every metal, long before we lock it down on a machine.” He was the best machinist I’ve ever known.

[@Neoprenesiren]

That’s a moronic requirement.

[@kugelblitz1557]

That's how my mentor was trained. I'm somewhat the same. I clean, sweep, deburr, and saw cut. When I run out of that I get to watch people run the machines, do the math for them, and press the go button. That way I learn the stuff like "always set your tool offset from a fixed point" the easy way.

[@konkon7767]

Congratulations, you've learned that Climb Milling is not for hogging out material. It's for a very light cut to produce a smooth, final cut finish.

[@Caseman91291]

Depends on your setup and tooling.

[@Peron1-MC]

@@Caseman91291indeed and this setup and tooling is not for that clearly.

[@dambroangling2828]

Actually that's only for a Manual mill. CNCs are the opposite. You almost only climb cut with CNC, and rarely with manual.

[@skurtov]

The tools should come with optimum settings for the material being cut from the manufacturer. Try taking smaller cuts in and use less radius of the tool. Where's your lubricant?

[@netherialdreyrimani]

depends on the material, different types of steel, different metals in general have different speed and feed rates for different heads depending on the number of cutting surfaces and the diameter of the endmill. Hell even the maximum rpm of the machine you are using goes into factoring the speed and feed rate you should use for it.

[@netherialdreyrimani]

you also dont need lubricant for end milling generally, but you CAN if you want to.

[@drakebletl7754]

It's climb cutting versus conventional cutting. Conventional cutting feeds right to left or against the cutting edge so the blades are pushing material toward the cut. This style of cut is used on manual cnc machines like Bridgeports. When using any automatic cnc machine you climb cut the material left to right and maintain a constant feed of coolant for a nice finish. I hope this helps in your future videos.

[@ReactionTime344]

Don't you have a 5 axis machining center now? Crazy to see how far you've come

[@BreakingTaps]

Haha yep! Quite a step up from this old desktop CNC :) Hoping to get some more machining content on the channel in the future, it's too neat of a machine to not show off sometimes :)

[@dannydetonator]

​@@BreakingTapsYou're living a dream of mine. Thank you, inspirational.

[@willrandship]

oh, you weren't trying to knurl the piece?

[@assassinlexx1993]

He was going for better gription ;)

[@canonicaltom]

There's a reason the Avid CNC and other CNC routers are not CNC mills and not rated for ferrous metals. The spindle speed can't be set low enough to cut steel properly. But as you've found by experiment, it's certainly possible to rub the steel off at high speed without really cutting.

[@wolf310ii]

It has nothing to do with the spindle speed, these routers are just not rigid enough

[@canonicaltom]

@@wolf310ii Having milled steel on a Sherline, I can tell you that rigidity is not the most important part of the equation.

[@wolf310ii]

@@canonicaltom Yes it is, more than RPM and a Sherline is far more rigid than a CNC-router

[@tophatvideosinc.5858]

Have you tried keeping to the optimal speeds and feeds of your mill but program in a reverse finishing pass? Taking a cut in the same direction the tool is spinning (like a wheel on pavement) makes for a very decent finish. Say you want to just make a square that is 1" and you have a billet that is 2 inches. You start normally, keeping to your speeds and feeds (minor adjustments for longevity of the machine and tool if needed) but otherwise ignore the quality and chatter. But once you get within a tenth of the part, make your last 2 passes shallower and slower. One being .05" and the other .045" if possible with your tool. Then the finishing pass can be done counter to the pathing orientation at 0.05" (in Anoka tech I was taught the term "walking off the chatter"). Of course these measurements are just made up and most of the time with accurate dimensions you'll be working in thousandths or even thoudths for finishing passes let alone hundredths. The same method applies, sneak up on the finish. This can be hard on machine that dont have ballscrew leads if you take heavier cuts. You probably know more about this than I do since you've likely learned everything I have and been around long enough to apply it professionally. I only went to school for 4 years for metrology, cad, machining and mechanical engineering and haven't been around long enough to apply what I've learned to great effect yet.

[@2098662]

The rotation of the bit is clockwise. Running left to right causes the bit to cut into the piece. Right to left will make the bit far less efficient and more likely to skip, bind or go off course entirely. Thanks for the knowledge eddy. (Cnc coworker)

[@hitmonkey2984]

"well it didn't like that" The number of times I've heard or said that on a fresh program. Lol

[@Meg_Lovegood]

Kennametal Jobber Length Drill Bit: 21/32" Dia, 143 °, Solid Carbide

[@cheifDeisel]

As others have said your feed direction is an issue and it may seem counterintuitive but often times we would slow our RPMs and up our feed. Depending on the material that you're cutting, taking bigger bites will help you stay in front of the work hardening. If you think about it if you are feeding at all your leading edge is always striking your material so if you're not taking as much each time then your leading edge is striking the material far more times over the course of a part than it would if you'd just let it eat.

[@beinganangeltreon]

This might improve CNC milling. I recently saw a youtube short about how a big magnet swung towards a piece of aluminum had a sudden slowdown right next to the akuminum from eddy current magnetic repulsion caused from magnetic damping. putting a nonferrous, or ferrous chunkt washer at what I think of as the connector to the spinny part, kind of like a chuck, and then putting a toroidal magnetic winding next to the chuckish thing would cause back and forth motion or cyclic oscillation of the cutting head to be greatly magnetically dampened, minimizing cut variability from being more on true. a nice bonus would be computer measurement of unpreferred vibration with dynamic adjustment to least vibration at each batch of identical machined parts. stuff would come out better, and cutting might be faster. Its as cheap, and kind of like a monochrome TV beam steering coil.

[@240sxRule]

Climb milling is fine. Especially with a solid carbide endmill. If anything it takes less energy and is more efficient. Its just the feed.

[@TritonTv69420]

(3.82 x 300 to 800) / tool diameter Take that number then multiply by n (flutes) x .001 to .0075 or more depending on what the machine can handle and your ratial engagement.

[@shwathekid]

Don’t know what you should do as I don’t know shit bout this but it looks dope 😂🙌🏽 keep it up

[@brandonmccaskey9337]

For such a light spindle in steel you'll have to cut the opposite direction. It's pulling the machine into the cut because of the cutting forces instead of forcing the cutter through the material

[@avocadoarms358]

Please do this again but actually cut a part out, I’d really like to see how it goes even if it’s slow, the more access we can give makers to make new stuff the better

[@corysnyder5862]

Try changing the direction of cut, also make sure you are using the right endmill. There is a conventional cut and a climb cut where the flutes are reversed

[@shoktan]

If you don’t have a rigid machine, never climb mill. The tool will want to dig into the material and “pull” the table along with it. I’ve seen this happen on a Bridgeport when someone was climb milling tool steel. The end mill “grabbed” the part and the the whole table was yanked to the right by several inches.

[@BloodThunda]

A word to the wise, if you are struggling with chattering like that, you did it the wrong way around, you actually want to decrease the spindle speed and increase the feedrate. Chattering is causes by vibrations and the tool is literally bouncing off the steel. You want to put more pressure on the tool so it is not allowed to start bouncing. Less spindle speed means less vibrations as well.

[@fightme5543]

Climb-milling buddy! Keep in mind you want your cutter to pull into your workpiece, not push away from it like that!

[@garywemmer9342]

Also helps to have coolant.

[@JesseHughson]

Some of those cuts were looking pretty good

[@jeepmanxj]

In general with a machine that's not super rigid you want to conventional mill, not climb mill. Try a lighter side cut, or take half of the depth and see what you get.

[@favorisofmyname]

In case you have a frame not stiff enough or steppers or motor not strong enough ( which looks like that), you should mill always counter clockwise.

[@justinbelshe]

Still a useful tool, potentially, and I'd be proud to have one in my shop. You just can't ask too much from it, it's a little baby! Maximum spindle, minimum feed, use some kind of badass modern cutting tool.

[@Brap_Lord]

Feed direction is wrong, also for a desktop end mill you could try a higher feed rate if you shaved off less each pass- ex: twice the feed rate but cutting half the thickness would do it in the same amount of time, but with it not being a full sized CNC then this would prevent the motor from bogging down and drawing more amps than you would want, which would also save your bit as well. This may not work with steel idk, I’ve mainly ran a router in wood, plastic, and aluminum, haven’t done any steel

[@bliviont]

Yeah climb milling in the wrong direction will make everything worse. Like everyone else has said, feed against the rotation of the bit.

[@itsamepersonio7338]

I thought this said a tabletop Civic and I was wondering why anyone would want a paperweight Honda

[@RacinJsn]

I recommend 7-flute fast spiral titan line form OD tool in Attleboro MA. .001 feed per tooth, conventional milling to start. Usually stick to multiples of 1600-1800rpm for best harmonics.

[@boldsword1]

Rigidity/ backlash Need to dampen the spindle movements

[@g8rh8r100]

Try feeding in the right direction. The chips should be coming off of the front leading edge of the cut not off of the trailing edge.

[@blakeengland7784]

Your bit is climbing whenever your feeding from right to left, and if you can take that much meat without breaking bits or spindle, youve got yourself a real workhorse for your small projects

[@lazyofficial3552]

Do Americans actually know that there’s cutting value tables ? You can actually calculate what the best speed + RPM is by knowing wich steel, wich cutter (material) and what diameter (cutter) you’re using….. at least that’s what machinists in Germany do 😅

[@ThielVision]

You can get feeds and speeds from the company you bought the tooling from

[@chrislea8239]

Been there done that. Same problem on a cnc router. All to fast ! Or use a buttload of coolant and then you'll struggle. Or have a fist full of end mills or slot drills.

[@outerthoughts30]

Try using surface feed. Or using a small step over at full length of the endmill. Maybe use a chip per tooth. Or. Idk. Open a machinist handbook or something

[@NickyDoyle]

This issue without seeing the machine build but this looks like the axis are not rigid enough. When the load is low key when high rpm or low feed it will be ok but once you push it will will climb and jump

[@cetyl2626]

Rule number one with machining: make your machine a rigid as possible. Way more than seems intutative. A relatively light machine will vibrate. In other words your chatter is almost certainly due to the machine. Taking a less shallow pass (less load) and making your end mill as short as possible (more rigid) will help.

[@vmac159]

The first cut is the deepest🎶

[@garywemmer9342]

Carbide... Miracle material!!!

[@johnjon4688]

Oosh. There is a ratio you need to follow for bit size, number of flutes, bit composition, type of cutting edge, and material being cut. Rpm and feed rates. Also, direction of cut depends on cut method and the material.

[@haavard1989]

Look up the vendor for speeds'n'feeds and then adjust it down to fit your machine 👌

[@omgnowairly]

Speeds and feeds are in the machinist handbook at the back. You need that and the chart with the endmill to dial it in. After that, slack will cause that chatter.

[@mannyvee]

You should try conventional milling instead of climb milling. Climb milling generates higher forces and is unforgiving on machines that are not rigid enough. Of course there are many factors involved but unless you have very heavy duty steppers it will likely never be rigid enough to climb mill steel.

[@WCGwkf]

Depth of cut is your issue (stepover and length of cut). You obviously know about feeds and speeds and how to play with it. Such a light machine you're very limited to how much tool engagement you're allowed. My guess is you're going to be limited to .005 or .010 depending on flute length engagement. You can't just say "feeds and speeds" and ignore the machines capacity of rigidity and torque.

[@DevS25]

Okay Step 1: Let the coolant flow in the area being cut.

[@ARM0RP0WER]

looks like its either air cooled because of the air blowing away the cuttings or there is none

[@solentshredders7929]

That's what I was thinking 😂 you shouldn't cut hard metals or it will do exactly the problems he's having!!!

[@Depth_of_Cut]

Looks like it's not ridgid enough for climb cutting or there is backlash in the lead screw. Try going the opposite direction if it goes away then its one of the above. If it's still there then the spindle bearings are too loose or the spindle is just too flimsy for that depth of cut.

[@kevinmerai6092]

I think using a coolant would help improve the quality of the cuts and the longevity of your bit

[@KittMonsta]

You know that there are tables for this so you don't need to try and error. You can calculate it.

[@whtkngofc]

whats the stepover?

[@NA-oq4ty]

Just read my previous post and my speech recognition made a mess out of it. You can't move the mill in the direction that the chip out is going. It makes the mill chatter the way you observed. Also I observed that you reversed the direction you were operating the mill when you were making the circle cuts. Keep this in mind. Planned ahead. Work carefully.

[@1ftintheflames]

Mild or plate steel is a high rpm and slow feed rate. Stainless because of the grain is basically the slowest speed feed rate you can run. Aluminum is a diff story. Cuts like butter and feed rate can basically be as fast as if your cutting mdf.

[@korieharris4086]

#1 climb cutting can cause tool chatter, #2 a little coolant goes a long way, #3 het yourself a copy of machinerys handbooks volume 24, it's gonna have all your speeds and feeds for different tooling and materials

[@aBusybee]

Also you need to apply waaaaay more cutting fluid while doing this. Don't apply drops, apply a consistent flow.

[@ipadize]

actually for steel you dont need to use coolant if you use carbide endmills

[@shadowgrizjr6782]

God that first cut hurt for that poor little cnc lol when it sounds good it's good if it looks smooth it's perfect faster isn't always better but hey curiosity can be a wonderful thing I look forward to seeing more from you man

[@michaelandersen7535]

What was the optimal feed/speed for you?

[@BreakingTaps]

Ended up being around 13k RPM, 100-130 IPM, 5% WOC and 0.5" DOC for this particular tool (more details in a followup video I made at the time: kzbin.info/www/bejne/nHatYa1nqtqhn5I). Although I have a lot more experience now, so not sure I'd end up at the same place as I did then! This was maybe two years ago? Something like that :)

[@jakeminner6650]

Some coolant on your tiny desk might help. I get your making a video but I can see my parts fine with TSC and outside coolant t. I don't knkw what your max spindle speed is or the tooling your using but it might.

[@oogaboogaman0046]

finally, someone with a relatable channel name

[@desertpunk6705]

You can’t just try stuff. You need to know your material, endmill material, endmill coating, flute count, power of your spindle, calculate your surface footage, calculate your chip load with any chip thinking, calculate your power requirements for the cut. Kenna metal has a good engineering calculator on their website. Don’t just try stuff

[@ipadize]

the endmill would be capable of much more sideload, but your machine does not. Thats why the endmill broke. Also climb milling is the way to go on CNC machines with ballscrews. Only manual machines you should do conventional milling so that the endmill doesnt pull the table because of the slop in the leadscrews and breaking the endmill or scrapping the part. Climb milling is better for the tool because it is rubbing less than conventional milling.

[@Kingkoopa00]

You are climb milling. You can't really do that on run-of-the-mill CNCs for deep cuts. You need to conventional mill for roughing/deep cuts, and climb mill for very very light finish passes.

[@billhamilton2366]

You could run the feed against the rotation of the end mill instead of with the rotation of the end mill. You will get a better finish if you feed left to right

[@lyn-jhonosia8981]

OMG, this one is an actual desktop CnC!!!

[@ScottHouston99]

You're using a climbing cut which is incorrect for the amount of material you're removing. Try feed in the opposite direction for rough cuts where you're removing a lot of material and then use a climbing cut to take a very shallow (0.1mm) cut on the last cut. (This should work for mild steel or low carbon steels like EN8)

[@Richard-v5r]

Should climb mill on steel when using carbide tooling. Try smaller fast step overs. 10% of cutter diameter. 6mm = 0.6mm stepover.

[@theoriginalbeanboy]

you're doing what is known as uphill machining, its not great for taking bigger cuts unless the machine can handle it (yours cant) try feeding the other way, and take smaller cuts to start, if that doesnt help, go slower, i mean literally feed slower not turn down RPM, just dont leave it in the same spot for too long

[@OLDSKUULGARAGE]

You are feeding in the wrong direction or what is known as climbing. Using a proper endmill for the depth of cut is needed too. Every cutting edge has a specific depth of cut.

[@DynaZor]

a channel I discovered recently (I hope it's not this one) talked about the collets; a cheap collet will produce any problem possible and be almost undetectable as the cause

[@thereasoninlifeisthatthere5326]

Try to use conventional milling instead of climbcutting.

[@biowaste179]

if your machine has backlash control, you can do a climbing cut like in your video, but if not, conventional milling would be better. conventional milling removes backlash but you lose surface quality

[@lateatday9826]

Climb milling with low rigidity will cause that try conventional milling should get much better results

[@aceofdiamounds]

Looks like climb milling, feed into the other direction so the milling bit isn't trying to climb up the material

[@psukheuk1778]

I haven't used a mill in 30 years, but still 1 second into hearing that first cut I was thinking, "You're cutting the wrong direction... Your home-made rig can't handle that!". Even now the sound makes me shudder 🤣

[@derrekvanee4567]

Feeds abd speeds ladies and gents feeds andspeeds. I miss Machongg I had a traumatic brain injury like you in 2p16 and havnt worked since 😔

[@patrickhouchins9074]

With a router C&C the higher the rpm the better is almost every case. Just spend the extra money on bits so they don't dull quickly

[@freemansfreedom8595]

Increase RPM's and reduce feed rate by an order of magnitude. When the machine does not have enough power, your only option is to cut it by being "annoyingly persistent". However if you do increase RPM's, you will have chatter in some capacity since the machine is not rigid enough. Doing conventional milling also helps in this kind of machines, as it will help dealing with the backslash these machines have. Also, as a kind of universal point: 12k RPM's, and between 200 and 1200 m/s per second are usually safe bets. Not great, but not wrong either. Source: My own painful experiences. I man a 3mx1.5m wood router to mill aluminium.

[@shawncollins1239]

It’s pretty obvious when having a rough timing cutting better to turn up the rpm and slow the feed rate idk why that is such a hard concept.

[@jackfrench8374]

Smaller cnc machines probably can climb mill like the cnc’s so I would stick to conventional milling with slow fead rate and medium rpm’s

[@EnlightenedSavage]

climb milling isn't as easy as standard. outside of that you definitely have some stability issues, I would check that everything is tight.

[@killerbunny7206]

I think your table is not strong enough so you get crazy vibrations. So if you just feed slowly in the right direction and don't cut as deep it will get better. but if you want to stop the vibrations that make the machine sad, you need to weld chonks of steel to it.

[@foxman150]

Yea climb cutting is a good way to break an bit or damage your servos

[@RHCPFAN-yk6sw]

Feeds and speeds. Also maybe try an endmill with more flutes.

[@connordupuy8462]

Look up the difference between climb milling and conventional milling. They have various differences that might be causing your problems.

[@TheWhiskyDelta]

The main problem is the CNC you are using lacks the rigidity to deal with the forces. The Router and Steppers have plenty of power, but the frame just can't stop the chattering, not enough bracing with the rails, too long spars, plus Aluminum for the frame is probably only A36 which is just inferior to steel for rigidity.

[@24framedavinci39]

Lubrication would help an eff ton too.

[@cray2602]

The only reason to ever conventional mill metal instead of climbing is on a hand machine such as a bridgeport etc etc which are a bit loose and have tons of backlash. It can be dangerous to climb on a hand machine. Conventional milling makes a chip from thin to thick which rubs causing heat and rapid tool wear..I have been a professional machinist for over 30 years, Ive seen it all many many times.

[@joiki7]

U need to lower the side cut percentage, 4-8% of the mill diameter in side cut when using full length of mill

[@Beemer917]

I have to agree with the other people here my desktop milling machine weighs 2 1/2 tons . I can cut steel with a half inch carbide 4 flute at heavy feeds. Any bigger mill and i start chattering and have to slow down. Its an yamazen 5BVK. If you really want to haul ass cutting steel you're talking about a heavy monthly payment on a new milling machine and even then I have 35 years experience in Machining and did a full 4 year apprenticeship with college level classes to boot.Thats not in your desktop software. The last Machining job I quit the guy called me for 3 years trying to get me to come back on, it's not generally a very good job.

[@jamestarbet9608]

Rate of feed, depth of cut (both vertical and horizontal), spindle speed, spindle rotation direction, direction of cutting movement. That was painful for the mill, and for us.

[@vortextube]

You can look this up in books. Your feed and rpm are way high and you should only be conventional milling on machines like this.

[@jackwillie2729]

Could the cut material be getting back into the cutters

[@kylewarren69]

This comment section is beautiful. Now clearly the issue is that you should run the spindle ccw and feed only in Z its right in the machinist handbook!!!