# Some interesting trivets - video added



## difalkner (Jan 3, 2012)

When we opened our Etsy shop a year ago I offered a Superman style trivet and the option to have it customized with the letter of your choice. I had made one with the S for my son because he likes to cook and I thought it would be cool. Turned out the very first order we got was for a customized trivet with a 'C' instead of the S. The finish is straight mineral oil and the notches are to allow air in/out since these are trivets for hot pans.

This is the 'C' we did - 








This is the original - 








Nobody has asked for one since that first order but all of a sudden this week we've gotten two custom orders. The first one was for a set of 7 trivets with B1-B7. Doing one letter is easy because I can fully support it around the perimeter but doing two meant thinking through the support to keep the numbers from breaking off or chipping while cutting so I added a cross-grain triangular piece on the back side.

These are the B1-B7 trivets - 








And the back side with the cross-grain piece - 








The next order came in the day I finished the Walnut set and this one is Maple with cherries. I had to make sure the stem of the cherries was thick enough not to break off during cutting but not be so thick that it looked odd.








I'm working on a video of the cutting and should complete that soon. What's neat about that is I used the CNC to cut all the way through the 3/4" material in one pass. In addition to the table saw, planer, drum sander, bandsaw for resawing and other tools in the shop there are 11 different steps in cutting these on the CNC with a lot of bit changes so it wasn't really a simple 'push the button and wait' sort of project.

I used a 1/4" downcut spiral on the back side and then glued the insert into place on all 7 Walnut pieces. When that dried I ran them all through the drum sander to get to 0.740" thickness and then used the same downcut bit to cut the initial 0.100" into the top. I don't have a compression bit and didn't want the top edge frayed like an upcut bit does. And since I planned to use Fusion 360's 3D Adaptive Clearing profile the way it is designed to be used with the bit cutting the full depth of the material thickness I really only needed to go just deep enough to make a clean cut edge. The next bit was the 1/4" upcut spiral and it's fascinating to watch it cut the entire 3/4" in one pass. Scary at first but definitely fascinating! I followed that with a 1/8" downcut spiral to finish the inside and then a 90° bit for chamfering the edges. It's possible the chamfer would have taken care of any frayed edges but I didn't want to risk anything splintering or tearing.

Enjoy!
David


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## RainMan 2.0 (May 6, 2014)

Wow David impressed with these very nice pieces . It’s like your teasing me or something lol


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## DesertRatTom (Jul 3, 2012)

Those are nifty David. Original for sure.


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## Pro4824 (Oct 17, 2015)

Those are great David. I can't wait to see the video showing your ingenious work holding technique. Keep up the great work!


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## 2muchsanding (Sep 17, 2018)

Very nice David. You using the painters tape and CA glue trick for hold downs?


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## difalkner (Jan 3, 2012)

No sir, these are screwed down to the spoilboard.

David


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## sreilly (May 22, 2018)

Cooking with class.....I like it a lot.


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## TenGees (Sep 12, 2012)

Nice work, David. Good idea with the cross-grain reinforcement.


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## honesttjohn (Feb 17, 2015)

Another cool one!!


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## papasombre (Sep 22, 2011)

The detail for air in and out is smart.
Very nice, David.


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## Gaffboat (Mar 11, 2012)

Those are really nice, David. How do you sand all those inside edges? Sanding areas like that is my biggest, and most annoying, hassle.


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## hawkeye10 (Jul 28, 2015)

Gaffboat said:


> Those are really nice, David. How do you sand all those inside edges? Sanding areas like that is my biggest, and most annoying, hassle.


If he had done it with a scroll saw there would be no sanding. :wink:


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## difalkner (Jan 3, 2012)

Gaffboat said:


> Those are really nice, David. How do you sand all those inside edges? Sanding areas like that is my biggest, and most annoying, hassle.


I don't sand the inside, Oliver. I have the 3D Adaptive Clearing profile set to leave 0.007" cutting in climb mode with the 1/4" bit. The next operation is a 3D Contour profile cutting 0.005" of the 0.007" in conventional cutting mode with that same bit. The last is with a 1/8" downcut spiral cutting in conventional mode and cleaning up the final 0.002" and it leaves the surface very smooth. 

The very first one of these I cut, the Superman S, had about 20 minutes of hand sanding and cleaning around arises and edges but I have these down now to less than a minute of touching up by hand. And they're far smoother and better than the first ones I did, too.

Btw, I find that sort of sanding annoying just like you so I figured out a way to have these come off the CNC almost ready to apply the mineral oil.

David


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## difalkner (Jan 3, 2012)

*Video added*

Here is the video for making these trivets - 






David


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## 4DThinker (Feb 16, 2014)

Thanks for posting that video David. Adaptive milling sure make good use of the entire cutting edge of an end mill. I'm periodically hinting to Vectric to add that capability to Aspire/VCarve Pro in future versions. It looks like a very stiff Z axis assembly/machine is key to the great results you ended up with. 

4D


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## difalkner (Jan 3, 2012)

Yes, it's a very aggressive cutting profile and a machine that has a bit of flex may not handle it well. I don't know how much deflection I get with this profile but based on the follow up cut it must not be much. I am definitely going to use this more now that I see how well it works!

David


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## Pro4824 (Oct 17, 2015)

Great video to go with my cup of coffee David! 🙂
Your Fusion 360 skills are really impressive. I've used it for a couple of projects but then keep returning to Vectric (because it just seems less complicated for me) but then you make another video and now I'm going back the other way. 
You should do a series of YouTube videos teaching Fusion 360. "In your free time" 🙂


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## beltramidave (Jan 6, 2016)

I too love the adaptive clearing method and have also asked Vectric to include it in their software. I have used it for machining aluminum plate and it works very well!

Keep up the great videos! Maybe add one on how to set up Fusion when using adaptive clearing. My experience with it has been when using Cambam software.


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## UglySign (Nov 17, 2015)

David , the Bionic Man Sound Effect comes to mind actually.
Hope link works.

https://youtu.be/KLuWuzSXmTM?t=337

Are you able to export those adaptive toolpaths to use in
other programs like Enroute?


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## difalkner (Jan 3, 2012)

Glad y'all like it! I can see many uses for this cutting profile and plan to use it often.

Ronnie - Fusion 360 generates the G-code for the controller software, like Mach3 or Mach4 or WinCNC or Acorn, etc. to interpret into something the CNC understands for its movements. So you would use Fusion 360 in place of Enroute to generate your G-code.

David


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## MEBCWD (Jan 14, 2012)

I hate to think about what the project would look like on my "flexible frame Shark" after it lost multiple steps in the clearing cut.:crying::grin:


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## 4DThinker (Feb 16, 2014)

Speaking about Sharks, I still have an early one in my garage. I do use it occasionally when I've got a simple job and my Probitix meteor is running. It uses a bosch trim router, far less weight than using a 2.5hp router. Less flex than their later models IMO. The Shark HD2 we have in our college shop is being replaced with a new Probotix Comet. Now that Probotix has redesigned their gantry/z assembly and added 2 more inches of Z travel above the bed that Shark is being demoted to a model shop for industrial design students to use/improve if they want. 

4D


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