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Custom Full Wrap Jaws

Custom clamping jaws, developed for a vertical machining environment. A Northfield 650 air chuck has been adapted to work with custom jaws.

FullWrap_Jaws_Clamping_Air_Chuck

The ‘pie’ shaped top jaws provide a full wrap clamping around the work piece. This project also includes a custom spring loaded locating pin assembly. Designed to orient the customer’s workpiece allowing fast and accurate change over.

Can we do the same for you? Reach out and an engineer will be in touch to collaborate on your next project.

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Northfield Pressure-LokTM Chucking System

Our recent product introduction, the Northfield Pressure-Lok TM Chucking System is an air chucking system that works without the air tubes and hoses.

Northfield Pressure Lok Chuck
Northfield Pressure Lok Chuck

The Pressure-LokTM air chuck once charged with air pressure can hold pressure for up-to 3 weeks! Ideally implemented in machining operations that do not have access to a continuous supply of air.

The quick connect fitting is compatible with all Northfield chucks. The air pressure can be altered between 5 & 80 P.S.I. to adjust the grip force as required, improving the flexibility offered by spring clamping alone.

Northfield Pressure Lok Chuck
Our model 450 (3-Jaw) Air chuck with .0001 T.I.R.

Email sales@northfield.com to learn more.

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Satisfying Unusual Requirements Is Just Business As Usual At Northfield

Monogram Aerospace

Monogram Aerospace manufactures highly sophisticated aerospace fasteners. If you have ever flown in a commercial airliner, you have probably seen Monogram fasteners dotting the wings of the plane. Unique because they are installed and tightened from one side. Much like pop rivets, although that is a oversimplification of these high tech components.

Each fastener has a hole drilled dead center through the head and shaft before an actuating rod is inserted. During installation, a ratchet tool is used to twist the actuating rod. This causes the end of the tube to deform outwards and hold the fastener in place. Monogram’s fasteners are made from an alloy that deforms to a specific size and shape. The actuating rod is snapped off, and the fastener is secure.

Challenge:

Monogram asked Northfield to develop a chuck to hold these aerospace fasteners during machining. The process requires hard turning and tapping. To accomplish this we had to address several challenges.

  1. Monogram stressed the importance of holding the parts concentrically during machining, otherwise the the build up of stress on the fastener could cause it to fail during use. The large size of the fastener heads the chuck jaws need to grip over, make achieving the required level of concentricity complicated.
  2. The two head styles, flat and button, presented an additional challenge.  Two different datums for axial banking need to be accommodated by our chuck.
  3. Finally, Monogram produce fasteners in hundreds of different sizes and lengths. This means that our chuck also needs to allow rapid and accurate changeovers from one size set-up to the next.

 

The Northfield Solution:

The chuck provided satisfied all of the challenges while providing a part-to-part repeatability of 0.0001 inch.

For the flat-head style fasteners, the gripping operation is fairly straightforward. The chuck jaws open wide enough to clear the head of the fastener. The part is pushed into the chuck until it reaches a standard fixed stop. The jaws close and the part is ready to be machined. A modification made to the stop is a special feature. It allows for a continuous chip to exit through the stop and out one side.

The gripping operation for the button head style fastener is more complex. The work piece goes all the way into the chuck, as if it were a standard style banking.  Then in a second step, the jaws begin to close in sequence with a pusher piston mounted on the face of the chuck that pushes the part back out so that the button head banks right on the back side of the jaws. The parts can be located with greater accuracy then previously possible before using this system.

The chuck is equipped with a sub-jaw/insert combination to accommodate the variety of diameters and lengths being machined. This allows Monogram to change from part to part by removing only three screws which hold the three inserts and one stop pad.

Finally…

This custom chuck has a flow control valve installed inside the chuck body. It allows the operator to adjust the speed of the pusher piston compared to the speed of the jaws for the button head family of parts. The flow control valve is set to cut-off the air supply, making the pusher a fixed stop when not in use.

Using our chuck, Monogram is able to run their machines twenty-four hours a day, seven days a week. Cycle times are measured in seconds and repeatability is within 0.0001 inch.

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Unusual shapes - Just business as usual for Northfield

Mascotech Sintered Components

Mascotech Sintered Components are the second largest powdered metal automotive parts maker in the world, and a valued Northfield Customer.

Sintering is not a new technology, but it can provide tremendous financial savings in parts processing.

  1. The process starts with metals in powdered forms. Several alloys are combined to create a new material with specific properties.
  2. Powdered metals are put into a mold then compressed, under several hundred tons of pressure, causing them to fuse.
  3. Finally, the piece is released from the mold, this is called the green state, put into an oven, and sintered.

The result is a strong, economically produced, near complete component.

In addition to doing the powdered metal work, Mascotech also performs roughing and finish machining on some of their parts. This is where Northfield comes in, supplying three unique custom solutions.

 

Transfer Case Component

For this automotive transmission component, Mascotech needs to finish the bore and cut two grooves. These hold a snap-ring and a wave spring.

The Challenge

Cutting the grooves with a forming tool develops up to 20 horsepower, meaning the part needs to be held very securely while the material is removed. However, the part has thin walls, making it difficult to grip without deforming it. Since all the machining operations will take place at the same time, maintaining roundness is critical.

Solution

We solved the problem by outfitting our standard 8″ Model 800 3-jaw chuck with custom full circle jaws that locate and grip the circumference of the part with a drive pin to pick up most of the torque.

 

Water Pump Component

Like many powdered metal parts, this water pump component comes out of sintering nearly complete, but still requires a final operation. In this case:  machining the bore, flange cutting the treads and tapping the holes.

To hold this part, Northfield provided one of our standard Model 670 2-jaw chucks fitted with custom jaws to grip the outside diameter of the part. Special orientation pins help locate the part for finish machining.

 

Crankshaft Sprocket

The final project is creating a family of sprocket gears. After sintering, the material has a particle hardness of 58/63 Rockwell “c” scale. Mascotech needed to hard turn the bore.

Challenge

The main challenge is the keyway between the gear teeth.  It makes one section of the work piece very thin and introduces an interrupted cut during machining of the bore.

Solution

Our solution employs a 4″ diaphragm chuck with six jaws to grip the major diameter of the gear teeth and three pads for axial banking. One of the jaws has a drive pin to insure no slippage while holding the part very gently.

Using our chuck, Mascotech is able to achieve a roundness specification of less than 0.0002 inch when machining the bore. Mascotech utilities Northfield work holding for over 80% of their turning applications at their Ridgway, PA facility.

Northfield Precision Instrument Corp.: Northfield is a custom work holding solutions company based in Island Park, New York.