Machine Shop Management, Machinist Tips and Tricks

Deciphering M CODES for Your CNC Machine

Recently we have been working with some Kipware® conversational clients assisting them in setting up their Kipware® post processor blocks for their G code output. With the addition of our EIA MENU option … users now have greater flexibility in using machine functions ( M ) functions in their G code to accomplish specific tasks. One example might be … parts catcher UP or DOWN to catch a part being parted-off … or chuck OPEN and CLOSE during a bar feed operation … or 4th axis CLAMP and UNCLAMP for CNC mill.

During these sessions we are coming across the situation where the end user doesn’t know the specific M for their machine to accomplish some of these tasks. And for whatever reason … manuals lost or misplaced … machine was purchased used and no manuals were included … or whatever … the end user does not have any Operator or Programmer manuals for their machine which would normally outline the M codes and their function. Without the manuals … they have no way of finding out what M functions control what. OR DO THEY ??

Let’s start this journey with a brief explanation of the HOW’s and WHY’s of CNC M functions. 

  1. First … there is no “industry” standard for M functions. Although you might find that M08 and M09 or M03 and M04 work for most CNC machines … there is not an industry standard that says they must meet a certain criteria.
  2. M functions are designed by the machine tool builder … not the control manufacturer. So you may have (5) Fanuc controlled machines in your shop … some Mori Seiki’s some Hitachi some Leadwell … all with different M functions. Because the M function circuits are designed by the machine tool builder and not Fanuc.

With those basic facts … when you ask your buddy “What’s the M function to open the chuck?” … and he says “M11” … and it doesn’t work on your machine … now you know why.

So how can you find out the M functions for your machine WITHOUT an Operators or Programming manual?

One of the best ways is to use either the electrical or ladder diagram for the machine. Although most Operator or Programming manuals get lost along the way … mostly because they are not kept with the machine but rather float around the office or shop … electrical diagrams ( which outline the electrical circuitry of the machine ) and ladder diagrams ( which outline the logic of the machine ) are most often kept inside the machines electrical cabinet. Open up the doors and you will usually find one or the other or both.

Even if you’re not electrical savvy … the circuits are pretty clearly labelled and you can find say the CHUCK OPEN circuit and trace things back to find the appropriate M function. Again … because they are built and designed by the machine tool builder and their electrical outline is outside the realm of the control … these circuits are contained in the machines electrical documentation … not the docs for the control.

electrical_circuit_pic

electrical_circuit_zoom_pic

Above is a pic of an electrical diagram for a Shizuoka CNC vertical mill … with an exploded view on the bottom. You can see fairly easily even without any electrical savvy that the M10 command will control the 4th axis clamping function. 

With today’s more sophisticated controls … oftentimes the ladder diagram is available directly on the machine controls CRT. You can pull up the ladder and even search for the appropriate function command … but in other cases the “old fashioned” printed ladder can also usually be found in the machines electrical cabinet.

Taking a look at either the electrical diagram or ladder will usually result in some additional road or path to travel to find the appropriate M function on your machine. A simple execution of an MDI command is a good test to see what happens. The old Trial and Error method will open up additional doors or produce the desired results.

M functions are powerful options on your CNC machine that can help automate many tasks and make your manufacturing more efficient. Know that you know the trick to discovering the M functions on your CNC machine … why not peruse your electrical or ladder diagram and see if there are any you might be missing in your programming?

Like what you see?
Please visit us at www.KentechInc.com

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management

Guidelines for Calculating Machine HOURLY RATE

We tout this fact all the time in our marketing … at Kentech Inc. we are MACHINISTS … we cut chips, we programmed, we ran shop floors for years … then we became software engineers and designers and built software products we saw were lacking during those years. What we refer to as Real World Machine Shop Software. 

As a result, many of our clients come to us to take advantage of that experience … especially those just starting out. Since quoting and estimating is one of the first tasks a new shop needs to get right … we get asked quite a lot of questions about these areas. Our KipwareCYC® ( machining cycletime estimating software ) and KipwareQTE® ( cost estimating / quoting software ) titles are two of our most popular titles. One of the “hot” topics we encounter during online presentations of these titles is often concerning the cost to charge for a machining or a shop rate. So we thought it was a good time to add a blog post with some guidelines we feel are simple enough … but important enough … that can get you to an accurate figure.

Since many shops will utilize an hourly rate as a basis for charging for machining time, this post is dedicated to some helpful guidelines on how to calculate that machining hourly rate. Below are some points we consider important when calculating the hourly rate for a particular machine. The areas requiring calculations include :

Equipment – Cost Per Hour of Operation … a common formula : (machine purchase cost + expected lifetime maintenance cost) / expected hours of operating life.

Direct Labor Cost per Hour … a common formula : (total annual labor costs + taxes + benefits + paid time off) / (total annual hours worked – breaks and training time)

Overhead Cost Per Hour  : Any costs not directly involved in machining a part is overhead. These include costs for administrative staff salary, equipment, furniture, building lease, maintenance and office supplies. Calculate the annual costs of these, then divide by total labor or machine hours for the year. This will be your overhead cost per hour

Once the above costs are calculated … you can use the formulas and guidelines below to arrive at either a “general” shop hourly rate or an hourly rate based on a specific piece of equipment.

General Machine Shop Hourly Rate … a common formula : Average overall shop rate = (average machine cost per hour + labor and overhead cost per hour) x markup

Machine Specific Hourly Rate … a common formula : (specific machine(s) cost per hour + labor + overhead cost per hour) x markup

Somewhat simplified … and usually a work in progress as factors may change. It is important to gather all the figures in the formulas above as best you can … as accurate as you can … and to keep tabs on any factors that may change along the way.

Estimating

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management

Shop Efficiency Series Part 6 : Gauging Your Shop’s Efficiency with the Magnificent 7

We have dedicated a lot of time and brought out a lot of ideas in our Shop Efficiency series … but most have been based “on the shop floor” and have targeted machining … set-up … and tooling. Quite a few clients have written us to ask about the business side … more of the “How do I actually know if my shop is efficient” … which is a great question. So in this post we turn our attention to the shop management and specifically ways of gauging your shop efficiency.

magnificent_seven

I have listed a few of what I consider critical areas in this Shop Efficiency post … one’s that I feel are among the easiest to gauge and important to watch … what I call the Magnificent Seven. The points below are not in the order of most importance … just simply a list of all the metrics. Creating a spreadsheet and taking a daily count with most of these factors will allow you to see the results as they happen … and over time will reveal the ups and downs of the shop in general … and allow you to make corrections. You can start your journey on the first of the month … for example … and take a few minutes every day or every week to fill in the numbers … building the information in the spreadsheet as you go along. Make a graph … and watch what these factors will reveal. If you stick with it … you will be shocked … maybe happily … maybe not.

(1) Revenue Per Man Hour

Revenue per Man-hour is the annual revenue ( or do it by month ) divided by the total paid man-hours, including paid vacations and overtime. Keeping a running total of these activities and although this is a general look at the numbers … it can be very telling.

(2) Lead Time

Customer Order Lead Time includes order-entry through production to shipment for every job. Again, start a running list from the first of the month and carry on. This stat will reveal your shop efficiency as well as give you a chance to look at the quantity of work going through the shop … and the time frame it takes to go from order received to revenue received.

(3) Labor Turnover

quittingLabor Turnover Rate is the number of voluntary and involuntary separations divided by the typical number of employees. Hopefully you won’t be keeping a monthly log of this stat … but keeping a log of the turnover rate will still yield a telling tale. Although this stat has it’s own revelation … it also shows one key point regarding efficiency. When an employee leaves a company ( for any reason ) he / she also takes a piece of that company’s memory and experiences with them. That loss of memory or experience can lead to efficiency and productivity loss. A company that experiences high turnover rates needs to find ways to insure that experiences and memory don’t leave the building along with the employee. A low labor turnover rate … as the inverse … helps achieve and maintain high performance, productivity and efficiency.

(4) Completion Rate

This factor can be described as the On-Time Completion Rate. It is the percentage of goods delivered on time. This is … obviously … a direct result of shop efficiency. Keep a log for every job going through the shop and how it fared in the On-Time Completion Rate.

(5) Scrap and Rework

scrap

This factor is the Scrap and Rework as a percentage of shop sales. Scrap and rework cost time and money. Some scrap and even some rework is inevitable … but this factor may be most useful as an indicator of how well things are going out on the shop floor. An high scrap and rework percentage is an early tip-off that something … or someone … needs a deeper look.

(6) Machine Uptime

Total Machine Uptime is the hours of production as a percentage of the total operating hours for the shop per week. In other words, what percentage of an average shift are each of your shop’s machines running. Basically put … your employees get paid every day whether they are productive or not … idle machines are not making that money even though the employees are getting paid. Therefore, how much a machine is up and running becomes an important factor for determining just how productive and profitable that shop is.

(7) Machine Availability

Machine Availability is the time machines are actually available for use compared to the time they are supposed to be available. Unscheduled maintenance or other problems will reduce a machine’s expected availability … and impact production schedules negatively which in turn reduce the ability of a shop to deliver product on time.

There will be some out there that utter the phrase “I know all this just by being out in the shop every day.” And that may be true. But seeing the numbers on “paper” ( it might be your computer screen ) is much more telling … and much more emphatic … and makes the point much more clearer.

So … there you have it … the Magnificent Seven. Keeping a close eye on these factors or metrics will most definitely put your shop’s efficiency in glaring focus … and will most likely open your eyes and mind to whole list of other metrics that may be pertinent to your particular shop and operation. Taking the time to develop and review your information as it develops will prove to be more than worth the effort … and keeping the faith will insure your shop is on the straight and steady track.

Estimating

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management, Machinist Tips and Tricks

Shop Efficiency Series Part 5 : Multi-Function Tools

Multi-function tools have been around for quite a while but oftentimes are overlooked for a variety of reasons ranging from lack of understanding to shop inventory. But the truth is that in many situations, multi-function tools can be a key to reduced cycletime … more efficient machining … better workflow … and that ultimate prize … increased shop efficiency.

In this installment of our Shop Efficiency Series … will take a quick look at some of the more common multi-functions tools … outline some of their features and benefits … to hopefully bring about a better understanding and start that “machinist mind” thinking about how these types of tools might be able to benefit your particular shop efficiency.

Milling : Multi-Function End Mill
Multi-function end mills are designed with two main features … low cutting resistance and good chip evacuation when center cutting / drilling and milling at an angle. These two features give these tools the ability to perform both drilling and milling … which makes them an indispensable part of your tooling inventory. Imagine being able to select either plunge milling or side milling when machining … or employing a combination of both because the tool has that capability. The image below gives the whole range of machining op’s that are available with this tool type … it illustrates well their flexibility and capability … and speaks volumes about why they should be one of your go-to tools. As you can see there are a variety of operations where they can make an impact.

endmill_1

Additional Information / Recommendation :

Tool Name / Manufacturer : Kyocera MEY – Ultra Drill Mill
Catalog / Brochure Link :
http://global.kyocera.com/prdct/tool/pdf/e-d_mey.pdf

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Milling : Thriller – Drill / C’Sink / Tap
If you have never utilized a combination drill / thread mill … this tools will really blow your mind. Center drilling … drilling … countersinking … thread milling or tapping as means of creating a tapped hole is SOOOO NOT KOOL !! 4 tools combined with the tool changes … stopping and starting … tool costs … etc. … make this method of creating threaded holes simply NOT ACCEPTABLE when discussing shop efficiency. You may have held off on these thinking that they are really for specific types of threaded holes … but the more you look the more they make sense as the go-to-tool .. with tapping and other standard operations as the secondary option. Our favorite tool comes from Emuge Corp. … which also has outstanding field support BTW … and combines drilling, countersinking and thread milling in one tool … quickly illustrated below.

thriller

But rather than yapping about all the benefits …we suggest watching the video link below … it tells the story way better than words.

Additional Information / Recommendation :

Tool Name / Manufacturer : Emuge Corporation – Thriller
Catalog / Brochure Link : http://emuge.com/media-resources/brochures-catalogs/4-fluted-solid-carbide-thrillers

Video Link : https://www.youtube.com/watch?v=OdOfHEzXMMA

Video Link : https://vimeo.com/6245960

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Turning : Groove / Turn Tools

For machining operations that include both turning and grooving … it oftentimes makes sense to combine those operations with one tool. Of course the type of material and type of groove machining play an important role here … but when possible, using a combination groove-turn tool can be very beneficial and efficient. Eliminating the tool change and related non-cutting time can improve cycletime … but the flexibility of the tool opens up a wide variety of machining options as well … beyond just grooving operations.

iscar

As the illustration above shows … machining operations such as PARTING OFF … GROOVING … BACK TURNING … and STANDARD TURNING are all possible with this tool type.

Additional Information / Recommendation :

Tool Name / Manufacturer : ISCAR – Groove-Turn

Catalog / Brochure Link : http://www.iscar.com/eCatalog/Applications.aspx?mapp=TG

Video Link : https://www.youtube.com/watch?v=HXhEtc1zl4w

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 Turning : Boring with an Indexable Drill

In certain non-turning tool applications … it is possible to utilize the same indexable drill used to drill a hole as a boring bar to open up the hole diameter. Benefits of course include decreased cycletime and the use of less tools … but this should be considered carefully and success involves many factors. As stated many times in our blog … we recommend Sandvik tooling quite often … and they have a great online resources that delves into this type of machining and the options to consider before giving it a go in the link below … just click the image to open up their information page :

sandvik

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Of course there are thousands of ways to use standard type tooling as a multi-function tool … and we are sure that your machinist mind has come up with some novel ones along the way. But we felt the need to include at least some of the more “common” options in any conversation about shop efficiency. So there you have it. Some food for thought … and some multi-function tooling options you may not have been aware of or considered.

Estimating

Please come back for our next installment in our series on Shop Efficiency.

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management, Machinist Tips and Tricks

Shop Efficiency Series Part 4 : Re-Thinking Your HEIGHT OFFSET Strategy

As we have been stressing throughout this Shop Efficiency Series … keeping your spindle running and the green cycle light lit is one of the main keys to making money and profits. In Part 4 we’re going to shift our attention back to the VMC and HMC world and send out some thoughts regarding Tool Height Offsets … “touching off” tools … and how to get that inevitable task done quickly, easily and efficiently … so that the spindle stays running and the tools gets in the chip.

Tool breakage or the need to replace dull or ineffective tools can cause huge loss of cutting times and spindle on time. With the implementation of the simple system we outline below … you can insure that replacing or setting up your tools for machining can be done quickly and efficiently with as little disruption to cutting time as possible. There are some initial costs involved … but the ROI is fast and you’ll see the results immediately.

We’ll take you through the Set-Up and Process first to show you how it works … then highlight some of the Features and Benefits that can achieved by utilizing this system. The basic idea is to utilize a MASTER TOOL to set the part Z0 position … and use the HEIGHT OFFSETS to calibrate the distance difference from the MASTER TOOL and EACH CUTTING TOOL. This system leaves us only the MASTER TOOL to re-calibrate for each workpiece … and allows us to leave the cutting tools unchanged no matter what part we’re running. Setting up ONE tool is obviously faster than setting up multiple tools.

What You’ll Need :

  1. Height Gauge … digital gauge will obviously function the best.
  2. Master Tool ( more details below )
  3. Tool Holder Adapter or Setting Fixture

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The Master Tool :

In order to utilize the features of this system, you’ll need to create a MASTER TOOL. What we refer to as a master tool would be a piece of stock, say a piece of turned, ground and polished stock or drill rod loaded and secured into a tool holder. It should be secure in the holder … the best way is with a shoulder butting against the tool holder face so it has a positive stop. Another feature is to make this master tool close to the length of the machine specs longest tool. This way you’ll know that no cutting tool can be longer than this master tool.

Tool Holder Adapter or Setting Fixture :

Once you have created your stable Master Tool … the next stable component should be your setting fixture. With a little thought and work you can turn a standard tool tightening fixture … such as the ones pictured below … into something suitable for this purpose … with the main criteria being the stable repeatability of the tool holder positioning.

fixture_complete

The Process :

On a surface plate, set up your height gauge and tool holder adapter to allow for the measuring of your tools. To measure a tool :

  • Place the MASTER TOOL in the setting fixture and set zero at the top of the master tool.

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  • Place a cutting tool to be measured in the setting fixture and record the reading at the top of the tool’s cutting edge. This is the distance from the master tool tip to the cutting tool tip. This dimension is the value that is to be entered in the machines height offset table for the measured tool.

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  • Repeat the second step above for each tool to be measured, recording the value on the height gauge for each tool.
  • Load the tools in the magazine and enter the measured height offset values from Step #2 above into their respective height offset table positions.
  • Using the MASTER TOOL, touch the Z0 surface of the workpiece and record the value from the home position to the Z0 location. This value should be entered in the Z table for the work offset (G54 – G59) to be used in the program.

That’s it. 

Your program is ready to run. Your program will call up the G54 – G59 work offset or similar and will know the distance from the master tool to the Z0 location. Using the H value call in the program, the machine will calculate the difference between the master tool and the measured tool and adjust as required.

Now that we’ve set the thoughts and ideas in your mind … feel free to deviate and expand on the basics outlined here.

 Some Features and Benefits :

  1. Let’s suppose you’re going to set up a new job next but will utilize some of the tooling from the previous job. The only set-up required is to use the Master Tool to touch the new Z0 surface, changing the value in the work offsets with this new value. Your cutting tools and their height offsets can remain the same. Save time by touching off one tool instead of many.
  2. You can set-up a spare tool or replacement tool off the machine using the master tool and the height gauge … insuring that your spindle will be back in the cut faster.
  3. You can load say a nice cutting carbide mill in the magazine and use it for a variety of different jobs. No need to touch it off all the time, just use the master tool to get your work offset in Z.
  4. Measuring tools becomes easier, allowing more people to assist with the tool setting . Setters don’t need to know how to operate the machine.

From experience, once you try this method you’ll find it saves you all kinds of time. The best advantage is being able to call out set tools that stay in the magazine. This really speeds up the set-up and changeover process.

Stay tuned for more posts in our Shop Efficiency Series.
Next up we’ll take a look at MULTI-FUNCTION tools that can perform multiple types of cutting and save your shop a ton of time in the process.

Conversational

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management, Machinist Tips and Tricks

Shop Efficiency Series Part 3 : Re-Thinking Your Lathe Tooling

We’ve always been a big fan of Sandvik Coromant and their tooling … not just because they are a member of the Kipware® family … but we have always found their tooling, inserts, support and design to be cutting edge and of the best quality. On the shop floor … they were our tooling manufacturer of choice and never let us down whether in standard type production or when we were looking for that new and innovative tool to get us through the toughest job or materials.

One of my personal best purchases was in converting our CNC lathe tool turret from standard lathe tooling to the Sandvik CAPTO system. I can compare this transformation to the points I outlined in Part #1 of this Shop Efficiency series … click here to read that article … and the transformation that takes place when you bring your VMC table into the 21st century. A CAPTO system will bring your CNC lathe turret into the 21st century.

First – What is CAPTO?

capto_1

The CAPTO system is basically a quick-change, modular tooling system for CNC lathes and turning centers. Instead of mounting tooling directly into the turret … tools are mounted to quick-change clamping units that are mounted onto the turret. Tools are then easily interchanged by simply changing the “head” mounted onto the clamping unit. Need to change from an 80 degree turning tool to a 55 degree … just simple swap the “head”. Need to change from a .750 insert drill to a 1.250 … simply change the “head”. For live tool turning centers … need to change from a 1″ drill to a face mill … simply change the “head”.

Second – Why Use CAPTO?

This type of modular tooling system comes with tons of advantages. Here are just a few of the more important ones pertaining to the Shop Efficiency factors which are the main focus of this series.

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  • Quick tool change which keeps the spindle running and the machine making chips / money. Not only in changing the complete tool type … but insert changes can take place off-line while the head is replaced at the turret involving less time than an insert change.
  • Greatly reduced set-up and changeover times because of the cutting edge repeatability when re-mounted in the clamping unit.
  • Greater tool stability leads to improved cutting and cycletimes.
  • Greater flexibility in tool selection and tool type.
  • Same tooling can be used throughout the shop … reduced tooling costs and inventory.
  • Greater options for through-tool coolant delivery … again, improved cutting and cycletimes.
  • Turning Centers with Live Tools can see the biggest impact. By simply swapping heads that tool station can go from a face mill to a drill to an end mill in seconds. With greater repeatability meaning less set-up / touch off times. In addition … turning that face mill station into a turning tool station can also be accomplished … quickly and easily.

I could go on and on … but I’m sure you’re machinist mind sees the point.

Third – Cost vs Features

capto_3

Like anything in life … the system does require an initial investment. How much can be spread out over time as you integrate the system into the machine and the shop over time. I will say from experience that the long term savings are there … in quicker change overs, increased cycletimes and reduced tooling inventory … especially if you integrate the system into multiple machines. The beauty part here is that once you have the clamping units on all your machines … all machine will now utilize the same tooling. That is a huge advantage including reduced tooling costs and inventory all around.

Conversational

RESULT – Increased Shop Efficiency

As you can see from the points outlined here … there are a ton of features that can lead your CNC turning department to increased shop floor efficiency with the transformation through a CAPTO system. By integrating the system into your shop bit by bit you can defer the initial investment a bit and still reap the long term advantages and savings as you build the system into your shop floor. From faster insert changes … to faster tool change-overs … to faster set-up … to improved cutting and cycletimes … your shop floor can certainly reap improved shop efficiency with a CAPTO system.

LINKS for ADDITIONAL INFORMATION 

  1. For a more in-depth look … take a peek at the Sandvik Coromant video by CLICKING HERE.
  2. For more information on CAPTO in general … download the informational PDF by CLICKING HERE

Please come back for our next installment in our series on Shop Efficiency. Until next time … Happy Chip Making !!

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management, Machinist Tips and Tricks

Shop Efficiency Series Part 2 : The Infamous MILLING Vise !!

Part 2 in our Shop Efficiency Series will expand a little on Part 1 … and key in on one of the most common workholding options used in the milling world … the vise. Some of the ideas we will present might be old hat for the more professionals in the group … but it’s never a bad idea to refresh and re-look at this subject. For me … something new always clicked when I looked at my vise set-up or holding configuration. Ideas usually led to different set-up ideas … how to position the vise or vises … as well as jaw ideas … material, change-over and others. So we thought it was a good plan to outline some of the newer options available … and to get your idea machine cranked up.

FIRST – DUMP the knee mill vise !!

We still see a lot of shops using an old style knee mill vise … or some revised configuration of one … on their new and modern CNC machine. Ya … you know the ones ….

old_vises

If these look all too familiar to you … the first step in improving your workholding and basically your whole shop floor efficiency is to dump these vises and step up to today. Sure in a pinch … they are OK … but you should really think about putting ’em on Ebay and stick some “hobby machinist” ( whatever the hell that is ) with these toys. If you have a CNC machine and want to be a pro … here are your new alternatives.

new_vises

Here a just couple of important reasons to dump your 1950’s vise for a new CNC vise :

  1. SIZE and SPACE : Without the “wings” sticking our from the sides, these types of vises are slimmer and trimmer ( not to mention lighter ) and will take up less room on your table or fixture plate. That allows for more efficient use of your machine travels and table capacity.
  2. MULTI PART MACHINING : configurations can include double vise jaws … again, multiple part machining. The whole concept of efficiency is to perform the most machining while the tool is in the spindle. That may entail multiples of the same part or combining different parts during the tools cycle.
  3. QUICK CLAMP : The ever present annoyance of rapping your fingers while turning the handle to clamp can also easily be eliminated by incorporating a power clamping system such as a pneumatic wrench instead of the handle … or if you want to “crank it up a notch” … check out the CHIC video below :

SECOND – Jaws for the Modern World

Now that you have upgraded the vise itself … it’s time to incorporate new holding options into the vise. Almost every shop with a CNC vise uses some sort of aluminum vise jaw that has been machined to accept the stock to be machined. It’s a basic … it’s a staple … if you don’t do it it’s time to step into the 70’s.

So the most basic step is to create a CNC program that will machine a blank aluminum vise jaw to fit your CNC vise. That way anytime you need some jaws … call up that proven program and machine some jaws for stock … or keep some on the shelf. Done.

But hold on … now there’s an even better method. We have talked about these jaws before in Making Chips and we are high on their use and rewards. No cap screws … 2 min changeover … and tons of configurations make quick change vise jaws the new go-to vise jaws. Here’s a sample video from Carvesmart … one of our favorites :

THIRD – Don’t forget the TABLE

Part 1 in our series dealt with how to bring your VMC machine table into the 21st century. Combining your new table configuration with these new vise and jaw options can really expand your efficiency. This is a really important read … if you missed that post … here’s the link : http://kentechinc.biz/shop-efficiency-series-part-1-cycletime-vs-workholding/

FOURTH – Don’t forget to MOVE THAT VISE !!

Always placing the vise so it looks nice in the middle of the table causes a lot more harm than you might think. Here’s a past Making Chips post dealing with that subject in detail … http://kentechinc.biz/move-that-vise/ … required reading if you use a vise ( and seriously, who doesn’t ?? ).

RESULT – New Shop Floor Efficiency … with the sky as the limit.

As you can see … these are some fairly simple but really important changes that will greatly effect your shop floor efficiency. From faster set-up changeovers … to more advanced configurations … to faster part load / unload … to simply better cycletimes … these tried and proven changes mean more profits … a happier workforce … with the sky as the limit. We are also confident that as you implement these changes … your “machinist” mind will think of even bigger and better changes now able to be implemented with the upgrades that come with the ones outlined here.

Estimating

Please come back for our next installment in our series on Shop Efficiency.  Until next time … Happy Chip Making !!

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management, Machinist Tips and Tricks

Shop Efficiency Series Part 1 : Cycletime VS Workholding

2 Comments

It’s the age old manufacturing quest … how to reduce the cycletime and machine parts faster. And although cycletime is a major factor in the making profits equation … concentrating too much on cycletime can sometimes make you miss the bigger problems … the bigger deficiencies in the shop … the bigger money wasting issues. While you are trying to shave seconds off the machining … the time your machine spends not running is hands down a much bigger problem. Any machine not cutting is burning money and profits. It’s easy to focus attention on cutting speeds and feeds … it’s a fairly obvious item especially for non-professional metalworkers. The fact is, however, every second or even minute you shave off the cycletime is probably no match for the large quantity of time you’re machine spends not machining.

What is the BIGGEST cause of your machine not cutting chips ??

The biggest contributing factor for shop machines not cutting chips and therefore making money (  other than not having work for the machines ) are primarily load / unload operations and changeover of the machine from one job to another.

money_burning

We are starting a new series here in our CNC MACHINIST BLOG to deal with these biggest money wasting areas in almost every shop … fixturing and workholding. Whether it’s the time needed to changeover the machine from one job to another … or the time required to load and unload the part … non-machining time is the biggest profit killer in any shop.

To start things out … I would invite you to take a walk out to your shop floor … and count the number of machines that are running? … how many IN-CYCLE lights are lit? I am betting you will be amazed at what you find. And if you look deeper into why the machine is not running … the reasons can usually be classified into two categories. The machine is being set-up to run production … or the workpiece is being loaded for machining.

Everywhere people are jumping on the “lean” manufacturing bandwagon … as they should … and striving to achieve the 80%-85% percent “in the cut” time target. The fact of the matter is that lean manufacturing goes well beyond just direct chip making. The time spent … or lost … in changeover or part loading / unloading … is probably a bigger profit losing factor than the time the tool spends in the cut.

This series will pull from our shop floor experiences to talk about the various areas of workholding for both milling and turning and machine / fixture changeover … two topics that are certainly inter-connected. We will publish new articles interspersed with our other topics of interest … so we invite you to check back frequently and keep up with the discussion.

Series Topic #1 :

Bringing The VMC Machine Table
Into the 21st Century

If you take a look at the table on your new VMC … and compare it to the table on a 1940’s milling machine … you’ll quickly notice that not much has changed. T-SLOTS, T-SLOTS and more T-SLOTS. Not much has changed in the design of the milling machine table since around 1940 … and that’s our first issue to tackle.

vmc_table_1

While no one will deny that the T-SLOT is an essential element in the table design … in today’s day and age we really need to think outside the box … or in this case outside the T-SLOT. A couple flaws enhanced by relying on the T-SLOT design include not utilizing all of the space available in the Y axis … and not having the flexibility of positioning fixturing anywhere on the table to maximize the whole table surface. The first step in accomplishing this is to change the table surface.

One way of altering the surface of the machine table is to use a sub-table … made from aluminum tooling plate or other suitable material. The main criteria is that the material is durable … while being fairly easy to machine because we will want to machine a variety of locating options into the sub-table. The two biggest advantages with a sub-table as mentioned above is that we now have the freedom to machine locating components to accommodate a wide variety of fixturing … we can more easily utilize all the area of the table surface … and we can always remove the sub-table and go back to the original table configuration if required.

vmc_table_2 Some of the major points for consideration when considering a sub-table and it’s design :

  1. Material : durable yet fairly easy to machine … aluminum tooling plate is one recommendation.
  2. Size : it should cover the majority of the table … thickness should be kept to a minimum as to not reduce the Z axis travels by an unreasonable amount … but thick enough to accommodate our locating components and maintain rigidity.
  3. Weight : aluminum will keep the weight down … but lifting components should be included in the event the sub-table needs to be removed or re-installed.
  4. Locating the sub-table can either be done with keys machined into the bottom surface or with the use of locating pins and dowels that can be used in conjunction with the original table T-SLOTS.locating_pin
  5. Once the table is installed … it may be necessary to skim the top surface to insure it’s parallelism with the machine axis. Keep this in mind when determining the size of the plate and the travels of the machine to allow for this type of machining. Periodically … this may have to be repeated if excessive wear of the table surface occurs. Also make sure to account for this when selecting and installing your locating components … which will most likely be hardened materials and not easily machined … and will need to be installed below the top surface of the sub-table.

Best Ways to Utilize Your New Table Surface

Now that you have transformed your table surface into a 21st century table … how can you get the most out of it? That really is only limited now by your imagination and design capabilities … but here  we will tackle what we would consider the top option.

fixt_2

Our recommendation … we have used this system extensively … is to utilize fixture plates located and clamped by a “ball lock” system. Fixture plates should be used for everything mounted to the sub-table … from a simple vise to multiple vises to dedicated fixturing. This allows for greater flexibility for positioning of workholding components and allows for quick changeover to other workholding components.

ball_lock1

The ball-lock system allows for quick and accurate positioning of the fixture plates to the sub-table. When designing the sub-table surface … create as many ball-lock receiver positions as possible to allow for multiple positioning options for your various fixture plate assemblies. You can machine and install these receivers prior to mounting the sub-table … but they can also be machined in place as their need arises.

fixt_1

Fixture plates can also be made from the same aluminum tooling plate material used for the sub-table. They should, of course, be quite thinner for weight considerations and should always include some kind of lifting component. Handles, as the ones included in the illustration, may need to be removable with a quick attachment mechanisms to reduce their interference in the machining motions.

If you have an HMC … you can take the same lessons learnt here and apply them to your tombstone or angle plate. Rather than using the standard “vise tombstone” … a tombstone which utilizes fixture plates can open up new possibilities for your HMC as well.

hmc_complete

Changeover Advantages

As mentioned above, the cycle start light goes out and the profit stops flowing when the machine is being changed over from one job to the next. The system described above can have a massive impact in reducing that downtime. Take for example the simplest task of working with a vise. To remove the  the vise … just un-clamp the plate with the vise and remove it. When re-installing it … just lock the plate with the ball-lock system … no tramming … no indicating … no center locating. The ball lock system locates the vise in a known position in seconds every time.

The same applies for all your fixtures … they mount in seconds in known positions. Fixture design will also be improved because the know facets of the fixture plate location and much of the needed configuration is pre-determined. With pre-set variables in place … your engineering mind will run rampant and you’ll be exploring many more time and money saving options as you go down the road.

Seems Like a Lot of Work and Expense

The above statement is true …  but it’s not easy to get from 1940 to the 21st century. The fact is that once you have completed the transformation … the possibilities for added efficiency are endless and the reduction of lost machining time will be fantastic … the payback and ROI will be fast. You will have new flexibility to :

  1.  Utilize more of the machine table and Y axis available stroke … more chip making means more profit.
  2. Quickly and easily mount your fixture plates making for faster changeovers … which means more time cutting chips … and making money.
  3. Have new capabilities to mount multiple jobs with multiple fixture types … easily run more than one job at a time.
  4. If utilizing a 4th axis … the new table design will give you more positioning options and result in faster mounting and removal of the 4th axis table.

Final Thoughts and What’s Next

As you can see from some of the ideas outlined here, changing the surface design of your machining center’s table can have quite an impact. While everyone is concerned with shaving seconds of the chip making … shaving hours off your set-up’s and changeovers will have an even greater impact on your bottom line. We hope that some of the ideas outlined here spur on your engineering juices allowing you to realize even more efficient fixture designs and ideas.

Make sure to return and check out other articles in this Series that will deal with fixturing and workholding … for both turning and milling. We’ll touch on things like vises … face drivers for turning … chucks and chuck workholding … and much more.

After all … we’re MACHINISTS … WE BUILD THINGS !!

At Kentech Inc. we are MACHINISTS who create Real World Machine Shop Software. Who creates the machine shop software guiding your shop’s future ?? 

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Check out all our REAL WORLD CNC & MACHINE SHOP titles at  www.KentechInc.com

Kenney Skonieczny – President
Kentech Inc.

Machine Shop Management, Machinist Tips and Tricks

Product Spotlight : ID Clamps from Carr Lane Manufacturing

Every once in a while we like to bring attention for our readers to new and innovative machining and workholding products and process that we feel are beneficial to our readers. Such is the case in the Making Chips post as we focus and bring attention to a new workholding clamp from Carr Lane Manufacturing – a leading supplier of workholding and fixture components.

Additional information and specs on the Carr Lane ID Clamps are available on their website through this link : CARR LANE MANUFACTURING

Carr Lane ID Clamps – A Brief Outline

id_clamps

Many of you will undoubtedly be familiar with expanding mandrels … most commonly used to grip on the ID when turning on the OD. The new Carr Lane ID CLAMPS bring that concept to locating and workholding for milling fixtures. As the image illustrates … the ID CLAMP is similar to the expanding mandrel technique where the id CLAMP expands and clamps on the ID of a workpiece, leaving the outside free for machining.  Tightening the tapered center screw with a hex wrench pushes the clamping segments outward, and slightly downward, to exert force on the workpiece’s internal bore. These clamps are designed to have their outside diameter finish machined by the customer to suit the bore size, because maximum diameter expansion is limited.

The flange diameter on the ID CLAMP is a machined to a close tolerance … which allows for maximum locational accuracy. A recess can be machined in the fixture base to fit exactly with the clamp’s close-tolerance flange diameter and the ID CLAMP can be mounted using flat-head mounting screws.
id_clamps2

In the image above … you can see how the larger ID is used for locating as well as clamping … and a smaller ID CLAMP is used in the slot to provide additional locating and holding force. With this type of set-up, the entire outside contour is available for machining.

This set-up also illustrates the fact that these ID clamps need not be confined to round holes … they can be utilized in almost an unlimited number of ID clamping roles … use that machinist mind and explore !!

Estimating

We are always on the look-out for new and innovative machining processes … techniques …. and workholding tips. If you see one which you think would be of interest to our followers of professional machinists and engineers … please drop us a line at Sales at KentechInc.com.

Until next time … Happy Chip Making !!

www.KentechInc.com

At Kentech Inc. we are MACHINISTS who create Real World Machine Shop Software.

Who creates the machine shop software guiding your shop’s future ??

Machine Shop Management, Machinist Tips and Tricks

CNC Lathe Headstock – Alignment Checks and Adjustments

We’ve all been there … Crashville. It’s not a place you want to visit frequently … but inevitably, we all make a visit. When I first started in CNC, one of my mentors told me “If you don’t bump it once in a while … you’re not experimenting … not trying new approaches … and not using it to it’s full potential.” Well … I’m not sure about that but there is a little truth in the concept.

Once you visit Crashville, you may notice some cutting errors and quirks developing in your workpieces. In this post we will be dealing with some of those unintended consequences of your visit to Crashville.

The first … tapers developing on your CNC lathe when turning or boring … the result of your headstock being bumped and not being square to the X axis ways. The result is that as the turret rides on the machine axis ways … and the headstock and ways are not “square” … you will be machining a taper. The amount of taper is the result of the amount of the mis-match between the headstock and the ways. It’s important to remember that the ways ( base ) of the machine and the headstock are not one-piece ( normally ) … the headstock is bolted onto the base. The illustrations below will give you a better idea.

Lathe-Design

So in our first post in our series … we would like to point you in the right direction and give some tips on re-aligning your headstock.

As the above pic and notes convey, the headstock is normally bolted onto the machine base … making the X / Z ways and the headstock independent of each other. Normally … there are alignment screws on the headstock assembly that allow you to move the headstock and thus align it “square” to the machine ways. When you visit Crashville … oftentimes one of those un-intended consequences is that that alignment is off because the headstock may have moved. So how do you get the correct alignment back?

There are a couple of methods … let’s start with my favorite … the one I consider the simplest and the one I used most in the field.

Conversational

First … you’ll need a piece of stock. Qualifications? You need a good material, easy to machine yet with the ability to produce a good finish. I didn’t like using aluminum … I preferred some grade of steel like cold rolled or similar. We want to insure that everything we do is reflected in the material … not the workholding. So it’s best to use hard jaws on the chuck … and you want to make certain that the chucked material is not flexing … so the material diameter to overhang factor should be appropriate to insure that the material isn’t flexing when you’re cutting. You also want to have a good length sticking out of the chuck … after all the longer the area to measure the better your readings and the better your adjustments. Yes … there are a lot of factors to consider here … but you’re a machinist !!! You know what to do and what is appropriate.

It’s important to note here also what may be obvious … don’t use the tailstock. We don’t want any mis-alignment in the tailstock to reflect in our measurements.

Next … chuck up the material and clean up the stock by cutting the material the entire length. Take whatever cuts you need to clean up the stock … just make sure the last cut is a nice finish cut and leaves a nice finish. Usually using MDI or the job / feed manual options are the best method. Creating a program is a little overkill and using the handwheel may result in an uneven cut and finish.

Now measure the diameter at the furthest and closest points to the chuck along the turned diameter. Not the same? That’s the reflection of your headstock mis-alignment.

tip_image

To adjust … you’ll need to find those adjusting screws on the headstock … the above illustration might shed some light on where they might be and how they work. You will need to slightly crack the bolts holding down the headstock body to it’s base … then use the adjusting screws to move it in the direction you feel you need to move it to re-align it. Tighten everything back up … and take another skim cut on the material. Repeat and re-adjust as necessary until the results are to your satisfaction. What should that be? As close as you can get it. If the material length in the chuck is short … it really needs to be spot on because obviously the error will get magnified on a longer piece of material. As with everything you do as a professional machinist … do it to the best of your ability.

One valuable hint : Place an indicator somewhere on the headstock to measure the amount you move the headstock with the adjusting screws. This will help you understand the relationship between the amount of movement with the amount of taper correction.

Another method which some people prefer … instead of using a piece of stock and turning the diameter … they will use a test bar. A test bar is a piece of stock that has already been machined and usually ground … it’s perfectly straight and true. They mount it in the chuck … indicate it in … and then use an indicator mounted to the turret which they then run back and forth along the test bar in Z as they adjust the screws on the headstock. This method works fine also … but you need a qualified test bar to start … and there are more variables that come into play. Is the bar indicated in and running true? Is your indicator on the turret reflecting the actual center of the test bar … etc.. For my liking … too many other variables … and a piece of stock is simpler, more readily available and cheaper.

So as you can see … this repair is not that hard … a little time consuming … but the result will leave you with a more accurate machine tool and a lot more money in your pocket … the amount you’ll save in a repair bill.

Hope this helps you recover from your inevitable visit to Crashville … and insures you are good chips … for years to come !!

Thanks in advance to everyone … and Happy Chip Making !!

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