Why do we need high powered grinders?

The obvious answer is that high powered grinders will save you money. 

• Higher power means you can remove more material or make more cuts per year.  Time is money right?
• Higher power also means that your abrasives will be working at their optimal speed, meaning you get a better finish and your abrasives will last longer.

Apart from this, abrasive manufacturers are coming up with more aggressive disks for faster material removal.  The problem with these new disks is that they will destroy most electric grinders and stall most air grinders because they need a high powered tool to run them.  Some examples are the PFERD ALU-Master, CC-Grind disks and the Maija Frästechnik milling discs. These unique new products offer extremely fast material removal but require high powered grinders.

The PFERD ALUMASTER high speed discs are a unique tool that offers very fast material removal.  It is ideal for use on aluminium because it does not produce hazardous or explosive dust. 

It uses ten replaceable tungsten inserts to machine the aluminium rather than grind it.  This also means that the tool doesn’t clog up.  

These discs suit 115mm or 125mm grinders with a max speed of 13,300rpm and PFERD recommend an air grinder of at least 1000watts or an electric grinder of at least 1400watts

Another new disc that requires a high powered grinder are the Maija Frästechnik milling discs.  These are available for a range of materials including steel, aluminium and titanium.  Maija Frästechnik tested and recommend Deprag Turbine powered grinders for use with their discs.

Innovative Sheet Metal Fasteners

Flow Drill Screws, Flow Form Screws

FDS® screws from EJOT and FFS® screws from Arnold have been around for a while.  They offer the benefits of a secure and strong joint from one side between two sheet metals.  A big advantage is that they can join dissimilar materials like aluminium, steel and plastics where spot welding is not possible (they are finding more and more applications in the automotive industry where aluminium and other materials need to be joined).  They also allow the use of thinner sheets without the use of additional hardware to strengthen the joints (this is making them more popular in the whitegoods industries).

The screws form a hole by high pressure and the speed of the screw, the heated material is then threaded and cools around the screw.  The joint is strong, and the unscrewing torque is high.  The thread formed is upto 3 times thicker than the sheet metal.

1. Heating the metal with high end load and high speed screwdriver
2. Penetrating the material
3. Forming of the hole
4. Forming of the screw thread
5. Engagement of the threads
6. Final tightening into the cool thread

Advantages for joining sheet metal:

• No swarf or chips
• Stronger joint, higher screw torque possible
• Higher torque means a larger torque window and less chance of stripping
• Screws can be replaced with standard metric screws
• No additional hardware required to strengthen the joint
• High unscrewing torque and vibration resistance
• Possibility of joining thinner materials
• Possibility to join Aluminium
• Can be accessed from one side
• Possibility to join sheets without pre-drilling (in automated applications)

Unfortunately compressed air turbine powered grinders are overlooked by factories because of their high initial cost compared with cheaper tools.  Here we are going to go through and explain some of the advantages of these grinders andd try to explain how they will actually save your organisation money in the long term.

ELECTRIC VS AIR POWER:

240V electric powered grinders are readily available and reasonably cheap, but iunder the stress of continual use an industrial quality air grinder will always outlast the electric grinder as long as it has a quality air supply.  Air grinders will not be affected by dust in the air, they cannot be overloaded or overheated.  The air grinder will also be lighter than an electric grinder with the same power output.  Especially in the case of 230mm grinder, air grinders are available with higher power outputs.  Please note! Most electric tool manufacturers quote the max power input to their tools.  Air tool manufacturers quote the max power output!  So a typical 1000W 240V grinder will only output 600 to 700W of power.  A 1000W air grinder outputs 1000W as long as you have enough air to run it.

POWER to WEIGHT RATIO:

Often we want maximum power without the weight right?  It's not helpful to have high power and high weight or low weight with low power.  Higher power with lower weight means that the work is done faster and with less fatigue.  Less fatigue means less chance of accidents, less breaks and less down time.

Air powered grinders are often chosen over electric tools because for a given power, the vane motor powered grinder is going to be lighter and smaller than a 240V electric grinder. Smaller and lighter tools mean that the operator is not going to be as tired, he can work longer without breaks and there is less chance of injury.

Turbine powered grinders take this a step further.  For example: 

HIGH POWER

Why is high power more important?              Because it saves you money of course!

• Faster material removal - time is money right?  If your trigger time is 3 hours per day, your extra material removal can be a tonne or more over a year compared to a vane powered tool.
• Optimal cutting / grinding speed means that your abrasives last longer - save over 30% on your abrasive costs if you are using quality abrasives!
  • If low powered tools are used, the speed drops when pressure is applied resulting in faster abrasive wear.  HIgh powered tools with speed governors do not slow down.

LOW MAINTENANCE COSTS

Turbine motors have all the advantages of vane motors - (cannot overload, cannot overheat, not affected by dust etc), but they do not have vanes, which is a wear part.  As long as they have clean, water free compressed air, you can depend on them for a trouble free lifetime whereas vane motors have wear parts - especially vanes, that have to be replaced every so often.

ENERGY EFFICIENCY

Compressed air is EXPENSIVE.  The turbine compressed air motor is already a comparatively efficient air motor (see the above comparisons) which of course means it will cost you less to run your compressor. Deprag has also taken advantage of some of the turbine motor's characteristics to make them even more efficient.

Deprag has included a speed governor in it's range of turbine grinders which means that when the tool is not under load it consumes less than half of the air that it uses when under full load.  As the load increases the govenor progressively opens the air inlet valve, increasing the air supply and thereby increasing the power.  The governor also maintains the correct speed no matter what the load - extending the life of your abrasives.

SUMMARY

To really understand the value of turbine powered angle grinders you need to look past the initial cost, especially if grinding is a big part of your business.  The lifetime cost of every tool has to be considered.  Compressed air, abrasives and man-hours are not cheap and they all add up over time.  Many companies have done the tests and have come to realise that the savings we are talking about are real and significant.  Don't ignore the facts!

Take a look at the Deprag 230mm Turbine grinder in action here: https://youtu.be/sufhzTdhMso 

Dirt or dust particles can cause damage to some products or the system into which the sub-assembly will be integrated.

In these situations it is important to avoid abrasion, reduce abrasion or target its removal! These are the basic requirements for screwdriving assembly in clean rooms to ensure the quality of the components to be processed. The DEPRAG CleanFeed Concept provides an overall solution.

Advantage: Integrated design for technical cleanliness. Deprag’s complete program is coordinated for all required individual components,  from the feeder to the screwdriver, semi automatic or fully automatic – all from one source.

Function: The screws are stopped in switch position 1 and the residual dirt is removed from the feed parts  via vacuum suction. The removed dirt particles are then collected in a filter with transparent inspection window and a replaceable filter element. In switch position 2 the cleaned connection element is fed into the screwdriving module (inline version) or prepared for pick up (Pick&Place version).

The components below can be used to obtain an optimal result:

Low abrasion parts feeder

• DEPRAG HSF sword feeder – vibration free screw feeding – therefore no component friction and minimal abrasion

Removes particles for the feed tube

• DEPRAG Particle killer – dirt particles from the feeder are targeted and removed in-line

Clean room pick point for screws

• DEPRAG Clean Pick-and Place unit – Screws are fed to to the pick point in the unit, which also has a vacuum to remove particles

Clean room ready Screwdriver

• DEPRAG SFM-V vacuum screwdriving module, which fits onto the screwdriver – residual dirt is removed by suction via an additional vacuum source when positioning the screwdriver.