Thread: Machinists general rules of thumb

Originally Posted by jkruger

Never, under any circumstances walk up behind someone running a machine and startle them in any way. Make your presence known by other means than speaking right in their ear at full volume to overcome the noise of the machine when they don't know you are trying to get their attention. My current boss does this just to get his kicks seeing us jump.

Easily entertained, isn't he? Only to his (and others) detriment. I hope someone hurts him very badly.

If it's worth doing, it's worth doing well. Screwing it up only makes everyone unhappy, including yourself when you have to do it again.

If it's not safe for your hands, it's not safe for anyone elses. Remove all sharp edges.

Hi,

1. if it looks wrong / it usually is
2.if it feels wrong / finish not good enough
3.if it sounds wrong / whatch that cutting tool
4. if it costs less to make than the cost of the material / beware
5. if it made a loss / don,t do it again unless you get more money
6.if a sales man talks the talk / make him walk the walk
7.if you make a mistake / admit it , analise it and try not to make it again.
8.if you have'nt made a mistake / you have'nt made anything
9.listen to the little man in the back of your head
10. never push your granny when she's frying.

Originally Posted by Gerrythewelshman

Hi,

1. if it looks wrong / it usually is
2.if it feels wrong / finish not good enough
3.if it sounds wrong / whatch that cutting tool
4. if it costs less to make than the cost of the material / beware
5. if it made a loss / don,t do it again unless you get more money
6.if a sales man talks the talk / make him walk the walk
7.if you make a mistake / admit it , analise it and try not to make it again.
8.if you have'nt made a mistake / you have'nt made anything
9.listen to the little man in the back of your head
10. never push your granny when she's frying.

Long time no hear

Gordon

Rule I live by:
ALWAYS lock your tools up at the end of the day, or if you leave the building for any reason, even if it's just to move your car. I got real tired of taking 30 minute "vacation walks" around the shop chasing "borrowed" tools.

Measure twice cut 10 times, Measure twice cut 100 times, measure twice cut 500 times, measure twice cut 500 times until the run is done.

There is no such thing as perfect there is only within spec or outside spec. Within is good enough; outside is scrap.

The machine will not feel the least bit sorry after it cripples you.

No good deed goes unpunished.

When your colleague, friend or whoever is looking for a thank you job put your hands in your back and leave them there. At no point should you get those hand out of your back and if you do and specially if you take that part in your hands it is yours they won't take it back. When you need something you go buy it why should you do it for somebody else and have a stressful day hiding from the boss and worse hurt yourself working to quick to cover the time. The beauty of that technique it works.

Robert

1) Vises are NEVER to be left on the machine that are not indicated!
2) No tools are ever put into a machine without IMMEDIATELY touching them off.
3) Don't be afraid to have others look over your job plan/ program / setup to offer different and possibly better / faster ways of making the part.
4) Deburr WHILE the machine is running if you can.
5) A clean, deburred, & polished part is 3X as likely to make it through inspection as compared to a dirty part with sharp edges and non-uniform surface appearance.
6) Clean your fixture, or vise jaws EVERY part! Nothing ruins a part like a chip pressed into your datum surface.
7) Think out every step of making the part thoroughly.
8) Don't be afraid to "no-quote" some jobs.
9) Don't be afraid to tell a customer that "shop XXX" can make the part more economically than you can. The honesty will pay off in the long run with that customer.
10) Don't hire any employees with mothers who are drunks and call other employees to threaten them in the middle of the night! LOL
11) Calibrate (or at least check against a gage) measuring instruments every time you use them!
12) Buy good tools 1 time. Not cheap tools multiple times.
13) NEVER speak to me when I am programming or editing a program at the machine. EVER!
14) Let other people know when you are about to make a loud noise. (Machinists are jumpy by nature. More so when our faces are inches from a 10" chuck spinning 2K rpm!)
15) Don't bang on my doors loudly when the shop is locked. It pisses me off, and scares the shit out of me! If the door is locked, it means I DON'T WANT TO BE BOTHERED.

Doug.

to newbes in the shop. 15 years experince translates in to 15 years doing the same parts,
you can tell a good machinist by the size of his toolbox
talk whatever you want, let me see your work done

5 points to be a real machinist.
1.-attendance never late never skip a dayof work
2.-have your own tools
3.-open to comments or sugestions even if you are the best
4.-shout your mouth with a cheese hystories
5.- have the job done on time

1. Measure your part as best you can before you take it out of the vise/chuck.
2. Clean collets out before using them, even if the tool you're putting in it is the same size as the one you just took out. Chips get in there when the collet expands, and then they get crushed/binded to the collet when you close the chips on it. Plus, your tool won't be as concetric.
3. Try different brands/styles of tooling so you have an idea of what cutter is good for what job.

Good luck,
Matt

1) Customers prefer a part that's out of tolerance and looks good to a part that's ugly and meets specs.
2) Customers who take 6 years to design a part will want it made tomorrow.
3) Customers willing to pay to design the part want it machined for free. Customers willing to pay to have the the part machined want it designed for free.
4) Never partner with a first time inventor.
5) Be clear about rates and charges up front, keep good time records and charge for every bit of it so the customer isn't surprised.
6) Simple setups take half an hour, more complicated ones 1 hour.
7) Estimate the time to produce the part by using a stopwatch to time all the manual motions. Then... multiply by two.

Maybe straying a little from the theme...

Neil

Originally Posted by neilho

6) Simple setups take half an hour, more complicated ones 1 hour.


Neil

I have regular setups that take 4-12 hours, so it depends a bit on what you do.

Bosses seem to follow a simple rule:

"Never tell your employee he did a good job even if if was the most beautiful thing you've seen in your life.
If you do, he may get excited and expect to be fairly compensated.

When he does not get fairly compensated(which was THE plan from the get-go) he ll gets pissed off with all resulting consequences. So...

Never tell your employee he did a god job"

Dunno about you guys but i can count on fingers of my hand how many times i was thanked to staying late or trying harder that i should have.
They only wish they payed you more once you are gone. (No hard feelings i gots mouths to feed)

So i guess here comes my rule of thumb: try as hard as you can but don't expect it to be recognized by anybody(hope maybe). just a part of our job

Originally Posted by zero_divide

Bosses seem to follow a simple rule:

"Never tell your employee he did a good job even if if was the most beautiful thing you've seen in your life.
If you do, he may get excited and expect to be fairly compensated.

When he does not get fairly compensated(which was THE plan from the get-go) he ll gets pissed off with all resulting consequences. So...

Never tell your employee he did a god job"

Dunno about you guys but i can count on fingers of my hand how many times i was thanked to staying late or trying harder that i should have.
They only wish they payed you more once you are gone. (No hard feelings i gots mouths to feed)

So i guess here comes my rule of thumb: try as hard as you can but don't expect it to be recognized by anybody(hope maybe). just a part of our job

If I ever get to be a boss like that, I hope to hell someone tells me. I've been on the other side of that also, and didn't feel appreciated. I always tell someone they did a very nice job when it's called for. And a simple , "Hey, thanks a lot for that", goes a long way.

Originally Posted by zero_divide

Bosses seem to follow a simple rule:

"Never tell your employee he did a good job even if if was the most beautiful thing you've seen in your life.
If you do, he may get excited and expect to be fairly compensated.

When he does not get fairly compensated(which was THE plan from the get-go) he ll gets pissed off with all resulting consequences. So...

Never tell your employee he did a god job"

Dunno about you guys but i can count on fingers of my hand how many times i was thanked to staying late or trying harder that i should have.
They only wish they payed you more once you are gone. (No hard feelings i gots mouths to feed)

So i guess here comes my rule of thumb: try as hard as you can but don't expect it to be recognized by anybody(hope maybe). just a part of our job

The only thing my current boss has ever said positive about my work is: "That's a good looking part."

Never mind the fact he didn't think it could be done at all on his machinery or the methods I used were completely out of his realm of thinking.
Never mind that I run some jobs in less than half the time he quotes, all I ever hear is "Why did this take so long?"

When I was the boss at my own shop I told my guys about it when they made good time and produced nice parts. The ones that consistently pleased me and our customers got raises and paid time off if they had errands to run during work hours. I would buy lunch at least once a week for all of them regardless of the quality of their work.

I never had one guy quit, had to let a few go but the ones worth their wages stuck with me.

One that has stuck with me was something a machinist told me about milling machines (applies to cnc..and machines in general) try to see yourself as that milling machine does, it sees you as lubrication, if you get in it, it will run just a little bit better! Macabre, but has a ring of truth.

My pet rule of thumb I call my "rule of one".....there is always one nut (or bolt, or screw...etc) that twists off or breaks, one hole you forgot to tap, one dimension you missed, one bolt missing on reassembly, ...etc

and +1 on just about everything everyone else said on list.

If your gonna wear shorts, ya'll still gotta wear socks!

Rule of thumb for rpm I learnt in Germany. Works for turning, milling and drilling. It's very handy!

RPM for HSS tool on mild steel = 7000 / diameter in mm of rotating element (work piece for lathe, tool for mill and drill.)

For carbide tool: this result * 5.
For alu work-piece: this result * 2.
For tool steel work-piece: this result / 2.

E.g.
10mm HSS drill on mild steel = 7000 / 10 = 700 rpm.

40mm mild steel piece in lathe, HSS tool = 7000 / 40 = 175 rpm.

40mm mild steel piece in lathe, carbide tool = (7000 / 40) * 5 = 875 rpm.

40mm alu piece in lathe, carbide tool = (7000 / 40) * 5 * 2 = 1750 rpm.

40mm tool steel piece in lathe, carbide tool = (7000 / 40) * 5 / 2 = 437.5 rpm

The day you stop learning is the day you are six foot under

First you get good, then you get fast... then crankyness sets in. ( I'm sure that used to be someone's sig line here)

50/50/90 - If you have a 50/50 chance of something being right, you'll be wrong 90% of the time.

When using a file on the lathe, make sure it has a handle, and make sure you angle the tip AWAY from the chuck jaws. (advice learned from this board after buying my first lathe)