# Downcut v-bit exist?

**URL:** <https://forum.avidcnc.com/t/downcut-v-bit-exist/2693>\
**Category:** General Chat\
**Created:** [December 1, 2023, 7:45pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693 "2023-12-01T19:45:01Z")\
**Posts on this page:** 14\
**Page:** 1

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**Author:** ![JtheB](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@JtheB](https://forum.avidcnc.com/u/JtheB)\
**Post date:** [December 1, 2023, 7:45pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/1 "2023-12-01T19:45:01Z")

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I’d like to do some very fine detail chamfering on shallow square-edge pockets where baltic birch grain splintering is almost guaranteed - at least when the exposed top layer would be a cross cut. Sanding at this scale would be a nightmare…  
It would be the perfect place for a downcut 1/4" 60 or 90 degree v-bit.  
It doesn’t seem like that bit exists.  
Why is that?  
Recommendations?

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**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\
**Post date:** [December 1, 2023, 11:54pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/2 "2023-12-01T23:54:43Z")

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Sanding mops can do wonders for fuzzies in detailed carves like that

> **[Sanding Mops](https://stockroomsupply.com/collections/sanding-mops)**
>
> Tools that just make sense

I have personally never seen a down cut V bit but that doesn’t mean they don’t exist….

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**Author:** ![barunita](https://avatars.discourse-cdn.com/v4/letter/b/4da419/32.png) [@barunita](https://forum.avidcnc.com/u/barunita)\
**Post date:** [December 2, 2023, 1:35am UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/3 "2023-12-02T01:35:43Z")

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Check these out. I have one but have not used it yet…

> **[8675309-V60 GrooVee Jenny | Cadence MFG](https://www.cadencemfgdesign.com/product-page/60-groovee-jenny)**
>
> 60° GrooVee Jenny specs:Designed by Woodworkers in the USA! 3/8 diameter 60° Vbit on a 1/4" shank.300" Cut length85ipm @ 14k rpm and adjust from thereImportant Tool Facts: Down-shear tool geometry3 flute, with Zirconium Nitride coating.2" overall...

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**Author:** ![jjneeb](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/jjneeb/32/244_2.png) [@jjneeb](https://forum.avidcnc.com/u/jjneeb)\
**Post date:** [December 2, 2023, 3:26am UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/4 "2023-12-02T03:26:04Z")

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I don’t know what bits you are using, but I have noticed a huge difference between the Vbits like this [https://www.amazon.com/Whiteside-Router-Bits-1502-90-Degree/dp/B000A804DA/ref=sr\_1\_5?crid=2NDB7REXJ05QG&keywords=whiteside+v+groove+router+bit&qid=1701487316&sprefix=whiteside+V%2Caps%2C151&sr=8-5](https://www.amazon.com/Whiteside-Router-Bits-1502-90-Degree/dp/B000A804DA/ref=sr_1_5?crid=2NDB7REXJ05QG&keywords=whiteside+v+groove+router+bit&qid=1701487316&sprefix=whiteside+V%2Caps%2C151&sr=8-5)

and the replaceable insert ones like this: [https://www.amazon.com/Amana-Tool-Signmaking-Lettering-Engraving/dp/B00IDEOLQO/ref=sr\_1\_7?crid=VFMWDLC1XY0R&keywords=amana%2Bv%2Bbit%2Bset&qid=1701487400&sprefix=amana%2Bvbit%2Bset%2Caps%2C163&sr=8-7&th=1](https://www.amazon.com/Amana-Tool-Signmaking-Lettering-Engraving/dp/B00IDEOLQO/ref=sr_1_7?crid=VFMWDLC1XY0R&keywords=amana%2Bv%2Bbit%2Bset&qid=1701487400&sprefix=amana%2Bvbit%2Bset%2Caps%2C163&sr=8-7&th=1)

I don’t know if its the Amana edge geometries, or just that they are extremely sharp, but I don’t use any other Vbit any more.

Then for the few remaining fuzzies, either those sanding mops Eric showed, or these work well [https://www.amazon.com/Mixiflor-Abrasive-Woodwork-Polish-Grinder/dp/B08D689WD4/ref=sr\_1\_3?crid=UUSMFUI7CEWM&keywords=nylon+sanding+wheel+for+drill&qid=1701487510&sprefix=nylon+sandi%2Caps%2C149&sr=8-3](https://www.amazon.com/Mixiflor-Abrasive-Woodwork-Polish-Grinder/dp/B08D689WD4/ref=sr_1_3?crid=UUSMFUI7CEWM&keywords=nylon+sanding+wheel+for+drill&qid=1701487510&sprefix=nylon+sandi%2Caps%2C149&sr=8-3)  
Use them from all 4 sides with a really detailed carving. The 600 grit will almost burnish the carving and make it shiny.

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<div class="post-metadata">

**Author:** ![JtheB](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@JtheB](https://forum.avidcnc.com/u/JtheB)\
**Post date:** [December 2, 2023, 9:14pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/5 "2023-12-02T21:14:02Z")

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I appreciate all the sanding recommendations.  
I’ve got a healthy collection of detail sanding tools which include the mops, flappers, polishers… I’ve found the super-fine wire brush wheels to be fairly efficient… those nylon brushes are an interesting material choice…

Chamfering will also serve an aesthetic purpose on the Baltic birch though. A clean angled cut exposing a glue layer or two on the contours is also a goal.  
I may try the Amana replaceable insert v-bits.

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<div class="post-metadata">

**Author:** ![JtheB](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@JtheB](https://forum.avidcnc.com/u/JtheB)\
**Post date:** [December 2, 2023, 10:03pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/6 "2023-12-02T22:03:52Z")

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Anyone ever use a zero flute countersink bit in a spindle?  
Will it handle high rpm’s?  
In theory the upper portion of the bore’s cutting edge would actually serve as a down cut, no?

 ![s-l1600](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/2/2b2e824e57b96d35c3728342ce4a5bdd566fed03.jpeg)

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<div class="post-metadata">

**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\
**Post date:** [December 3, 2023, 8:05pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/7 "2023-12-03T20:05:29Z")

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Another thing you could do is cover the carved area with blue tape, or Oramask. That might help with tearout.

In general I’ve had pretty good luck VCarving Baltic…

I have never tried one of those zero flute bits. As long as it’s rated for the RPM you want to use it at you could try it…

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**Author:** ![Aerojunkie](https://avatars.discourse-cdn.com/v4/letter/a/77aa72/32.png) [@Aerojunkie](https://forum.avidcnc.com/u/Aerojunkie)\
**Post date:** [December 3, 2023, 8:19pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/8 "2023-12-03T20:19:55Z")

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I would be hesitant of using a counteraink like that one. The center of it doesn’t cut so it can align with a predrilled hole. One similar to this would allow you to ease edges in a smaller area. I would look at carbide carving burrs as well, definitely rated for higher rpms and the finish is typically very good.

Aleric Countersink Drill Bit Set,High Speed Steel Counter Sinker Drill Bit 5Pcs 5 Flute 6mm Hex Shank with 82 Degree Mill Cutter Bit Countersink Bits for Wood Metal in Size 1/4” 3/8” 1/2” 5/8” 3/4” [https://a.co/d/1I1JcKQ](https://a.co/d/1I1JcKQ)

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<div class="post-metadata">

**Author:** ![JtheB](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@JtheB](https://forum.avidcnc.com/u/JtheB)\
**Post date:** [December 4, 2023, 2:20pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/9 "2023-12-04T14:20:37Z")

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Here’s a detail shot of the square edges of the 0.1" depth pockets. The contours wander very close to one another so getting a 30/45 degree cutting edge down in there would require a 1/8" (ideal) or 1/4" (max) diameter bit.

 ![IMG_2703](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/9/919094a49ee1838d30217941331304c863efb5df.jpeg)

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<div class="post-metadata">

**Author:** ![JtheB](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@JtheB](https://forum.avidcnc.com/u/JtheB)\
**Post date:** [December 4, 2023, 2:24pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/10 "2023-12-04T14:24:36Z")

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> [@Aerojunkie](#):
>
> I would look at carbide carving burrs as well, definitely rated for higher rpms and the finish is typically very good.

That’s in interesting idea!  
Along with the higher rpms anything else to be aware of with those?

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<div class="post-metadata">

**Author:** ![barunita](https://avatars.discourse-cdn.com/v4/letter/b/4da419/32.png) [@barunita](https://forum.avidcnc.com/u/barunita)\
**Post date:** [January 23, 2024, 3:26am UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/11 "2024-01-23T03:26:41Z")

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If you still are looking for a downcut v bit take a look at Cadence Manufacturing. They have an interesting bit that might fit your needs. I have one but have not used it yet.

> **[30­° GrooVee Jenny | Cadence MFG](https://www.cadencemfgdesign.com/product-page/30-groovee-jenny)**
>
> 30° GrooVee Jenny specs:Designed by Woodworkers in the USA! .250" diameter 30° Vbit on a 1/4" shank.467" Cut length60ipm 30plunge @ 23k rpm. Adjust as needed.Important Tool Facts: Down-shear tool geometry3 flute, with Zirconium Nitride coating.2"...

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<div class="post-metadata">

**Author:** ![Stephen](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/stephen/32/2569_2.png) [@Stephen](https://forum.avidcnc.com/u/Stephen)\
**Post date:** [January 23, 2024, 12:48pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/12 "2024-01-23T12:48:36Z")

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> [@jjneeb](#):
>
> I don’t know if its the Amana edge geometries, or just that they are extremely sharp, but I don’t use any other Vbit any more.

What feed rates are you using? Amana’s [RC-1102](https://www.amanatool.com/rc-1102-insert-v-groove-90-deg-x-3-4-x-1-2-inch-shank-cnc.html) insert V-bit has a listed feed rate of 40 ipm, while their [45716](https://www.amanatool.com/45716-carbide-tipped-v-groove-90-deg-x-3-4-dia-x-3-8-x-1-2-inch-shank.html) carbide-tipped V-bit is at 90 ipm. I decided not to buy the insert bit based on that difference, but I’m curious if I could run it faster.

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<div class="post-metadata">

**Author:** ![JtheB](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@JtheB](https://forum.avidcnc.com/u/JtheB)\
**Post date:** [January 23, 2024, 2:31pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/13 "2024-01-23T14:31:02Z")

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That’s definitely an interesting find!  
Mind getting back to us on it’s performance?

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<div class="post-metadata">

**Author:** ![jjneeb](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/jjneeb/32/244_2.png) [@jjneeb](https://forum.avidcnc.com/u/jjneeb)\
**Post date:** [January 23, 2024, 2:53pm UTC](https://forum.avidcnc.com/t/downcut-v-bit-exist/2693/14 "2024-01-23T14:53:21Z")

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> [@Stephen](#):
>
> What feed rates are you using?

I never noticed they called out a power feed rate. To be honest for wood and plastics I don’t go by what the bit manufacturer says, I go by cut quality and sound.

I use Vbits mostly for smaller signs and some scene cravings. These tool paths almost never have a straight segment even a half inch long, so they spend most of the time accelerating and wouldn’t get up to a 100 ipm federate very often, unless I was running a very high acceleration setting on my motors, but if I did that the machine shakes too much and the cut quality is bad.  
So I usually run acceleration at 15-20 I/s2, and 50 ipm feedrate. That gives me really clean, chatter free cuts on hardwoods that don’t need to be sanded.
