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Javid
Oct 21, 2004

My sole partiality is to that delectable spiced meat. Any additional confederation of vegetables shall not compromise the pie as I see it.

The coloration of the tip indicates that it's heated up significantly which ruins the heat treating/temper and causes the bit to soften and rapidly dull rather than cut.

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The Eyes Have It
Feb 9, 2008

Third Eye Sees All
...snookums

[Butters] Neato! [/Butters]

MohawkSatan
Dec 20, 2008

by Cyrano4747


Mister Sinewave posted:

[Butters] Neato! [/Butters]

It also shows it was approaching what's needed to friction weld, where metal parts weld together purely based on friction.

Lathespin.gif
May 19, 2005


Pillbug

shalafi4 posted:

Remember kids, no friction welding in the machine shop.





Mister Sinewave posted:

What exactly am I looking at there? I think it's maybe an "obviously" dulled or broken cutting bit but I am super uneducated about this stuff.

Unless I am mistaken that would appear to be what's left of a center drill, originally used for popping center holes for lathe workholding, but in reality mostly used for making an accurate starting hole for drilling so the next bit doesn't wander...



It also means the pip of HSS is now buried in the work, extremely smooshed over/welded into place, and probably in the exact spot you'd like a hole to start. Good times, as it's as hard/harder than drills, so enjoy burning up a small carbide end mill crunching it out if you want to save the part

shalafi4
Feb 20, 2011

another medical bills avatar

Lathespin.gif posted:

Unless I am mistaken that would appear to be what's left of a center drill, originally used for popping center holes for lathe workholding, but in reality mostly used for making an accurate starting hole for drilling so the next bit doesn't wander...



It also means the pip of HSS is now buried in the work, extremely smooshed over/welded into place, and probably in the exact spot you'd like a hole to start. Good times, as it's as hard/harder than drills, so enjoy burning up a small carbide end mill crunching it out if you want to save the part

Very very close. I was using one of these with the central web thinned out instead of a center drill.



I got incredibly lucky.

It actually got hot enough to weld/melt the point off. (under full flood coolant) Between the heat and the spotting drill acting like a blender the spot underneath was actually fairly soft. I poked at it with a scribe a little to see if I could figure out where the point was and it had dispersed across the hole pretty uniformly. To get it out/drill through it I started with a carbide end mill plunging down to see if it had been buried under the surface. Still squishy. Switched out to my 1/2" drill bit and crossed fingers I wouldn't find a hard spot. Only ran into one small spot and it was off center enough that the drill bit popped it out without taking too much damage.


remember....

4.0

is not

40.

(put the decimal place in the wrong spot and drove the bit into the part 10 times faster than it should have been)

Normally it'll make this kind of soft hissing sound as the bit plunges in. It did that, and then sounded about like pouring a cup of water into a cast iron skillet that's really hot. And then it was done, and glowing...

shalafi4 fucked around with this message at 07:06 on Jan 3, 2016

A Wizard of Goatse
Dec 14, 2014



jeezus that fast huh

The Eyes Have It
Feb 9, 2008

Third Eye Sees All
...snookums

"When things go bad, they tend to go bad very quickly" is true of so many things




Also known as "We were doing well until everyone died" in videogame land

Roundboy
Oct 21, 2008


Optionally preceded by "hey guys, watch this"

shalafi4
Feb 20, 2011

another medical bills avatar

Alright. Back to it.

Apologies on the long hiatus I had to scramble to finish all of the CNC machining before the 1st of January. Short version, I left my job on the 1st and have been wrapping up lots of loose ends and personal things that were put off over the holidays. BUT, the parts are done.


Now... where were we.

So we have CAD models of all the parts. Yippee! Now to do the role of the man behind the curtain and make them.

First choice, what to make them out of?

We have the bottom pieces and the rails. One thought was to make them all out of Aluminum. That got axed pretty early on. While it would probably work, these are prototypes and we'd rather have them built like tanks.

That narrowed our options down quite a bit. We didn't want to go with a low or medium alloy steel because we didn't want to mess with bluing or Parkerizing them.

That pretty much left Stainless steels and Titanium.

*looks up the price of a bar of Titanium big enough to make 3 sets of the lower parts*



OK then Stainless it is.

We wound up choosing 304 alloy Stainless for our parts. (If people want me to go into the reasoning that lead us to that let me know)

Fast forward a week and a half and a hunk of stainless arrives.

Laying out the parts.



The red is called Layout Dye. It's a super fast drying paint essentially. It allows the scribe marks on the bar to show up MUCH clearer. (silver on red vs slightly shiny silver on silver)


Here's all the parts laid out.



The Black sharpie corner is a reference corner. I do it out of habit but on some high tolerance parts and some materials (*cough*Ti 555*cough*) you need to know the orientation of each part to account for stress relief as you're machining.


Horizontal Band saw GOOOO



Slow and steady is generally the name of the game in Stainless. A LOT of machinists despise the stuff but as long as you stay in it's "happy zone" and don't try to push it your tools will be fine.



About ~3 min in .... My minions at the time hadn't ever really delt with stainless before and they were really surprised how long it takes to cut. (95% of their stuff is out of Aluminum)



Different angle on another cut.



Cleaning up one of the ends.


Pile o'parts




Up next we'll start making them actually square.

The Eyes Have It
Feb 9, 2008

Third Eye Sees All
...snookums

What's a horizontal bandsaw made out of that it can saw through a block of stainless? Even if it takes forever to do it?

Man the idea of cutting a block off another block being an all-day job, it blows my mind.

Lathespin.gif
May 19, 2005


Pillbug

Modern bandsaw blades are usually HSS teeth on a tempered carbon steel band, same tech as 'bi-metal' hacksaw blades. Tungsten carbide toothed blades are also available but $$$$$. You probably won't run into a plain carbon steel blade anymore unless you buy the cheapest poo poo you can find.

Stainless is hard, but not unreasonably so- after all you can file it or hit it with a punch/cold chisel. It just takes time to gnaw through it, especially compared to 6061 aluminum, which has a SFM of approx. the speed of light


e: of course, the bigger the tool the better!



apparently 26" throat capacity

Lathespin.gif fucked around with this message at 22:49 on Jan 22, 2016

z06ck
Dec 22, 2010



I don't know what blades we use because I dont change them. I've cut through stainless a few times at where I work on a horizontal bandsaw with ease, I guess we get the expensive poo poo.

shalafi4
Feb 20, 2011

another medical bills avatar

Lathespin.gif posted:

Modern bandsaw blades are usually HSS teeth on a tempered carbon steel band, same tech as 'bi-metal' hacksaw blades. Tungsten carbide toothed blades are also available but $$$$$. You probably won't run into a plain carbon steel blade anymore unless you buy the cheapest poo poo you can find.

Stainless is hard, but not unreasonably so- after all you can file it or hit it with a punch/cold chisel. It just takes time to gnaw through it, especially compared to 6061 aluminum, which has a SFM of approx. the speed of light

Yup it was a bi-metal blade.

Gnawing through stainless is a really good description.


Also speaking of crazy warp speed SFM materials, look up Renshape 460.


Edit:
Generally as long as your blade is sharp it'll go through Stainless pretty easy. It's when you try to push the envelope of where it's happy to cut is when issues crop up.

Lathespin.gif
May 19, 2005


Pillbug

shalafi4 posted:

Renshape 460.

... roughing @ 2,500 SFM?! what the fuuuuuuuuuuuuuuuck



for non-machinists Surface Feet per Minute is how fast the blade/cutter is passing the work, like how fast a needle might be traveling on a record, etc. Most steels and stainless steels are somewhere between like, 50-120 sfm, aluminum 300++ sfm...

2.5k, JESUS CHRIST

e: nearly 30 miles an hour, fuckin lol

Lathespin.gif fucked around with this message at 23:19 on Jan 22, 2016

Doctor Grape Ape
Aug 26, 2005

Dammit Doc, I just bought this for you 3 months ago. Try and keep it around for a bit longer this time.


Lathespin.gif posted:

... roughing @ 2,500 SFM?! what the fuuuuuuuuuuuuuuuck



for non-machinists Surface Feet per Minute is how fast the blade/cutter is passing the work, like how fast a needle might be traveling on a record, etc. Most steels and stainless steels are somewhere between like, 50-120 sfm, aluminum 300++ sfm...

2.5k, JESUS CHRIST

I'm pretty sure even a warm knife through butter can't go that fast.

shalafi4
Feb 20, 2011

another medical bills avatar

Lathespin.gif posted:

... roughing @ 2,500 SFM?! what the fuuuuuuuuuuuuuuuck



for non-machinists Surface Feet per Minute is how fast the blade/cutter is passing the work, like how fast a needle might be traveling on a record, etc. Most steels and stainless steels are somewhere between like, 50-120 sfm, aluminum 300++ sfm...

2.5k, JESUS CHRIST

e: nearly 30 miles an hour, fuckin lol



The stuff it crazy to play with though on the spec sheet the "roughing" speeds it called for was something like 5000 rpm with a 1" end mill. The crazy part is it called for full engagement with it. (normally you only engage at most 1/2 ~ 5/8 of an end mill's width assuming a perfect setup)

Javid
Oct 21, 2004

My sole partiality is to that delectable spiced meat. Any additional confederation of vegetables shall not compromise the pie as I see it.

Sounds like machining a bar of soap.

This whole discussion has shed light on why my stainless barrel has eaten a series of drill bits, though. :|

MohawkSatan
Dec 20, 2008

by Cyrano4747


Lathespin.gif posted:

2.5k, JESUS CHRIST

Sweet loving gods what kind of insanity is this? Like holy loving poo poo what in the hell even.

Imagine turning that poo poo on a lathe. 1" bar? TEN THOUSAND REVOLUTIONS PER MINUTE, gently caress YOUR WORKHOLDING METHODS BITCHES

Action Jesus
Jun 18, 2002



shalafi4 posted:



We wound up choosing 304 alloy Stainless for our parts. (If people want me to go into the reasoning that lead us to that let me know)



I'll bite, I'm curious why you went with 304 over a more free machining stainless such as 440 or 416? the small amount of 300 series SS I've played with has been befuddlingly difficult to machine, and after doing some research, is apparently the poster child for "why people don't like working with stainless"

Nice bandsaw action, even my (cheap and diminutive) 4x6 takes about 12ish minutes to cut through a 1.5" bar of solid 17-4ph, one of the handiest tools in my shop.

shalafi4
Feb 20, 2011

another medical bills avatar

Action Jesus posted:

I'll bite, I'm curious why you went with 304 over a more free machining stainless such as 440 or 416? the small amount of 300 series SS I've played with has been befuddlingly difficult to machine, and after doing some research, is apparently the poster child for "why people don't like working with stainless"

Nice bandsaw action, even my (cheap and diminutive) 4x6 takes about 12ish minutes to cut through a 1.5" bar of solid 17-4ph, one of the handiest tools in my shop.

YEY someone asked!



(pulled from wiki because )

SAE 304 stainless steel, also known as A2 stainless steel (not the same as A2 tool steel) or 18/8 stainless steel, European norm 1.4301, is the most common stainless steel. The steel contains both chromium (usually 18%) and nickel (usually 8%) metals as the main non-iron constituents. It is an austenite steel. It is not very electrically or thermally conductive, and is non-magnetic. It has a higher corrosion resistance than regular steel and is widely used because of the ease in which it is formed into various shapes. It contains 17.5-20% Chromium, 8-11% Nickel, and less than 0.08% Carbon, 2% Manganese, 1% Silicon, 0.045% Phosphorus, and 0.03% Sulfur .

Corrosion Resistance
304 Stainless Steel has excellent resistance to a wide range of atmospheric environments and many corrosive media. It is subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above about 60C. It is considered resistant to potable water with up to about 200mg/L chlorides at ambient temperatures, reducing to about 150mg/L at 60C.

Application
304 stainless steel is used for a variety of household and industrial applications such as screws, machinery parts, car headers, and food handling equipment.



You're probably thinking, OK great.. it doesn't rust. That tells us nothing on why you picked it.

We're going to go deep into the metallurgy sperg rabbit hole so go grab some coffee or beer.

I'm going to write this like I'm writing it as a metallurgy paper. If there's terms that I forget to say what they are please point them out.


OK

Stainless steels generally come in 3 types. (there's a 4th but not getting into that group)

Ferritic, Austenitic and Martensitic


For "normal" household items Austenitic and Martensitic are the most common. Ferritic stainless steels are "generally" used in more wide scope projects to save money.

So, some details about each,

Martensitic stainless steels
Generally these are your 4xx series steels. Martensite is a BCC crystal phase type that can be formed in steels with a high enough carbon content. The short version is Martensite is what can make steel hard. Knives, chisels, drill bits, endmills are all Martensitc steels (albiet except for knives rarely stainless)
It's generally formed by heating a part up, cooling it quickly (quenching) then tempering it afterwards. (without the tempering it can be incredibly brittle) I always tell people when they ask why tool steels need tempered that when they're fully hardened they're more akin to a coffee cup than "steel" that everyone knows.

Ferritic stainless steels
Generally used in more large scale projects to help on cost. Ferritic stainless steels *generally* have lower amounts of alloying agents (primary ones in stainlesses are Chromium and Nickel) which in turn starts to affect their corrosion resistance slightly. The one textbook example used in metallurgy classes. Everyone's seen a stainless handrail that's been outside that has flecks of rust on it? Those are Ferritic stainless steels. They fall under the "It'll work for its intended purpose but may wind up with cosmetic rust after while"
(Also to help confuse the @#$@ out of people... some martinsitic stainlesses are ALSO listed as Ferritic... 416 is one of these.... Technically a Martensitic stainless is Ferritic until it's heat treated. But not all ferritic stainless steels can be Martinsitic. It's one of those not all rectangles are square but all squares are rectangles things. )

finally

Austinitic stainless steels

These are generally the 3xx series stainless steels. Austinitic stainless steels are FCC crystal structured steels. They're generally the highest alloyed of the stainlesses and also have the highest corrosion resistance of them. 304 and 316 stainless steels are the poster children of Austinitic stainless steels. They cannot be hardened via heat treatment due to their crystal structure. (see tje beginning of the post for the info on 304, most of that info holds for the 3xx series just with varying alloying elements)


[/sperg]

ok so why pick 304 vs 416 vs 440?

Both 416 and 440 are Martensitic stainless.

Pros:
Easier to Machine
Easier on Tooling

Cons:
Not as corrosion resistant as 3xx
very sensitive to welding due to being heat treatable. (416 has an additional issue I"ll address in a minute)


304

Pros:
more corrosion resistant
welds without filler metal

Cons:
OM NOM NOM tools


So some of the machinists are probably going why not use 303? It's the "easier to machine" version of 304?

The only difference between 303 and 304 stainless is about 0.75~1.0% sulfur. The 303 stainless has a tiny bit of sulfur added to it that interferes with 304's workharding issues it's notorious for. (416 also has sulfer added for the same reason)

As we were going through I realized that I really DIDN'T want to try and machine the gas tube. So instead we're going to weld a stainless one in place. So 4xx series ones become trickier to weld (they generally require filler metals) So we wanted to go 3xx series as it welds much better.
Back to the 303 vs 304 (and 316 as well)
That tiny bit of Sulfur added to 303 that makes it easier to machine? That makes welding a complete bitch to do. The sulfur likes to segregate out into weld areas and makes them crack like crazy.

Since I"m mediocre at welding we're back to 304 vs 316. (316 is a smudge more difficult to cut but they're about on par) From there it came down to the 304 was a little cheaper than the 316.



If there's questions you know the drill


Also this does a pretty good job of going into all of the different types

https://www.youtube.com/watch?v=xvZdcucQDAE

shalafi4 fucked around with this message at 03:05 on Jan 24, 2016

Action Jesus
Jun 18, 2002



shalafi4 posted:

Autistictitic Stainless Stuff

Ah, VERY cool, that actually makes a ton of sense. I presume that without the need for filler metal, TIG process welding will be how you go about affixing the gas tube etc? Also, what are some of your tricks for cutting the 3xx series stainless, anything more than just feeds & speeds (& carbide & lube) ?

shalafi4
Feb 20, 2011

another medical bills avatar

Action Jesus posted:

Ah, VERY cool, that actually makes a ton of sense. I presume that without the need for filler metal, TIG process welding will be how you go about affixing the gas tube etc? Also, what are some of your tricks for cutting the 3xx series stainless, anything more than just feeds & speeds (& carbide & lube) ?

You are correct. All TIG all the time. (I actually have the inverse to what's "Normal" welding experience wise. a shitton of TIG and hardly any MIG or stick)


Other than STAY in your feed/speed range and don't push it. flood coolant is your friend, Stainless barely conducts heat so all of the heat generated by cutting goes into your tool which can make for a bad day.


Actually, unless I'm doing multiple parts or production runs. I prefer M42 cobalt HSS for doing small Stainless parts. The sharper edge than the carbide helps with the work hardening issues that come up with Stainless.

shalafi4
Feb 20, 2011

another medical bills avatar

Project isn't dead I've just been too busy to get another effort post done up.


I may try to get one made up tomorrow in between studying for "how to read sound waves in metals"

TopherCStone
Feb 27, 2013

I am very important and deserve your attention


shalafi4 posted:

Project isn't dead I've just been too busy to get another effort post done up.


I may try to get one made up tomorrow in between studying for "how to read sound waves in metals"

Please also do an effortpost on reading sound waves in metals tia

shalafi4
Feb 20, 2011

another medical bills avatar

TopherCStone posted:

Please also do an effortpost on reading sound waves in metals tia

Actually I might... I have a non destructive weld evaluation exam on Wednesday and It goes over Ultrasonic testing of welds. Might be a good way to wrap everything together

shalafi4
Feb 20, 2011

another medical bills avatar

Double post for extra lack of effort.


Here's the tldr; version of the sound effort post.

Click to make readable

froward
Jun 2, 2014


watched a coworker burn up a bit drilling a hole in stainless, today. now I know why it gets so hot. pouring oil all over the shop drill press is a very messy solution tho. bless u shalafi4.

MazeOfTzeentch
May 2, 2009

rip miso beno


I am so glad the only stainless I'm cutting on for my suppressor build is a 1/16" or less thick freeze plug, the rest is ordinary carbon steel.

Anything I should be aware of when taking a drill press to that stuff? I picked up a pair of Dewalt Cobalt bits, are these absolute poo poo or will I be okay?

shalafi4
Feb 20, 2011

another medical bills avatar

MazeOfTzeentch posted:

I am so glad the only stainless I'm cutting on for my suppressor build is a 1/16" or less thick freeze plug, the rest is ordinary carbon steel.

Anything I should be aware of when taking a drill press to that stuff? I picked up a pair of Dewalt Cobalt bits, are these absolute poo poo or will I be okay?

They're alright quality wise. In the proper machining world they kinda crap but if you're not doing full production work you'll be fine.

What diameter are they?

MazeOfTzeentch
May 2, 2009

rip miso beno


1/8" and 3/8", 3/8" being the final target diameter of the holes.

Got a 1/4" carbide center cutting end mill coming for baffle clipping purposes.

Lathespin.gif
May 19, 2005


Pillbug

sizing sounds good, 1/8" pilot should be about right for the larger drills web. you might want to grab a 23/32", or better yet a U drill and just take the last few whiskers out with the 3/8", you'll get a nicer finish and less deburring to do.

be wary at the press while step drilling thin sheet metal, it'll screw on you. if you're doing smallish parts I'd make a jig for workholding- at least a stick with a hole in it to go on top. saves on the fingers.

shalafi4
Feb 20, 2011

another medical bills avatar

Lathespin.gif posted:

sizing sounds good, 1/8" pilot should be about right for the larger drills web. you might want to grab a 23/32", or better yet a U drill and just take the last few whiskers out with the 3/8", you'll get a nicer finish and less deburring to do.

be wary at the press while step drilling thin sheet metal, it'll screw on you. if you're doing smallish parts I'd make a jig for workholding- at least a stick with a hole in it to go on top. saves on the fingers.

A jig and make sure you're out of the way in case something happens.

Remember.. multihorsepower motors do not care about squishy bits.

shalafi4
Feb 20, 2011

another medical bills avatar

yea doubleposting....


Sorry I've been away all. I'm going back through and catching up on where I left off here and planning on getting a post up this weekend.

Safety Dance
Sep 10, 2007

Five degrees to starboard!


I'm excited to read that.

shalafi4
Feb 20, 2011

another medical bills avatar

Hey Tuesday is the weekend somewhere right? .... right? ... no? well poo poo...


anyway back to it.

last time we had some chunks gnawed off of a bar and have a pile of rough blocks. Now it's time to make them flat.

Meet Mr/Ms Seiki




It's a descent variable speed bridgeport knockoff. Once you know it's quirks it's a really nice machine.

On the mill there's a vice. It's been indicated square to the spindle so things gripped in it can be cut square.

Next we need something to make sure the parts are sitting flat.



Parallels are for raising the part up in the vise and also (when you tap the part down) you can make sure you're not grabbing your block crooked.

Hmmm.... they don't want to sit flat...



I attack them with a file to try and see if there's any high points. Lo and behold, yup... (the shinier bands on the block are post filing)




Lock the quill, raise and snug the quill stop.... Bring the table up until you take a TTTIINNNNYYY bit off. (shiny spot on the lower right of the block)



Zero the table out. That indicator is for the height of the table. Each line is 0.001in



Dial in ~0.020 in



buzzbuzzbuzzbuzzbuzzbuzzbuzzbuzzbuzzbuzzbuzz

Once one side is done then flip the block over and do the other side (same operation)

So far we've just skinning the part flat by taking a little bit off. Once both sides are flat we start measuring and bringing the parts into size.



It's supposed to be 0.990in I'll take 0.9895in

Lather rinse and repeat on the other sides and parts.

[Insert imaginary photo of finished blocks piled neatly for a photo]

Somebody Awful
Nov 27, 2011

BORN TO DIE
HAIG IS A FUCK
Kill Em All 1917
I am trench man
410,757,864,530 SHELLS FIRED




Thread continues to deliver.

TopherCStone
Feb 27, 2013

I am very important and deserve your attention


shalafi4 posted:

Double post for extra lack of effort.


Here's the tldr; version of the sound effort post.

Click to make readable



Can't believe I didn't see this til now, neat. Also you have excellent markersmanship

shalafi4
Feb 20, 2011

another medical bills avatar

TopherCStone posted:

Can't believe I didn't see this til now, neat. Also you have excellent markersmanship

I can't take full credit for it but it helps having 3 years of professional drafting training


Not bad at the class, but freeking hate it. (mainly cause of the prof.... material is interesting)

The Eyes Have It
Feb 9, 2008

Third Eye Sees All
...snookums

The tolerances machinists work with boggles my mind. Not as much as fractional inches as a standard measurement unit, but still pretty boggled.

Here's my approach to such things:

I don't have a CNC router I can program the exact sizes into and gently caress doing it by hand with a goddam file for a clean hole so drill and jigsaw it is - time is all any of us really have on this earth and I'm not loving made of the it now am I



That row of holes is pretty straight

Now I can just laser cut a goddam window out of 1-2mm black plastic to fit exactly and slap that in between the LCD and the protective polycarbonate window going over it, no one will know how ugly it is underneath

Oh and it's a little uneven oh well E-6000 some scrap onto that fucker problem solved

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The Eyes Have It
Feb 9, 2008

Third Eye Sees All
...snookums

im an animal, i dont deserve to post in this thread

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