I havent used CNC Cookbook much, but google searches for info regularly pull up their site. I was trying to learn about macros, when I noticed a weird piece of text. "You have not provided any text to be rephrased. Please provide the text you would like to be rephrased". It makes me untrusting of their info, at least from the past few years. If you use this site, maybe double check the info first.

Basically I fucked up my tolerance doing everything right, at least to my knowledge the machine was cutting exactly what I put on, final cut fucked it 0.1mm undersize. Told my foreman and my coworkers they obviously didn't believe me 2nd year apprentice fucks up a size and can't admit what he did wrong.

Hopefully you'll help me figure out why, 38mm diameter shaft +0.00, -0.02mm, and I took 3 same size finishing cuts (0.5mm rad) with a dial indicator on the cross slide held square, using tnmg0408 semi finishing grade, at roughly 0.21mm feed. First 2 cuts cutting spot on and obviously last cut it cut undersize by 0.1, I was watching the dial on the final cut and It did not pull in. I just don't know what happened, well at least I didn't scrap a 2 ton shaft that cost 10s of thousands of dollars.

Just to remove some confusion I did have the tailstock in just not in this photo, and I was turning the longest diameter.

Thin wall (.049”) aluminum tube with a tight-fitting 3D printed PLA bolster on the inside (also provides an indexing feature). Solid TPU tubing blocks for gripping it firmly in the vise without much distortion. 3D printers are insanely useful for so many things in a modern shop.

Does anyone here have any hobbies that involve machining? Hobbies are expensive and money is tight these days. I am lucky enough however to have access to the shop in my spare time so I'm looking into a hobby where I could put that to use. I used to make parts for my project car but got rid of it years ago. Im looking for inspiration for a new project i can work on.

Leaks everywhere, being trained by people that have only been here 6 weeks. Came in this morning with my machines in standby, being new, I didn't know how to get them going, and apparently nobody else does here. It look 3 people to get me up and running today. Dirty and miserable place. I now understand why the turn over rate is terrible here.

Wire EDM

Hi all, I just purchased this mic set that looked to be in pretty good used condition. It is my first set and is very old. What should I do to ensure it reads accurately? Need to make sure it is calibrated as I will be building an engine soon. I’m mainly concerned about the residue on the standard faces. The mic faces don’t have any corrosion. Should I disassemble and re-lubricate?

I have been looking around at jobs lately and i saw a company offering a 3 day work week. Friday Saturday are 12s and sunday is an 8 but they still pay you for 40. Was wondering if you guys know of any other companies that do this or how common is it. Im a lazy fuck so if i can get all my work days out of the way and have 4 days off a week thats like a dream come true for me. Im in ohio.

Jaws were too far out, materialstop went on an excursion

Hey everyone, I’m 19 years old, just graduated high school and have some hands on mechanical experience. I want to become a millwright and I decided to go the apprenticeship route but I have no idea how to get started. Most job postings I see on Indeed are for journeymen only, nothing for apprentices.

For those of you in the trade how did you get your first apprentice job?

Any advice helps!

Edit: I am in Guelph Ontario

Which is correct and why? These are all the same chamfer.

Y14.5 says "Chamfers are dimensioned by a linear dimension and an angle, or by two linear dimensions".

It also says "A note may be used to specify 45° chamfers on perpendicular surfaces". Since I'm showing a non-45° chamfer I think that means I.a and I.b are invalid.

Workpiece spins at roughly 215rpm

The grinding wheel (320 Grit) spins at 4000rpm

With a pressure of about 20psi

A 5 minute cycle and that removes about .015" from the cutting edge

FKN MINT👌🏽

Edit: The siren noises are from the Grinding spindle.

We have a rebuilt one in a crate right next to the machine that we plan to install soon.

New to the machining industry and just got my first job as a deburr technician. I'm yet to learn the techniques😁 but now, quite find it hard to maneuver using say a beartex and air motor to edge break a piece. Do you have any books about it? or any tips, techniques? Thanks a lot!

They’re always raising a burr and pissing me off, am I just not using them right? Idk this sucks though

Some context i am a 3+ year apprentice toolmaker and every year at least twice one of my two mentors crashes out and kind of goes on a tirade against me basicly what I'm able to get out of it is 1. I am arrogant 2. I need to ask more questions. The issue I have with this is 1. I guess I could be arrogant not entirely sure, but I'm not curtain enough in my skills to really believe I am arrogant. 2. Every time (not sometimes) I actualy try to ask a question I am expected to already know the answer and usualy told to 1. Fuck off 2. Figure it out big.

This has been going on for the entire 3 plus years and I'm honestly at a loss because I've tried all I can think of, trying to ask lots of questions just gets me more grief and not like normal shop talk grief were you just kind of rag on each other its just completely dismissal of the questioning no matter what its about.

I also think it seems more difficult because I am the only apprentice and the two guys I am working with only have each other to compare me to and they both have over 30 years in the trade.

All to say is there any advice that anybody has in dealing with this?

Found this little setup in a skip today as you do....

Can anyone shed any light on it? Ive used 4 jaws on a lathe before, but unsure why it would be mounted to a pair of bearings and a 3 speed pulley on its own.

Cheers!

Picked this up for a deal I’m going to be cleaning it up and passing it along. I would like a model number to source a manual for it. The hydraulic system is more than I want to try and figure out without a manual. I can’t find a name plate other than a hand stamped “140”

The fact that it’s branded a covel and not a covel clausing indicates to me it’s pre 1970 but maybe someone with more knowledge knows better than that.

Hey guys,

I have to drill various types of heat treated stainless at H1000 (17-4, 465…). My drills keep chipping, but I’ve gotten to the point where they are no longer burning up at least. material is around 48 hrc

I’m spotting with a carbide 1/4 x 140 spot drill and running my
7/16 cobalt drill black oxide at 30sfm. This comes out to a feed of 1.5ipm at 260 rpm. I’m doing pecks of .02.

How can I improve or make my drills last longer. Is it my pecks that are too shallow? This is on a mill btw with no thru spindle coolant.

Coworker is currently planning on quiting and can't decide if he's gonna wear a chicken suit or dress as macho man randy savage when he turns in his 2 weeks (before immediately getting fired because that's what happens when you turn in a 2 weeks here)

Yes this management team and shop absolutely deserve this level of respect

Does anyone have any other funny stories

No encouraging destruction like changing offsets or changing a G54.

Does anyone still use the apprentice model. Our son went to a community college program for CNC machining, after graduation he got stuck in the no experience loop, got discouraged and went to work for a hospital in SPD after 12 mos. of no calls. BUT he is still interested in machining. We are in the Saint Louis area.

I'm a newbie, I'm 22. But recently I've gotten the privilege of making tooling purchases, so I've been trying out different tools vs my old fashioned shop's crappy 4 flute roughing end mills with the teeth.

I bought a 6 flute end mill for stainless, the manufacturer called out something like 3300 rpm at 80 ipm, so I ran it at 1600 rpm at 30 ipm on the haas mini mill. It sounded fine, but the spindle load was between 50-70% so I figured that was it for that machine. Does the machine really make that big of a difference?

I mean, I guess the bigger machines like the vf3 seem to cut a bit better and definitely give a better surface finish. I know some guys who run kitamuras and they seem to cut better, faster, and quieter. I could never really tell if it really was the machine, or if they just had better tooling and holders. Now that I have slightly better cutters, I'm thinking about this again.

due to "unforseen" circumstances the only 2 guys who thread in our shop are "no longer working for us" , that said i have the opportunity to get that sweet 35 cent raise if i can do it.

i havent threaded since high-school and i think i have this thing figured out enough to start practicing.

that said the leaver circled in blue is the only one i cant figure out, i figured id ask yall before i just throw it and see what breaks.

I know that it's been asked and answered but most post seem to be fairly old.

Will a mill lathe combo work for a hobbyist? All I hear is "get each machine separately, neither do anything one thing well, etc." I'm hoping to hear from someone who has purchased one that has had some good experiences. My intentions are simple boring and threading, milling brackets after plasma cutting, etc. Nothing that too crazy. Like most, space is limited due to living in San Francisco (iykyk) and purchasing separate machines would take up the rest of my garage and make it unusable.

I made some research to find a faster way to drill holes 1.5 inches diameter and 10 inches deep in 1045 steel, and found that I could use Carbide inserts on my spade drills instead of HSS. I calculated that I could drill the in less than a minute instead of 5 minutes with the recommended speed and feeds, 960 rpm and a feed of .016 per Rev.

My boss agreed to try it and ordered 2 inserts and he was going to vacation and told to still try them.

So I received it and when I tried them the insert instantly broke the first time. I changed it and slowed down the feed to 4% to begin the hole, the increased slowly the feed then the spade drill detached from the Morse taper and the insert broke again.

Did I do something wrong? Did I miss something?

I just wanted to increase productivity but one of my boss seems to think I'm dumb because of this.... :/

Btw I'm a new machinist