Bore Gaging Flexibility Boosts Productivity

A key machining operation at the plant is the boring of metal; consequently, improved inner and outer diameter measurement ability is required.

Case Study From: 9/15/2001 Modern Machine Shop

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Long barrel instrument

Fowler/Bowers Holematic XT bore gages help Kinze Manufacturing produce more simple, cost-effective and accurate measurements of inner and outer diameters. Here, inspector Dave Clemens uses the long barrel instrument on a typical part. Some of the company’s typical parts are 24 inches deep.

The main products sold at Kinze Manufacturing, Inc. (Williamsburg, Iowa) are its lines of agricultural planters and grain wagons, for which it previously bought the various machined parts to manufacture them. Today, however, the company manufactures most of its own components, and as it has evolved along the road to more integrated production, Kinze has found it increasingly necessary to add to its CNC machine capacity. This has resulted in tighter production controls and stronger emphasis on more accurate dimensional measurements.

“We call it ‘first piece and periodic inspection control,’ but it embodies our basic philosophy of relying on operator process control,” says Gaylen Vance, manufacturing engineering manager at Kinze. “Without the idea of reinforcing the measuring function at the workstation itself, nothing would have been accomplished in improving our quality to meet our changing production needs.”

A key machining operation at the plant is the boring of metal; consequently, improved inner and outer diameter measurement ability is required. Previously, standard bore gaging equipment was used at great cost due to long setups and a high number of steps involved. “Once you set a standard bore gage,” Mr. Vance says, “that’s the only size it can measure. That means consuming a lot of time with all the changes you are making in production for the various parts we are manufacturing. An aspect of that heavy drain on time is an inflexibility that we found was highly undesirable.”

The company began to search out its options for reducing measuring costs and improving flexibility and found the Bowers Holematic XT series of pistol grip gages that gave it “huge benefits,” according to Mr. Vance. The gage is distributed by the Fred V. Fowler Company (Newton, Massachusetts) in the United States.

“Use of the Fowler/Bowers bore gage on the shop floor is critical for us, particularly the pistol grip with three available heads,” he says. “It’s far superior for deep ID grooving. There’s nothing on the market with modified anvils. This XT series makes measuring deep ID grooving as easy as handling regular bore—plus the fact that you get consistent results. It’s well known in the field that obtaining consistent ID grooving measuring results is a serious problem. A standard bore gage simply can’t do it. Special anvils used with extensions are routinely employed for measuring bores of hydraulic cylinders 24 inches deep, something normally tough to do.”

The eight Bowers XT (extended travel) gage kits at Kinze cover a range of 1/4 to 8 inches (6,200 mm) and have wide measuring scopes to avoid the need to change anvils. Graduations are 0.00005 inch (0.001 mm) with 3-point tungsten carbide anvils above 0.5 inch (12.5 mm). It features several extensions for deep measuring jobs.

With a 5-year warranty, these gages take special anvils for threads, splines and slots. A large, easy-to-read display is featured. It comes with a setting ring that can cover the entire range to be measured.

According to Mr. Vance, this avoids the user’s need to purchase multiple ring sizes as well as to reset the gage itself. “When we stick the gage in a hole,” he adds, “we can release the lever and set it for a direct read.” He indicated that the normal tolerance the company has to deal with is 0.001 inch.

Mr. Vance reports that compared to normal dial bore gages, the XT allows a setup time that equals one-third what the company used to achieve, and overall inspection setup time savings is 50 percent.

Another benefit to Kinze is the simple training that is needed for proper use of the gage. “The operators actually enjoy using it, and when we purchased our first one a year ago, there were arguments about who would get to use it first,” says inspector Dave Clemens.

Beyond its basic philosophy of total operator process control, Kinze has instituted a routine of posting a list of all available measuring instruments at every workstation, of which there are a dozen in each of two separate departments at the plant. Not only is this list kept up to date, but a supply of these devices is available at each station. “We basically are bringing our supply of instruments out onto the production line,” Mr. Vance states. He also says that Kinze is now using a variable thread gaging system, as opposed to hard gaging, which permits quick setups and easily reveals thread size.

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