90 degrre v-groove depth?

[jaustin]

I need to make numerous cuts using the 90 degrre v-groove bit.
I am going 1/2 inch deep what would be a safe maxium depth per pass I should use?

It will be in mdf 3/4 unless i can find some 5/8

[mtylerfl]

I need to make numerous cuts using the 90 degrre v-groove bit.
I am going 1/2 inch deep what would be a safe maxium depth per pass I should use?

It will be in mdf 3/4 unless i can find some 5/8

Hi John,

You should be fine with a .25" Max. Pass with your 90-degree v-bit. I think you could go deeper than that per pass...the default depth for that bit in the CW software is set at .375", but I would set the Max. Pass at .25" to assure a clean cut.

[lawrence]

one more trick that I've learned with my pass depths-- I like to do a final pass where I only take off a whisker-- which cleans up the carve significantly. For example, if I am going .25 deep overall I like to set max pass depth to .23 so it does a .23 pass then a .02 pass which just barely touches the wood.

Lawrence

[bergerud]

Nice trick Lawrence. I will use that one.

[mtylerfl]

That is a great tip...never thought of that with the CW. I do "cleanup passes" regularly with my "other" CNC (basically just run the V-carves twice to shave out the crevice of any whiskers left from the first pass). Your CW tip has the same advantage - thank you, Lawrence!

[jaustin]

Thanks Michael

Lawrence should I run .24 so it will do 2 passes at.24 and 1 pass at .02

[Dan-Woodman]

I'm not sure you can do 2 passes at .240 unless you copy and paste a second image. I think with flat bits the shallow "clean up pass" is automatic, not sure about the V-bit though.

[dbfletcher]

I'm not sure if a "clean up" pass would really do anything when carving MDF either. My experience with MDF is since there is no grain, you dont get any "fuzz" to begin with... just lots and lots of really fine dust (hazardous).

[AskBud]

I'm not sure you can do 2 passes at .240 unless you copy and paste a second image. I think with flat bits the shallow "clean up pass" is automatic, not sure about the V-bit though.Here is the screen!
AskBud
52071

[lawrence]

Bud nailed it-- max pass can be your best friend for both cut outs and vector cuts

Lawrence

[bergerud]

I think what Dan-Woodman says is true for the decorative bits. The software does take control using its own max pass and clean up pass. (At least as I remember.) I can see, however, cases where you might not want the finish pass. For example, outline text where a finish pass might chip out unsupported parts of text. During the first pass, the yet uncut wood supports the delicate parts as they are being cut.

[AskBud]

Here is a page from the manual.
AskBud
52080

[mtylerfl]

I think what Dan-Woodman says is true for the decorative bits. The software does take control using its own max pass and clean up pass. (At least as I remember.) I can see, however, cases where you might not want the finish pass. For example, outline text where a finish pass might chip out unsupported parts of text. During the first pass, the yet uncut wood supports the delicate parts as they are being cut.

You must "engage" the Max Pass option yourself via the Bit Menu...there is no automatic finish pass on anything.

[bergerud]

You must "engage" the Max Pass option yourself via the Bit Menu...there is no automatic finish pass on anything.

I do not just make stuff up Michael! Try it. Make a path and assign the 3/8 classical bit at the default depth of 3/8". Do not choose the max depth option. It will slowly plunge in and follow the path at a depth slightly less than 3/8". Then it will return to the start and do a finish pass. That is what my machine does.

[mtylerfl]

I do not just make stuff up Michael! Try it. Make a path and assign the 3/8 classical bit at the default depth of 3/8". Do not choose the max depth option. It will slowly plunge in and follow the path at a depth slightly less than 3/8". Then it will return to the start and do a finish pass. That is what my machine does.

Very interesting...I'll have to check into that.

[mtylerfl]

Ok. On thinking some more about your example of the decorative 3/8 bit, that did start sounding familiar regarding a final pass. It has been a few months since I've used a decorative bit, I had forgotten that.

I also put a call in to one of the software engineers at CarveWright to confirm the behavior (actually, I called Joe, then he called over a tech). He tells me yes, the decorative bits are intentionally programmed to cut "shy" of the total (final) depth during the main pass(es), then the cut motor RPM's are automatically adjusted before a final pass is made to finish the cut to the full depth specified. The amount of material left for that final pass varies, depending upon which bit is being used, but it is a very small amount, say, around six thousands of an inch or so.

Also, just a point of information...some of the heavier decorative bits are pre-programmed to make limited depth passes automatically to help a user avoid trying to hog out too much material all at once (this I had not noticed, nor was I aware of). Even when the user sets their own Max Pass setting, if the pass amount set by the user exceeds the (hidden) pre-programmed pass depth, the machine will default to the lesser of the two. This prevents stressing out the mechanics and chipping or splitting of wood.

One of the presentations I'll be giving at the CW Conference is the use of the CW Bit Set and the creative things that can be accomplished with it. By that time, I will have very specific data regarding which bits do what, how they are programmed, etc.

Oh...very important!...Thank You bergerud for the memory jog!!