Advice on endmills for Aluminum and Nomad

I am about to start milling a low end vise for my Nomad Classic. Feeling ok about my strategies but feel there might be room for improvement. Over 14hrs of milling time. For the most part I am trying to get as best finish as possible. I have 1/8" Zrn coated 2 flute endmills as my main cutting tool. For the most part I am running a 0.001 in feed per tooth running @ 20 in/min and 0.0055 in depth of cut. The 1/8" endmill has a cutting depth of 0.5" and my part is 0.625" deep. I am concerned about rubbing through that extra 0.125". Would a 1/4" single flute Zrn coated endmill help me?. Too much for my Nomad?

Unfortunately, 1/4" tooling is only supported for cutting easily machine materials such as Renshape or machinable wax — some folks hold that the added rotational mass will help to power through a cut, but that doesn’t seem to prove out in practice.

You could relieve the endmill above the flutes, just take a stone to it for a light pass, but I probably wouldn’t worry about rubbing for 2 and a quarter passes (round up to 3).

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Unfortunately, 1/4" tooling is only supported for cutting easily machine materials such as Renshape or machinable wax

Lol, hold my beer! But seriously, on stock machines this is correct. @patofoto, you are using Fusion 360 correct? In your extrusion dialog box, add a 0.5 degree draft angle to the part and your end mill won’t ever rub and is much easier than relieving tools. But also, I did none of these things on my .75" deep parts and it was fine. :cowboy_hat_face:

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I use 1/4” tooling on HDPE but I doubt I could go to much harder material so aluminum would be out of the question - though truthfully I haven’t tried. With respect to over cutting the flutes I tend to do that on a regular basis. The real punishment is it tends to spoil the surface finish a bit when the shanks starts rubbing on the stock wall and the flutes start bouncing around a bit.

Thank you all! Suspected that the 1/4” was not the answer but since I have no experience with single flute endmills I wondered. I embarked on this project with the idea of getting the best finish possible. I want to try having a 0.001 radial stock to leave and doing a thin finish pass with a 1/4” endmill. Opinions?. Maybe more radial stock to leave?. I am playing in the grey area around my Nomad’s limits. I am using Fusion 360. @TonyDangerCoiro Would extrude with a draft not leave you with a not perpendicular wall?. Hmmm. Now that I am writing this I want to think about it a little more.

It does not leave a perfectly perpendicular wall, the intent is it’s so close you don’t notice or care. Check out some injection molded parts around where you live; they will all have draft angles. Draft angles are everywhere, they are just so slight we don’t notice them. It’s just an option. Honestly, this draft will happen anyway; as more length of the cutter engages the workpeice, it deflects more which naturally puts a draft/taper on things.

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Thank you @TonyDangerCoiro. Will test that. I have started milling now. At 0.005 doc I can cut @ 40ipm which has halved my time in some long operations. Trying to adjust at the beginning of each op to see how much I can finesse the cut. So far cutting sounds creamy!!!. Will show results once I have them.

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