Need help again - engraving issue

[compunerdy]

I am trying to engrave some pretty small images and I am having wierd results.



On the left is a section of what I am trying to engrave, it has nice clean lines. When I add it to the engraving job it shows up like the right image. It does not follow the lines it just make straight cuts and at wierd angles.

Anyone got a clue what I am doing wrong here?

Thanks, Tim

[RTP_Burnsville]

Tim,

Not sure I totally understand what is happeneing but you may look for a check box labeled something like 'use arcs between points'.

I also assume the item on the left is one complete or joined curve created using the 'join' feature. I don't understand the multiple colored paths on the right drawing, it's like you have several toolpaths defined.

Robert

[compunerdy]

As far as I can find evrything is checked to use arcs.

The left image I have all of the edges selected and I have tried joining them all first which did not make a difference. I can select all the edges or select the face and either way when I hit add pocket it ends up looking like the right image.

[mayhugh1]

Could you post your project? - Terry

[compunerdy]

It can be downloaded here.

http://www.thecustomsabershop.com/im...ngravetest.zip

[davidperry3]

When you use smooth by arcs you have to adjust the tolerance or it will just mill straight lines between points that are exactly on the line (not using arcs at all).

[compunerdy]

"smooth by arcs" is not available for engraving. If this is the issue then what other operation could I use that would allow me to engrave on a cylinder as well as have the "smooth by arcs" option?

Also, as you seen in the pic, it doesnt even follow the straight lines for some reason. It just seems to do whatever it wants. Has anyone tried my file to see if it works differently for you?

Thanks, Tim

[RTP_Burnsville]

Tim,

The simulation appeared to run on my version much the same as yours.... I have not played around with the engrave machine model so not sure what is happening. What machine did you use to generate the G-code? I picked the PC1100 but the simulation only did three axis and this looks like it should be a forth axis process of engraving on a cylinder.

If you look at the attachment it appears that you model contains many faces. Could it be that you need to join the faces and then somehow select the edge you wish to engrave? With all the edges how does the machine model know what to use?

I have used the 2D contour model to do engraving of a curve, but it was on a flat plat. Currently building a 4th axis so you are a bit ahead of me.

Robert

[compunerdy]

The section I posted a pic of does not have many faces at all. It has 3 straight sides and 3 curves. I can select the face in the middle, the top edges, or the bottom edges and either way it does the same thing when I add the pocket. I have tried joinging the edges into a single curve, same thing. I have tried joining the side faces, same thing. Nothing I do will make it follow the path of the curves, it always reverts to cutting everything in straight lines. I tried setting the tool diameter to .001 since it is a very small image and that did not change anything either.

You would think that if nothing else it would follow the straight edges and cut off the corners but it doesnt even do that.

Also does anyone know why sprut always cuts the part in half on a cylinder? It puts lines down the sides which mess things up for me alot.

The machine I have it set to is - 4th axis milling machine (A)

EDIT - I imported the job again and this time it is following the lines except in the corners. It still will not follow the radius's but at least it is much cleaner looking. I noticed when I imported the model from solidworks it had 0 curves listed, is this the issue? In sprut when you select the curve is sure looks like a curve. If I select all the curves and tell it to join curves it cuts the corners onto straight lines though. Nto sure what was different on this import..

Here is what it looks like when I select the upper edges (pic on left) and then click on "join curves" (image on right) Why does it turn the corners into straight lines?

[mayhugh1]

Tim,
I played with your project for an hour or so and could not improve on the toolpath approximation. I don't believe there is anything wrong with the model as I was able to create a perfect 2D contour, but of course this projection is not what you want. There seems to be a resolution limitation with the engraving and pocketing operations when doing continuous 4 axis contouring on a cylindrical surface. I went into the machine parameters and changed the resolution for the A axis but this didn't seem to affect the result at all and so I'm not sure this parameter is functional from a user perspective. I also changed the minimum arc radius for the X-y and again this had no effect. I would send the project to Yuri or at least post it in Sprutcam's forum and maybe UK Dave can comment. He doesn't respond to posts on this forum. - I'm interested in what you find out on this. - Terry

[compunerdy]

Thanks for taking the time to confirm that I am not nuts (at least in this case)

Can you link me to the forums I should post it in or provide a E-mail for Yuri?

[mayhugh1]

Yuri's email adress is:

cherry@sprut.ru

and Sprutcam's own forum is at

SprutCAM forum (Powered by Invision Power Board)

You have to join the forum in order to post but it just involves filling in a form. I don't remember there being any waiting period to post after joining.
If you get a solution via e-mail, I would appreciate if you report back what you learn. To get the best response from Yuri, you should include the jpg of the toolpath in your first post as well as the project itself in your email to him along with a short concise comment about your problem. The toolpath picture should catch his attention pretty quickly. His English is a lot better than my Russian but pictures are worth a 1000 words. - Terry