Vcarve help

[James Huggins]

Hi Guys and Girls,

my first post but have been viewing the forum for a while.

I am after some advise if you dont mind, I am trying to cut 1.5 mm laminate (round holes and rectangles) but my holes are coming out 3.2mm to big and my squares are coming out 2.5mm to big.
I am using Vcarve, a small cnc machine and a 3mm vbit.

Any ideas on what I am doing wrong?

[Sotos Patistas]

First thing to check is that you have your bit dimensions correctly defined in VCarve. Also, there are much more experienced CNC guys (and gals) around,but if it was me, I'd not be using a V Bit for cutting, I believe an endmill to be more appropriate.

Lastly, although there is a good bit of forum crossover, there are likely more VCarve users in the CNC section, you might try posting there.

HTH

[Ross Moshinsky]

Most likely you're picking the wrong mode to cut the material out. You also really can't make interior cuts with a V-Carve bit. You really want a straight bit for that.

For the exterior cuts you want the bit to follow the actual line. You do not want to cut inside or outside the line. I think on V-carve pro it might be called an engraving cut. I really don't know, but that's probably your issue.

For the interior cut, you're going to want to change bits most likely as mentioned above but if you don't want to do a bit change, you need to make sure the cutter is offset enough to allow accurate cuts. This is determined by the angle of the bit in relationship to the depth of the pass.

This is all assuming that your CNC is actually calibrated and running correctly and you're just having problems on this file.

[collin diefenbacher]

use a endmill bit and use the profile tab and cut inside the line

[Russ D Wood]

I think I understand the question and if so I think this is where the problem lies. The software is using the very tip of the tool as its point of origin so when 'cutting' your rectangle the point is on the correct measurement BUT the taper of the v bit is NOT. As others have said wrong bit to cut out with and probably the wrong profile cut. Just a thought. Russ

224298

[Mick A Martin]

I agree with Collin, use an end mill and choose the profile toolpath and select inside the line. The other option is use an endmill with the pocket toolpath. A V-Bit is not the correct tool to use to cut out parts unless you want a chamfer on the edges.

[James Huggins]

Thanks for your replies.

I am using a Vbit for a bevelled edge on the outside cuts, doesn't really matter if the inners are bevelled or not so to save a tool change I just use the same cutter.

I am still having troubles with this, I have just done a label and the circle inner cuts came out fine - profile tool path cut on the line, 3mm Vbit selected .. No probs there. Just tried to cut the outsider edge out to give me my finished label and the width is 1.5mm under and the height is 0.5mm under.

Very frustrating

James

[James Huggins]

Here is an image of what I am trying to do.

First i cut the holes, then engrave and then cut out of the sheet of Laminate to give me this label which is say 250mm x 250mm. the centre holes are perfect size but the 105mm x 135mm is coming out to small

http://i4.photobucket.com/albums/y146/neutron604/label1.jpg

[Jerome Stanek]

If you want to use the v bit set your offset at 1.6 mm for your round holes and 1.25 mm for your square holes.