Wierd engraving issue

[osmithcarpentry]

Hi 

I have been testing out my CNC router machine this week and doing some engraving ( in hardwood) using Fusion 360 and UCCNC.

I started off with a 90 degree v bit and made a few name plaques for the kids and a couple of vector drawings. This all went fine and I was pleased with the results. 
Today I tried some tiny 1/8th inch 30 degree cutters, the flat single edge ones. So first I just did a test just trying different sizes of font I went from 15mm high letters down to 1.5mm high. The cuts were very sharp indeed ( in american black walnut) and I could read down to the 2mm ones.

So I designed a sort of business card for some little off cuts. I did the toolpath 20000 rpm at 2000 mm/min posted it and ran it. 
It looked fantastic, with super crisp lettering, then I noticed it had missed out 2 letters from my email address and one digit from my phone number. When I looked closely in UCCNC I could see it was missing the letters out in the toolpath  posted there, so checked back in 360 and sure enough the toolpath was not going into those missing letters.

I tried re-doing the toolpath with slightly different perameters but it was the same, missing two letter r`s and the number one.

I can`t select the letters individually just the whole word or line so can`t correct this at the moment.
I changed the design a bit and the font and did another one, this time it missed out the letter h from the word telephone, nothing else.

Not sure what to do here, it can`t really be the font itself as the rest of the line in the same font and size is carving perfectly. Is there another way to select the engraving.

Another Fusion question is why sometimes in preview mode it shows me the 3d result of the cutting path and sometimes it doesn`t. It just shows the bit travelling but not the resulting cut in 3d, I don`t think it matters much but it is wierd. (probably one simple option to tick somewhere) .

Thanks 

Ollie

[julia.paganucci]

Hi @osmithcarpentry , 

Thanks for posting! Can you please share a your file so that I can take a closer look at the toolpath? You can always private message me a link to the file so that it is not on the public forums. 

As for your preview mode question- are you referring to the simulation of the toolpath? 

Thanks, 

[osmithcarpentry]

Hi Julia 

Thanks for replying, I will try to share the file. https://a360.co/2OmkXUA     It is just a quick one for testing purposes.

this time it looks like it has missed out an n and 2 r`s but done the 1

Yes for the preview I mean the simulation of the toolpath. When it shows the path cutting through the (green in my case ) stock. Sometimes I get a nice 3d representation of the cut and sometimes it just follows the blue path but doesn`t show the resultant cut.

Thanks

Ollie

[julia.paganucci · Accepted solution]

HI @osmithcarpentry , 

Thank you for your file! I was able to get all the letters/numbers to engrave by increasing the tolerance in the passes tab of the toolpath (i used a tolerance of 0.05). I also noticed that all the letters are engraved when using a larger font size. 

As for the simulation, as long as you have stock checked in the simulation window, you should be able to see the resultant cut. Turning off the visibility of the model might help in seeing the cutting. 

Thanks, 

[osmithcarpentry · Accepted solution]

Hi Julia 

Sorry its a bit of a boring file ! I am just learning this and trying to get the machine, me and Fusion 360 to all work together. More interesting stuff coming soon.....

I have just simulated the file with the tolerance changed to 0.05 (was previously on 0.01) as you suggested and it looks like it has worked perfectly. I would probably never have found that on my own and now I will pay attention to this setting.

Sure enough turning off model visibility has worked great as well.

Thank you very much for your time and knowledge.

Ollie

[julia.paganucci]

Hi @osmithcarpentry , 

Not a boring file at all- I'm happy I could help! 

Thanks,