V-carve tool paths - Long Machine Times

[dstacey]

Can I ask for some advice? I am starting to learn how things work, but I tried my first v-carve sign today and realized that the machine time are terribly long. It's a simple 22" x 11" sign with a business name in the center with a rectangle arround the outside. I planned to cut out the area out around the letters with a v-carve tool path. The .25" flat bottom was cut out with a 1/4" straight bit and it worked fine. However, when I switched to the 60 degree v-bit it seems to take for ever. It looks like the v-bit cuts are only plunging .001" at a time or something small like that. When I looked at the estimated machine time I found it was expecting 8 hours! I found that I can shorten that somewhat by increasing the clearence step over, but if I raise the step over up to .5" the machine time is still almost 3 hours. It seems like I must have something set up wrong.

Can anyone help?

Thanks,
Dave

[joe]

I can't imagine! Every V carve job I done has been fast. But of course if it's highly detailed and very large there could be a time issue.

Please post photo's so we can see the file.

Joe Crumley
www.normansignco.com (http://www.normansignco.com)

[MogulTx]

Dave,

I am no expert but what do you think about posting the file for a couple of the real experts to review and make suggestions on? A few quick suggestions may not help THIS job, but it would probably teach you where you can modify next time ( and me too!).

If I were suggesting where to look, I would start with the (1) run calculator- they need to be kind of calibrated and may be completely off ( mine was always doubling my machining times. I have it calibrated so that I am within about 20% now) (2) you may be able to run your Jog and Move speeds faster (3) do you have a lot of starts and stops for the different attributes? Some that take the router/spindle back to 0,0? Just the stops with the Z needing to cycle up to "safe Z" and back down causes a lot of delay. I don't yet know how to edit out the starts and stops in PW - ( the next thing I need to learn how to do)- but I know all those starts, stops, and repositions take tons of extra traverse time that does not need to happen.

Good luck ( and please do me the favor of keeping this moving forward. It will help me and others!)

All the best,

Monty

[srwtlc]

Dave,

Check the tool cutting parameters and see if the pass depth for that tool is set very shallow. That would cause it to run many passes to get to a final deeper depth of cut.

Scott

[dstacey]

Here's the file. I used Niagra solid True Type for the font, and the letters are 3" high. I was using a 60deg v-bit and the flat is .25" deep.

Oh, never mind. The pass depth was set at .005! Obviously that would slow things down.

Any idea what that should be set at for MDF and a 60deg v-bit? Is .1 about right?

Dave

[myxpykalix]

sounds to me like you are using a endmill to do your relief carving path and then the vcarving path is going over the same area AND doing the vcarving for your letters, correct?

Post a picture or file for us to look at. Sounds to me like you need to confine your vcarving toolpaths to your letters and not the whole project.

When selecting the vcarving toolpath make sure that only your letters are selected and not the whole project.

[srwtlc]

Dave,

I generally set the pass depth to the max of the v-bit, unless of course if you are running a very large diameter v-bit. ;)

[MogulTx]

Whats the new run time after changing from .005 depth change? And what are you selecting as your new depth per pass?

I see some recommendations(?) in PW for depth and overlap... but I usually fiddle around and choose my own ( and change them per material and per job)- I just got the new PW and haven't started setting up bit characteristics per job- but that will be on my menu SOON.

Monty

[dstacey]

I set the pass depth to .125 and it took 8 minutes. Much Better!

I'm sure I should have found this before I started, but I'm learning alot of good things.

Thanks for your time everyone.
Dave:)

[myxpykalix]

Like Bugs Bunny says...."What a maroon!" :D LOL

That is why we are "on call" here for you...to keep you from making all the same mistakes we made when we first started:)

good luck!

[joe]

I'm with Professor Jarvis on this one.

If this was my job I'd do a simple, fast, V carve around the letters and border with a regular sharp V bit. Then do the area clean, for the background, with a strait 1/8" or 1/4" bit. This is such a small sign it would probably take more time to get ready, change out bits, and do the zero's than it would take to do the carving.

One note on V carving: It's extremely important to get the depth precise. I make several trials, on every V job, before I set the router in motion for the final pass. The best, most accurate Z plate ever made will only get you in the ball part. To make those deliclate little passes takes several trials. Part of this depend on the size of letters and how deliclate they are. On this file I'd be testing the little copy at the bottom of the panel. It makes all the difference to get it right. I seldom see V Carving done accurately. The fellows making decorative chip boxes are experts at it.

Easy Peesey.

Joe Crumley
www.normansignco.com (http://www.normansignco.com)