My first ever attempt at milling

[ksouers]

Tony,
Nice job on the Tee nuts. Great feeling of accomplishment, isn't it?

Fear not about the $25 Tee nuts. I made a copy of a Zero-It that you can get all over the internet for about $15US. With the time put into it (counting mistakes) I call it my $600 indicator holder ;D

Cheers,
Kevin

 

[baldrocker]

Beauty is in the eye of the beholder

I see negativity is creeping back, some need "OOHS & AAHS of an
adoring audience, the others like myself get a tremendous kick
out of fabricating something functional, not pretty, but it works.
Perhaps anal retentiveness is something that creeps up on SOME
with much experience.

I could go further but this is after all a family forum.
BR

 

[hammers-n-nails]

i would say a dro would be well worth your investment, a purist would probably tell you that its cheating but its faster and you are less likley to make a mistake. mine has an arc function on it, i use it quiet alot and i dont know how you would ever do a large radius arc without it"larger than you could get on a rotatry table"-not being what you would call an expert myself-. i also came up with an old computer with autocad r14 on it, with the two combined machining farly complicated parts without alot of math on paper. but thats a whole other topic. now that im done rambling about that can anyone give me a fairly detailed procedure for doing this oil blacking like whats on the T-nuts?

 

[joe d]

Tony

Those nuts turned out very nice. (Better than my first set...and my second set... :bow I've made some amount of tooling in the last couple of years, nearly all of which would have been cheaper to buy outright but instead I've learnt things, and had some fun. Also managed to increase the contents of the recycle/resize containers, but that's ok too.

Enjoy yourself

Joe

 

[rake60]

Great results for your efforts! :bow:
Sometimes you just have to DO IT to learn how to do it.

Rick

 

[tmuir]

i would say a dro would be well worth your investment, a purist would probably tell you that its cheating but its faster and you are less likley to make a mistake. mine has an arc function on it, i use it quiet alot and i dont know how you would ever do a large radius arc without it"larger than you could get on a rotatry table"-not being what you would call an expert myself-. i also came up with an old computer with autocad r14 on it, with the two combined machining farly complicated parts without alot of math on paper. but thats a whole other topic. now that im done rambling about that can anyone give me a fairly detailed procedure for doing this oil blacking like whats on the T-nuts?

A Dro is on my list of wants but my list is larger than my wallet so it all takes time.
I've had this mill for 6 months now and only finally managed to have the cash spare to buy the vice and other bits I needed to actually use it.
I'm personally all for cheating and using anything to make my minimal skill stretch further. :big:

Blackening couldn't be easier.
Make sure the metal is clean, I also wipe it down with a rag with meths on it, don't know if you really need to do that though.
Get yourself a metal tin or tray and put some clean motor oil in it, or peanut oil if the item will ever be touching food (pretty sure my T nuts won't be so I used motor oil).
Some people say to use old dirty oil but I wouldn't as a lot of cars now have their engines made out of alloys which contain nasty elements in them and you wouldn't want to vaporise them when dropping a hot item into the oil.

I hang the item on a little bit of fencing wire and then heat with my blow torch until the whole item has 'blued', any parts that haven't reached the blue stage probably won't blacken.
Then quickly drop it in the oil.
Do this outside as the oil will smoke and stink.
Also make sure you have something on hand to put out the oil if you heat the item up too much and set fire to the oil.
Leave it to cool in the oil.
As I attached fencing wire to what I'm blackening I just use that to lift it out and then wipe off the excess oil on a rag.

It looks good and gives some measure of protection against rust and better still is dead simple to do.

 

[zeeprogrammer]

Having had it pointed out to me that I did things ____ (wrong, incorrectly, stupidly, apply appropriate adjective here)...I couldn't wait to try milling again.

But...still not happy with my milling...
6061 aluminum.
I took a +/- X cut, a +/- Y cut, and a +Z cut (or is it -?...the other direction is air)...
so I have a few questions....

Your Z tooling marks look similar to mine...but when I run my thumbnail across mine...it's like a very fine nail file. I've trammed the head (twice) and get .001 or less across X. I'd be surprised if I can do better. But maybe you all wouldn't be. Have to admit...I haven't checked Y but at this point...I don't know what I'd do. I've seen some discussions about shimming but I don't know what that's about.

The Y direction cuts feel very very smooth. But mirror finish?

X direction cuts are the worse. Certainly...one direction is worse...climb cut to be sure.

I put a digital caliper on the spindle...+/- .005 or thereabouts. On the shank...worse! +/- .001.

I have no idea how the cuts should look. And, to be honest...I haven't studied/learned enough about feed and spindle rates.

Anyway...

Does anyone know of any close-up pics of what aluminum should look like when milled in 3 directions? And/or what it should feel like? (My fingers are still sensitive...cause I'm a sensitive guy.)

Any thoughts on what else I can do to improve the machine? I've broken it down twice...polished gibs...adjusted adjusted adjusted.

Oh...I did lock down the two degrees that weren't moving during the cut. Besides you all's advice...I notice the cranks move quite a bit due to vibration.

Thanks.

I'm here to make everyone else feel good.

 

[ksouers]

zee,
What kind of mill? If it's an X2, you'll have to do the same dance you did with the lathe; cleaning, adjusting, deburring etc.

Is this and end mill or a fly cutter?
Though my first inclination is your feeds and speeds. Turn up the RPMs a little and slow down your feed.

See how that works for you, report your progress (or lack there of).


Kevin

 

[zeeprogrammer]

Yeah...I believe it's called an X2. HF 44991.
Did the cleaning, adjusting, deburring. Made it better.
End mill (would love to try a fly cutter...I have some but haven't gotten the gumption yet to grind the tool bits for it...but actually...no point in it if I can't master this yet).

Feeds and speeds is very likely...I'll do some book learnin' and more experimenting.

From your reply I have to assume I should expect better in all 3 axes.

Still...would like more info for comparison and any thoughts on the run-out on the shank and spindle.

Thanks.

And I'll say it as often as I can...this is a great forum and a great set of people. There's a thread running about being a machinist...I'm so hooked...I read this with my morning coffee...during lunch at work...as soon as I get home.

I was surprised it's been less than 2 years for this forum (do I have that right?).

Am I correct that rake60 start this?

Great job. Great job everyone. This is such a joy for me.

 

[ksouers]

zee,
Yes, Rake60 (Rick) started this forum in July 2007.

Yep, it's an X2. I have one, HF flavored also. The gibs need to be pretty tight on it. The head locks pretty good though you have to be careful not to strip out the locking handles. LMS has replacements that are much better than OEM.

First off, it's normal to have some ridges when facing a part. The trick is to get the ridges close together with a higher RPM and slower feed. You will never get a "polished" look on a manual mill, so it's useless to strive for it. Too much variation in hand motion on the wheels. However, you should get a fairly nice shiny finish in aluminum and brass. Steel, forget it.

Odds are the spindle is in decent shape. Most of them are out of the box. Seems to be about the only thing they get right. I hope you are using a collet or end mill holder and not the drill chuck. The drill chuck is only good for drilling. Still, in a pinch, you should get a decent finish with the chuck.

Can you post a picture?

Kevin

 

[mklotz]

I put a digital caliper on the spindle...+/- .005 or thereabouts. On the shank...worse! +/- .001.

Not sure what you're describing here. Do you mean dial indicator? I don't see how you can "put a caliper on the spindle". Also, how is 0.001 "worse" than 0.005?

I have no idea how the cuts should look. And, to be honest...I haven't studied/learned enough about feed and spindle rates.

Speed calculators are everywhere on the web. If you wish you can download SPEED from my page.

Basically, there's a "desirable" surface-feet-per-minute (abbreviated SFM) for every material.

Now, SFM relates to RPM via the circumference of the work or tool.

SFM = (pi*D/12) * RPM

where the 12 is needed to convert the diameter (presumed measured in inches) to feet.

Solving for RPM, we have:

RPM = (12/pi) * SFM/D

12/pi is close to 4 and RPM dosen't need to be known perfectly so this is often reduced to:

RPM = 4*SFM/D

As an example, here are some low/high SFM values from the SPEED program

ALUMINUM AND ALLOYS	200	300
BRASS AND SOFT BRONZE	100	300
LOW CARBON STEEL	80	150
MEDIUM CARBON STEEL	60	100
HIGH CARBON STEEL	50	60
TOOL AND DIE STEEL	40	80
ALLOY STEEL		50	70
MALLEABLE IRON		80	90
SOFT CAST IRON		100	150
MEDIUM CAST IRON	70	100
HARD CAST IRON		40	60
COPPER			60	80
HIGH TENSILE BRONZE	70	90

 

[zeeprogrammer]

Kevin,

Yes I'm using a collet (it's why I started with 'being stupid'...it was pointed out to me not to use the chuck and that's why I couldn't wait to try again).

Thanks for your reply...maybe I'm not so far off. I'll try a picture when I do some more practicing (and figure out how to get the macro feature to work).

Got the LMS tweaks package...that's when I polished the gibs.

Marv,

My mistake (can't be anyone else's)...lost a zero....0005 vs .001. and yes...it was a dial indicator not a caliper. And before anyone talks about .0005 on a cheap indicator...the amount was one thing...I was concerned about the end mill being 'bad'.

It looks like I can count on you for formula (which I like)...we 'talked' earlier about drill bit size vs tapping size. Very much appreciated.

All,

I haven't got the jargon down yet...but I think I'm learning...that or it's signs of getting old.

Thank you all. Thank you Rick.

Can you believe it? Wife is home this week from Europe and asking what the 'ell I'm doing down here? Come to think of it...bye all.

 

[mklotz]

My mistake (can't be anyone else's)...lost a zero....0005 vs .001. and yes...it was a dial indicator not a caliper. And before anyone talks about .0005 on a cheap indicator...the amount was one thing...I was concerned about the end mill being 'bad'.

Ah, yes. Proofreading is a virtue.
I have no problem with reading a DI to a half a thou in a comparative mode. However, accuracy to that level is suspect if using it to actually make a measurement.

It looks like I can count on you for formula (which I like)...we 'talked' earlier about drill bit size vs tapping size. Very much appreciated.

You can find the formula relating SFM and RPM nearly anywhere. An explanation of how it is arrived at is less easy to find, hence my bit of impromptu lecturing.

Now that the wife is home and getting suspicious of what's happening in your "man cave", it's a good time to start thinking about making some placatory projects. Candlesticks are always good but may be a bit much for your current skill level. How about some nice polished brass napkin rings? Or, since you're devotees of Bacchus, perhaps an over-the-top fancy wine bottle stopper? If, like Arnold and I, you never recork a bottle once opened, a decorative pouring spout or a copper and brass bottle "saucer" (there's a name for those things but I can't recall it) will allay SWMBO fears about what you're doing with those machines.

 

[zeeprogrammer]

Good ideas. Yes, it would have to be a spout.

I think I've taken too much of tmuir's thread.

My apologies tmuir.

Thanks Marv.