Circular motion in a horizontal plane

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MAXJ
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Circular motion in a horizontal plane

Post by MAXJ »

I have been wondering if there is a method, or maybe it needs to be a gadget, that you can simulate the motion action of hand lapping, in a straight line. So to say circular motion in a horizontal plane

With that I mean, that when you do a large surface cut, like a spoil board, instead of the cutter, cutting in a straight line, with a slight overlap, it follows a path of circular shaped cuts, that overlap themselves. And the next row/cut then slightly over lap the first cut, and so on.
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Circular motion in a vertical plane.png

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TReischl
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Re: Circular motion in a horizontal plane

Post by TReischl »

I may not recall this correctly but I think that is called epicycloidal or something similar.

And yup someone would have to write a gadget to do it.

Curious, what would be accomplished by flattening a spoil board that way?

If the idea is to prevent those stepover marks, well, it is a spoilboard and if it is not just cosmetic then they will also appear in workpieces.
"If you see a good fight, get in it." Dr. Vernon Jones

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jarm2
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Re: Circular motion in a horizontal plane

Post by jarm2 »

It would create a very interesting pattern on whatever piece was being cut. Kind of like an engine finish on machined pieces.
Vectric Aspire 10, AutoCAD lite, Corel Draw 2019, ViaCAD Pro 9, W 10

SteveNelson46
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Re: Circular motion in a horizontal plane

Post by SteveNelson46 »

You could use the existing spiral gadget and create an archimedes spiral. Then use a profile toolpath and bit with the correct diameter and step over. Then use the array copy tool to create a pattern. Kind of klunky.
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Archimedes spiral.jpg
Steve

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adze_cnc
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Re: Circular motion in a horizontal plane

Post by adze_cnc »

My machine has a built in spoilboard creation function so I’ve never actually needed to create a file to do so.

Attached is my attempt at a swirly spoilboard clearance file as suggested here. The toolpath is not calculated—doing so adds 63 megabytes to the file size! Why?!

As it is adding the 49 spiral vectors increased the file size from 124 kilobytes to 6.5 megabytes! Why?! That’s 133 kilobytes per vector. It can’t be that memory intensive to store 10s of node points.

As always the settings in the file need to be altered to fit your machine. In particulare my machine has Z zero set to the machince bed not the spoilboard top.

Steven
Attachments
spiral_spoilboard_clearance.zip
VCarve version 9.519
(2.26 MiB) Downloaded 39 times

MAXJ
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Re: Circular motion in a horizontal plane

Post by MAXJ »

Hi Steven,

Thanks for posting the file. It looks great and is just what I was looking for.

Cheers

Max

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adze_cnc
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Re: Circular motion in a horizontal plane

Post by adze_cnc »

Not having access to a machine to test things out I created the file “in my head”. One change should be made to it:

change the material thickness to 0.001 inch (VCarve / Aspire won’t allow 0 thickness). There will be a warning, when you recalculate the toolpath, that the cut will be too deep—that’s pretty much what we want.

Now the output NC file can be used for any thickness of spoilboard. If you are setting Z-zero to the spoilboard (the so-called machine bed) it’s fine. If you are settting Z-zero to the stock top that’s OK too as that will be the spoilboard top anyway.

Steven

MAXJ
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Re: Circular motion in a horizontal plane

Post by MAXJ »

Hi Steven,

Thank you for the update

Cheers

Max

MAXJ
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Re: Circular motion in a horizontal plane

Post by MAXJ »

Hi Steven,

I used this spiral spoil board vector and modify it for my application and cut my spoil board on the weekend. It came out perfect flat and not a ridge in sight.

Thank you for your help

Cheers

Max

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martin54
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Re: Circular motion in a horizontal plane

Post by martin54 »

If you are getting ridges when you surface your spoilboard then you might want to check the tram on your spindle :lol: :lol:

MAXJ
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Re: Circular motion in a horizontal plane

Post by MAXJ »

Hi Martin,

Thanks for the advise. After I finished the spoil board, I followed the directions of Mark Lindsey and the machine was within tolerance. When the earth starts turning again, and we can order from Avid CNC, I will order a Tramming GMT Spindle Mount.

Cheers

Max

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