1/8 BN setup question

[rickbw]

I am doing a number of 10.5 inch round plaques out of Sapele. They have 4 animals and V Carve text. I have made (10) already and they are taking about 5+ hours each. The majority of the time required is the 3D finish, it is taking 4.5 hours. The finished product is coming out beautiful, but I have (10) more to make and I was wondering if I have the 1/8 BN bit set up correctly and if it should take 4.5 hours to do the finish? If so, fine.. but if I could do the finish quicker it would be great. Thanks in advance.

Tool Setup:

Ball Nose (0.125 inch)
Diameter 0.125
Stepover 0.0125 inches 10%
Soindle Speed 1200 r.p.m.
Feed Rate 50.0
Plunge Rate 20.0

[Brady Watson]

Post a pic of the relief...either actual part machined or screenshot of the 3D.

-B

[rickbw]

Hopefully this works

26121

[rickbw]

I guess I can't count (there are 5 animals) :)

[Brady Watson]

OK...

First, you want to create vector boundaries for the following:

1) Each of the 5 animals, where the vector wraps to the relief nicely (unlike my example below)

2) Vector boundary that 'fences in' the raised bead around the border, on both sides.

Then...

Offset each of these boundaries 1/2 the dia of the bit (.0625" for an 1/8" ball) to the outside for the animals and outer most circle, and inside for the inner side of the raised bead.

Select all of the relief boundaries that go around the 3D animals & the inner most boundary for the raised bead. (NOT the offset bead vector or offset animal vectors).

Create a pocket toolpath to drop the Z around the animals up to the border/bead. Raster is probably faster.

Now select just the offset animal areas. Choose raster, not offset in the 3D finishing toolpath.

Now select the outer bead & the offset inner and outer vectors that go around it. Create a 3D finishing toolpath for them using an Offset/spiral option, not raster.

Then do your V-carving & profile cut...or in an order that minimizes tool changes.

Does this make sense or???

If you need help with the file setting this up send me a PM with your email address. You can send me the file.

-B

[cowboy1296]

Brady, i know you are light years ahead of me. But i seem to have better luck doing the whole plaque as a 3-d cut even the flat areas. Either that are i am too lazy to change the bits. doing a pocket up to the rope seems to be tuff in this example. if my z on the pocket tool is little different than the ball nose i would create a small ridge. Truth is i am waking up slow this morning so i can only assume that i understand you.

Rick are your feed rates in inches per minute or second? I am fairly happy with 2.6 inch per second feed and plunge. My router speed is set at 16000 for the finish tool path.http://www.talkshopbot.com/forum/attachment.php?attachmentid=26135&stc=1

[Brady Watson]

Cowboy,
If I were making these regularly, it would behoove me to make them go as fast as I could, while yielding the best quality. My focus is on quality, because I feel that is why the customer chose to deal with me and not some 'toad down the road'.

The first thing that stands out to me with this plaque is the flat background. Unless the customer provided the material, I would think about separating the 3D from the 2D background by machining each component separately. This would result in nice clean breaks against the background with no tool marks or radii to contend with. I cannot tell from the pic the scale/thickness of the plaque, but I would imagine that there is a decent amount of material just being hogged away and wasted. However, this isn't always practical.

If you asked me to make suggestions as to how I would begin to optimize this project, while keeping it one piece, I would do the following:

1) Create vector boundaries of the 3D components. Use these boundaries for a 2D pocket to clear away the flat background. A 1/4" square end mill will machine that area better, and 10x faster than an 1/8" ball @ 10%. (.25" @ 40% SO = 0.1" per pass; .125" Ball @ 10% = .0125 per pass)

2) Off set the 3D component boundaries you created, 1/2 the dia of the bit; let's say @ 1/8" ball, offset vectors .0625" outward. Around border, make two 1/16" offset vectors to contain the rope border. Create 3D roughing (if necessary) and 3D finishing, using a raster for the center component & 3D offset finishing for the rope; using the offset vectors.

3) Do the 2D operations (engraving, profile etc)

Now...if your machine isn't tight enough to hold a consistent Zzero, even when you Zzero in the exact same XY location (Zzero on bed, then MZ your material thickness, then ZZ...hint...hint) you still get tool marks from the tool change in Z, Drop your background pocket down .01". This will give you some allowance and keep the ball end mill from ever touching it, unless your Z is REALLY off...then you need to do some maintenance.

For the rope border, because of the way it is shaped, a quick profile toolpath @ pocket depth will tighten up any radii left from the 1/8" ball. Sharpening operations like this make the piece 'pop' because you get a defined edge and not a washed out radius. You may want to profile the center 3D with a 1/16" as well to 'pop' it. If you have the bit in there already, why not.

Does this make sense?

-B

[cowboy1296]

more sense now then it would have 5 years ago, thanks.

[rickbw]

Not sure if TJ sees this, but perhaps this would make a good training session? As a novice, its hard for me to follow along.

[cowboy1296]

he did do a 3-d class which should be part of their videos. But i am still curious about your feed speeds.

[Brady Watson]

Read my article on VR & Ramping (http://www.shopbotblog.com/2008/03/a-ramping-the-vr-command-and-how-to-tune-your-tool-for-maximum-performance/) towards the end for recommended 3D feeds & speeds.

Adjusting VR per job when doing production, can result in a lot of time savings.

Also, see this Public Service Annoucement (http://www.talkshopbot.com/forum/showthread.php?21218-Public-Service-Announcement-Make-More-in-Less-Time-via-Tuning) ;)

-B

[cowboy1296]

I for one use them Brady, thanks.

[rickbw]

Brady,

Thanks for your help, it worked great! Maybe Shopbot should hire you as a consultant!!

[Brady Watson]

Brady,

Thanks for your help, it worked great! Maybe Shopbot should hire you as a consultant!!

You're welcome...

They did for many years...I retired to focus on my own business.

-B