Register a SA Forums Account here!
JOINING THE SA FORUMS WILL REMOVE THIS BIG AD, THE ANNOYING UNDERLINED ADS, AND STUPID INTERSTITIAL ADS!!!

You can: log in, read the tech support FAQ, or request your lost password. This dumb message (and those ads) will appear on every screen until you register! Get rid of this crap by registering your own SA Forums Account and joining roughly 150,000 Goons, for the one-time price of $9.95! We charge money because it costs us money per month for bills, and since we don't believe in showing ads to our users, we try to make the money back through forum registrations.
 
  • Post
  • Reply
shalafi4
Feb 20, 2011

another medical bills avatar

Shaocaholica posted:

I see listings for 1.5mm on random places online but all the big industrial suppliers don't have it in both the US and EU. I wonder what the story is on why 1.6 and 1.4 exist but not 1.5.

Metric version of #5 or #7 screws?

Adbot
ADBOT LOVES YOU

Shaocaholica
Oct 29, 2002

Fig. 5E


Yeah its definitely niche use at that size. Watchmaker/camera territory.

shalafi4
Feb 20, 2011

another medical bills avatar

Shaocaholica posted:

Yeah its definitely niche use at that size. Watchmaker/camera territory.

From the guy who taught me nearly everything I know about machining.

"5-40 screws only exist for when you gently caress up a 4-40 and have to keep the same thread pitch"

boxen
Feb 20, 2011


shalafi4 posted:

From the guy who taught me nearly everything I know about machining.

"5-40 screws only exist for when you gently caress up a 4-40 and have to keep the same thread pitch"

That's a good quote.

"Okay, now we'll just tap this 6-32 hole...gently caress...okay, now we'll just tap this 8-32 hole...gently caress... now we'll just tap this 10-32 hole..."

shalafi4
Feb 20, 2011

another medical bills avatar

boxen posted:

That's a good quote.

"Okay, now we'll just tap this 6-32 hole...gently caress...okay, now we'll just tap this 8-32 hole...gently caress... now we'll just tap this 10-32 hole..."

YYYYYUP


also you can just run a 5-40 tap straight into a 4-40 hole. it's almost the exact tap size drill already.

darnon
Nov 8, 2009


Likewise, strip out a 5/16 or 8mm bolt hole? Welp, guess it's a 3/8-16 now.

Shaocaholica
Oct 29, 2002

Fig. 5E


Welp plot twist the 1.6mm fasteners I got from McMaster measure slightly under 1.5mm. I had to do a double take and check the invoice and label and for sure its spec'd at 1.6mm so....


e: and they fit fine so mission accomplished.

Shaocaholica fucked around with this message at 09:23 on Feb 4, 2021

Vindolanda
Feb 13, 2012

It's just like him too, y'know?


Shaocaholica posted:

Welp plot twist the 1.6mm fasteners I got from McMaster measure slightly under 1.5mm. I had to do a double take and check the invoice and label and for sure its spec'd at 1.6mm so....

The master 1.6mm screw in Paris must have worn down a bit, Ill hop onto a ferry and have a word.

Gray Stormy
Dec 19, 2006



Can I just use this thread to post about how much I want to set my swiss lathe on fire?

shalafi4
Feb 20, 2011

another medical bills avatar

Gray Stormy posted:

Can I just use this thread to post about how much I want to set my swiss lathe on fire?

I'll gladly take it off your hands

Gray Stormy
Dec 19, 2006



shalafi4 posted:

I'll gladly take it off your hands

The choices made with it baffle me: collet tension adjustments on stock coming into the main spindle head? Theres a collar you tighten or loosen manually. When we got it, the tech helping with the install told us, "You just do it by feel. Eventually you get it."

Precision equipment.

Tool touchoffs are done by using a bent metal bracket and adjusting a set screw. You only get one bracket.

The coolant/cutting oil chiller reservoir? Yeah, sometimes it just 'forgets' its alarm parameters so maybe you walk into the shop to find 40 gallons of swiss lube on the floor.

Ive had field techs come out to look at issues we have with the coolant return filters(they get clogged up like five times a year) say to me, "I dont know why they send me to look at these. I dont know how to work on them."

I homestly cant say enough good things about my Haas equipment though.

CarForumPoster
Jun 26, 2013
I have a high school diploma AND a hobby coin project

Now that you're sufficiently in awe, you motherfuckers shut up and let me tell you how human safety in your self driving car works in the REAL WORLD


shalafi4 posted:

YYYYYUP


also you can just run a 5-40 tap straight into a 4-40 hole. it's almost the exact tap size drill already.

Thats what helicoils are for.

shalafi4
Feb 20, 2011

another medical bills avatar

CarForumPoster posted:

Thats what helicoils are for.

True

Unless you're in a lab environment that'll eat steel (including stainless)



I used to work with some weird poo poo.

Shaocaholica
Oct 29, 2002

Fig. 5E


What material do you use in environments that are harsh to steel and SS?

shalafi4
Feb 20, 2011

another medical bills avatar

Shaocaholica posted:

What material do you use in environments that are harsh to steel and SS?


With what I was dealing with?

High oxygen, High temperature environments.


Typically we would have to either use fully hardened 750X Inconel one of the Rene alloys (French company's counterpart to Inconel)


Or in the other lab that was doing normal atmosphere tests at 550C we'd use (in a pinch) pure Nickel or (ideally) an alloy that I can't remember the name of that's like 95% Nickel and a splattering of small alloying agents for the rest.

3xx stainless steels have this temperature bubble that they do HORRIBLE in that runs from like 475C to 600C? (take that range with some salt its from memory) At that range the iron and nickel try to phase separate from the chromium. The technical term for it is "Sigma phase embrittlement" if anyone wants to go down the rabbit hole.


IF it's low temp really harsh environments. PTFE or whatever the trade name for fully crystalized PTFE is (we hated that stuff with a passion)

shalafi4 fucked around with this message at 19:11 on Feb 8, 2021

Shaocaholica
Oct 29, 2002

Fig. 5E


Lol that's like rocket engines or some poo poo?

I just saw some YouTube about some satellite solar array not deploying because they didn't test it in a vacuum and the parts had cold welded (that's the theory anyway).

shalafi4
Feb 20, 2011

another medical bills avatar

Shaocaholica posted:

Lol that's like rocket engines or some poo poo?

I just saw some YouTube about some satellite solar array not deploying because they didn't test it in a vacuum and the parts had cold welded (that's the theory anyway).

One of the research groups I did work for did materials tests on the hot turbine blades in jet engines.



Also that's a VERY good chance that's what happened. Most engineers don't realize that there's just a cushion of air/oxide between iron and especially aluminum welding its self together.


Fun fact. All of the joints on the space shuttle arm were out of a machinable ceramic. As horrible as that probably sounds to try and to it's surprisingly pleasant to machine. It tends to chip like 360 brass does, fine chips that'll crumble/crunch out of the way. You need carbide tooling cause any steel endmill will wear down really quickly though. (we'd be able to drill 2~3 roughly 1/4" holes in a 1in thick block before a cobalt drillbit would get too dull to cleanly cut it anymore)

Styles Bitchley
Nov 13, 2004

FOR THE WIN FOR THE WIN FOR THE WIN

shalafi4 posted:

One of the research groups I did work for did materials tests on the hot turbine blades in jet engines.



Also that's a VERY good chance that's what happened. Most engineers don't realize that there's just a cushion of air/oxide between iron and especially aluminum welding its self together.


Fun fact. All of the joints on the space shuttle arm were out of a machinable ceramic. As horrible as that probably sounds to try and to it's surprisingly pleasant to machine. It tends to chip like 360 brass does, fine chips that'll crumble/crunch out of the way. You need carbide tooling cause any steel endmill will wear down really quickly though. (we'd be able to drill 2~3 roughly 1/4" holes in a 1in thick block before a cobalt drillbit would get too dull to cleanly cut it anymore)

From what very little I know about them, jet turbine blades always seem to be pushing the limits of material science. I had some metallurgy training and the instructor mentioned they can "grow" turbine blades out of single grains. ???

As for the shuttle arm, I know some ceramics can be machined in a "green" state and then sintered to final hardening. Wonder if that's what they did? I know trying to machine porcelain insulators is no fun.

shalafi4
Feb 20, 2011

another medical bills avatar

Styles Bitchley posted:

From what very little I know about them, jet turbine blades always seem to be pushing the limits of material science. I had some metallurgy training and the instructor mentioned they can "grow" turbine blades out of single grains. ???

As for the shuttle arm, I know some ceramics can be machined in a "green" state and then sintered to final hardening. Wonder if that's what they did? I know trying to machine porcelain insulators is no fun.

I have a chunk of grown blade I keep on my desk at work as a reminder that I used to do stuff that people said couldn't be done. (it's conventionally machined CMSX alloy)
To give a couple experience/reference points for this the bar had done the following before it was finished.

Ground the teeth off of a brand new HSS horizontal band saw blade under full coolant going at 25sfm.

Dulled 2 carbide endmills that had to be resharpened (not chipped/broke, wore the edge down via abrasion)

Galled 3 taps. yes you read that correctly. The taps galled off trying to cut this stuff.


With the shuttle arm it's actually machined after full heat treating. The material is called Macor. 50,000 ft view that isn't technically correct but close. It's originally a 3 phase ceramic that when it's heat treated it partly crystalized out and partly becomes a glass. Large crystals (we're talking micro land here still) in a glassy matrix. The glass is also bonded to the crystals so it doesn't have any substantial distance to crack.

shalafi4 fucked around with this message at 20:37 on Feb 8, 2021

Shaocaholica
Oct 29, 2002

Fig. 5E


So I'm taking apart a cheap AR upper and the rail was held on with some 8-32 fasteners but the hex drive didn't fit any inch hex sizes but fits a metric 2mm very nicely. So...why does an inch fastener have a metric drive?

ThinkFear
Sep 14, 2007



Probably 5/64. Was it a low profile head?

Shaocaholica
Oct 29, 2002

Fig. 5E


ThinkFear posted:

Probably 5/64. Was it a low profile head?

Yeah. I guess I didn't have a 5/64 driver to check.

shalafi4
Feb 20, 2011

another medical bills avatar

Shaocaholica posted:

So I'm taking apart a cheap AR upper and the rail was held on with some 8-32 fasteners but the hex drive didn't fit any inch hex sizes but fits a metric 2mm very nicely. So...why does an inch fastener have a metric drive?

A badly made 5/64 hex falls almost exactly at 2mm

it's like 0.074" vs 0.078" when they're proper size.

Gray Stormy
Dec 19, 2006



I have been struggling with ways to speed up turning hardened steel rectangles shapes into round shapes on our lathe.

Until today.

On a whim I wrote a program to run our OD insert .09" directly into the hardened rectangle(previously we were doing something like .005" passes). And the insert held.

Thinking it was a fluke, we ran more parts through...the insert continued to hold.

Im pretty jazzed about it.

shalafi4
Feb 20, 2011

another medical bills avatar

Gray Stormy posted:

I have been struggling with ways to speed up turning hardened steel rectangles shapes into round shapes on our lathe.

Until today.

On a whim I wrote a program to run our OD insert .09" directly into the hardened rectangle(previously we were doing something like .005" passes). And the insert held.

Thinking it was a fluke, we ran more parts through...the insert continued to hold.

Im pretty jazzed about it.

If you've got an insert that's on the "tough rather than hard" end it'll hold up for a while.

Biggest thing to watch is you may start running into dimensional consistency issues over the insert life.

Shaocaholica
Oct 29, 2002

Fig. 5E


So how do people end up as machinists for university labs or JPL or high science industries as opposed to commercial manufacturing? Science undergrads that pickup machining on the side and then kinda dig into it?

shalafi4
Feb 20, 2011

another medical bills avatar

Shaocaholica posted:

So how do people end up as machinists for university labs or JPL or high science industries as opposed to commercial manufacturing? Science undergrads that pickup machining on the side and then kinda dig into it?

That's how I wound up at the positions I did. (University lab/research machinist)

Engineering undergrad who wound up having a knack for it.

shalafi4 fucked around with this message at 21:54 on Feb 26, 2021

ThinkFear
Sep 14, 2007



Shaocaholica posted:

So how do people end up as machinists for university labs or JPL or high science industries as opposed to commercial manufacturing? Science undergrads that pickup machining on the side and then kinda dig into it?

Tom Lipton was just on the Essential Craftsman podcast and talked about his career trajectory a bit. Worth a listen.

bulletsponge13
Apr 28, 2010


I have no clue how he got there, but one of my gunsmith instructors (graduated there in the 70s) spent something like 10+ years machining at JPL. Left there to come back and teach gunsmithing.

Shaocaholica
Oct 29, 2002

Fig. 5E


70s JPL probably more likely to do that I assume.

Styles Bitchley
Nov 13, 2004

FOR THE WIN FOR THE WIN FOR THE WIN

I would like to know about machining 17-4 PH. Milling, drilling, tapping it as-annealed and at H900 temper. Supposedly dimensionally stable when heat treating, would say a 3/8-16" tapped hole get boogered up? On paper looks great you just heat to like 900, air cool, and it goes from like 30 HRC to 45 HRC. Never worked with it though but looking into it for castings.

bulletsponge13
Apr 28, 2010


Shaocaholica posted:

70s JPL probably more likely to do that I assume.

Yeah, I have the impression he got it in the late 70s- early 80s. I honest recall him saying he retired from there, but I don't want to pass on parts I'm not sure of. He did smithing for a few years, then got in there.

Super nice old dude. I really liked him. I also appreciate anyone who is up front about poo poo like "I'm deaf as hell. Please be prepared to speak up, or repeat yourself a few times."

E- I'm sure he knew CNC and all that stuff, but dude was a really good manual machinist.

bulletsponge13 fucked around with this message at 01:59 on Feb 27, 2021

shalafi4
Feb 20, 2011

another medical bills avatar

Styles Bitchley posted:

I would like to know about machining 17-4 PH. Milling, drilling, tapping it as-annealed and at H900 temper. Supposedly dimensionally stable when heat treating, would say a 3/8-16" tapped hole get boogered up? On paper looks great you just heat to like 900, air cool, and it goes from like 30 HRC to 45 HRC. Never worked with it though but looking into it for castings.

Do you have any experience with cutting 3xx series steels or copper? It's similar to those, however it tends to dull tooling faster as it's more abrasive.

Did some quick digging, it shrinks on heat treating. ~ 0.0005 per inch at H900. So for a 3/8-16 you'll *probably* be okay not having to get a + size heat treat tap. (also with it only going to ~mid 40's HRC just run a sharp tap back through the hole after hardening)


Any particular reason on going with 17-4? It's not something people typically go to on a casual basis.

Styles Bitchley
Nov 13, 2004

FOR THE WIN FOR THE WIN FOR THE WIN

shalafi4 posted:

Do you have any experience with cutting 3xx series steels or copper? It's similar to those, however it tends to dull tooling faster as it's more abrasive.

Did some quick digging, it shrinks on heat treating. ~ 0.0005 per inch at H900. So for a 3/8-16 you'll *probably* be okay not having to get a + size heat treat tap. (also with it only going to ~mid 40's HRC just run a sharp tap back through the hole after hardening)


Any particular reason on going with 17-4? It's not something people typically go to on a casual basis.

Yeah 3xx stainless and copper no issue. I have two projects looking at the 17-4: one is a 440C stainless casting that is heat treated and machined after heat treat. We have issues with warpage, I assume these are quenched. Also it's kind of a pain to machine after hardening. The other and main reason is a multi-component part that had case hardened elements, i am looking to cast as one piece and thru harden after machining. When I proposed the design to the foundry engineers they also recommended 17-4 so that made me feel better. Having 3D printed tool samples made now so we'll see. Didn't think about +Hx taps or something, that should work if the shrinkage is uniform. Barring some flatness requirements that was my main concern.

Admiral Bosch
Apr 19, 2007
Who is Admiral Aken Bosch, and what is that old scoundrel up to?

Yall are making me mad all over again about something that happened to me right after trade school - I interviewed for a scientific instrument maker apprenticeship position at CU Boulder and thought I stood a good chance of nabbing it - would've been 4 years learning about scientific glassmaking and laser reflecting and a bunch of other poo poo, plus teaching grad students how to turn on a lathe safely. I interviewed and then they told me the requirements had changed to need a 4 year degree. I was so loving pissed. Sometimes I wonder how the Admiral Bosch in that universe is doing.

my kinda ape
Sep 15, 2008

Everything's gonna be A-OK


Oven Wrangler

Admiral Bosch posted:

Sometimes I wonder how the Admiral Bosch in that universe is doing.

I didn't see that was your username and was like "The guy from Freespace who talks to the Shivans???"

Admiral Bosch
Apr 19, 2007
Who is Admiral Aken Bosch, and what is that old scoundrel up to?

Lmao yes, that guy. This is my handle for literally everywhere except the still-active Freespace community forums.

shalafi4
Feb 20, 2011

another medical bills avatar

Styles Bitchley posted:

Yeah 3xx stainless and copper no issue. I have two projects looking at the 17-4: one is a 440C stainless casting that is heat treated and machined after heat treat. We have issues with warpage, I assume these are quenched. Also it's kind of a pain to machine after hardening. The other and main reason is a multi-component part that had case hardened elements, i am looking to cast as one piece and thru harden after machining. When I proposed the design to the foundry engineers they also recommended 17-4 so that made me feel better. Having 3D printed tool samples made now so we'll see. Didn't think about +Hx taps or something, that should work if the shrinkage is uniform. Barring some flatness requirements that was my main concern.

With the hardness range that you're shooing for in the 17-4 the +H taps might not even be needed. Although if it's a production run they might be a good idea out of QC safety.

I haven't had good experiences with hardened 440C in shapes that aren't knives. Warp/ distort/ move after you machine it etc. Although in *theory* they might not be tempering it correctly? It's been a long time since I've messed with 440C from a heat treat angle and can't remember if there's a more aggressive tempering schedule that minimizes internal stress. (D2 Is like this, we had a specific heat treat for any precision EDM work cause it would shift/collapse with normal heat treats)


Edit:

Yea I looked 440C temper procedures back up. They are some LONG temper temper times that need to happen a few times. They're also relatively low temperatures so some heat treat places have issues controlling the temp that low.

shalafi4 fucked around with this message at 22:05 on Mar 1, 2021

shalafi4
Feb 20, 2011

another medical bills avatar

Probably a stab in the dark but any goons have access to an ID grinder or a good lathe with a toolpost grinder?


I'm starting down the messy rabbit hole of making a set of bullet forming dies and there's at least one part that I don't really have the equipment to do it "correctly"

Adbot
ADBOT LOVES YOU

Gray Stormy
Dec 19, 2006



shalafi4 posted:

Probably a stab in the dark but any goons have access to an ID grinder or a good lathe with a toolpost grinder?


I'm starting down the messy rabbit hole of making a set of bullet forming dies and there's at least one part that I don't really have the equipment to do it "correctly"

Ive got a Haas TL1, a Nomura swiss lathe, plus pretty much any kind of grinder you could think of.

Lots of tools for knife making really.

  • 1
  • 2
  • 3
  • 4
  • 5
  • Post
  • Reply