You taught me a new technique! The few stainless sheet jobs I have done were a nightmare like your dramatized beginning. Never to old to learn something new and thanks for your great content. ATB, Robin

Stefan you’re a brilliant teacher. I finished my apprenticeship a decade ago and still learn something new every time you post a video. Thank you!

At 12:45, my hand was throwing away my cup of coffee and reaching for the E-Stop.... I broke more than one endmill milling flat sheets like this, held down by clamps not modeled in CAD. Personally, i love those kant-twist clamps. Problem is, my endmills hate running into them at G0🤣Also, at 15:50, i would highly recommend using two clamps. Otherwise, the cut off piece tends to rotate below the clamp, getting pulled into the cutter.

Another masterclass from Stefan, but the "neglectable" at the end puts a smile on my face

This is a lucky coincidence. I have to do this exact thing Monday morning. Same material and all.

I guess this is the closest thing to an April Fool's joke that we're gonna get on this channel.

Excellent video, answers a lot of problems I've had with sheet metal milling looking like someone chewed it off ! You know I'm going to learn somethng when Stefan gets the pen and paper out ! Thankyou !

Thank you Stefan for the masterclass. Interesting and informative from beginning to end. 👏👏👍😀

Great advise on using chamfered corner endmills. I recall you mentioning those before and I really need to order some. In addition to clamping the waste stock, using tabs helps keep off cuts from getting thrown around and jamming. I do a lot of milling of ~1mm (.040) aluminum sheet on a small router. Using the tool probing and material mapping helps with the initial cut on GRBL based CNC routers. It helps to use a sharp pointer to do the mapping with a slow Z feed to avoid deflection on thin sheets. The control then compensates for the height variations and it really cuts down on burrs. I have not seen this feature in real CNC machines, but i assume anyone running those has a better processor for cutting sheet metal.

I wish you would have shown this technique a week ago would have saved me a lot of heart ache. Never mind I’ll start again and put your info to good use. Many thanks.

Absolute wonderful video! I have never given this process any thought and would have done this machining operation in one pass. Thankyou for sending me on the right path1

Thank you Stefan, for this lesson. As you explained it, it became obvious that your approach is how it should be done.

Depending on the size of my raw material and the size of the finished part, I will use a spray mount adhesive to mount the metal to the wood. The adhesive is gives an extremely strong bond so you can clamp the material much farther away from the cut path which means it's less likely to bow. Also, I will sometimes use Medium Density Fiberboard (MDF, AKA Medite) as it is usually far flatter than your average piece of plywood. If you use coolant it will pretty much destroy the MDF but that's a small loss. To remove your part from the MDF, apply a bit of heat from a heat gun and the glue will soften and release the part.

Excellent video Stefan, as always. Thanks for sharing your knowledge and expertise with us.

Always learn something new watching your videos. Thanks.

Very well explained,Stefan.Thank you.

You're teaching experience! Stop, Look and Listen. Always enjoy!

as always Mr. Stefan you educate us with another informative video ! thank you for all you do and taking the time to show us.

Danke für den Tipp und die ausführliche Erklärung! 👍

Very useful. I just milled some stainless sheet and the end mill (about 6 mm dia) was fine for the first 20mm. Then it got red hot and end of cutting. I was cutting full sheet metail thickness. Then I swapped to another cutter and used very small DOC as Stefan describes. OK job. Great to see Stefan is describing exactly what worked for me. Thank you Stfan - pity I didn't see you video before I started my job!

Stefan, I've been dealing with this very issue today trying to get a good clean cut on a customer's part. God bless you! I changed my approach as you suggested, and i am now going to be able to deliver descent parts. Cutting .8mm 316L Stainless Sheet using 1/16 inch diameter end mill. Now my cut matches the mirror finish on the material! Beautiful!

The one thing I learned about drilling/milling/turning stainless is to use water. Basically flooding it with water keeps the temperature low and prevents stainless from hardening. At work we use cheap hole saws in stainless and they last a long time as long as you cool them with water

Actually this is very helpful to me, as I've just had a nightmare in the workshop trying to mill stainless sheet, so this video is timely, albeit a bit late for me, I could have done with seeing this before I ruined my cutters! but now I'm a bit wiser, so thanks for this.cheers, Dave

Another great video Stefan. The chamfer on the end mill at high feed is forcing the material down into the spoil board. I wonder if the edge finish improves with a aluminium spoil board so there is less micro material movement. Maybe the spindle bearings are loaded up just a little more with the chamfer cutter also. All these small things that make a difference are long in the learning, but with the help of your excellent videos, im sure most of your viewers are getting bettrr results more often. Thanks again.

Thanks for the tips and demo Stefan, always fun to learn a little something looking over your shoulder. Thanks!

Thx for sharing this tip, very useful. I also (sometimes) hava to fiddle around with sheet metal, and in stainless you have to watch out for workhardening. Gruß aus dem Badischen, from another Stefan :)

We do quite some stainless sheetmetal (13-8PH) and to be honest never had issues with just going full slot and as fast as possible. Key is the fixturing imho. I only use precision milled aluminium plates as a backer and drill a bunch of holes to really clamp down the sheet. Think this also helps with getting the heat out of the sheet and into the aluminium. All roughing is done with a 6 mm 3-flute from Garant and finishing with a 4mm 6-flute. And a VMC with TSC to get the chips out of the slot also helps..😅

As always, excellent description and discussion, understandable and convincing. Thanks for continuing to share your experience and expertise!

Stefan thanks for another very helpful in depth tip/trick. Always enjoy your tips and musings, First Rate Stuff!

Thanks Stefan! You never disappoint! You're always on your game! It's such a treat to be able to freely benefit from your knowledge and experience! I'm so glad you choose to share all of this great info with the rest of us!❤ 😊

Exceptional video Stefan. Thank you so much for going the extra effort to show us why.

Stefan, this is a great video. I have liked milling cutters with a chamfer for a long time. I even "save" the ones that get their corners worn by hand-stoning a chamfer on them. But I have never thought that a chamfered end mill would be good for thin/sheet metal. Along with taking shallow cuts and using a high feed rate, I have really learned something today. Thanks for a great video!

Thanks Stefan you're brilliant. This will help me a lot. I'm planning to make kant twist clamps. And that's a lot of cutting in sheet metal.

Ich nutze meistens meine Vakuumspannplatte für Blech. Dadurch ist es von der Höhe her sehr gleichmäßig. Ab und zu nutze ich auch die Technik wie du sie hier zeigst. Das Abfallstück sichere ich mithilfe von 2-3 schnellen Bohrungen mit dem Akkuschrauber und ein paar kleinen Spaxschrauben. Dadurch hat man auch keine Störkontur durch eine Klemme.

Excellent and really useful tips. Thanks!

Great demo and really good advise. Thanks Stefan!

Awesome demonstration and explanation, as always. Thank you!

Thanks for the excellent tip! That's one kind of cut I've done from time to time and it's nice to learn a better way.

Really enjoy your vids Stefan. I’ve been a hobby machinist for 20 years (stress on ‘hobby’) and i always enjoy how you break down details so i can not only learn how but why. Thank you

Thank you, Stefan; i‘m looking forward for the next hard-to-mill-topic 💪

Many thanks once again. Very concise presentation, valuable information.

Very informative and helpful video. Thanks for posting, I know it's a lot of work to make these videos so please know it is appreciated!

Thanks for sharing. Today was the first time I successfully used a self-made 1-tooth cutter to cut a 'Simmerring'-seat 4 mm deeper into cast iron. Having watched over your shoulder over all those years was all it took. Thanks.

Thanks again Stefan for the efforts You spend sharing this information. Best Wishes to everyone.

Hello Stefan! I have been watching your channel for a long time and thanks to you I receive a lot of useful information. Thank you so much for sharing information with us. Big greetings from Belarus, Minsk!

Very helpful. Air starting/wood thickness variance and end mill discussion are my takeways. Thanks from Colorado.

This is a great tip. Thanks! My last low precision sheet metal project I glued a 1:1 scale drawing to it and cut it on the bandsaw

Another excellent tutorial Stefan. Hope all is good in the land of precision machining and Black Forest cuckoo clocks. Cheers!

I learn something new pretty much every video You make, nice trick!

Fantastic info as always.

Just what I needed to know! Thanks, Stefan.

Good practical information Stefan,thanks.

Indeed, that works way better. It's all in the details. This is something I think I would never have figured out myself.

Thanks for sharing your knowledge and experience. I'm a little wiser today 👍 🇬🇧

Thank you. Another wonderful and important tutorial 👍🏽

Great info Stefan . saved in the grey matter for reference . Cheers Ade.

Great tips Stefan. I have had some very ugly results trying to make cuts in sheet metal, both aluminium and stainless so thank you very much for sharing your expertise.

I use that technique in wood or plastic or metal cutting.... it takes a little longer but usually it is almost as fast..taking deep cuts heats up your blades / tool and is harder on your Power tool too... shallow multiple cuts are going to be easier on your tools ..reducing the heat and force needed to make the cut depth.. . it is something i learned about 40 years ago and i find it the best way to do cuts.... i don't care if it " seems " to take longer because i know it is going to allow me to do the cuts without problems every time....especially when using Piwer tools that are just powerful enough but doing long cuts it is going to overwork your tool and the cutting tools too... you can relax and get alot done if you are patient.... 🇨🇦🤓🤟

great video Stefan, Another one to go in my apprentice training playlist.

Thanks for the lesson, Stefan 👍

Thanks for sharing this approach.

Thank you Stefan. I run a CNC Router on Aluminum and Hard plastics. This information will serve me well

Very helpful. Thanks Stefan.

I will be trying this approach on cuts that need it. This, id scribe, band saw, one rough and one finish pass at full depth.

Well done in all aspects. I have a few projects using thin metals I've been putting off for lack of knowledge/expetience. I feel much more confident I can take them on, now. Close to 10 yrs ago, I was in the market for my 1st lathe or mill. Looking for a machine, I saw an ad for end mills, '40 pounds of end mills, $35.00'. Knowing nothing about end mills other than they aren't cheap, I went to look at them. 95% were brand new, some still in the rubberized protective coating. Got them home & was looking at one, to chk the cost on the 'net. My heart sunk when I saw the corner of the flute chipped off. Being ignorant of something, the 1st thought is, 'No wonder they were cheap. They're effed up.' Started looking at each end mill. At the 3rd-4th, I realized they were all 'chipped'. By then, I began to get familiar w/ them & realized the 'chips' were very uniform. It was then I understood they weren't ruined & it was a great deal, after all. I got a lathe that same day, but it wasn't until last year before I got a mill, (cancer detoured me for 4+ yrs) & I've been able to put the 40# to some use. I've read a lot & watched a lot of vids about end mills & milling in the intervening years. You are the 1st to discuss anything about chamfered flute ends, their use or even their existance. Thanks. GeoD

I learn a boat load here. Stephan, you’re the best!

Thank You Stefan for this very useful advice! I have used MDF board similarly, find it much flatter than plywood. Usually glue a piece of hardwood to the back for quickly putting it in the vice for less critical stuff. Easy to attach clamps around the sides.

Sehr schönes Video. Danke für die praktischen Tipps!

Thanks Stefan. That was very interesting. I was an expecting an April Fools joke but I'm glad I watched. All the best, Mart in England.

Another aspect: For slotting (on home shop/less rigid machines) the 3 flute endmills work better than 4 flute ones. Which kinda makes sense with lower cutting and pulling forces (from flute helix). The surprising bit is that 3 flutes also work better than 2 flutes. With 3 flutes the load (both magnitude and direction) on the cutter varies less whereas with 2 flutes when one flute starts disengaging the other starts engaging. This results in the cutter forces making an almost 180 deg switch, producing bad vibrations. Worse, because the shock loads happen when the flutes are engaging the sides of the slot, overall the slot will end up oversized. Actually, the same shock loading will happen when slotting with endmills with any even-number of flutes though the shock will be less for 4+ flutes and expensive variable flute geometry cutters. But don't just take my word, make similar slots with 2, 3 then 4 flute endmills at the same chip load (or less scientifically same feed) and listen for vibrations and measure the slot width. Do check the runout (on the flutes) of each cutter beforehand as that can easily be bad enough (from bad collet, spindle, debris or wear) to invalidate the test.

Thanks for that information. Thanks for the video keep on keeping on.

Thanks for sharing and Happy Easter to you and your family 😅

Great video and very informative. I’ve been using the super glue and painters tape hold down method like NY CNC on an aluminum plate for thin stuff and it works great. Actually, not just thin stuff. It works great at anything I want to get around without worrying about the clamps. If I don’t hold it in the vise, I’m probably gluing it to a plate. I even glue pieces of aluminum scrap to the top of the vise hard jaws to make soft jaws out of for smallish parts. You’d be surprised how much force it takes to break them loose. For really thin material, you need to use heat or solvent to break the bond because prying them apart will actually bend the part

Thanks Stefan, I think I have learned a lot here. 👍

Thanks for sharing, Stefan! I'm going to update my OS to use this technique for sheet metal in the future. Thanks again, and I hope the world is the even better than the best it can be on your end. ^___^

Brilliant as always and many thanks for this machining tip. I have a somewhat tricky project coming up where I have to cut square windows out of a curved piece of aluminum. I better come up with a way to clamp the center part so it doesn't jam or ruin the cutter. Obviously clamps won't work as the cutter will pass through its position. But, at least this vid has made me think about it.

I use double stick tape and leave two tabs to keep things from flying on the cnc.

I love those Uvex safety glasses, look way better than the usual, gonna get some of those.

That is super helpful - thank you!

Thanks for the sheet metal tip, I didn't know that!

Massively helpful! Sehr hilfreich. I wish I'd known this, two years ago, when I tried to make myself an instrument panel by milling sheet steel clamped to plywood. It was a total dog's breakfast. (Früstück des Hundes?) I concluded that a Bridgeport was not a sensible machine to use on thin sheets... but you have shown me that it can be done, if one knows how. Thank you.

Exactly what I needed, as tomorrow i need to millout holes in some electrical panels. Earlier tried full depth and that was not nice. Will try this approach. Thanks for the video 🍺🍺🍺

Thank you Stefan!

Very helpful (as always)!

LBFU School, has always been a solid teaching tool...💯

Very interesting. Thanks. I’m sure it going to be very useful.

Thank You Stefan.

Thx for another great video.

Very good info, thank you!

Excellent job! Thanks... ...a lot!

Love the reinastment!

Excellent as usual. Glad to see that you do not use some form of super plywood that will make go into depression. :) Very useful technique.,

I only have a small horizontal Atlas Milling machine. If you ever get the time, I hope to see a video for doing this on a similar machine. I have so much to learn, and work-holding is my biggest weakness. Thanks for sharing.

Thanks. I will give it a try

👍 thanks for sharing. Very helpful

Excellent!

It's very rare that I cnc sheet, but sometimes I have to do 1.7mm cold-rolled. I picked up a couple of cutters the same as I use on my wood router at home - downcut spirals that tend to push the work down. (The sheet has a wood backer the same as you showed).

great tips, great explanation (as always). also some of these tips apply to different areas of crafts too, eg don't clamp bendy wood in multiple places when cutting or resawing. Fortunately I learned that using cheapish wood and not metal :D

That is one to remember for sure . Even for large cuts on my other mill ( 4 1/4 ton Stanko ) with a face mill i often go the multiple lighter cuts, high reed & rpm . Seems quicker & less load on the machine . 👍

Nice lesson! Thanks!!