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Custom Hard Turning Partnership with Hembrug

Brief

Our customer is looking to save cycle time by hard turning instead of grinding. The part is a type of valve body that has bores on both sides. They need to be concentric within 10 microns.

Northfield model DPH-700 (7in. diaphragm chuck)

 

Challenge

The part is eccentric. Meaning, when it rotates it is out of balance. Additionally, the chuck must be capable of 3 microns T.I.R.

 

With the part in the customers lathe.

Solution

Northfield teamed with Hembrug of Holland who produce super-high precision lathes. They can replace grinding operations at a fraction of the cycle time whilst maintaining the same accuracy.

A Northfield model DPH-700 (7in. diaphragm chuck) was used with additional special tooling. This offsets the out of balance condition so the chuck can operate at speeds over 4,000 rpm.

On completion of the project the parts were cut and inspected with results of 2 microns run out.

 

Do you have a specific chucking requirement? Then reach out to Northfield Precision. Contact the Northfield Team.

 

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Lathe Finish Turning

Our customer is an OEM manufacturer of welding equipment.

Brief

The work holding requirement is for a lathe. Our customer needs a chuck that expands to grip the inner diameter of welding shield caps so they can finish-turn its rough outer shape.

Northfield Solution

A Highly-Specialized, 4.500” Diameter Northfield Collet Chuck
A Highly-Specialized, 4.500” Diameter Northfield Collet Chuck

Shown here is a highly-specialized, 4.500” diameter, Northfield Collet Chuck with custom top tooling mounted.

As the chuck’s internal diameter collet expands, it also acts to pull the part down and onto its outer banking surface shown in the photo at the right. This insures repeatable location onto the datum surface, saving time and reducing error.

This is just one of many examples of our work across a variety of industries and machining situations. Do you have a project that requires a custom solution? Then get in touch with our team and chat with a Northfield engineer to see how we can help solve your problem. Contact Northfield – Northfield or call – Phone: (516) 431-1112.

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Custom Parts, Custom Colors

No, we’re not making a fashion statement for chucks here!

At Northfield, we affectionately refer to the aluminium anodized chuck as “BIG RED”. Creed Monarch use “BIG RED” to manufacture close tolerance parts for Robert Bosch Power Tools.

We designed “BIG RED” to accommodate the unusual shape of the ‘Wobble Plate’ part of the drive mechanism in a Bosch reciprocating saw. Improving accuracy and dramatically reducing change over time.

Model Big Red Custom Chuck
Northfield custom work holding, model ‘big red’

The “Wobble Plate” is made from 52100 tool steel and heat-treated to 58/63 Rockwell. Spinning at 3,500 rpm for hard turning the “Wobble Plate” internal diameter, creates the outer race of a bearing set.

“BIG RED” is a example of our custom work holding at Northfield beyond the chuck.

  • The spring-loaded plunger and locator ensure accurate locating of the “Wobble Plate” to four specific reference points.
  • When hand mounted on the face of a fixture, the unique design provide repeatability of 0.002 inches.
  • The fixture allows automatic operation after the initial loading.

“BIG RED” solved previous holding problems and saves a tremendous amount of production time.

Do you have a special work holding need that we could help with? Get in touch now.

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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. Video Below ⬇.

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.

Video
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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.