Second Operations Don't Have To Be Costly

The 2nd-Cut milling and deburring machine was developed by Bud Buddenbaum, a job shop owner in Illinois. Currently manufactured and sold by S&T Machine Lab (Denver, Colorado), the machine was designed for components being made for the Tow Missile Program. The parts were made out of 440 C stainless steel on an automatic machine, and the only operation left was protrusion tip removal. This operation was completed on a belt sander with V-block fixturing. The protrusion had a very sharp point and it did not take long to slice into the belt. The missile parts had a tolerance of 0.002 inch on the overall length. Many parts were scrapped when operators would press too hard on the sanding belt.

With the milling and deburring machine, however, this operation could be done with a positive stop, bushing and a carbide cutter. After perfecting this operation, Mr. Buddenbaum naturally started thinking of other uses for the machine. He soon found that it can do screwdriver slots and, with the adjustable V-block bolted to the top of the machine, that it is ideal for flat stock chamfering. Included in the V-block is an attachment for flat stock plastic deburring. By adding a plate, bushings, spacers and cutter to the front of the machine, it can deburr tube IDs or ODs, or both simultaneously. A second carbide cutter with spacers, plus a slotted bushing and a positive stop on the back of the machine, enables the operator to mill one, two, four or six flats. Each bushing is made to the proper depth for a particular part. The machine has accurate adjustments to 0.002 inch.

The milling and deburring machine will save money on many secondary machining operations. It is constructed of steel and powered by a 1/3-horsepower motor. The unit includes a carbide cutter, a severance cutter, shims and spacers, bushing blanks and V-block. It is essentially a small, horizontal mill weighing just 55 pounds. With its versatility, the machine can be used by just about any machine shop. The machine is safe, accurate and fast. It will deburr stainless steel, remove tips from round stock, chamfer edges on flat stock and ID- or OD-chamfer tube stock.

Dick Bronst, owner of job shop Brenco Machine (Barrington, Illinois), explains how the machine has helped his operation. "It saves money and time, improves quality on a part, and is responsible for getting the part out faster, more uniform and clean," he says. In the past, Brenco used a drill press to deburr its ID tubes. Now, Brenco uses the new machine to do ID and OD chamfering, or both simultaneously. It also does solid bar chamfering simply by adjusting the cutter.

When it comes to tip removal, every shop is familiar with tedious setup procedures. Using a belt sander is inefficient and time consuming. You need a skilled setup man and a careful operator. With 2nd-Cut, a simple setup is all that's needed. It has a solid carbide cutter with a positive stop that you insert. There is no adjustment until you change the operation. "With the belt sander method you get no guarantee of precision," says Mr. Bronst. "If the operator pushes too hard against the belt, you end up with a part that won't fit your customer's specifications. But with this new machine an operator can't make a mistake—it's foolproof."

All shops need expensive equipment for primary machining. But why tie it up for simple operations like milling flats or screwdriver slots? This unit is perfect for that type of operation. "By having this machine," Mr. Bronst says, "we can now deburr the parts while we are producing the run. We are just beginning to tap all the applications for 2nd-Cut. We have a lot of secondary operations." If you have many secondary operations and are looking for a way to make that job easier, this could be a solution.