Tuesday, September 29, 2020

Dotco Die Grinders | Guide to Inline Die Grinder Selection

 Dotco Die Grinder Guide Part #2 | Inline Die Grinder Selection by Application and Usage

Posted by Mark Schieber on 29th Sep 2020

After 15 years in the pneumatic tool business, we get asked a lot about the best brands of pneumatic grinders. While we represent many world class air tool manufacturers, the grinders that seem to hang on the longest are made by Dotco. In fact, we call on a foundry in San Diego that still has Dotco and Cleco grinders on their floor that were made in the 80's and 90's. It's hard to distinguish the exact year they were produced because the engraved serial numbers have worn off the housings from so many years of intensive use. This is due to the fact that this particular customer grinds highly abrasive aluminum castings, two shifts a day, 6 days a week. We attribute the longevity of Dotco tools to their advanced engineering, tight manufacturing tolerance, and use of premium materials throughout. Furthermore, Dotco Air Tools are still made in the USA.

In this guide to Dotco die grinders, we help you choose the best tool for the job at hand... The die grinders are organized by their horsepower rating and suggested use. Please note that due to the recent re-branding of the Dotco and Cleco brands of air tools, we use these names interchangeably throughout the guide. All the tools in this guide are of the rotary vane variety and each is designed for intensive production or heavy maintenance use. The Dotco grinders that follow are designed to be rebuilt over and over again, as opposed to tossed in the landfill at the first sign of trouble. They are expensive, but worth every penny if you depend on these tools to make a living.

The grinders below are shown with 200 series or 300 series collets. Many of them can be ordered with either style. For a refresher on the difference between the two series of collets, please visit the first blog in this series titled: Dotco Die Grinders Part #1 | Pencil and Precision Grinders. All of the grinders shown below need to be ran at 90 PSI and supplied with adequate air flow as measured in CFM. Many of the tools are offered with front, rear, or side exhaust. Check the specific model number for details. Tools that begin with the number "12" feature the ergonomic composite housing, while those that start with "10" come with a rugged aluminum body.


SECTION #1:

Low Horsepower Dotco Die Grinders for Tool, Die, and Mold Work - Series 12-05, 12-10, and 10-10 - The tools in this section are compact, lightweight, high RPM, and low horsepower. They are designed primarily for finishing work in tight spaces. These tools are built with high quality bearings which makes them rotate concentrically and with very little spindle run out. Most users of these precision style die grinders opt for the higher RPM models in order to obtain the cleanest possible finish on machined surfaces.


0.2 HP Inline Die Grinder for Tool, Die, and Mold Work - 12-05 Series - with Collet Guard 40,000 RPM 0.2 hp (0.15 kW) - 1/4" collet, composite body, 0.7 Lbs. weight, 5.9" length, variable speed throttle, 1/8" NPT air inlet, ergonomic hand rest.

The Dotco 12R0500-36 is the original die and mold grinder which has been continuously refined over the past 60 years. The ergonomic egg shape housing offers great speed control, fits nicely is the palm of the hand, and is comfortable to use over extended periods of time. At less than 6" in length and weighing under half a pound, users will appreciate the tools small footprint. The spindle speed is controlled by a variable RPM dial throttle appropriately located at the rear of the tool and away from the work.

0.3 HP Die Grinders for Detail and Finishing Work - 10-10 Series aluminum body and 12-10 Series composite body - 1/4" collet, RPM's ranging from 12,000 to 34,000, weighs under 1 lb. The aluminum body measures 4.7" in length while the composite tool with its collet guard measures 6 inches. Both series have lever start activation with the safety "kickstand" style throttle.

More of a traditional style die grinder than the 12-05 series above, the 10-10 and 12-10 series are still very light, compact, and well suited to detail work in small spaces. The major difference is that these 0.3 HP tools utilize lever start as opposed to the dial throttle mentioned above. Some operators prefer the lever style throttle because it's easier to stop the motor by just releasing the lever instead of fussing with the dial. Also, with .10 more horsepower, the ai motor and housing are a tad larger than the 12-05 series. Our best seller in this category is the Dotco 10L1080-36 which spins at 30,000 RPM and is great for leaving a clean finish when deburring parts in a machine shop.


SECTION #2:

Mid Horsepower Inline Die Grinders for General Purpose Grinding - 10-20, 12-20, 216, and 236 Series - This is the heart of the Dotco Die Grinder line up! These proven work horses have enough horsepower to take off stock but can double as finishing tools as well.

0.6 HP General Purpose Industrial Inline Die Grinders - 10-20 series aluminum body, 12-20 composite body, 1/4" collet, RPM's ranging from 12,000 to 25,000 RPM, weight equal to 1.4 lbs. or less. Collet style and housing material dictates the overall length, but no model in this series exceeds 6.9" in length. Check specific model numbers for details.

The 0.6 HP Dotco die grinders are the bread and better of fab shops, aerospace plants, sheet metal shops, and general manufacturing facilities worldwide. These tools are great for material removal, maintenance, or pre-finish work. The advantage of the aluminum housing is durability, but perhaps at the expense of comfort. While aluminum die grinder housings hold up to drops better than their composite counterparts, they also transfer cold to the arm of the operator. Composite tools feature an insulated coating over the tools housing which creates a barrier between the air motor and the operators hands. Use these 0.6 HP Dotco die grinders with your favorite 1/4" shank carbide burr. As with all Dotco die grinders, the throttle features a safety lever to prevent activation in the event the tool is accidentally dropped. Our best seller in this series is model 12L2080-01. At 25,000 RPM and 0.6 HP, it is well suited to handle a variety of general purpose applications. It also doesn't exceed the speed ratings of most commonly used accessories.

0.6 and 0.7 HP Heavy Duty "Shipyard Style" Die Grinders for Fast Material Removal and Maximum Durability - 1/4" collet, 18,000 to 25,000 RPM, 3/4" abrasive capacity,  weight =  1.3 lbs., length =  6.3", 1/4" air inlet. Heavy duty cast aluminum housing.

The extra thick advanced alloy housing on these rugged body die grinder make them ideal for use in harsh environments such as steel mills, foundries, and shipyards. These tools are built to take a beating. Both the Cleco 236 Series and The 216 series offer an excellent power to weight ratio and keep operator comfort foremost with available rear, side or front exhaust. This "shipyard style" grinder utilizes a robust 200 series 1/4" collet to hold mounted points or carbide burrs firmly in place. An internal speed controller regulates air flow for added torque, which makes them well suited to rapid metal removal when used in the industries mentioned above.


SECTION #3

High Power to Weight Ratio Grinders for Fast Stock Removal - Series 10-25 and 12-25. These tools are designed to take down welds fast but without crossing the threshold from "die grinder" to two handed horizontal grinder. At nearly 2 lbs., these tools are heavier in the hands of operators, but are designed to take off as much material as possible while still being held in one hand.

0.9 horsepower inline die grinders for fast weld take down in fabrication shops, aerospace, truck and trailer, structural steel and manufacturing plants - 1/4" shank burr capacity, 200 series collet, weight under 2 lbs.,  6.3" to 8" length depending on configuration, 12,000 to 25,000 RPM. Aluminum and composite housings available, front or rear exhaust.

The 10-25 and 12-25 series are the big dogs of the Dotco die grinder line up. Consistent with the rest of the series, the models that start with "10" are equipped with the aluminum housing while those that start with "12" have the more ergonomic composite housing. The safety lever with the "kickstand" is standard on both types of tools as is the robust 200 series collet. While not clearly stated on the Dotco Website, higher horsepower tools require a large amount air air flow to run at their peak performance. A 1 horsepower air tool needs to be used with a minimum 3/8" diameter air hose and paired with air compressor capable of producing at least 20 CFM per tool. If you plan on really digging into the material you are grinding, opt for a "torquier" model such as the 18,000 RPM 10L2582-01.

 

SECTION #4

Light Industrial Die Grinders for General Purpose and Maintenance Use - The MP series grinders were formerly blue in color and known as Master Power. These are Dotco's import-value line and are commonly used for deburring parts and taking down sharp edges on sheet metal.

0.3 HP and 0.5 HP general purpose, medium duty die grinders - A $600 die grinder is not suitable to every crowd and sometimes you just need a tool for intermittent or occasional use. Cleco's answer to this call are models MP4430 (0.3 HP) and MP4458 (0.5 HP). The MP series offers decent entry level tools that are made in Taiwan. The major difference between the industrial grade tools and the MP Series is that the internal components of the MP series are made from cast components that are later machined. In contrast, the industrial grade tools start with purer metals from solid stock, which are precision machined, heat treated, and oftentimes coated. The MP series uses general purpose bearings as opposed to precision beaings. Nevertheless, for the shop who's tools have a tendency to grow legs, or for occasional use only, the MP series is a fine choice.


SECTION #5

Extended Length Inline Die Grinders - Single and Multiple Extensions - Ideal for Reaching into Deep Recesses - Used in Casting Houses and Foundries -  Series 10-11, 12-11, and 12-26 - Offered standard with 3" or 5" extensions. Some models can be customized to obtain up to a 36" reach.



0.3 and 0.9 HP extended length die grinders - 1/4" Collet for carbide burrs or 3/8"-24 threaded spindle for use with mounted points (select models), 18,000 to 28,000 RPM, composite or aluminum body, accessory capacity up to 1/2", extension range from 3" to 36" in length, weights and lengths vary by extension selected.

Dotco extended die grinders are commonly used to reach the bottom of molds, castings, various aerospace parts, and wherever a long reach tool is required. They are often used in foundries to deburr and remove parting lines or remove gating along the bottom of a cylindrical part. The standard extension lengths are either 3" or 5" long, but series 12-26 can be ordered with up to 36" of reach. Dotco extended length die grinders with a 1/4" part are sometimes used first with a carbide burr, then later with a flap wheel as a secondary process.

At 0.3 HP, the series 10-11 and 12-11 are lighter duty tools designed for finishing projects. In contrast, the 12-26 series jumps up to 0.9 HP and is better suited for bigger jobs requiring a larger diameter accessory.

In conclusion, Dotco makes a die grinder for nearly every application. From repairing molds to grinding a gusset turbine engine work or metal fabrication, Dotco tools have withstood the test of time in nearly every manufacturing environment. More importantly, when you invest in a Dotco, you invest for the long haul by purchasing a sustainably engineered tool which can be rebuilt again and again.

In the next and final installment of this series, we cover the complete line of Dotco right angle die grinders, their salient characteristics, and how to select the right tool for the job. Until then.

Thursday, June 18, 2020

Guide to Dynabrade Pneumatic Belt Sanders | Features, Benefits, and Uses of The Dynafile and More

Dynabrade belt sanders are the most recognized shape in portable abrasive belt tools. Based in Clarence, New York and founded in 1969, Dynabrade is a top tier manufacturer of American made abrasive air tools. As an industry leader, their promise is to ensure that your sanding and finishing needs are met with consistency. Great attention to detail can be found in every Dynabrade product and the company prides itself on performance, quality control, and durability. Best of all, every Dynabrade industrial air tool is made in the USA. Their air-powered sanders and pneumatic files are used in a variety of heavy industries across the globe. Given the extended service life over the long term, pneumatic belt sanders often prove a more cost-effective solution than buying a comparable electric tool.
Before we get started, It should be noted that air tools do require an adequately powered air compressor to provide stable air flow, power, and speed. Also, keep in mind that although slightly louder than electric tools, air tools don't generate as much heat and with proper lubrication, can run around the clock, 24-7. Lastly, remember that although generally more expensive, air powered tools are a long term, sustainable investment that leads to a safer workplace and less environmental waste.
Why Use a Pneumatic Belt Sander?
Some of the advantages of using Dynabrade belt sanders include:
  • Versatility -  Use one handy tool for multiple surface preparation and material removal applications
  • Throughput - Increased productivity as result of less manual, hand sanding
  • Agility - Compact size and extended reach for maneuverability in otherwise inaccessible areas
  • Ergonomics - Lightweight design for greater operator comfort over extended periods of use
  • Adaptability - Compatible with many different sanding belts when used with the right contact arm
  • Durability - A properly maintained air tool last much longer than a similar electric tool
Below is a discussion of some of the most popular Dynabrade Belt Sanders on offer and the various applications they can be used for:
The Original Dynafile 
Dynabrade's founder, Walter Welsch, designed the original Dynafile to replace tedious hand filing and sanding. It remains the best tracking handheld abrasive belt tool on the market today. The Dynafile can be used to grind on the contact wheel (tip) or the platen pads (sides). There are a several different versions available. Here is an overview of the three series of Dynafiles on offer:
Dynafile I
● Dynafile 14000 ("The Original"), for 1/8, 1/4", or 1/2" wide x 24" long belts - Includes the 11218 Contact Arm - Use this tool for turbine blade rework, cleaning off rust (using Scotch Brite style belts), grinding down welds, or sanding the inside of slatted surfaces. A heavy duty shroud protects the motor pulley and keeps debris from accumulating on and around the belts drive wheel. A spring loaded contact arm allows for quick bet changes.

Dynafile II
Dynafile II is the evolved and more ergonomic version of the original Dynafile. Also, notice how the shroud doesn't cover the air motor of the tool allowing for better access into tight spaces. Several models are available, most come with a 1/2 HP, 20,000 RPM air motor with the exception of the slow speed 40381.
● Low Profile Dynafile II: This is the compact version of the Dynafile II for work in low clearance spaces. Model 40352 accepts 1/2" x 18" coated abrasives belts. Model 40353 is similar to 40352, but is designed for use with non woven Scotch Brite style belts. The major difference is that the 40352 has a rubber drive wheel to prevent non woven belt slippage instead of the standard knurled metal wheel. The non-woven version is great for graining and applying decorative satin finishes to stainless steel.
● Vacuum Dynafile II Model 40330 -  3/4" x 18" long contact arm plus dust collection for reduced mess and improved industrial hygiene. The tool's shroud has an exhaust port and it comes with a hose and dust collection bag. You can even hook it up to your shop-vac or central vacuum system with the right couplers.
● Mini-Dynafile II: Two different models on offer for 12" belts (model 15003) and 13" belts (model 15013). This is a smaller tool, ideal for working in narrow openings and performing strap style polishing. This little tool is good for taking down welds on two adjoining plates placed at a 90 degree angle. It is also handy for de-burring round cut outs or getting inside channel.
Dynafile III
● Dynafile III: Model 15300 is the highest horse power tool in the Dynafile line up. The Dynafile III features a larger 0.7 HP motor for more aggressive material removal jobs as well as a side handle so you can apply extra force to the work. Use it to blend scratch patterns, take down welds, or strap sand. The contact arms for the Dynafile II models also work with this tool.
Dynabelter
The Dynabelter is a popular option for even heavier material removal requirements. Use it for heavy blending, weld grinding, and finishing on metal and other surfaces. The Dynabelter is similar to the Dynafile but for bigger jobs. There are three different models:
There is also the unique, but slightly odd Accu-Grinder Model 11486 which features an adjustable depth wheel to prevent undercutting and scrapping parts. The adjustable guide tires help you "stay within the lines" when applying uniform patterns and taking even passes. The Dynabelter is great for pipe and tank work and comes equipped standard with a hard durometer 2" X 1" contact wheel. Pro Tip: For best results the accu-grinder should be used at a 45 degree angle and pulled toward the operator (not pushed) when making your passes.
Features of the Dynabelter:
● Great for stainless steel, carbon steel, aluminum, wood, and composites
● Higher horsepower for faster material removal rates
● Safety-lock lever prevents accidental activation if the tool is dropped.
● Use it to de-burr castings, grind cylinders, and take down welds fast
● A variety of accessories are available to expand its use including contact arm extenders that allow the tool to accept belts up to 60" long.

Dynangle I
Yet another Dynabrade original, the Dynangle I is Dynabrade's answer to the traditional belt sander. What makes it special is that you can either slack sand tubes by removing the platen pad, or use it with the platen pad in place to grind on flat surfaces. Another money saving feature is the use of a gearless, direct drive, 0.7 HP air motor which helps keep maintenance costs down. At under five pounds the tool is light and nimble and as with all Dynabrade belts sanders, there are a variety of application specific contact arms available. Out of the box, model 14200 accepts 1" x 18" belts and the belt advances at 6,5450 Surface Feet Per Minute (SFM)
Features and Benefits of Dynangle I:
  • Compact (only 11" long x 5" tall), ideal for work in tight spots. Great for blending radiuses and graining stainless steel.
  • Fast and easy belt changes, plus the tool works great with either coated or Scotch Brite style belts
  • Multiple application specific contact arms available
  • Standard equipped with contact arm 14266 which is a 1" x 18" arm with a serrated 2" X 1" medium hardness rubber contact wheel.
Dynangle II
The Dynangle II is a two handed belt sander that can be used in either parallel or perpendicular to the work. Use it with the platen pad in place to surface grind, or remove the platen pad for strap polishing applications on cylindrical parts. There are three models available with either single or dual air motors depending on your horsepower requirements. The dual motor models accept two belts, allowing you to get larger jobs done in shorter amounts of time. Work slats, polish, and grind contours using this tool. Also beneficial for weld take down, surface preparation prior to welding, and blending and finishing weld seams.
Dynangle II Model 14300 - Single Motor, 1.2 HP, 13,000 RPM, 8,500 SFPM - Uses 2" x 34" belts and has a span of 11-1/2" which allows you to sand cylindrical parts up to 3 feet in diameter. Dynabrade sells a conversion kit that allows you to upgrade to the dual motor version when the time is right.
Dynangle II Model 14303 - Heavy Duty, Dual Motor, 2.4 HP, 13,000 RPM, 8,500 SFPM - Uses 2" x 34" belts and is the same in form function as the single motor model, but with more power for bigger jobs. Note: this tool has a large CFM requirement of 106 CFM and if you want to get the most out if it you will need at least a 30 HP compressor.
Dynangle II Model 14306 - Heavy Duty, Dual Motor, 2.4 HP, 13,000 RPM, 8,500 SFPM - Super heavy duty and also just plain heavy, this is the largest Dynangle on offer. It uses 2" x 45" belts and the tools overall length is almost 2 feet. With a belt span of 17" you can grind pipes up to 48" in diameter. Both dual motor Dynangles, come with a 2" x 6" removable platen pad.
Features of Dynangle:
● Quick and easy belt changes
● Accepts multiple types of belts, including non-woven and coated abrasives
● Interchangeable contact arms can be used for refinishing pump screws and drilling screws
● High horsepower motor increases production rates and throughput

Take-About Sander
The Dynabrade "Take-About Sander" Model 52900, is an air powered abrasive belt tool that can be used for finishing, graining, and surface leveling. The opposing grips placed at 45 degree angles are reminiscent of an old Skil 100 planer. It is a heavy-duty (and heavy weight sander) equipped with a a robust a 1.3 hp air motor. It uses a 3" x 24" belt which allows for aggressive remove material on metal and wood. Perfect for use with high performance ceramic sanding belts.
Features of the Take-About Sander
● On/Off toggle switch for effortless belt tensioning
● Pistol-grip handle and top control knob for superb operator control
● Works well with your favorite brand of non-woven nylon or regular coated abrasive belts
● Safety-lock throttle lever prevents accidental activation if the tool is dropped

Kits and Accessories
Once you choose your belt sander, you might want to consider some accessories to accompany it:
Versatility Kits
Many of the tools discussed above are sold in versatility kits which, in addition to the bare tool include: abrasive belts, wrenches, replacement platen pads and a handy carrying case. The 40321 Dynafile II versatility kit is our best seller.
Contact Arms
Dynabrade offers a ton of application specific contact arms to choose from. We have most of them loaded on our website and organized by the tool that they go with. View Dynabrade Contact Arms Here You might also want to Download the Dynabrade Catalog for specifics.

Air Tool Oil
All of the air tools mentioned in this article require air tool oil. Dynabrade has there own variety as does Ingersoll Rand and Chicago Pneumatic. In a pinch, you use use any non detergent 10 weight motor oil, but actual air tool oil contains special conditioners to maximize motor vane , bearing, and o-ring life. Nevertheless, heat is the enemy and  when it come to lubrication, something is always better than nothing. Oil your rotary vane air tools frequently. We stock Ingersoll Rand 10P Air Tool in pint size bottles here at our shop.

Air Line Swivels
Air line swivels not only extend the life of your air hoses, but they extend the life of your operator's elbow too! By installing air line swivels, workers will experience less "hose fight" and  work more comfortably which ultimately results in better productivity.There are many generic air line swivels on the market that look like this:
However, for a modern take on the airline swivel, we like the Chicago Pneumatic CP Air Flex which is made from machined 6061 aluminum. Not only does the CP Airflex rotate smoother, but it allows for better airflow to your tools, in turn maximizing air tool performance.

Filter-Regulator-Lubricator Units
Last, but not least remember that clean, dry, and lubricated air is the key to getting the most life out of your pneumatic tools. Dirty, dry air is a recipe for disaster and if you plan on paying the high price for an industrial grade air tool, you need to protect your investment. For more on FRL units, check out this blog we did a few years back: How To Maximize Air Tool Performance.
In conclusion, Dynabrade has thought of a pneumatic belt sander for nearly every application. They manufacture high quality, rebuildable air tools designed to help you get parts out the door faster. If you need help choosing or configuring your Dynafile, Dynabelter , or any of the other models mentioned in this article, give us a call, we are here to help.
International Air Tool Company - (619) 795-7955
San Diego, California USA

Sunday, January 22, 2017

THE CASE FOR PNEUMATIC TOOLS - 5 ADVANTAGES OF USING AIR POWERED GRINDERS INSTEAD OF ELECTRIC

Savvy manufacturers never stop looking for ways to reduce costs while improving throughput... While the up front price of electric power tools is undoubtedly attractive, pneumatic tools offer a lower total cost of ownership and greater productivity over the long term.  In this article, we explore 5 clear cut benefits provided by the use of industrial grade pneumatic grinders.
1. No Risk of Electric Shock - Grinders of all varieties are frequently used in environments where moisture, conductive materials, and flammable liquids are present. Damaged cords and wires pose a risk to operator safety resulting from electrical shock. Furthermore, metal fabricators often rely on flammable chemicals, such as acetone, to clean and prep metals prior to welding. Pools of spilled liquids can quickly be ignited by faulty electrical cords. Vapor concentrations can be higher when working in confined spaces such as those found in the mining and tank cleaning industries. In contrast, air tools use no electricity and their rotary vane air motors generate no spark.
2. Superior Ergonomics and Power to Weight Ratio - Pneumatic grinders offer a better power to weight ratio than electric grinders. Simply put, pneumatic grinders produce more horsepower in a smaller and lighter package. Misleadingly, electric tool manufacturers often classify the power of their tools by the wattage fed into the electric motors. (incidentally, as a general rule of thumb, 750 watts equals roughly 1 horse power) What's not stated in electric tool specifications is that the power fed into the electric motor is not the same wattage that arrives to the spindle. In fact, only 50% to 60% of the rated wattage actually arrives to the abrasive mounted on the tool. Conversely, with pneumatic grinders, power in equals power out. An air tool rated for 1 horsepower will provide one horsepower of material removal power at the spindle. To further illustrate power to weight ratio, let's compare two popular 4.5" angle grinders: the Dewalt DWE402 and the Chicago Pneumatic CP3650-120AB45.
Dewalt DWE402
Chicago Pneumatic CP3650-120AB45
Weight: 6.2 Lbs.Weight: 4.2 Lbs.
Watts: 1320Watts: 1725
HP: 1.8HP: 2.3
Power To Weight Ratio: .29 HP per Lb.
Power To Weight Ratio: .54 HP per Lb.
In summary, the Chicago Pneumatic Grinder offers nearly twice the horse power per pound as the Dewalt.
3. - Increased Productivity - Let's put ergonomics and ratios aside for a moment. If increasing worker output is a priority for your operation (and when isn't it?), pneumatic grinders can help you meet your goals. When working with grinders of any type, Revolutions Per Minute (RPM) play a critical role in the material removal equation. Abrasive products (grinding wheels, fiber discs, flap wheels, etc.) are engineered to perform optimally at a specific RPM. Fortunately, modern pneumatic grinders are equipped with a speed control mechanism, (also know as governor), that ensures proper RPM by regulating the air flow to the tool. As the operator places downward pressure on the abrasive, the governor "opens up", increasing air flow to the motor and ensuring the correct spindle speed.
A side note on feed force - Many operators when presented with a new tool will immediately attempt to stall it by placing large amounts of downward pressure on the abrasive. They do this in an effort to test the tools power or torque limitations. Stalling out a power tool not only places undue wear on the tool, but also poses an injury risk to the operator themselves. Furthermore, this practice actually detracts rather than contributes to material removal rates. Pneumatic grinders and abrasives perform optimally when RPM limits are respected. In a non flammable working environment, you can gauge the optimal RPM by noting when the spark stream emitted by the grinder is at its brightest.
4. - 100% Duty Cycle + High Performance in Harsh Environments - Mitch Burdick, Product Manager for Concrete Tools at Bosch Tools says "The two biggest threats affecting electric tool life are debris (dust) and heat — dropping them in water, or baking them under a hot sun doesn’t help either." By their very nature electric motors have a rated duty cycle which must be respected. Without a periodic rest, the heat generated by the motor itself will diminish performance and eventually cause premature tool failure. Furthermore, the generation of particles is inherent in any material removal process. With the open grate style motor compartments required for cooling, electric tool motors are more susceptible to the accumulation of dust and debris. In contrast, Industrial Grade Air Tools are designed specifically for use in foundries, shipyards, off-shore oil platforms, power plants, metal fabrication facilities, and petro-chemical refining plants. Air tools have a 100% duty cycle, meaning they are designed to run 24 hours a day 7 days a week (when used with a filter regulator lubricator). Air tool housings are made of aluminum or steel, not ABS plastic which makes them more resistant to the impact from repeated drops. Pneumatic grinders can even be used under water if the exhaust is vented above the surface!
5. - Ease of Servicing - An industrial grade grinder is not a disposable piece of equipment. They can be periodically rebuilt and serviced over many years. The average electric tool maintenance interval is between 60 and 120 hours afer which the tool will typically need brushes. Comparatively, a garage / maintenance grade air tool averages 200 hours between service intervals while an industrial grade air grinder can run 2000 hours between tune ups. When the time does come to service your air tools, convenient and clearly labeled kits are available that contain the most common wear parts.
Bottom Line - In conclusion, regardless if you are de-burring parts in a machine shop, preparing a surface for painting, or parting gates and risers in a foundry, everyone's goal is to get product out the door faster. With pneumatic grinders, you'll spend less time accomplishing your task and feel safer and more comfortable doing so. Additionally, with their 100% duty cycle rating and long service intervals, you'll spend more time working and less time servicing your tools. While the up front cost of a pneumatic grinder may be higher, it's the total cost of ownership that matters. Air tools are a sound investment that results in significant gains in manufacturing productivity.

Wednesday, May 15, 2013

How To Maximize Air Tool Performance Part #1 | Pressure and Flow

San Diego, CA - April 21st, 2013
 
Throughout the course of our daily operations, we often receive calls from customers asking which is the best "brand" of air tool. This is almost always a loaded question and rather than engage them in the Ford versus Chevy debate, a little further questioning usually reveals dissatisfaction with the performance of one of their tools. While in almost all cases an industrial production grade air tool is going to provide better performance than an automotive / maintenance style tool, there are some sure fire ways to ensure optimal performance regardless of the quality of the tool selected. In this article we will focus on the two most important factors in air tool performance, these being pressure and flow.
 
Proper Air Pressure (PSI) - The vast majority of air tools on the market are designed to run on 90 pounds per square inch of pressure, commonly known as PSI. The misconception is that a 2-1/2" drive impact wrench requires more air pressure than a small right angle die grinder. The reality is that both of these tools are designed to run optimally on the industry standard 90 PSI. Exceeding the manufacturers recommended air pressure can actually damage components, shortening tool life and creating a potentially dangerous situation by compromising the burr, wheel, or other accessory in use. Furthermore, you want to be sure that you are getting 90 PSI of pressure when the air tool (or tools if working with multiple stations) is running. Use an air regulator to gauge the pressure while the tool is wide open. If the needle reads 90 PSI when the throttle of the tool is closed but dips below that when the tool is engaged you need more pressure. Again, most air tools are designed to run at 90 PSI and will underperform if under pressurized.
 
Air Flow (CFM) - What varies widely from tool to tool is the required air flow rate which is measured in cubic feet per minute (CFM). Before selecting an air tool for any application be sure that your air compressor can generate the necessary CFM. As a very generalized rule of thumb you can conclude that for every one horse power that your compressor puts out, you will receive 3 to 4 CFM. To put it in perspective a small right angle die grinder uses about 25 CFM while a 1" impact wrench requires 60 CFM. In addition to verifying that your compressor has the guts to power the tool on hand, make sure you aren't starving the tool by restricting air flow through the use of a small diameter air hose. Never use reducers to adapt a 3/8" NPT or 1/2" NPT to a 1/4" air line. In fact, if you can avoid it try not using 1/4" air lines at all. Free unrestricted air flow is paramount to maximizing air tool performance and it's better to error on the side of too large a hose rather than choke the tool. Nothing will sabotage your project faster than an underpowered tool and lack of flow is definitely a deal breaker.
 
In the next installment of this five part series we will look at why every air tool deserves to be paired with a good filter, regulator, lubricator.
 
Thanks for reading...
 
Mark Schieber
 
About the author:
 
Mark Schieber is an air tool entrepreneur, international business fanatic, internet marketer, and avid surfer. He is the owner of International Air Tool & Industrial Supply Company and is passionate about helping his customers maximize productivity related to air tools and their applications. For questions about this topic or anything else air tool related that might be on your mind email info@intlairtool.com

Tuesday, June 14, 2011

Pneumatic Assembly Tool Ergonomics - Preventing Torque Reaction

Pneumatic Assembly Tools -  When is it Appropriate to Use Clutch Tools, Pulse Tools, and Torque Arms when Attempting to Reduce Torque Reaction?

By Mark Schieber, MBA - Director of Sales at International Air Tool


When working with assembly customers in the field I frequently receive questions about torque reaction and more specifically, at what level of torque should some type of reaction limiting device be implemented.... In order to properly answer this question, let's first define the vocabulary that will be used in the discussion:

Clutch Tools - (aka Torque Controlled Screwdrivers featuring an Adjustable Precision Shut Off Clutch)

Clutch tools are pneumatic screwdrivers (either inline or pistol grip) that utilize a mechanical spring, ball, and cam type clutch (see picture below) to limit the amount of torque delivered to a fastener. Rather than have the screwdriver bit connect directly to the pneumatic screwdrivers motor via the spindle, an adjustable clutch is installed between the bit and the motor to regulate the amount of torque delivered to the fastener. Different screwdriver models offer clutches with different torque ranges (typically measured in inch lbs.) from which to choose. This torque range is adjusted by changing the clutch adjustment settings by either loosening or tightening the tension placed on the clutch spring. During a run down, when the force applied to the fastener overcomes the driving force of the tool (controlled by the clutch) a rod trips and stops the air flow to the tool thus limiting the torque applied to the fastener. These clutches are highly accurate and since they shut off automatically when the proper torque is reached, they also prevent operators from influencing final torque applied to the fastener. In other words, the operators can't give the fastener "one last nudge for good measure." The final resting torque of the fastener is determined by the tool, not the operator. Here is a picture of a torque controlled clutch, (disregard the oil free blades text):



You can check out one of my all time favorite torque controlled screwdrivers at: http://www.intlairtool.com/products/Ingersoll-Rand-1RPMS1-Torque-Controlled-Assembly-Screwdriver.html

Now the negative (Con) aspect of clutch tools - Since the air flow to the tool and hence rotation of the bit is stopped abruptly by the activation of the mechanical clutch, a torque reaction (jarring motion) is produced at the end of the cycle which is transferred to the arms of the operators. This reaction can be harmful to the wrists and elbows, but can be prevented... More to come on this later...

Pulse Tools

A pulse tool combines the speed of an impact wrench with the repeatability and precision of a shut off clutch tool. However, in contrast to a spring, ball and cam type clutch tool, a pulse tool uses a hydraulic cylinder to amplify, regulate, and apply the torque generated by the air motor. This hydraulic cylinder is often referred to as the pulse unit. Not only does the pulse unit generate torque, but it also absorbs the torque reaction, noise, and vibration making it a highly ergonomic (but expensive) tool. Since a picture is worth a 1,000 words, here is a cutaway of a pulse tool...


Pulse tools are usually used for higher torque range applications which are measured in ft. lbs. (12 inch. lbs. in 1 ft. lb.). They are also very quiet and consume very little air (low CFM). IMPORTANT: Pulse tools are virtually reaction-less because the torque is applied to the fastener in a series of rapid starts and stops that are visually undetectable during use. Think of the second hand on a clock and the way it pauses before it moves to the next position... Now imagine this same motion at 8,000 RPM's and you have the method by which a pulse tool delivers torque! Here is an example of a high quality Ingersoll Rand Pulse Tool...
Check out a classic Ingersoll Rand pulse tool here

Torque Reaction Arms
Lastly, let's talk a minute about torque reaction arms... A torque reaction holds and supports a torque controlled clutch type screwdriver during operation. See the photo below:


Since a torque controlled screwdriver comes to an abrupt stop when the desired torque is reached (due to the clutch engaging), a torque reaction arm is used to absorb the transfer of torque (twisting force) before it reaches the arm of the operator. This in turn prevents injury associated with repetitive motion. Torque reaction arms also force the operator to follow the preset pattern/motion of the arm thus performing the assembly in a disciplined and ergonomic fashion. Torque reaction arms come in a variety of materials and configuration, but all share the same goal, which is to prevent injury to the operator caused by torque reaction and repetitive motion.

Selecting the Right Configuration

Sorry for that long winded explanation, but it was necessary... We are now ready to explain how to choose the right tool to get the assembly job done while adhering to proper ergonomics... As a rule of thumb, a clutch tool should be used with a torque reaction arm anytime there is a visible torque reaction noticeable when monitoring the operator perform a series of run downs.... Additionally, the operator should be questioned as to his or her comfort level after performing multiple cycles. See how they feel about 1/2 way into their shift and question multiple operators all the while assuring them that their input is contributing to plant wide increases in productivity. When in doubt however, implement a torque reaction arm. Some experts in the field will assert that a torque reaction arm be implemented only above certain levels of torque (i.e. - above 15 inch lbs.). However, we at International Air Tool have found that torque reactions vary greatly based on the type of joint (hard or soft) being assembled. While some operators may resist the implementation of torque reaction arms, assure them that it is for the benefit of their health as well as the overall well being of the business.

You might have already figured out that by design, pulse tools do not require torque reaction arms. While many plants prefer to implement a combination of clutch tools with torque arms due to lower costs, when possible, it is advisable to use pulse tools. Additionally, since the pulse tool requires no torque reaction arm, it reduces clutter and better supports a lean manufacturing environment. However, pulse tools are mainly offered in higher torque ranges because as you might have guessed, greater amounts of torque cause greater reactions and thus require a countermeasure to diffuse that torque. With borderline medium-low torque ranges i.e - 10 to 20 inch lbs., pulse tools are not typically offered and therefore, you will have to be vigilant and see whether a clutch tool and torque arm combination is required.

In summary, when working with a clutch tool, a torque reaction arm is always a good idea when there is any noticeable torque reaction present at the end of the run down. For higher torque applications, bypass the torque reaction arm entirely and streamline your process with a highly ergonomic and repeatable pulse tool. If you have questions regarding a specific application feel free to call our office during normal business hours or send an email to mark@intlairtool.com

Thanks for reading...

Mark Schieber