Point Cutting Bit - Sequence of Use

Point Cutting Bit - Sequence of Use

Postby wb9tpg » Wed Nov 21, 2018 11:58 pm

I just picked up a Whiteside 1572 1/4"R Point Cutting Bit. I want to use it to put a round over on the outer edge of some things I'm carving. Should I cut the round-over before or after the Cutout with 1/4' End Mill . I'm wondering which tool path to cut first....

Note: The cutout will leave tabs to hold the work piece in place
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Re: Point Cutting Bit - Sequence of Use

Postby Rcnewcomb » Thu Nov 22, 2018 12:07 am

The answer may change depending on the material you use and the characteristics of your own system. Also, climb or conventional may make a difference as well. You will need to experiment to see what works best for your setup.
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Re: Point Cutting Bit - Sequence of Use

Postby scottp55 » Thu Nov 22, 2018 12:50 am

I'd probably use it first, as when it gets full depth it can exert some force and sometimes vibration if speed/feeds are off.
Only ever used it for cutouts on small items that were an absolute PITA to sand in quantity by hand to 600G, but finally got it dialed in for Tiny stuff in all 5 species for minimal sanding.
I was lazy and simply copied the Magnate's profile,and never bothered to mod it for the actual flat :oops:
IF using the pointed profile, max depth without the sidewall cutting is about.235" if wood is Flat.
Offset about .01" and you'll avoid the tip cutting into your cutout.
Make sure it won't be cutting into your tab material on thin stuff, or actually raise to avoid the tabs if you decide on using last(Pain to sand!).

I've found it easier to use my laminate trimmer and a bearing 1/4" roundover in one pass after cutting it out, as usually cleans my tabs off on bigger stuff.
For a couple years I used that bit a lot for cutting out buttons and keyfobs in Cherry to Bloodwood production on .19-.23" thick blanks.
In 2 years these settings saved us probably weeks of sanding or more on my machine on this tiny stuff.
Oh...Last pass of .005" was always used.
Rambling again. :)
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Whiteside .5PRO for small object cutouts all woods.jpg
8.8.17 MM DRAGONS 3 ONSRUD .005 INCH FLAT.jpg
Maine keyring 0.jpg
WHiteside .5D .25R PRO Pointed round over bit.jpg
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Re: Point Cutting Bit - Sequence of Use

Postby wb9tpg » Thu Nov 22, 2018 2:01 am

Thanks, that's extremely helpful!
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Re: Point Cutting Bit - Sequence of Use

Postby adze_cnc » Thu Nov 22, 2018 5:44 pm

wb9tpg wrote:I'm wondering which tool path to cut first....


Like many things it all depends. If the stock is thicker than the round-over and I don't expect hideous tear-out I would probably do three paths (easy when you have an automatic tool changer):

  1. profile pass to the depth of the round-over with a straight bit as a relief cut to ease the load on the point bit
  2. profile cut with point bit to round over the edge
  3. profile cut with a straight bit to free the piece
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Re: Point Cutting Bit - Sequence of Use

Postby ger21 » Thu Nov 22, 2018 6:16 pm

Doing the roundover first will eliminate any chance of tearout. So I'd almost always do the roundover first, unless there's some special reason not to.
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Re: Point Cutting Bit - Sequence of Use

Postby IslaWW » Thu Nov 22, 2018 8:24 pm

+1 to what Gerry says, but sometimes you need to cut the outside profile first, then offset about .010 to eliminate the roundovers point. Side benefit is that the roundover cuts easier and cooler if only cutting 1/2 diameter engaged
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