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Plastic Tooling - Ceramic Grinding

Brief & Challenge:

Our customer manufactures delicate ceramic rings. They needed a way to carefully hold them on the outer diameter so they could grind the inner diameter. In order to protect the parts, they requested the chuck had no metal contact points.

Ceramic_workholding_Grinding_Chuck

Solution:

We produced a 6” Diaphragm Chuck with non-metallic top tooling in contact with the customer’s part. The top tooling, made from the most abrasion-resistant plastic available can be quickly changed, for new ones, should a future need arise.

Northfield Precision Instrument Corporation is a leader in developing custom solutions for difficult work holding problems. Click here to get in touch.

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Pitch-line Gear Chucks

Introducing the series of pneumatic actuated pitch-line gear chucks.

 

Helical Gear Chuck
Helical Gear Chuck

Spur Gear Chuck
Spur Gear Chuck

How can we help you?

These two chucks are 7-inch diaphragm chucks. For multiple gear sizes, chucks can be provided with interchangeable cages and top jaws.

How do we do it?

We attach a custom designed axial locator cage to a standard chuck. This contains a series of floating gage pins in a flexible mounting. Then, we load the gear over the pins into the chuck. The jaws clamp over the pins to center and grip the gear providing a “best fit” centerline of the pitch diameter.

 

Pitch line gear chucks can be provided in sizes from 3-inch to 12-inch diameter, sliding jaw or diaphragm models and can be applied to spur or helical gear applications.

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Custom Diaphragm Chuck for milling precision gears

Every week exciting new projects are heading out the door, such as this Custom Diaphragm Chuck for milling precision gears.

Brief: The customers work piece is a small precision gear that requires milling on one face, timed to existing geometry.

Challenge: The outer diameter of this gear could not be touched so it needed to be gripped on the root diameter.

Solution: A Northfield DPH-400 (.00050” T.I.R.) 4” diameter diaphragm chuck was provided, with sub jaws, changeable inserts and stops for different sized work pieces.

  • The inserts are wire cut to clear the major diameter and clamp on the root diameter.
  • Changeable stop pads have timing pins, to orient the work pieces prior to clamping.
  • The base stop has a ground indicating band for initial setup.
  • The chucks ‘pull-back clamping’ action ensures the part is seated flat.

 

Don’t forget you can also follow our most recent projects on LinkedIn.

 

Do you have a unique working holding requirement? Then get in touch now. Our sales team are always available to answer your questions. https://www.northfield.com/contact/

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Northfield Chucks Help Dana Corp Stay On The Road To Success

Dana Corporation

Manufactures drive shaft components for the big three auto makers. At Northfield, we’re proud of the part we play in helping them solve their production challenges.

8000rpm_Diaphragm_Chuck

 

Challenge – Getting a grip on the situation

Dana needed a chuck to be mounted on a balancing machine holding a drive shaft on one end, gripping the component called a slip yoke. These drive shafts, for the Daimler Chrysler Corporation, were complicated by several factors.

  1. The shape of the part – long and thin –
  2. The grip force required to hold a 5ft. long drive shaft
  3. The accuracy 1/10,000 T.I.R.
  4. The speed – as high as 8,000 rpm – during the balancing process.

Normally, balancing operations are performed at only 900 rpm, but Dana needs to balance this part at simulated road conditions. Since the shaft will deflect (bend) at high speeds, this is the state they want it balanced at. For production cars, drive shafts typically rotate up to 3,000 to 5,500 rpm. This component, used in Daimler Chrysler’s high-performance stock racing cars hit 200 mph with their drive shafts rotating at 8,000 rpm.

Solution – Sometimes, two chucks are better than one.

To solve the problem, Northfield engineers decided to use a diaphragm chuck, rather than a sliding jaw chuck. Before making the final decision we conducted several tests using solid models on our CAD systems. This ensured that our diaphragm chuck wouldn’t lose grip force at these high rpms.

Our solution consists of two separate diaphragm chucks, with two separate sets of jaws, mounted one in front of the other. This  accommodates the long, thin shape of the part. With one set of jaws gripping near the front of the piece and the other gripping near the rear.

Results

The result is accuracy of a 1/10,000 T.I.R. and repeatability to 50 millionths of an inch and extreme rigidity.

The chuck also uses a male spline driver mounted in the center of the chuck. This helps drive the shaft on start up and stop, and guide the shaft into the jaws during loading. These drivers are .002in. undersize of the internal spline and must not influence the centering of jaws. The spline driver is a gauge quality piece of tooling supplied by Michigan Spline Gauge Co.. Providing a concentricity of less than 50 millionths with the chuck.

In Dana’s production car area, the chuck runs the same component. In the stock car application it is used to run a several different components. Parts and tooling can be switched and still maintain an accuracy of less than a 1/10,000 T.I.R.

Finally…

This chuck was designed to be air opened with a self-contained clamping system to meet Dana’s safety standards. It uses the spring pressure of the diaphragms for clamping that will hold the part in place if air pressure and power are lost during the balancing operation.