Jewelers burs for end mills for light finish work.

[BillGEGHV]

So back in the day I was in the toy industry as a sculptor, model maker, CAD designer, 3D modeler, prototype maker etc. I used CNC milling for about 90% of my work, milling very complex sculpts and models. I used to use Jewers burs for the fine detail milling I used to do. All this milling was done in plastics and mostly sculpting wax.  

I am currently working on machining some casting molds in 6061 T6 and wanted to know if these jewelers' burs would work on aluminum for very light finishing machining.  One feature  I need to machine is to clean up some letters and the stock left to machine is about .04-.06. These also have some undercutting so I want to take advantage of the lollypop profile of the jewelers burs.   The other would be finishing some really small chamfers around my logo, pretty small .022 chamfers  They are made with vanadium steel I looked it up and it sounds to me like its better than your average HHS?  Most of these are 6 flutes and are basically the same as your typical Dremel bit with the 3-32 shank.  Big advantage is I have tons of them from back in the day, LOL  

I actually tried one but was such I light cut Im not really sure it was even cutting that much since the letter shapes were basically already machined I was just trying to make them a bit deeper.  

Will they work for the type of cuts Ive described??

[brad_francola]

Aluminum is gummy and will load up a cutter very quickly if you don't clear the chip.  You may want to consider using a machinable grade of Aluminum:

https://youtu.be/cpIVQqfKcoY?t=470

That said, there are several toolpaths in F360 that can drive a lollipop:  Blend, Flow, Steep and Shallow (Steep only mode).  There is also an awesome toolpath called "Deburr" that does a great job of removing burrs.

[BillGEGHV]

Who knew, I already have all the stock purchased, and my 1st 2 molds are almost done and are pretty darn nice.   The amount of material I need to remove and me being very conservative Im not even making a chip "I KNOW your supposed to" (make a chip) so the flutes will not likely pack up and I do run coolant.  You never gave any input on IF these jewelers' burs will work? 

[brad_francola]

Hi.  I have not personally used a jewelers burr for this type of application.  But, I have seen grinding wheels inside of CNC mills and lathes so I'm pretty sure you will be successful with the burrs if you take your time to get the speeds/feeds/DOC just right.  

[BillGEGHV]

Thanks for the input on this, just wanted to update the thread in case anyone had the same questions.   Im using these burs and they are working out very well.  Its a .086 di, and again only very little material is removed for the final finish pass.  

[seth.madore]

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@BillGEGHV wrote:

Its a .086 di, and again only very little material is removed for the final finish pass.  

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What's "very little material" out of curiosity?

[BillGEGHV]

Between .04-.06. "I THINK:???? Im doing a .002 step over and the burs are working out really well for this.   Would be REALLY nice if fusion would allow you to measure random distances for things like this. So this is only an estimate based on the stock left after the general finish pass.   In Rhino I can measure ANYTHING i want to, I do NOT have to snap to a point, edge or surface,  you can just click in any viewport to measure.  This drives me CRAZY in Fusion I just want to measure things for a reference point OR just general measurements.   This would be my # 1 wishlist item for Fusion. 

[brad_francola]

@seth.madore we have OFTEN complained about this very same thing.  Why can't we measure what's on the screen during simulation?  

[seth.madore]

Yeah, we've been neglecting that side of things, it's a frustration felt by many users. Someday....I hope?