Are eBay carbide mills any good?

I’ve upgraded my machine to a Kress FME1050-1 spindle and really the first thing to notice is OH MY GOD THIS THING FLIES. Compared to the 24V default spindle, this spindle is just unimaginably good on aluminum. However, this also immediately highlighted how crappy my $2 eBay HSS mill bits are. The edges of an aluminum routing job I did yesterday are just all messed up, even with cooling and a relatively conservative feed rate (25krpm at 400mm/min, 0.5mm step-down).

So it’s time to get some good mill bits. I have a really good source for mill bits near me, DamenCNC. They sell very competent uncoated carbide mills specifically for milling aluminum for about €20-€30 (http://damencnc.com/en/tools/cutting-tools/milling-cutter/240). However, now I wonder: how do non-lowest-bidder eBay mills compare? For instance stuff like this:

http://www.ebay.com/itm/4Pcs-Of-1-2-3-4mm-Finish-Profiling-Carbide-End-Mill-Bits-Milling-Cutter-/221627543209?hash=item339a07eea9

or this:

http://www.ebay.com/itm/1-pc-Solid-carbide-3Fl-Mills-Aluminum-End-mill-Cutting-dia-2mm-HRC-45-Endmills-/121774813436?hash=item1c5a5830fc

Has anyone tried and compared this stuff already? Especially as I’m still exploring my machine, I’d like to be able to just break or dull my tools like there’s no tomorrow without going broke, so it’d be nice to save on the mills.

Many people here order from:
http://www.ebay.com/usr/drillman1

We have some recommendations and a section on eBay vendors on the Shapeoko wiki: Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable

ive bought from drillman1 and ive been very happy with the bits

Conservative feed rate could be part of the problem, if your taking a light cut at such high rpm the bit spends a great deal of time just rubbing on the material. A heavier chip load can greatly reduce heat buildup, I use cheap single flute endmills to cut aluminum and get great results. That is spinning the endmill at 2500 rpm on a cnc mill though, not 25,000 rpm on a router.

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I agree with @Shawn1, 25k RPM is much faster than recommended and will cause excessive heat on the bit, which is never good.

I’ve just used my standard speed&feed calculator for this (10% lower feed than recommended because grbl was capped to a max x/y speed). The low chip load is mostly a function of the sheet of aluminum being much thinner in this instance than otherwise.

But I can guarantee you that even with PEBKACs, my $2 mills are still shitty :wink:

edit: oh I forgot to say here: I don’t really have much use for Drillman1’s items, as they’re overwhelmingly imperial sizes and stationed in the US. With shipping it’s more expensive than damencnc for what I assume is basically the same quality. I’m specifically looking for metric bits.

Tools Today is very reliable source if money doesn’t a problem. Anything I purchased, works perfect. No burs, no splits. I’m sure they have special bits for different materials.

Agree with @AlanDavis, I bought a 90 degree V Bit from ToolsToday that takes replaceable carbide tips and it’s perfect. It’s razor sharp and goes though wood & polycarbonate like a knife through butter. Beautiful cuts with sharp edges and zero sanding. Worth every single dollar and then some.

At the same time, I’ve also bought a couple of 10-packs of Chinese 1/8th spiral carbide bits on eBay that were so cheap, they’re essentially disposable. They’re sharp, they cut reasonably well and if I lose one or break one, it’s not a problem.

For accurate work, I’d suggest measuring them as their diameter isn’t exactly 1/8th, but at less than a dollar each, who cares.

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I also purchased bit holder and two different blade for it. They’re awesome. When you buy holder you can either buy a set or single blades you need, including ball end mill blade.

http://www.toolstoday.com/p-6009-in-groove-cnc-insert-engraving-tool-body-replacement-solid-carbide-insert-knives.aspx?&variantids=11445,0&keywords=AMS-210

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I’ve never seen one of those… That thing is cool.

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here are a couple I have ordered. So far they are doing well in my test. Haven’t done any serious carving yet however.

If you’re into V carving at all, I bought one of these (which is what I was referring to above), I cannot recommend one of these enough…
http://www.toolstoday.com/p-6015-in-tech-series-insert-v-groove-router-bit.aspx
Very very very good

+1 for drillman1 on eBay

High quality, low cost

So far, I’ve been stocking up on cheap eBay bits. I figure I’ll be breaking a few while getting to know the x-carve and better to break the cheap ones than the expensive ones.
As most of these Chinese eBay sellers sell a wide range of stuff, e.g. clothing, toys, etc as well as the CNC bits, I’m not sure that there will be a lot of difference in the quality of the bits from one seller over another. A better bet might be to go through aliexpress and deal with a specialist tool supplier.

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Ditto!!!

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