Tuesday, August 28, 2012

Frequently Asked Questions An In-Depth Look: Magnetic Parts

The sPINner deburring system uses a magnetic field, so there are several factors to bear in mind when processing parts with a magnetic property. This document will help explain the variables to factor in when processing or evaluating magnetic parts.

The parts will “stick” to the bottom of the container:
When magnetic parts are introduced in the sPINner, they will be attracted to the magnetic field. As the magnetic field is concentrated to the bottom of the container, the parts will tend to “stick” to the bottom and the media will move around the part. Non-magnetic parts will tend to tumble with the media in a circular motion. Magnetic parts (depending on size and material) will tend to move slowly along the bottom of the container during machine operation in the opposite direction of the flow of media. This is caused by the parts trying to keep up with a very fast moving magnetic field. Heavy part or parts with very sharp edges that are pulled along the bottom of the container by the magnets may score the container and may wear through the container over time. If this happens the container will need replaced. Also fixturing the parts can limit their movement and decrease the wear on the container. See below the Fixturing section for more details.

The parts will stay in the magnetic field:
Parts with a magnetic property will be attracted to the magnetic field at the bottom of the container. The parts will stay in the strongest parts of the field during operation. The parts will tend to “line-up” with each other during processing. As the parts are responding to the magnetic field, they will attract other magnetic items in the container. This includes the magnetic media and other magnetic parts. The result is the parts developing a layer of media around them during processing and parts sticking to each other during processing.

Picture of fixture used with magnetic parts. Shown here with a few parts, each part is placed on an arm. The angle of the arms allows the parts to sit in the flow of the media while preventing the parts for damaging each other. Parts are free to rotate insuring that all areas are exposed to the action of the media.
Single layer of parts:
As parts with a magnetic property will tend to attract other magnetic items in the container including other parts, only a single layer of parts should be added to the container at a time. If parts are allowed to stack on top of each other, they will “stick” to each other and may prevent areas from being exposed to the media. 

Again, a fixture may be required to insure the parts do not damage each other during processing.

Sometimes it helps to fixture the parts in the processing container. This can provide some benefits and eliminate some issues that can arise when processing magnetic parts. Fixturing parts can keep them in the flow of the media to insure the parts are being subjected to the action of the media. Also, fixturing the parts will help keep them separated preventing any damage from other parts and eliminating any void areas (areas where the media cannot get to) from parts ”sticking” to each other.

Types of Fixtures: There are as many different types of fixtures as there are different parts.  Below are some common fixture types that can either provide a station for each part or simply “cage” of “harness” the parts.

These fixtures are placed in the processing container. Since the parts can no longer contact each other during processing, the potential to damage each other is eliminated. The associated batch size is limited to the number of stations on the fixture. Please note, many different designs of fixtures are possible and the design is dependent on the specific application. Precision Finishing can help design and build a fixture for any application. Call us for details.

Machine Speed: In order to minimize the cushioning effect of a layer of media around the part, the spin rate of the magnetic field may need to be slowed to about 30-40 Hz.

ID burrs are difficult with magnetic parts:
Because the sPINner uses a magnetic field to impart energy to the media as opposed to gravity or vibration, one advantage of the system is the ability to deburr ID areas. This benefit is primarily limited to non-magnetic parts. For a 

Heat build-up:
During processing the friction of the media and the parts will produce heat. For non-magnetic parts the amount of heat is less than that of magnetic parts. The reason is that the magnetic parts create vibration that generates heat. Processing times of 30 minutes and longer in the sPINner on magnetic parts will generate heat and the contents of the container should be allowed to cool prior to handling.

There are several materials that magnetic parts may be made of that will need a compound other than the soap and water solution typically used in the sPINner. When rust of other corrosion is a concern, a compound should be chosen that has an inhibitor. The results from using various compounds may vary greatly and should be carefully tested prior to mass usage. When using a compound other than the compounds provided by Precision Finishing, make sure to use a compound that has a flash point above 180° F. Also, make sure to try the compound in a little media first to help determine the effects on the media.

Please contact us at 317-842-8934 to discuss any specific application or if we can help provide any additional information on processing magnetic parts.

Wednesday, August 22, 2012

Our Power Coated ER Collet Nuts really ARE special

We view CNC tool holders for routers and milling machines to be a critical component of the entire machining process.
Each component of our toolholder systems has been looked at in great detail to determine who we can improve tool life and reduce cycle time for our customers. 

One of the most important elements of the toolholding 'system' is the collet nut. Each toolholder "system" consists of a precision ER tool holder that comes with a special "Power Coated" high power nut that holds tighter than any other nuts. John Stagge, President of Techniks, says: "The 'Power Coat' nut is the secret to our high holding power. Because it holds so tight, the 'Power Coat' nut improves T.I.R., extends carbide tool life, and even permits light milling operations". Techniks recommends that for best results always tighten the nut to the proper torque using a torque wrench with a tightening stand, and never over-tighten the nut because this can damage both the collet and the collet pocket.

What makes the difference?
As anyone knows who has changed a flat tire on their car, tightening down a nut on a 60 degree thread involves some friction as the mating metal surfaces interact.  That's why nuts can be a bit 'hot' to the touch when you take them off. Our objective with our "Power Coated" nuts was multifold: 
First we needed to reduce the coefficient of friction on the thread angle to enable more lubricity for the nut to tighten down farther. As we all know 'heat' causes metal to "grow" so what may at first appear to be tight, in fact, loosens, as soon as you stop tightening it.
Second we needed to make sure that the front surface of the collet that engages the shorter 30 degree taper on the front of an ER collet did not 'twist' as the night tightened down.
Both problems really involved reducing friction and through a combination of engineering tolerances and unique coating process we believe that we've found the most economical solution to eliminate the use of cheater bars and collet over torque. Here's what we've found  our in testing our "Power Coated" Nuts:

  • Up to a 75% increase in holding power
  • Can extend tool life by 20% by reducing TIR
  • "Engineered" balance for high speed machining

“Power Coat” is an innovative, permanent coating that increases clamping pressure of the nut up to 75% compared to standard ER nuts. More holding power reduces the chance of spinning the shank of the tool inside the collet, which can cause premature failure of the collet.

Wednesday, August 15, 2012

You know our toolholders...

...but did you know with Techniks you also get:

  • Live phone support - 8:00 am to 6:00 pm by our experienced team of customer support representatives
  • Fast, friendly response to your quote requests(phone or email)
  • Each order checked 4 times - 99.9% shipping accuracy
  • Same day shipping on orders in by 2:00 pm EST (standard ground orders - expedited orders ship same day until 5:00 pm)
  • In-house applications support – toolholding and workholding – call us with your questions
  • Field support provided as needed by our customer support team
  • All products backed by our 100% satisfaction warranty! 
Stocking over $6,000,000 toolholder inventory for CNC machines and CNC routers in our 42,000 sq/ft central warehouse. We also provide turn-key solutions for magnetic workholding and magnetic deburring machines as well as out complete line up of CNC modular boring tools. 

Thursday, August 9, 2012

sPINner Stories: Gear Deburring Made Simple

Here is an example of an 6061-T6 aluminum gear application that is being deburred with the sPINner. The part is run for 10 minutes and as you can see the burrs on the teeth are cleanly removed.

Friday, August 3, 2012

CNC Aggregates used for Insertion & Glueing of Dowels In Light Weight Panels

For many applications, new, light weight panel technology is being used considered because it provides both high stability and light weight for ease of handling. However, the insertion and glueing of dowels can be a tedious and time consuming process.
We've solved this with automatic insertion and gluing of dowels or other fasteners with our ATEMAG CNC router Aggregate head.
The new ATEMAG system can be used for panel thicknesses of 18 mm through 50 mm, and for different dowel lengths. Fasteners are inserted evenly with the surface and glued in with accurately dispensed amounts of glue.
The insertion process is very accurate, and the panel surface is not damaged in any way. Most importantly, there are no visible pressure marks left on the surface.
The hole does not have to be dust free, because the dowel or fastener will not touch the bottom.
Generally, any CNC machine with c-axis and compressed air connection can be used with the new ATEMAG high performance aggregates. Contact TechniksUSA with questions or to get a quote on how we can retrofit your machine with one of our units. Here's a look at how the unit works.