# My first ever attempt at milling



## tmuir (Apr 10, 2009)

As I've never used a milling machine before I wanted to do something simple and cheap in case I messed it up so I settled on making myself some T-Nuts.

All marked out.






First pass done.





First pass with the swarf brushed off.





Half way through the final pass.





Finished surface.






My thoughts after my first attempt at milling.
It's not as noisy or scary as I thought it would be. :big:
Preparation is everything.
I can see me fitting a DRO to this soon.
I now fully understand why people motorise the X axis, winding is tedious to say the least.

Unfortunately bolstered with my success I started on the other side and on the second pass I wound too fast and the endmill bit in and broke, as this is the only endmill I have that's my milling finished for the long weekend.

Not how I wanted it to end but it was a good learning experience anyway.


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## Brian Rupnow (Apr 10, 2009)

Were you climb milling when you did the other side?


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## Cedge (Apr 10, 2009)

Brian
That was my first thought too. I killed off several end mills before it became natural to spot when I was climb milling. 

Tony...
Milling was initially intimidating to me too. Now I seem to gravitate to the mill for mos things. Funny thing... I too expected the mill the be a bit more "violent" the first time I powered into metal. The power feed is definitely a plus and the one offered for the mini mill, by LMS works quite well. 

The mods I made to mine that made the experience most enjoyable were the power feed, the belt drive, the collets and the extended Z rack. All were well worth the investment. 

Now.... about that climbing cut....(grin)

Steve


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## tmuir (Apr 10, 2009)

Brian Rupnow  said:
			
		

> Were you climb milling when you did the other side?



No, well atleast I don't think so.

The front side was cut with the tool going away from me and the back side with the tool coming toward me which as I understand is the correct way to do it.
I was only using a 7mm end mill and I just think I fed too fast with it.
If a $15 tool has taught me to pay closer attention to what speed I feed at it was worth it.


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## Lew Hartswick (Apr 10, 2009)

Yea. For that kind of a job I'd be using at least a 1/2" (12 0r 13MM) cutter.
Maybe even a 3/4" one. 4 flute for sure. 
 The cutter dosent travel the table moves.  "push the material into the cutter"
  ...lew...


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## cfellows (Apr 10, 2009)

I'm no expert by any means, so somebody correct me if I'm wrong, but, based on your picture, it seems to me that you were taking a pretty big bite out of that bar in one pass. I usually limit the depth to about .050" per pass in steel.

Chuck


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## tmuir (Apr 10, 2009)

The cut was 2mm across and 5mm deep


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## Brian Rupnow (Apr 10, 2009)

tmuir  said:
			
		

> The cut was 2mm across and 5mm deep


That is a MASSIVE cut for a small machine with a small endmill. No wonder it broke.


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## kvom (Apr 10, 2009)

I have been taught that the max cut in aluminum is 1/4 the diameter of the mill, and less as the hardness increases. So in steel with a 7mm endmill a 1mm cut is probably a reasonable bite.

You should also calculate SFM. For HSS cutter in CRS a value of 80-120 is good, so your spindle ought to be around 800-1200 with a 7mm endmill. It's hard to determine feed rate manually, but if the swarf is blue then you're going too fast.


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## tmuir (Apr 10, 2009)

Did have the speed in the vicinity of 800 RPM, no rpm meter on my mill so set the dial at around 3/4 on low speed which maxes out at 1100RPM so had to be close to 800RPM as I had worked the speed out to be around 750RPM.

My book said 1/3 of diameter of endmill so I took that as 2mm would be ok.

I will be ordering a couple of endmills of larger diameter and will take shallower cuts


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## Cedge (Apr 10, 2009)

Tony
After studying the photos, I believe you were indeed probably making climbing cuts. With the cutter at the far end ( as pictured ) you should be cutting back toward the camera. On the back side you'd want to cut going away from the camera. 

You want the cutting edge of the end mill to enter the metal like a shovel would enter a pile of sand... along the bottom of the cut rather than pulling fresh metal back toward it.

Steve


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## steam mad (Apr 10, 2009)

I was told, right or wrong I am not sure, that the feed rate should be 1 thou per tooth on cutter by speed of cutter = feed rate per minute. I use this formula with no problems. 
i.e. 4 teeth on cutter = 4 thou
RPM 750 x 4 = 3000 thou per min. or 3" per minute feed rate.
This feed speed would be for the maximum cut the size of cutter is recommended for on material being milled.
With a lighter cut then faster feed rate.
This is what I was told anyway. ;D


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## kvom (Apr 10, 2009)

That 3ipm feed rate calculation agrees with my textbook. Assuming your table advances .1" per revolution of the crank that's 30 turns/minute or 2 seconds per turn. I suppose you could get close by estimating a 2-seocnd interval for each turn of the crank.


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## tel (Apr 10, 2009)

Yes, if the cutter ended up where it is shown after the cut in the first two pics you were climb milling.


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## SBWHART (Apr 10, 2009)

Hi Tony

Easy way to remember if your milling the correct way is to think of a pile of snow or coal, shuffeling the pile from the bottom is OK shuffeling it from the top is bad Ie your climb shuffeling.

Tip for the T bolts burr the bottom of the threads over to stop the bolt comming through if it does it acts as a jack and can seriously damage your T slots.

Stew


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## Tin Falcon (Apr 10, 2009)

> Tip for the T bolts burr the bottom of the threads over to stop the bolt comming through if it does it acts as a jack and can seriously damage your T slots.


The other options are just do not tap all the way through just leave the last couple of threads semi finished. 
The other option is use short bolts that do not bottom out. 
Tin


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## tel (Apr 10, 2009)

For conventional milling, the table (and workpiece) should move thus;


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## seagar (Apr 10, 2009)

Hi Tony,I had never even seen a vertical mill used untill I purchased my mini mill,so to learne how to use it I decided to make a JinggleBell engine I found on www.npmccabe.tripod.com ( free download) as it is made mostly on the mill.Much to my suprise it runs.I have not done any clean up or bling so as to show my first attempt at building an engine.






IMG]http://i210.photobucket.com/albums

Ian (seagar)


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## putputman (Apr 10, 2009)

I have always used a conventional cut for stock removal and leave a few thousands for a final climb cut. A light climb cut will generally give you a better finish. I find this is true with most materials also. 
Does anyone else find this works for them?


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## cfellows (Apr 10, 2009)

putputman  said:
			
		

> I have always used a conventional cut for stock removal and leave a few thousands for a final climb cut. A light climb cut will generally give you a better finish. I find this is true with most materials also.
> Does anyone else find this works for them?



I do the same. Make one last, very light pass, doing a climb cut.

Chuck


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## mklotz (Apr 10, 2009)

putputman  said:
			
		

> I have always used a conventional cut for stock removal and leave a few thousands for a final climb cut. A light climb cut will generally give you a better finish. I find this is true with most materials also.
> Does anyone else find this works for them?



Absolutely. I do it all the time. In fact, with many materials, there's no need to dial in a final cut. Simply running the cutter back over the surface in the climb direction will improve the finish.


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## tmuir (Apr 10, 2009)

tel  said:
			
		

> Yes, if the cutter ended up where it is shown after the cut in the first two pics you were climb milling.



Doh!

And I went to so much effort to make sure I wasn't, maybe I should turn my book upside down to read it. :big:

Atleast we have an explanation as to what went wrong then which is always good.

I better go back and read my book again and figure out how I got it the wrong way round.

Thanks for the help everyone. I'll get a new endmill next week and have another go.


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## Cedge (Apr 10, 2009)

Tony
I'm told that toilet water swirls the wrong way down there too....(grin). You might as well expect a few tool casualties along the way. You'll get a feel for the machine soon enough and then speeds and depth of cuts will come almost naturally.... as will cutting from the right direction. Luckily the machines are pretty tough and the base of the learning curve isn't too terribly steep.

Steve


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## bob ward (Apr 10, 2009)

tmuir, I like the way you held down your piece of steel to the mill table. Well suited to the job, nice and simple with sacrificial nuts.

My first mill project was to make T nuts, I won't embarrass myself by detailing the convoluted holding methods I used.


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## tmuir (Apr 10, 2009)

I can't lay claim to the hold down method. It's straight out of Workshop practice series book 35
Milling a Complete course.

Its the catch 22 situation isn't it.
How do you hold down anything when you are first making all the things you need to hold down everything? :big:


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## tel (Apr 11, 2009)

tmuir  said:
			
		

> I can't lay claim to the hold down method. It's straight out of Workshop practice series book 35
> Milling a Complete course.



A couple more chapters and you will be up to where I am then. Actually bought the book for the grinding rest, but couldn't resist this one. I'm considerably further along than this pic tho', I'll try and get one of current progress later.


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## tel (Apr 11, 2009)

Here's a couple of quick and fuzzies


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## tmuir (Apr 11, 2009)

Looking good.
I've look at these projects a few times but think it will be some time before I'm ready to try something like that.
Once I've made the T nuts I will skip a chapter and then make the clamps.
Then I can actually start thinking about making something other than tooling on it.


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## cfellows (Apr 11, 2009)

Tel, that's an interesting device. Is that a dividing head? Are you using it on the mill, lathe, or what?

Chuck


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## tel (Apr 11, 2009)

Yes Chuck, it's the start of the 'Harold Hall Dividing Head' from his book 'Milling, A Complete Course'. I'm building it for use on the RF30 mill, but the beauty of it is it will accept the chucks, small faceplate, MT2 collets etc from the Myford lathe.


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## tmuir (Apr 14, 2009)

Went to a different tool shop on my way home today and bought myself an endmill.
I normally only use this shop for taps and dies and odd size drill bits as they usually have everything in stock unlike other shops. But as this shop really caters to industry not hobbiests they tend to stock only high quality expensive stuff, but atleast if you buy from them you know it will last.
I was quiet surprised to see the endmill they sold me was made in Australia, which makes the higher price easier to swallow as you know it wasn't made by almost slave labour in China.

This time cutting in the correct direction everything went much smoother and I finished milling the T to size.
Forgot to take any photos but I still need to drill and tap the T nuts, cut them away from each other and then endmill the cuts square.
Will take photos of the finished products.

Thanks everyone for your help.


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## Lew Hartswick (Apr 14, 2009)

You don't really need to clean up the ends of those T nuts. Just saw them apart.
I know at the beginning everything has to also "look good"  You'll eventually
grow out of it. 
  ...lew...


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## Cedge (Apr 14, 2009)

Lew
I hope I never get that jaded. Being able to take personal pride in even a mundane project is one thing I never want to lose. Here, the last step is just as important as the first step. When I can no longer enjoy that, I'll offer my machines up to someone who can. "It'll do" is not my definition of craftsmanship. 

Steve


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## Maryak (Apr 14, 2009)

tmuir,

Glad your T nuts went well. Remember this is a hobby and we do it for pleasure. If it pleases you to have your T nuts all ship shape and Bristol fashion - go for it. ;D ;D You will feel much better and that's what counts.

Best Regards
Bob


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## tmuir (Apr 14, 2009)

I know I don't need to finish it off like that but Its still an easy operation and gives me more practice on the mill.

My wife tells me I'm a perfectionist so I don't think I could live with leaving it rough.
I draw the line at getting a mirror finish on the nuts but I don't like to leave saw marks on something I will hopefully be using for some time to come.

Once it is all machined I will oil blacken them to  o.

There not perfect due to me stuffing up by milling the wrong direction and breaking my endmill on my first try but they will definately be serviceable and I already feel a lot more confident in using my mill.

It's pay day today so might have to have a look at buying some of those upgrades for the mill tonight. ;D 

I think a DRO will be one I want very soon as the backlash is huge and makes it hard to reposition exactly.


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## tmuir (Apr 16, 2009)

Well 3 nights playing in the workshop for an hour or two each time and I have ended up with these.






Yes I could of just bought them for $15 but the point of the exercise was to get practice on my mill with something simple and I'm quiet pleased with them for my first attempt on the mill.

To stop the threaded rod from screwing right through and bottoming out I top the simple but effective option of using a coal chisel to put 4 marks on the last turn of thread, damaging the thread so the bolt can't pass through it.






It might be a 'dirty' solution but it works well.


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## Majorstrain (Apr 16, 2009)

Sweet job, Nice work. 

Phil


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## tmuir (Apr 16, 2009)

I do find it funny that I spent 3 nights and $25 to make the parts of could of bought for $15 but it wasn't so much the end result that was important as me getting practice on the mill. :big:


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## Cedge (Apr 16, 2009)

Well done Tony. 

Steve


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## zeeprogrammer (Apr 16, 2009)

And then there's numb-nuts like me who didn't know that and tightened the bolt too much...damaging both the bolt and the nut.

Thank you for posting.

Some of us just started...and engines are down the road a piece...I like seeing things I can try as I travel down that road.


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## ksouers (Apr 16, 2009)

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


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## baldrocker (Apr 16, 2009)

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


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## hammers-n-nails (Apr 16, 2009)

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?


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## joe d (Apr 16, 2009)

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


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## rake60 (Apr 16, 2009)

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

Rick


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## tmuir (Apr 17, 2009)

hammers-n-nails  said:
			
		

> 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.


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## zeeprogrammer (Apr 21, 2009)

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.


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## ksouers (Apr 21, 2009)

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


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## zeeprogrammer (Apr 21, 2009)

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.


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## ksouers (Apr 21, 2009)

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


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## mklotz (Apr 21, 2009)

> 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
```


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## zeeprogrammer (Apr 21, 2009)

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.


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## mklotz (Apr 22, 2009)

> 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.


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## zeeprogrammer (Apr 22, 2009)

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.


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