Perfect Deep Wood Inlay - How to get perfect inlays with a CNC machine using straight bits (no gaps)

Hi CNC woodworkers! This video is how to get perfect inlays with a straight bit. Using a straight bit is required when you want a deep inlay; something greater than 1/2" thick and up to 1" thick. You may also want to do a deep inlay in order to have the design on both sides of the wood. I cover a lot of detail: why to do them, how to properly work around vector design limitations, speeds and feeds, leaving material, and inlay tolerances. Then I'll discuss what parameters to change in two of the most popular CAM/toolpath generation programs: Fusion 360 and Vectric VCarve (also applies to Vectric Aspire). You can skip over to the chapters that discuss the program you use. I'll quickly cover how to make an inlay in each program, but this video is more about how to find the right inlay parameters, and not how to use VCarve or Fusion.
/ corbincncwoodworking - Corbin's CNC Woodworking Group on Facebook!
The alternative way to do an inlay is with a v-bit, and vcarve the inlay. I prefer VCarve inlays when doing a design that will only appear on one side of my project.
* My email list / newsletter: www.corbinsworkshop.com/newsl...
* Amana bit I disucssed and use: amzn.to/46AFCKY
* Bit information: www.amanatool.com/45611-k-sol...
Note that this bit has a slight taper; I set it up as a 1/8" bit, and assume no taper. One thing I didn't mention is that this slight taper helps a tiny bit with the fit on these deep inlays. If you use this bit, be sure to push your inlays together from the sides you carved on; this should be no problem, if you follow my instructions on leaving a "skin", as you won't be able to get it wrong.
Testing Bit/spindle runout: www.precisebits.com/tutorials...
* Free 3D printable dust shoe design: • CNC Build Ep 10: Print...
* 3/8" spiral up cut bit: amzn.to/46PJUyD
* 3/8" downcut bit: amzn.to/3LOuLWq
* 1/4" spiral up cut bit: amzn.to/46xWfrFx - also try Whiteside RU2100, which works well too,
* 1/4" ball nose from 2L: www.2linc.com
* CNC Machine: www.avidcnc.com -- I have a Pro 4x8', but my ATC spindle is from www.cncdepot.net (I have no affiliation with either company)
* Hex Bowl With Inlay: • My Hardest CNC Project...
* Deep Inlay Salad Bowl: • CNC Salad Bowl - 5" DE...
Let me know if you want me to update the file to include this inlay. PS: the inlay shape is the top of a pineapple to give it a tropical feel.
Thanks everyone!
Corbin Dunn
www.corbinstreehouse.com // Blog & Website
www.corbinsworkshop.com // CNC Files, Products, Woodworking Portfolio
#cncwoodworking #woodworking #cnc #cncmachine #cncrouter
Chapters:
0:00 Intro
0:38 Deep Inlay? Why and What
1:24 Proper Design
2:02 Speeds, Feeds and DOC
3:31 Leave Material
5:01 Inlay Tolerances
6:45 Fusion 360 - Tolerances
10:12 Vectric VCarve - Tolerances
13:41 Test Pieces
15:21 Glue Up
17:22 Machine Setup / Issues
19:50 Conclusion

[@billstrahan4791]

Love your videos! There is a third way to make the inlays work. It's using the same idea as a v-carve except doing it as a draft angle and some long toolpaths. So if you give the inlay and the pocket each a 2 degree taper along the walls...like a draft angle you would use to get it to release from a mold, then they will slide together until it wedges in place. Hopefully that makes sense. I've used this 2 degree angle to create an inlay of C360 brass into aluminum. No adhesives (unlike wood) but I just heated one and cooled the other and then the 2 degree is more than enough to lock it when it shrinks to fit. If you try this out, play with the 2 degree angle, and if want to find out about where the interference starts to occur you can make the inlay and the pocket part of a component on a sliding axis. Then turn on contact sets in Fusion 360 and do a contact set between the components that contain the inlay and the pocket. Fusion will detect when they begin to touch. If none of that makes sense let me know and I'll be happy to try to explain it better. The advantages would be that the fitup would be perfect and you'd just need the slightest clamping pressure while glue dried. The disadvantages are creating the tapered walls requires a longer toolpath, but since it would be engaging less material as it spiraled down the tapered wall you could definitely run at much higher feeds without deflection. I suppose another disadvantage is the inside pattern is slightly smaller than the outside but 2 degrees over an inch, I doubt anyone could even find it. Anyway, just thought I'd throw it out there. The brass/aluminum piece I made was polished to a mirror finish and the seams arent detectable even under a jeweler's loupe.

[@CorbinDunn]

Awesome, yeah, that is a great idea! I did do this for some really old projects; like my "batman dovetails"; I designed it with a machinable taper. It definitely takes some engineering, and I like the idea of using Contact Sets in Fusion -- I hadn't thought of that! When you do your tapers, are you using a ballnose and just machining the sides? Or some other technique?

[@CorbinDunn]

I'll also pin this comment, so other people can be sure to read it!

[@billstrahan4791]

@@CorbinDunnI didn't even bother with a ball end mill. I just did a 3d contour with a flat end mill and a very small stepdown. I think I used .2mm. I suppose you could use a ball end mill and get even better results but at the time I didn't even have one! To be sure I communicated the process, I extruded the inlay with a -2 degree taper. I extruded the pocket as an extrude-cut into the stock with a -2 degree taper as well, both from the same sketch profile. At this point the two parts will fit perfectly and the sides will touch when they are fully engaged. So then I did an offset face on the pocket to make it a little smaller. I used a small value, like .05mm. So now the two pieces won't fully seat before coming into contact. This is where the contact set is helpful. By having the sliding joint and contact set you can pull the inlay into the pocket and if you have the sliding joint visible it will show where along the slide it is touching. You can then play with the offset faces to get the parts to touch at a depth you're comfortable with. I would assume you'd want as much engagement as possible while still having some room left for your skin on the pocket side. I love your work and enjoy how you make your videos.

[@CorbinDunn]

Thanks @@billstrahan4791 - that does make sense! I also like the idea of extruding with a taper; I previously was doing it with a loft from one shape to another shape, where it was offset on the second one to make it smaller or larger. I think the taper idea is an easier way to do that..as lofting can sometimes be hard to control.

[@yasinkolgu]

Great idea.

[@peterg902]

Probably one of the best informative CNC videos I have seen.

[@CorbinDunn]

Thank you!

[@MarkLindsayCNC]

This is an excellent video with a lot of fantastic information. I really appreciate you sharing your experiences. I constantly preach to "test with scrap material until you get the result you want," and it's nice to hear someone with the same philosophy. Sometimes we need to just slow down and remember that it's not a race, and that the final result is more important than the time it takes to get there.

[@CorbinDunn]

Thanks Mark! Yup, doing small tests is definitely the way to go. I also like doing destructive testing; cutting things in half and seeing how well it worked out.

[@huntercottrell3720]

Absolutely my new favorite channel on KZbin! Fusion360 CNC, woodworking, electric bug, aerials, aquaponic gardens? All of my hobbies in one place. Excuse me while I spend my entire day binging your video catalog.

[@CorbinDunn]

Awesome, welcome!!

[@Samson484]

Wow. Really impressed on how in depth this video is. Hats off

[@CorbinDunn]

Thanks!

[@FishersShop]

Very helpful! Thanks for the info!

[@CorbinDunn]

No problem, I'm glad it was helpful!

[@justinlaney5003]

I appreciate you taking the time to explain your methods, and how you developed them. Showing your trial and error experience is a great learning tool for me! I’ve been developing a line of relief carvings since beginning CNC work 18 months ago, and now I’m anxious to experiment with some inlays. Thanks!

[@CorbinDunn]

Cool! Feel free to ask me questions if you need help along the way.

[@Phenrica]

Probably the best explanation of creating an inlay. I use MasterCAM (legacy use as I ran a cnc programming company many years ago) and I’ve just got into cnc wood working so using your well described principles I’m sure will be invaluable to my learning. Thanks for sharing 👍 Cheers Steve.

[@CorbinDunn]

Thank Steve! I hope you have good success with these techniques.

[@Sbregher]

Great video! Very helpful tips and tricks! Thanks much Corbin!

[@CorbinDunn]

No problem!

[@chadbennett]

Great video. Thank you for sharing all the lessons you have learned in such a great way.

[@CorbinDunn]

No problem!

[@stephencameron6074]

Thank you Corbin, this was a great help for my inlay issues. Your projects look great!

[@CorbinDunn]

Thanks! I'm glad it could help yah out.

[@jamesmartin5277]

Great video Corbin. Thank you... I look forward to following your future posts. Of the many interesting things you mentioned, I found your tip about avoiding witness marks (using lead in) and adjusting the allowance variable based on bit wear really interesting!

[@CorbinDunn]

Thanks James! Yeah, it is crazy how long it took me to figure out some of those small details. Another thing I overlooked until recently: make sure your machine's backlash and precision is dialed in. Mine was a little off, which may have made things more difficult.

[@brooksmartin2665]

Great tutorial!!

[@CorbinDunn]

thanks!

[@yasinkolgu]

This is like a lesson.

[@jimking9646]

Awesome very good

[@CorbinDunn]

Thanks!

[@JohnJensen-xr7fk]

Good Video

[@CorbinDunn]

Thanks!

[@modelmaker007]

Great info. Keep up the great work. Thanks for sharing your knowledge, it is greatly appreciated and helpful. When selecting your ATC spindle, did you consider others? Thanks

[@CorbinDunn]

Thanks! I sent you an email too...but yeah, I would look at everything CNC Depot offers. I talk about it a bit in this video: kzbin.info/www/bejne/f5XOqatsoqmJi9E

[@user-tn5bw4gq6k]

excellent video on the straight bit inlay, excellent. Did you do one on the VBit inlay as well??

[@CorbinDunn]

Thanks! I have not done one on the vbit inlays yet; it definitely takes some practice to get them to seat right. I'm eventually going to do some inlay cutting boards, and at that point I'll do a video on the technique.

[@souprmage]

I wonder if you try epoxy instead of wood glue as it shouldn't swell the wood quite like wood glue does, and gives you a bit more time to get the pieces together.

[@CorbinDunn]

It would definitely be worth trying! I think I've seen some inlay people using epoxy (like BroInWood - who does amazing work). It can definitely help when you need more time for the glue up. I think the longer open time might actually cause more swelling as it enters the pores of wood, but this would be an interesting experiment. I found that the swelling wasn't really an issue once I could press the inlays together really dead straight with a press.