CR4 - The Engineer's Place for News and Discussion ®
Login | Register for Engineering Community (CR4)

Speaking of Precision

Speaking of Precision is a knowledge preservation and thought leadership blog covering the precision machining industry, its materials and services. With over 36 years of hands on experience in steelmaking, manufacturing, quality, and management, Miles Free (Milo) Director of Industry Research and Technology at PMPA helps answer "How?" "With what?" and occasionally "Really?"

Upset Testing--Steel in Compression

Posted April 22, 2016 10:00 AM by Milo
Pathfinder Tags: compression machining steel

Mechanical properties of a given steel under compression compare closely with its tensile properties. An upset can be performed to determine how the steel will perform under compressive load.

A brittle steel under compression will ultimately fail by breaking along cleavage lines at an angle approximately 30 degrees from the axis of pressure being applied.

A more ductile steel flattens out, rather than cleaving, showing vertical cracks around the outer circumference. This ductile steel will not break, but will continue to flatten as more stress (load or force) is applied.

This compression or upset test is helpful for assuring that a steel will successfully cold work.

It can also be used to determine the extent of seams, laps or other surface imperfections on the surface of the bar. That's what I used to do when we were producing drawn wire for cold heading applications.

Editor's Note: CR4 would like to thank Milo for sharing this blog entry, which you can also read here.

4 comments; last comment on 04/26/2016
View comments

Scissors Lift Fatalities Prompt OSHA Safety Alert

Posted April 20, 2016 10:00 AM by Milo
Pathfinder Tags: aerial work osha Scissor lift

OSHA Issues Safety Alert- Scissors Lifts

10 fatalities and 20 serious injuries over a one year period spurred the alert.

What you need to know:

  • Only trained operators permitted to use;
  • Training must be complete;
  • Equipment must be properly maintained;
  • PPE must be worn;
  • Lift platforms must have guardrails in place, and employees must not stand on guardrails;
  • Never move a lift when the platform is elevated per Manufacturer's instructions;
  • Outdoor operations only when wind speeds are below 28 mph.

Pre-shift scissors lift inspection Graphic Courtesy Toyota Lift Truck of Minnesota:

Link to OSHA Alert: Scissors Lift Hazard Alert

ToyotaEquipment of Minnesota Graphic

OSHA Aerial Lifts Fact Sheet

Editor's Note: CR4 would like to thank Milo for sharing this blog entry, which you can also read here.

13 comments; last comment on 04/21/2016
View comments

Lean Explained in Just 2 Photos

Posted April 15, 2016 10:00 AM by Milo
Pathfinder Tags: efficiency lean manufacturing

Editing to remove non-value adding distractions and waste is the true essence of Lean.

There are many distracting non-value-added elements in this photo.

Lean eliminates those distractions to reveal the true value.

Who is the "Lean Editor" to cut the non-value-added distractions and waste throughout your shop?

Editor's Note: CR4 would like to thank Milo for sharing this blog entry, which you can also read here.

12 comments; last comment on 04/20/2016
View comments

3 Keys to Productive Drilling

Posted March 22, 2016 11:00 AM by Milo
Pathfinder Tags: drilling fabrication machining Tools

Here are three of my favorite and most shared ideas to get the most from drills in your shop.

  • Keep the drill short.
  • Get the feed rate right.
  • Replace the drill on schedule before it dulls.

Keep the drill short. Drills need a rigid setup. Having extra length can lead to deflection and drill wander. There is a reason that drills for screw machining applications are short- we need the rigidity. I learned this while working as the metallurgist for a steel bar company. I got a call from a customer that my steel wouldn't drill straight. After a 3-1/2 hour drive to the customer's shop out of state, I found a very narrow diameter drill (maybe 3/16″) being held in a Jacobs chuck the size of my head, being held on a Morse taper the length of my forearm. Or maybe a bit longer. Add to that a very short cycle time, and the drill and chuck never got to a repeatably steady location- they were vibrating until they entered into the next workpiece. They could enter that workpiece at a number of different locations based on that vibration and moment arm. We shortened the setup considerably and suddenly the steel that we provided was drilling straight, true and on center.

Get the feed rate right. When I was learning machining, I was taught that the feed rate determines your success in drilling. After years and years in shops like yours, I am convinced that what I was taught is correct. Yes, the wrong speed can burn up a drill. But getting the feed right assures that the chips break up appropriately. that they will flow smoothly down the flutes. Proper feed assures that the drill won't "chip out" on the cutting edge, and also that the drill itself won't crack or split up the center from too heavy of a feed.

Planned replacement of the drill before it dulls will make you more parts per shift. This is an under- appreciated way of thinking. In most companies, they have a purchasing culture and want to get the most out of a tool before replacing it. In the most profitable companies, they have a "respect the process" culture that focusses on maintaining process control, not maximum tool life. By replacingthe drill before it gets dull, they minimize downtime, They minimize the production of defective parts. They minimize the creation of workhardening in the parts produced prior to tool replacement. This means less downtime, more trouble-free uptime, and more parts at the end of the shift. Twenty extra minutes of production on a part with a ten second cycle time is an extra 120 parts at the end of the shift. Shippable, billable, no- anomaly parts.

There are other factors besides feed that influence drilling, I will grant you that.

Proper speed, proper coating, proper geometry, effective delivery of coolant- we could create quite a list.

But in my experience, the three factors that hold the secret to productive drilling in our precision machining shops are short rigid setups, proper feed, and planned or scheduled replacement. These three factors are the keys to getting more parts with less trouble out of your shop.

What do you think?

Photo credit: ENCO

Editor's Note: CR4 would like to thank Milo for sharing this blog entry, which you can also read here.

6 comments; last comment on 03/23/2016
View comments

Automate to Elevate—Not Eliminate!

Posted February 23, 2016 2:00 PM by Milo
Pathfinder Tags: Automate employment machining

"When we install this automated line we can eliminate three jobs."

This is probably the stupidest thing that I have ever overheard. (I was eating lunch at a rest stop on the turnpike home from a recent trip.)

There are at least 600,000 high tech manufacturing jobs currently unfilled in the US and Canada.

We know that there are about 391,000 Baby Boomer generation machinists that will be leaving the workforce in the next few years.

  • Who in their right mind wants to eliminate people?
  • They have proven that they can come to work
  • They have proven they can do the work
  • They have proven that they can add value

The point of automation isn't to eliminate jobs. It is to eliminate non-value added labor.

The employees have already demonstrated that they can add value. Automation should free them up to add even more, higher value added to your operations.

I believe that people should be engaged at their highest and best use. Or, as Norbert Wiener once wrote - The Human Use of Human Beings.

The inventor of the feedback circuit figured this out a long time ago

The point of automation is to let you elevate your existing talent to their highest and best use.

Any thing else is The 8th Waste- unused creativity of our people.

Automate to elevate. Not to eliminate. Good people are hard enough to find.

Why would you eliminate your great ones?

Editor's Note: CR4 would like to thank Milo for sharing this blog entry, which you can also read here.

Make It Work Or Make It Right?

Posted January 12, 2016 12:00 PM by Milo
Pathfinder Tags: equipment machining repair

Making it work might get the machine back up and running in half an hour, but if a quarter of the parts produced are then rejected, what was the point?

The paradox that our operators face daily is they often need to choose between "Make it work," versus "Make it right."

Are you a "make it work" or "make it right" kind of guy?

Is yours a "make it work" or "make it right" kind of shop?

Keep your answer to yourself until you finish this short piece.

Make it Work.

How many times when you were working production and an obstacle arises, were you given this sage counsel from the boss: "We really need to get these parts out. Just make it work!" So using all of the brainpower of MacGyver, we cobble together some patch, blend of adjustments, shims, love taps with a hammer, regrinds, or other chicanery to get the process up and running- making it work.

Making it work…

And then the parts go to quality, where a substantial percentage of them are rejected, if not for the original issue, then for a new issue-an unanticipated but very real consequence of the "just make it work we've got product to ship" adjustments that you made. Bottom line, fewer parts than plan, fewer conforming parts than produced, fewer shippable parts at the end of the day, and very low earned hours of production, despite the time and materials used to "make it work."

Can't Ship. Don't get paid.

Make It Right

Professional machinists don't buy the "make it work" instruction. They know that a part that won't ship to the customer is a part that company won't get paid for. It's waste. A waste of the material, machine time, utilities, and their time to make a non-conforming part. Instead of trying to "make it work, professionals work on trying to understand the problem, determine its root causes, and then take effective corrective actions. Making it work might get the machine back up and running in half an hour, but if a quarter of the parts produced are then rejected, what was the point?

By taking the time to do more than just "make it work" with a cobbled together workaround, the professional eliminates the root cause and returns the process to statistical control, making it right.

Yes, maybe the machine was down an extra half hour or hour compared to the quick "make it work" fix that hopefully, but likely doesn't, really get you back up and running good parts.

At the end of the day, I'm betting that more shippable parts will be produced by the "Make it Right" philosophy, than the "Make It Work" philosophy. Urgent is not a synonym for Good. The tyranny of the urgent is the enemy of good.

Yes, we all know that we get paid when we ship good parts. We all know that we can only ship good parts when the machine is running. Nope- correction. We all know that we can only ship good parts when the machine is making good parts- under statistical control, using the approved process. Make it work is at best a risky gamble - minimizing short term gain for longer term rejection. We shouldn't be gambling in our shops.

Make it right.

Photo credit Make it work

Photo credit MacGyver

Photocredit Reject Tag

Photocredit Picard

13 comments; last comment on 02/03/2016
View comments

Previous in Blog: Bolted Joints: More Than You Think  
Show all Blog Entries in this Blog


New Privacy Policy

We have adopted new policies. Please read each one carefully.