Cambam + CNCwrapper + 4th axis

[dh42]

Hello,

Today I try the possibility of using 3D profile MOP with my 4th axis and CNCwrapper to do twist.

That works well 

Here is a video of the trial.

<a href="http://www.youtube.com/v/HMPQ-fJNKq4" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube.com/v/HMPQ-fJNKq4</a>

I attach the CB file and the wrapped nc file (for Ø 40 mm)

Have fun

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David

[kvom]

Interesting video.  How long was the total machining time?

[dh42]

Interesting video.  How long was the total machining time?

Hello

~ 1h20 for roughing and first finishing.

~ 2h00 for the second finishing (stepover of 0.015, tool Ø 6mm) ... the part is always in the machine, I must sand it, then after I make photos

I will try another method with the "side profil", maybe I can get a better finish without spend hours .... wait and see 

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David

[Bench_Top_Precision]

Very nice work.

[dh42]

Hello,

The part sanded and waxed.





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David

[Orifice62]

Hi dh42,
That is really nice!! Makes me want to put a 4th axis on my DIY machine

Bret

[Bubba]

Nice job David. I did try today to machine the spiral on my diy 4axis and overall I'm happy with the result. the only problem I had I miscalculated the diameter for the wrapper program(to small) and only one spiral leg was good other two are misaligned. If I may ask at what radius or diameter you have your cnc wrapper program set to? Thanks.

Here are pictures of the "misfortunate" spiral. Cut it with .25 dia endmill. did not bother with a finish cut...

[dh42]

Hello,

I set a diameter of 40 mm in CNCWrapper  


Edit: it's me eyes or you have 4 twist instead of 3 ?

++
David

[dh42]

more info

-   The width of the drawing must be at least equal to Ø x Pi (perimeter)
-   the Z coordinates of the top of the 3D model must equal to the radius (ex for a cylinder of 40mm, the top of the model must be at Z = 20)
-   You must use a limit for the 3D profile because if not, the tool cut the end of the model at the left and right sides. The limit must be a bit larger than perimeter, then the cut overlap after each revolution.

[Bubba]

Hello,

I set a diameter of 40 mm in CNCWrapper  


Edit: it's me eyes or you have 4 twist instead of 3 ?

++
David

David, I have used your model and it cut what appears to be one complete spiral leg and 3 partial legs. The diameter I ended up with measure 1.625" so it is bigger by about .125 of a inch. As soon as I find suitable material I will give a go again and see the end result. Thanks. 

[Bubba]

more info

-   The width of the drawing must be at least equal to Ø x Pi (perimeter)
-   the Z coordinates of the top of the 3D model must equal to the radius (ex for a cylinder of 40mm, the top of the model must be at Z = 20)
-   You must use a limit for the 3D profile because if not, the tool cut the end of the model at the left and right sides. The limit must be a bit larger than perimeter, then the cut overlap after each revolution.

Yes, I my case I figured wrongly based on using the CB "Object Extrema" feature and converting it to the inch. The circumference was @5.75" , radius @.915" and diameter set@ 1.830".

"-   You must use a limit for the 3D profile because if not, the tool cut the end of the model at the left and right sides. The limit must be a bit larger than perimeter, then the cut overlap after each revolution."

Do you mean the limit setting will affect how the spiral itself is cut or the overall length?  The length measure about 14.5cm...

[dh42]

Hello,

For the limits:

Look at the first picture, if there are no limits the tool with down in Z to cut the side of the model as in the bottom picture. ... and you get a hole at the joint after a full revolution.

To get a correct overlap, it's not the width of the part or of the width of the limit that is important but the fact that the right and left side overlap FOR THE PERIMETER SIZE. (sorry, difficult to explain in English)

On the second picture, the green arrows show the perimeter for a 40 mm model (125.66mm), that mean that the model must be created for a given diameter, in other word, the model must be identical at the left and right for this perimeter value. It's the same that for texture in 3D.

No sure it's more clear  

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David

[Bubba]

David, I appreciate the explanation, and I understand what I did wrong. I did not calculate the length of the X axis in relation to the diameter of the spiral...

[Bubba]

Hi All, After solving my problem and successfully machining the spline, I have decided to approach the machining part differently. I simply don't care about how the 3D surfaces are machined. I realize fully how those surfaces must be machined. But, if i can find way around it, I do it in a second! All of it was accomplished with CamBam (I love this program) and CnC Wrapper. From the 3D surface David created I did the  "Surface, Plane Z slice" and used those perimeter lines, to do a  pocket MOP. Thanks to David for providing the 3D profile and for guidance. I created a quick video to show how my diy router and 4th axis is handling the spline carving. Sorry about the picture and video quality. The last picture show completed and sanded spline, the sanding sealer and the polyurethane will be next. Hopefully the YouTube link works.

http://www.youtube.com/watch?v=t4w0qaEOizI

[dh42]

Hello,

Nice and maybe more smooth and speed.

Another way to do, with waterline rather than scanline, I get almost the same toolpath as you.

your 4th axis turns very quickly !! how his your gear ratio ?

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David