Machinist Mondays

[Defiance Machine]

Defiance Machine is built upon innovation and the founder loves to leverage technology. We have more
machining technologies than most machine shops regardless of what industry they are involved in.

Our extensive list of CNC machines allows us to make every part for our actions, including all the custom
options, in house. These machines are running almost 24/7 and we are producing better actions than
ever, and more of them.

OK, but what if you need to make a repair to a fixture or make some specialized tooling? These types of
things could be done on a CNC but the set up will take a while and besides, they’re completely booked
with production parts.

Aside from all the cool CNC machines we keep a couple manual lathes, a couple manual Bridgeport style
mills, several manual grinders, a heat treat oven, and other basic machine tools at our disposal. They
are not ran every day, and sometimes not for months. They cost a mere drop in a bucket compared to
the production machines. But when you need something done quickly, having the machines and a
talented machinist that knows how to run them is priceless.

When you have so many customers counting on you delivering product, you need to be prepared to
adapt and overcome.

The show must go on.

 

[Makinchips208]

Nice! Those older manual machines are beautiful!
Just a thought, we put DROs on them, it is cheap, easy, and increases the potential for precision and accuracy.

 

[Defiance Machine]

Kitamura CNC Milling Machines​

Founded in 1933, Kitamura Machinery has been the leader in CNC Milling machines. With vertical, horizontal, and 5-axis lines of ultra-precise and incredibly rigid machining centers, Kitamura is a perfect fit for machining pre-hardened steel in critical parts. Their commitment to Research and Development has led to over 200 patents and patents pending in machine tool design.

Kitamura’s company motto is, “Limitless Creativity”. So, it’s no surprise that our founder saw them as a good fit with Defiance.

13 years ago, one Kitamura 5-axis mill was the only CNC machine at Defiance, (other than a Fryer toolroom lathe). We currently have 4 Kitamura 5-axis machines and have recently purchased this 4-axis version with a twin spindle rotary.

Utilizing 4-axis vs. 3-axis allows us to machine more features in one operation and enables closer tolerances. Having a twin spindle rotary allows us to machine features in two parts before changing tools. Cutting tool changes in half allows us to make more parts per day.

This Kitamura got us caught up on scope rails in a hurry and is proving to be a worthy investment.

We are constantly finding ways to increase production capacity while improving the quality of our products.

 

[Earnhardt]

How many Kitamura 5-axis machines would you need to catch up on current orders?
Or to stay ahead of current demand?

 

[Defiance Machine]

Sinker EDM (Electrical Discharge Machining)​

​

There are some features that you just can’t machine with rotating tools such as those found in milling machines. A round tool will leave a radius in every corner. You can use a smaller diameter to get into tighter corners, but then you are limited in the depth of cut.

Our receivers have “ramps” on the locking lug abutments. These allow the bolt to start turning when the primary extraction surfaces have met, but the bolt lugs are not yet even with the lug abutments in the receiver.

What are primary extraction surfaces and lug abutments? That will have to wait for another post.

The geometry of these ramps requires a bit more “non-conventional” machining process.

Sinker EDM utilizes an electrode made of graphite or copper, an insulating dielectric fluid, and electricity to “burn” the desired shape. Our products require different electrodes for different diameters of bolts and right and left hand. We machine the graphite electrodes as a mirror image of the shape we need in the steel. The steel part is submerged in the fluid and the electrode emits a spark that erodes the steel, creating the ramps with remarkable precision.

There are other ways to create the clearance needed, but to get the proper geometry without inducing stress into the steel, Sinker EDM is right tool for the job.

 

[Digetydog]

This thread is fantastic.

 

[Mike at Defiance]

How many Kitamura 5-axis machines would you need to catch up on current orders?
Or to stay ahead of current demand?

In manufacturing, there is always a bottleneck. One machine or process that dictates how much product you can assemble and ship. When you "fix" one bottleneck by purchasing a machine or improving process, it moves the bottleneck, and now you have to "fix" that. This is a good thing. It keeps us growing and innovating. So, it's not necessarily multiple Kitamuras that we need next, but maybe a new small parts machine or a 5th wire EDM. We also need qualified operators to run them. We continue to buy new machines, usually a couple every year if not more. Our greatest concern is serving the customer and that means increasing throughput while maintaining and improving the quality we are known for.

 

[LeftyJason]

Sinker EDM (Electrical Discharge Machining)​

​

There are some features that you just can’t machine with rotating tools such as those found in milling machines. A round tool will leave a radius in every corner. You can use a smaller diameter to get into tighter corners, but then you are limited in the depth of cut.

Our receivers have “ramps” on the locking lug abutments. These allow the bolt to start turning when the primary extraction surfaces have met, but the bolt lugs are not yet even with the lug abutments in the receiver.

What are primary extraction surfaces and lug abutments? That will have to wait for another post.

The geometry of these ramps requires a bit more “non-conventional” machining process.

Sinker EDM utilizes an electrode made of graphite or copper, an insulating dielectric fluid, and electricity to “burn” the desired shape. Our products require different electrodes for different diameters of bolts and right and left hand. We machine the graphite electrodes as a mirror image of the shape we need in the steel. The steel part is submerged in the fluid and the electrode emits a spark that erodes the steel, creating the ramps with remarkable precision.

There are other ways to create the clearance needed, but to get the proper geometry without inducing stress into the steel, Sinker EDM is right tool for the job.

How long are burn times? Have you considered using gang tooling to burn multiple at once?

 

[Mike at Defiance]

How long are burn times? Have you considered using gang tooling to burn multiple at once?

About 10 minutes per part when we run 4. We "probe" each part to locate X,Y, and Z axes, so we are sending the single tool down the exact center of each part and to the exact Z height.

 

[Defiance Machine]

Machinists have their own language. If we say the dimension of a feature is .500” “plus or minus ONE,” we’re talking about .001” (one one/thousandths of an inch). But that’s not really precise. Even an analog micrometer can accurately read to .0001” (one ten/thousandths of an inch). To get this type of accuracy, even when doing something simply as drilling a hole, special care must be taken in tool selection, feeds and speeds, and setting up and locating the workpiece.

​

What if you have a part going from one machine to another, such as a round lathe-turned part that is going into a milling machine for additional operations? How do you know that the part is centered and “normal” to all axes in that second machine? Many machine shops will set up a fixture that will locate and hold the part, finding the location in all axes. If the first part is centered, the next will be also. Or is it? What if the 27th part you put in the fixture has a small metal chip on it that gets embedded into the fixture? That piece and the others that come after may be slightly askew, and the new feature won’t be normal, concentric, perpendicular, or otherwise “lined up” with the existing features, and can really ruin your day.

We extensively use CNC touch probes to “locate” each part. Probes work by touching features on a workpiece to collect multiple data points and writing to user-defined offsets in the CNC controller. For instance, the probe moves down in the Z axis until it touches the top of a part. It then stores that data to be used later in the CNC machining program. It can also go into a hole and touch the inside in at least 3 places. It then calculates the center of that hole and writes the “X and Y” coordinates for the center. In a 5-axis mill, we can probe for the center of a hole in two different depths, then the program uses trigonometry to calculate adjustments to the “A and B” axes. This will tilt and rotate the part until that hole is straight up and down, then we will probe again and find the center in “X and Y”.

Although the touch probe process adds to the cycle time, it makes up for it by greatly reducing scrapped parts and producing higher quality parts.

 

[Defiance Machine]

Catching up from being out of town last week, so today we have two Machinist Monday posts for you!

What is a machinist?​

What about a CNC programmer, operator, or tool maker?

The term machinist can be used in many fashions, but for our discussion we are talking about someone who operates a machine that cuts metal. Manual machines require a person to be constantly present, turning handles to create the cuts needed to make a part. A skilled manual machinist can create intricate parts with exacting detail, but each tool is changed by hand and parts may need to be set up multiple times to generate all the required features and dimensions. A tool maker is a machinist but can also make tools, dies, jigs, and fixtures. Tool makers are expected to take an idea, and maybe a napkin sketch, and make it a reality.

CNC, or Computer Numerical Control, allows a machine tool to be programmed to move in multiple axes and automatically change tools. The programs are created by a CNC programmer with CAM (computer aided manufacturing) software. Efficiency is increased by rapidly moving from one location to another and being able to generate angles, radii, and complex surfaces that would be difficult or impossible on manual machines. Automatically changing pre-measured tools in seconds and knowing the exact location of the workpiece reduces time, exponentially. Operators load, unload, and inspect parts as well as monitor and change tools.

In a machine shop you may have job titles for machinists, tool makers, programmers, set up people, and CNC operators. Or you can place people in areas where they are able to thrive and contribute to the common goal of the company. Some will settle into a position where they excel, and some will move around and learn as many new skills as possible.

We want our employees to be fulfilled and that could mean learning one machine or all the machines. We have a lot of very talented people that work together to keep our product shipping to our valued customers, regardless of any job title.

 

[Defiance Machine]

​

Tool Length Measuring​

Within a CNC program there will be “Work offsets” and “Tool offsets”.

Work offset means that wherever you set a part inside the machine you can locate it in all axes, down to .0001” or .001 degrees by electronic probing and it will store that data. When a tool is called up to machine a feature in the existing workpiece, we know exactly where that part is.
Tool offsets compensate for the diameter and length of each tool, which varies as the operator takes out a dull tool and replaces with a new tool. In this video you can see “touch setters” and lasers being used to measure tools. The touch setter senses contact of the tool, backs up and approaches slower for a more precise measurement.

The laser works in similar fashion but uses a laser beam instead.

“Laser”…

When to tools breaks the beam, the receptor senses the disruption. The CNC control will store the data in a tool offset. The laser setter can be used to measure diameter and length, detect broken tools, tool wear, chipped flutes, etc.

Because we know exactly where the part is (work offset) and exactly the diameter and length of the tool, we can program features to be machined and expect exact results. This automation allows operators to load new tools and new parts without “manual” tool setting and part locating.

More efficient and more precise.

 

[Baron23]

​

Tool Length Measuring​

Within a CNC program there will be “Work offsets” and “Tool offsets”.

Work offset means that wherever you set a part inside the machine you can locate it in all axes, down to .0001” or .001 degrees by electronic probing and it will store that data. When a tool is called up to machine a feature in the existing workpiece, we know exactly where that part is.
Tool offsets compensate for the diameter and length of each tool, which varies as the operator takes out a dull tool and replaces with a new tool. In this video you can see “touch setters” and lasers being used to measure tools. The touch setter senses contact of the tool, backs up and approaches slower for a more precise measurement.

The laser works in similar fashion but uses a laser beam instead.

“Laser”…

When to tools breaks the beam, the receptor senses the disruption. The CNC control will store the data in a tool offset. The laser setter can be used to measure diameter and length, detect broken tools, tool wear, chipped flutes, etc.

Because we know exactly where the part is (work offset) and exactly the diameter and length of the tool, we can program features to be machined and expect exact results. This automation allows operators to load new tools and new parts without “manual” tool setting and part locating.

More efficient and more precise.

Love this series.

Got a BA spun by Ern at Altus in May w a Deviant action and I’m loving it. Only have 200 rounds on it and it’s smoothed out wonderfully and feeds and ejects consistently. All in all, I’m very happy w this action from Defiance.

Hope you continue this series. Very educational for a fella like myself.

 

[kyzim311]

So I am curious why you measure your tools in the machine vs presetting them ahead and not messing with offsets (or at least minimizing them). Is it just a number of tools and machines thing? There are also major cost implications for a presetter, but they can pay for themselves fairly quickly in terms of machine runtime. Or maybe you have found the in machine measurement systems more accurate and reliable?

 

[Mike at Defiance]

So I am curious why you measure your tools in the machine vs presetting them ahead and not messing with offsets (or at least minimizing them). Is it just a number of tools and machines thing? There are also major cost implications for a presetter, but they can pay for themselves fairly quickly in terms of machine runtime. Or maybe you have found the in machine measurement systems more accurate and reliable?

That's a great point! We have a Zoller pre-setter and use it too. I should have included it in the video, but I'm keeping them down to one minute. We have been using the touch setters and lasers since day one and added the Zoller more recently. The Zoller is very accurate and is the only way to go in some applications. The laser and touch setters are also very accurate and more convenient for some machines. The pre-setter is definitely a great addition and we will continue to incorporate its usage throughout the shop. Thanks for your input.

 

[Defiance Machine]

What does it take to work at Defiance?​

This is a great question. One might think we would require a certain number of years of experience, or a degree to work here, but that is not always the case. Our great team certainly has some folks with lots of experience. Some employees have degrees, and those may or may not be in machining and manufacturing. We also hire people with little or no experience to train on the job and have had great success.

So, it might seem like we are inconsistent. But what I didn’t mention we look for is character, personality, aptitude, and work ethic. We consistently hire for these traits. We can train somebody to operate a CNC machine or assemble bolt actions. But these aforementioned core values are the foundation of each successful employee. When we find someone that seems like a good fit to the team, we generally don’t pass them by. They could end up working out in the CNC shop, shipping & receiving, or sales.

We have been fortunate to have increasing demand for our products year after year, giving us the ability to keep growing and our shop is getting filled up with high end CNC equipment. We are always looking for good people, the right people, to keep it all running.