Tapered Ballnose entry in Tool DB - question

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Ton80
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Tapered Ballnose entry in Tool DB - question

Post by Ton80 »

I have looked around on the forum and watched the tutorial video for entering new tools into the DB but I have a few questions that haven't been answered.

I am using the Precisebits ( same as many of you ) and I entered the info supplied from their website for my particular cutter ( CM404-0625-100B which is the .0625 tapered BN - 4 flute ).

The video doesn't explain the difference in this section - CUTTING PARAMETERS and the STEPOVER vs CLEARANCE PASS STEPOVER
Am I to interpret this with STEPOVER for final or finish pass cuts and the CLEARANCE PASS STEPOVER as the setting that would be used if I selected this tool for a roughing cut?

Something else which I am unclear on is the PASS DEPTH setting under this same section. I entered the recommended .125 pass depth but the software ( VCarve Pro in my case ) is carving out .310 in a SINGLE PASS... why is the pass depth being completely ignored by the software? Also, the software doesn't display this setting when I look at the tool path / EDIT.

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Adrian
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Re: Tapered Ballnose entry in Tool DB - question

Post by Adrian »

The finish pass is always done in one go, it doesn't use the pass depth which is why it's important to use the roughing toolpath with a bit that isn't wildly different in diameter (1/2" rough, 1/8" finish for example) as there would then be several full depths places for the finish tool to attempt.

Ton80
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Re: Tapered Ballnose entry in Tool DB - question

Post by Ton80 »

Adrian wrote:The finish pass is always done in one go, it doesn't use the pass depth which is why it's important to use the roughing toolpath with a bit that isn't wildly different in diameter (1/2" rough, 1/8" finish for example) as there would then be several full depths places for the finish tool to attempt.
I see.. I think I was assuming that was the answer but I really wasn't sure. Some of those tutorial videos assume a certain level of experience on the end users part. SO the Pass Depth would be applied to a ROUGHING pass if I chose this bit and assigned it to that purpose.

Adrian, I noticed in one of the threads about the tapered ballnose type cutter you mentioned you rarely use the roughing pass. That is pretty much what I have decided on since I rarely carve anything which is going to exceed .375 in max depth and the majority of my projects are set to .25 max depth. With the tapered ballnose bits this seemed to be the way at least 50% of the forum users said they also run their jobs.

I have started to design my projects with a slower rate of feed and then I gradually step it up after the first passes have been made. I know it might be a little riskier strategy but it's been working for me with the type of jobs I run.

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martin54
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Re: Tapered Ballnose entry in Tool DB - question

Post by martin54 »

A tapered ballnose is far stronger than a straight shank ballnose where the shank diameter is the same as the ball diameter which is probably the main reason some people don't run a roughing toolpath before the finish cut :lol: :lol:
What materials are you generally cutting ? Reason I ask is because generally you would be better off with a 2 flute cutter rather than a 4 flute, especially with 3D machining where the selected feed rate is quite often never reached due to the constant changes with the z axis.
There are always going to be exceptions but generally speaking 4 flute cutters are better suited to milling machines rather than routers where the spindle speeds would be a lot slower :lol: :lol:

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Rcnewcomb
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Re: Tapered Ballnose entry in Tool DB - question

Post by Rcnewcomb »

As Martin said, a 2 flute bit, such as the CM204-0625-150B, might be a better choice if you are working with wood.
- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop

Ton80
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Re: Tapered Ballnose entry in Tool DB - question

Post by Ton80 »

I primarily cut Oak 50% of the time. The other 50% would be split mainly between Maple and clear Pine, occasionally Cherry. Nothing super hard. I'll order a few of the 2 flutes instead of the 4 flutes.

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