Custom Solutions

Altering a Magnetic Chuck for Custom Setup

Adding a fine pole top plate (top tooling) to an existing magnet.

When discussing how to choose a fine pole magnet vs a hard milling magnet, there are times when we want to combine the benefits of both. Here is a real-world example:

A customer wanted to build custom tooling into the top of a fine pole magnetic chuck for in their sinker edm.

The customer had it all planned out –

  • Four fine pole magnets palletized to EROWA
  • Each magnet would have its own pin layout for part locating
  • Jig grinding locations to press in pins in for work locating
  • Flushing holes drilled

The customer proclaimed, “This is all we do and it will work great.” I had a different approach to the challenge.

Here is some of the reasoning I took to show the customer how they could achieve the results they needed, while reducing costly tool alterations.

The Hermann Schmidt Approach

FPH on HSM Pin BackI am usually very against altering a magnetic chuck. Any mistakes or damage will result in a costly chuck rebuild and then another rebuild of the custom component.

So after a review of all the customer requirements first – then a review of the ideas they had on how to do it – we developed the following solution:

We used a fine pole top plate as a build basis for the customizing.  The top plate can be treated like a solid piece of material, and altered as needed.  Specific alterations were as follows:

  • Plate was ground parallel top & bottom, with 2 sides square to be used as referencing edges.
  • Flushing holes were added as needed.
  • Instead of jig grinding locations:
    • Tapped holes were added at the nominal location.
    • Set screws were inserted.
    • Locations were milled at the nominal location.
    • Once installed in the machine a female electrode was used to accurately burn the stop locations.
  • Thru holes were added for mounting to supporting magnet below.

A hard milling magnet was chosen as the base magnet so we could get the magnetic power through the top plate to the workpiece.

These operations were repeated for three other top plates, allowing for one base palletized magnet to do all of the work.

The Customer Benefits

By minimizing customization, and by building a more flexible tool set up, the customer received the following benefits:

  • Cost savings of 53%
  • Ability to build the fixtures themselves as they had no internal jig grinding
  • And, as expected, the part did change two years later and they had to change the top fixtures.


Customizing Precision Stainless Steel Chucks

Much of our designs tend to lean toward the smaller side of things.  For example our 3 jaw chuck line has a version which will hold a .008” diameter part.

Well, we do go the other way.

This is a 9-Jaw beast with a capacity of 7 to 8 inches.  Sense of scale is that the thru hole shown is 8”.  Customer is a medical device OEM who needed to position parts on center within .0002” but the part diameters were ranging +- .050”.  This did it with tolerance to spare.

Custom 9 Jaw Precision Stainless Steel Chuck
Custom 9 Jaw Precision Stainless Steel Chuck Close Up

Other options are horizontal jaws instead of vertical jaws.

A die-stamping customer had parts with a cylindrically ground 30° taper almost 4” diameter at the base.  We took a standard design 3 to 4” capacity 6 jaw and turned the jaws 90°.  Now as the jaws close the work piece is forced down to a stop and centralized.

Custom Tool Solutions for Your Manufacturing Requirements

Hor jaw closeupFPH on HSM pin front w part


Customers looking at our custom solutions area ask why there are no descriptions to the pictures.

We do special versions of our products on a continuous basis. Usually they are variations of a concept of our standard offerings or a special mounting of a standard tool.

We cannot show all we have done nor do we show our products being used. Different industries or different areas of the world use our products in unique ways. I have seen many of them but by no means all of them.

We are trying to show concepts and ideas to stimulate your mind and use us to accomplish your unique requirements.

Please ask us about custom solutions.

Many applications can be addressed by taking a standard product and altering it by size, orientation or material. This keeps cost down from a true full custom solution and provides you with a tool that has most of the engineering decisions already proven.

I invite you to call me so we can discuss your specific applications.

Why Doesn’t Hermann Schmidt Still Sell…

NBIwPNM_webAP_EML_CUSTWe are often asked: “Why don’t you still build…?”

That list of tools still requested include angle plates, non-magnetic sine plates, edge finders, v-blocks, 123 blocks, squareness gages, etc.

Product life is not forever in this now fast-paced industry. Products have generally been dropped as stocking items when the market has indicated to us that we cannot support having items in stock at the price we need to sell them at.

That being said, we still regularly build angle plates, non-magnetic sine plates and 123 blocks for customers. Rarely is it price effective to have one built, but it is effective once quantities of three or more are needed.

Recent custom version tools include:

  • Angle plates
    • Special bolt pattern
    • Stainless steel
    • With integrated wire edm magnets
    • With System 3R, Erowa, Hirschmann referencing chucks installed
  • Non-magnetic sine plates
    • No holes in top plate for inspection
    • Custom size with spin fixture mounted
  • 123 blocks
    • Stainless steel
    • Custom hole pattern