I recently bought my first milling machine and of course some

>>1240957
use and endmill holder with a set screw.

>>1240957
According to my inch conversions, your runout is pretty small still. I mean, a little more than 2 thou runout is fairly reasonable. What kind of collet closer is it? You should be able to stick a finger indicator into it and spin the spindle by hand to see the runout. The other question is, of course, what does the part look like? Does it taper excessively when side milling a wall? If everything checks out, then why worry?

>>1240965
You'll likely have similar runout with a weldon or whistle flute setup like this. The advantage though is more rigidity, but you need a different holder for every diameter shank.

Anyway, OP, even fancy shrink fit holders still have runout. I mean, the collets may very well be bad. But like I said, if the results are acceptable, I wouldn't loose too much sleep over it.

>>1240957
.01mm is about the best you're going to get period without spending thousands on specialized tooling anyway.

>bangs like crazy

Answer all of these questions. They are all required to give you good answers.

>material you're cutting
>how and by how much you're holding it
>how are you cutting, conventional milling, climb milling, plunging, circular interpolation?
>feed rate
>rpm
>coolant y/n
>depth of cut
>step over (how much of the tool diameter is working inside the material)
>what your machine actually is
>how long is the tool total from spindle
>how long is the tool from the collet

>>1240957
sounds more like you've met the limit of your tool, not your tooling.

>>1241137
I'm cutting mild or free cutting steel. The mill is an RF45 clone so i'm pretty much limited to conventional milling. I guess my cutting parameters are mostly ok because they work with my other end mills (and other collets). I can take 8mm slotting passes with an 8mm endmill without a problem.

I'm not concerned about a little bit of runout especially because it's a roughing endmill anyway. The problem is it sounds like a very bad fly cutter and sometimes even rips the part out of the vise. I guess it's because of the very uneven chipload.

What i'm wondering about is how the runout can be ok before milling but then change so much. For tightening i use one of these standard chinese ER collet wrenches.

>>1241451
>RF45 clone
I googled it and the machine looks so flimsy
It could be that you exceeded the limit of your machine
Also slotting 8mm and 20mm is a whole different story

>>1241451
>What i'm wondering about is how the runout can be ok before milling but then change so much
Something might get bent
If you're lucky it might be just the collet or the shank you're using to measure the runout

>>1241495
yes it's flimsy but it also happens on super light cuts
>>1241501
If i take it out and put it back in the run out is fine again

>>1241451
Define "light cuts"? Like the previous guy said, what's your feed, speed, DoC, and stepover? A good rule of thumb for a starting point is 1/2 the diameter of the tool as a DoC, and 1/3rd of the diameter of the tool stepover. BUT, that's likely on a more rigid machine than what you've got. I've never worked on a small mill like that, but likely there may have to be further compromises. The good thing is that mild steel doesn't work harden hard core or anything like that. So you could take fairly light cuts with not much of a penalty (aside from time).

I think >>1241495 is likely on the right track: the machine rigidity is the issue. Are you taking steps to maximize rigidity? Like locking all the axis that aren't currently being fed?

How are you measuring runout anyway? Are you loading up the tool in the machine and putting an indicator on the shank? If you feel like it, you can even go buy a dowel pin from the hardware store or something that is the same diameter of the tool shank, and then load that and indicate off of that. That way you can indicate further down the length of it and get a better idea of how much it's swinging out.

>>1241451
Answer ALL of my questions. If you can't follow basic instructions I can already tell your problem is that you're a dumb fuck.

>>1241580
light cuts means it doesn't matter if i'm slotting 2D deep or just facing 0.1mm with 2mm stepover. Feeds and speeds are hard to tell (it's a manual machine) but it's pretty independent from it.

I'm measuring with a test indicator (swiss made) at the shank (and i also tried at the flutes but it's hard to get a halfway consistent reading). I tried the same with a cold drawn rod (not precision ground but all i have right now) and the runout is < 0.02mm. But as i can't cut with it i can't reproduce the effect.

Machine rigidity is definitely not the issue here. It's a small machine yes but people use face mills with it all the time. You can hear and feel it starting to complain way before the cut gets too heavy.

>>1241599
It's independent from RPM, DoC, step over and feed rate. And i can't see how coolant will have any effect on runout. It's mild steel not some weird kind of alien space metal. But i'm not using coolant just a little cutting oil.

Tool from collet is about 2 to 3". Add 2" for the chuck for total from spindle.

A question you didn't ask which may be important is the cutter material. It's HSS i guess carbide would shatter right after the first contact.

>>1241627
>Tool from collet is about 2 to 3". Add 2" for the chuck for total from spindle.
Is it a chuck or a collet holder? Those are two completely different things that are not compatible with each other. Please good don't tell me you're trying to mill with a drill chuck. That's also still pretty long, do you have the tool all the way inside the collet.?


>A question you didn't ask which may be important is the cutter material. It's HSS i guess carbide would shatter right after the first contact
No, I knew it was HSS because there's no way a hobbyist would spend $200 on a carbide 20mm EM.


Your issue isn't runout unless you shoved a chip inside the collet. The runout you got after was a result not the cause. The fact you're ripping posts out of the vice means you do have a rigidity issue. Either you're cutting too hard and too fast for your machine or you're not tightening things enough. The part you had this issue on, were the sides against the jaws machined or were they saw cut/foundry edge?

>>1241633
I looked at it again it's more like 1.5". As i said it's an ER32 collet system. A collet chuck is a chuck and a drill chuck is a different chuck.

Btw milling with a drill chuck (besides getting shitty results) isn't that ultra bad on small hobby machines. The cutting forces are too small to loosen the taper and if it does happen it just falls down scratching your work piece and maybe destroying your tool.

Carbide tooling is quite common for hobbyists here (in germany). I'd say 50:50. 20mm EM would be 20-50€ reground or used and much cheaper when buying packs.

The part is cold drawn steel so parallel to <0.01 and smooth surface finish. Grinding vices are not super strong but if used correctly should be way enough for light milling. As i said light cuts so just imagine the lightest possible cut. As soon as it starts to cut it starts banging because just one flute is cutting with too much chipload.

>>1241633
>unless you shoved a chip inside the collet
i buy alot of chinese collets, because they are cheap, and they frequently have the chips from the slitting operation still inside the slots,

The banging is you're recutting chips. Don't feed it so fast

PS the end mill you are using is shot

>>1241781
I normally run a finger through them before use but i will look into that.

>>1241789
It's brand new but maybe it's shot anyway if it's also chinese (not sure)

>>1242008
Have you tried cutting all the way in with your 20mm endmill?
From my experience my EM bit had to cut into the work for about half the diameter of the EM and it start to have a smooth cutting noise. I guess having multiple teeth engaging work at the same time stabilize them a bit

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Just a little update today i put in a 30cm (~12") bar and also had little runout. But testing the stiffness i could feel that i could push it back and forth between two positions in one direction. With the other hand on the spindle i could say it was definitely moving in the collet.

So i looked up the torque for ER32 and it said 105Nm (~75ft lb) (which i did absolutely not reach by my tightening method).

So i cobbled up pic related thingy and put as much torque on it as i could without a cheater bar.

After that the runout before milling was <0.005mm and after it was still <0.01mm.

It still sounded very rough so as >>1242155 suggested i tried heavier cuts which were a lot smoother. Now i understand why people like roughers it really is a lot of fun just plowing through the material :).

I guess i have to apologize to all the chinese workers i insulted in my mind :D.

>>1242675
Are you sure you are using the collet correctly?

First the collet "clicks" into the nut, then you thread the nut onto the ER tool holder shank a few turns, then insert the cutting tool at the desired length, finally, tighten the nut.

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>>1242723

If life were fair, everyone would have a full set of collets, granted to them on birth, but only available to them on their 22 birthday.

Hillary wanted that. But you said no, we prefer Trump and shit chucks.

Why do people vote against their interests?

Evil Witch
Sad Clown
what a choice
the Owner of All
behind the curtain
wants war
and civil war

>>1242675
>tfw taught someone how to machine over the internet

>After that the runout before milling was <0.005mm and after it was still <0.01mm.
That's impressive enough