How to Design Parts for CNC Machining

I this video, I will go over some of the top tips and tricks on how you can improve your designs and decrease cost while optimizing for manufacturing on a CNC milling process.
I’ll cover everything from fillets, chamfers, setups, drilling, tapping, undercuts and even text. Shortcut links are for everything below. Full article posted on my website below.
00:28 - CNC Milling Machine
01:06 - Common Cutting Tools
01:52 - End Mill Deflection
02:39 - Internal Fillets
03:05 - Fillet Specifics
03:37 - Dogbone Corners
03:45 - Feature Height
04:00 - Threads and Tapping
04:36 - Raw Stock Size
05:01 - Chamfers
05:31 - Setups
06:07 - External Fillets
06:28 - Isolate Tight Tolerance Areas
06:47 - Drilling
07:15 - Bottom Floor Fillets
07:38 - Edge Break Fillets
07:56 - Edge Drilling
08:21 - 3D Surfacing
08:41 - Undercuts
08:58 - Text
09:18 - Bad Example Part
09:47 - Fixing a Bad Part
10:09 - Price Comparison of Good and Bad Part
10:19 - Good Books for Going Further
10:33 - More Links for Learning
Good Books (Affiliate links, your help supports the channel):
- Metalworking, Sink or Swim: amzn.to/2VBHOh4
- Machine Shop Trade Secrets: amzn.to/2YIESBl
CNC Online Quoting:
- www.protolabs....
- www.fictiv.com/
- www.xometry.com/
Finding Material:
- www.mcmaster.com/
- www.onlinemeta...
Machining Videos:
- / haasautomation
- / saunixcomp
My Website: www.adambender...
Instagram: / bender_designs

[@mouhaahaahaa]

nice video but are you an extremly heavy smoker or something

[@RadicDotkey]

You don't need to add forced vocal fry to sound pro. In some parts you sound normal and those are way easier on the ears.

[@47EZ_DRIVER]

yeah Adam should re-record this with his normal voice. I turned on captions because i cannot stand the audio

[@pvtimberfaller]

It’s too creepy to listen to.

[@EYes-zy6my]

“NU VOIS” is fried…

[@DarksChannel567]

Literally said exactly what I was thinking

[@benjaminmcintosh857]

Pretty sure old mate just had a sore throat guys

[@kateiry4719]

The crispy deep fry voice is too distracting 😂

[@adrianhood4368]

As a newly graduated mechanical engineer, thanks for teaching what we actually wanted to learn!

[@gokiburi-chan4255]

This sht was never taught in my school lmao,

[@JB-dv7ew]

@@gokiburi-chan4255 Bro nothing was taught at my school. Not how to design for assembly, design for CNC or sheet metal, or detail drawings properly, etc. I can solve quadratic equations and find the Jacobian of a matrix though.

[@jay89boy]

@@JB-dv7ew too acurate :D

[@shawarebs]

As a mechanical Engineer, this is one of the most helpful videos I've ever seen. I'd love for another video similar, but with more advanced topics (flatness, perpendicularity tolerances wrt features done on the same vs multiple setups ... etc). Great content!!

[@Omsip123]

2:47 shouldn't the radius be LARGER than a third of height, like you show a few seconds later?

[@BenTheMagnifice]

Surprisingly great video to find on KZbin! Packed with accurate information and no fluff. Please make more!

[@russwizinsky8041]

What a fantastic video. As a machinist I thank you and will be forwarding it to my design team. Very much appreciated!!!

[@gokiburi-chan4255]

Trying to learn this so I won’t torture the manufacturing team in the future 😂

[@InnerBushman]

Just so you know, the vocal fry caused me to back out of this video immediately.

[@casemerasheed3875]

At this point im just going to comment every time I come back to this video, to reassure my self before I submit a design to be fabricated. This is an extremely informative video👍🏾

[@VitaminDeth]

Very informative video but the guy sounds like he needs a cough drop

[@ChrisTrunek]

Watching this ten minute video just helped me save a lot of money. Excellent clear and simple information. Subscribed!

[@jumpyjumped]

bro talk normally you cant tell me this is how you talk everyday

[@ivanvazquez7465]

Damn,vthis video is helpful, but the voice is a pain

[@easylivinglife6284]

As a logistics manager, I appreciate you adding the stock size to part size comment... however, I often find that CNC programmers have a unique mind, and may prefer to use larger or smaller stock if it means holding a fixture a certain way, making more than one part pert blank, or decreasing machining cycle time. For example, say you have a part thats 2'' thic by 2'' wide. A programmer may request a blank thats 4.5'' thick by 2'' wide, cut into blanks for length and machine two parts from said blank. While technically increasing cycle time, it actually reduces it the total time per part- less time loading and unloading the fixture, and less time cutting the material. And think about it, would you rather have 200 12foot bars strew about because you have to mass manufacture some small dinky part? No! You want a few decently sized bars that the CNC program can make the most use out of.

[@lephtovermeet]

Some good basic advice that I wish was still standard in many engineering degrees. That being said some of this is quite dated. For instance flat bottom holes are extremely common with helical milling, in fact that's the go to for many machinists, albeit the length and depth requirements still apply. Similar critique for thread tapping. It's not super common to use taps on a CNC. There's too many thread types and type styles, plus the break easily. If you're tapping on a mill, you're likely thread milling, which does have diameter requirements, but again is basically the go-to for many of not most machinists. Also chip clearing taps are super common. Also, t-slot cutting and undercutting are again super common, but you do have to work within the limits of your tools and common sense. Also never just put break edge. Someone is just going to hit it with a file after it comes off the mill. I've seen some real disasters. Finally, much of the increased costs when quoting with autoquoters is fairly arbitrary - they charge more because they can and that's what their algos and data have optimized for - especially xometry, they're a huge offender with really unreliable quality. They're actually just a re-sourcer, so you never know what you're going to get. If you are machining in house what drives up cost is having to buy more tools and holders for those tools, and added setups. If your CNC has a tool changer, it's common to leave 2 or 3 slots open to change in specific tools for the job. It usually adds very little extra time or cost to fabricating. But nice vid, thank you.

[@Frrk]

Absolutely great video man. Very clear to understand. I'll forward this to teachers!

[@qazthegreat1068]

Your voice seem need cnc cut.

[@swamppifi6186]

I work as a CNC programmer and the amount of times I get a cad models that people poorly design, and then expect to be able to machine , is just mind blowing. I often have to go back and make some suggestion on how to change the design to allow for easier machine. Thank you for this video...

[@JB-dv7ew]

Yup and you'll keep having to do it because engineering schools don't teach this shit and I have no idea why. It's the reason why I'm here as a mech engineer.

[@JayP0205]

I’m one of those fools and got zero quotes back because of a design that even a 5 axis couldn’t build lol. This video saved me a ton of unanswered questions

[@AlojzyZyrokompas]

What's with the shy growling? Otherwise pretty informative. I wouldn't agree with R being 3 times smaller than H though, in most cases You can successfully make it 6 times smaller without compromising milling precision.

[@etchmfg]

Great info! I had a hard time hearing you though, perhaps its your microphone.

[@HannahBright-g1l]

It is even easy to understand for me, even though I am not a machinist,I am just a project manager who are working for promoting the cnc machining services in China.

[@angelalexandrov2831]

Great video - thanks! If you make something similar for lathe parts it will be very useful.

[@AdamBender]

Good suggestion! I will add it to my list

[@bhekidlamini51]

Do you have pdf content of this video. Excellent!

[@eviebee4]

Whoa. Thanks so much for this video. So much useful information delivered clearly and quickly. Cheers!

[@chrischalabi]

Great stuff, but definitely try to avoid the monotone. Also you should rename this video to CNC Milling and also make a video for turned parts.

[@AdamBender]

Thanks for the feedback, I'll definitely work on the voiceover in future videos. Lathe video is on the list!!

[@haavard1989]

I used to make parts for a company where some of the designers were former cnc-operators. No really insane parts, no tolerances were smaller than necessary and the RA was often just general.

[@AlJay0032]

Seems you got your axis wrong. CNC mills don't use left handed coordinate systems.

[@AdamBender]

Good catch! looks my labelling got flipped

[@AlJay0032]

@@AdamBender Thanks for this great educational video.

[@casemerasheed3875]

Ima a self taught product engineer. Its amazing how many time i come back to this video, when designing parts. It literally answers 90% of what ever design flaws im making.👍🏾👍🏾👍🏾👍🏾👍🏾👍🏾👍🏾👍🏾👍🏾

[@MrKillermeatball]

About to give a presentation on this, was watching videos to see if I'd forgotten anything in my notes... INTERNAL FILLETS SUCK! XD

[@n4ko]

this was a very good video, thx u. but pls stop smoking. its not good for your health =(

[@JosefdeJoanelli]

That vocal fry

[@mihailazar2487]

But floor fillets can be perfectly reasonably machined with a bullnose endmill, which is what they usually use anyway for roughing. So having sharp floor corners actually requires an extra finishing operation with a flat endmill

[@grateful4068]

found this via Hackaday. Subscribed because of this video. Great work.

[@AdamBender]

Thanks!

[@ranjah76]

Me too!

[@guessagainkk6322]

If you are a Design Engineer "don't be that idiot" who like sending "over the wall" drawings without checking with your machinist first. If not they may kindly turn you down as a design / fabricator relation, then you are screwed. This is beginner video 101 for all wanna be "design engineers" for machined parts.

[@brandons9138]

Dude totally forgot about the lathe. On tapping blind holes the pitch of the thread is critical. With a bottoming tap you should allow for at least 3X the pitch for the lead of the tap. If you can get away with rolled threads this completely mitigates the chip build up issue. Not all materials are good candidates for roll tapping.

[@jesseskellington9427]

On a CnC milling machine Do you have a video on how you can take square stock and turn into brown stock? I find a lot about ladies doing this but not on a mill. I have 1 in by 1 in square stock that and what one in 1 in down round... Do you have a video on this operation? :-)

[@thomasprice5728]

Fantastic video! I'm a design engineer with a bit of machining experience and this is an incredibly concise, comprehensive and accurate view on designing for milling. I especially liked the deflection graphic and math. Looking forward to seeing more videos my dude

[@drew79s]

Good stuff... The floor radius information isn't exactly right though. Using a small floor radius can work really well if you're using a radius endmill, as a 10-12mm endmill will have about a 1mm corner radius, this means that you can go for a fine floor radius with a wide vertical corner radius. Additionally, the undercut feature you've drawn isn't possible to machine, but there are t slot cutters and dove tail that do a nice job of particular feature types, so as long as you're standardising on those feature types undercut isn't a problem at all.

[@AdamBender]

Good feedback Drew! Yeah bull nose end mills with small corner radius can be great for harder to machine materials like stainless, or lowering stress concentration. Agreed on my undercut drawing, I got a bit lazy with that one, but I was hoping it would get the idea across. T slots and dovetails are two exceptions for undercutting when done correctly. Thanks for the input and watching the video!

[@foxzerox1000]

At one point you say to always add fillets to the exterior, but then say to never have fillets on the top part instead gave a champher but if they are going on the out side anyway wouldn't thst make any given side the "top" for that operation? Like how do I know which to use?

[@StaleCookies]

As someone who is designing milled parts for product design this video is invaluable. Subbed👏

[@patrikdahlberg1825]

Thanks bud. Some great advice here! :D

[@pentikimahougami8348]

2:10 For pedants, the words diameter and length are switched for this timestamp.

[@james2749]

What about machining draft angles for moulds? are there bits for that?

[@robwgeorge]

Fantastic presentation and explanations. Thank you.

[@joemac-q4x]

I have spent the last 2 weeks trying to get to know about cnc designing and work and I unquestionably learned much more in your 10minute video than over the whole 2 weeks, !thank you!

[@ambroseliu6207]

Very helpful to mechanical engineer

[@free_spirit1]

Excellent! I wish there was a similar video for designing for turning!

[@Unl0gic]

Thanks for a very informative video without any "Cool KZbinr nonsense"

[@pentikimahougami8348]

Speedymetals is also pretty good about price/selection.

[@tri5431]

Very helpful video, thank you ! You're saving a lot of headaches for many machinists out there. The only comment I have would be the extreme vocal fry. My Bose speakers don't have a bass/treble adjustment, so it's very difficult to make out the speech.

[@steelcannibal]

Dude! Fantastic video breakdown! If only more engineers understood this 🥴😵‍💫

[@BlackSmokeDMax]

Those top fillets aren't too terrible if necessary... As long as you pick a radius that is a standard cutter size. Search "corner rounding end mills", and usually the smaller you can live with, the better!

[@paullamb7697]

sorry i cant listen to your voice

[@SinaRa-yj1xo]

Bruh, what the f is going on with your voice

[@TijmenHatesads]

Imagine uploading a video where the cnc machine itself tells you what it wants. It would save me like a year in education and trail&error.

[@LongMai-h5h]

Hi Adam, Thank you for the videos, it helps me a lots. I have a question. In case of internal fillet, is it harder if we machine an internal chamfer instead?

[@TheeAthis]

Great basic information!

[@ItsJustWolff]

As a machinist, this is great.

[@kyeeralamala7567]

omg thank you bb

[@ekingorgu]

Adam this is an amazing video. Please make more videos like this. Subscribed.

[@m.berger2370]

Thank you !

[@sreerajpanayancheril7206]

great video

[@martinjensen4714]

Are these "design rules" covered in the mentioned books? If so, I guess they are a must read for any engineers like myself!

[@majorchungus]

Zed. Lol.

[@kdprocnc]

Tihis really help me a lot,thanks for sharing~

[@brucewilliams6292]

Really well done! Thanks for the video and Merry Christmas.

[@LibertyWarrior68]

This is good information.

[@GMBurov]

Thank you very much for your advice! 😌

[@someotherdude]

This video is extremely effective and straight to the point. Well done!

[@fake08]

such a good, informative video

[@casemerasheed3875]

Truly Great and informative video 👍🏾👍🏾

[@donfite2081]

BRAVO!!!

[@PettiMusicStudios]

This is a fantastic video. Thank you

[@sayfmateen5754]

Thank you for the info. Waiting for more on turning and fixtures..

[@ashjo17]

Wow! such simple and cleared explained concepts.

[@zaccomusic]

nice contents I hope you keep update :)

[@enricodesign619]

great video, thank you

[@captainmurphy4720]

WHAT A TON OF GREAT INFO IN 11 MINUTES. THANK YOU SIR.

[@mantimanufacturing9770]

Mandatory for all engineers lol

[@financialchimes4546]

@6:29 I've heard you should avoid bosses because it's more cost-efficient to mill a surface flat than to mill several different small bosses within the same flatness as the edges on the bosses leads to reduced tool life. @7:15 I've been taught that fillets at the floor of a pocket can reduce costs if you use the same radius as standard corner radius end mills because the sharp edge on flat end mills breaks and wears a lot easier. What are your thoughts on this?

[@typhoys]

From my experience it is true that bosses are expensive but it is easier and cheaper to achieve flatness for a smaller area

[@EricBrummer]

If the bottom of your pocket has no impact to your design, you can always call out in the drawing something like "R0.5 MAX, sharp corner allowed." Then the machinist can choose based on what they have and what they think is easiest. On some materials, using a bull nose end mill can be a major tool life saver. As for bosses and flatness you can really get in the weeds on details. Size and thickness of a part matter a lot. Holding flatness in 2 small spots on either end of or across the whole surface of a partrhats 4ft long is going to be difficult. Same thing with thin stuff that is being warped clamped in the vise. Also depending on the amount of material removal the part will change shape as you relieve stress in the material and/or reduce the rigidity by making it thinner while clapped. If the part is smaller, like a fits within the visse, then you can rely on the accuracy of the machine heavily and get a decent flat surface especially if using a fly cutter to cut with a single point. Having discontinuous cuts (tooth cutting then not touching then cutting) is bad for tool life especially carbide but with the bosses shown you might not even have that issue. Face the whole thing first, then relieve around the feet. Although on a small part there's probably no reason to have feet. Much larger stuff the feet help although for anything requiring really tight flatness I'm probably existing grinding anyways in which case I don't think the feet have a major negative impact (and save time on grinding) but I'm far less knowledgeable on grinding.

[@jordanp8003]

Great video, but...ribbit lol.

[@ajayjb8727]

Great video , really helpfull, Thank you

[@pravinrathod7781]

Asentrik work ka video banaeye

[@dexterc7050]

Very clear and excellent video!

[@iamthebiker]

Great video

[@asheshshrestha]

It is a really great content. Keep it up!

[@wangqiaozhang4827]

wow, really helpful!

[@leonidassavalas745]

Interesting topic but that voice...it's like someone dragging a rock. Can't stand to listen. I hope it's not throat cancer or some other illness. Hopefully, it's just laziness.

[@TimDonk]

Zed axis? I didn't notice an Aussie accent.

[@AdamBender]

Canadian!

[@abhiadsul6538]

Very informative

[@coralsign]

great !

[@ashkancncpart8083]

Sehr gut

[@TimDonk]

Vocal Fry!!

Excellent, more! 🙂

[@zeljkanenad]

Why forcing this irritating voice? At times you forgot to force it, it sounds pleasant. Good content, though.

[@Metalbrix01]

Your voice is very rough

[@patkcorcoran]

Henry Kissinger voice, hard to listen to.

[@jnewbon00]

awsome vid, had to mute and use CC.