At Broach Masters all Spline & Gear Broaches are ground on state of the art CNC equipment. We specialize in fine to medium pitch Spline & Gear Broaches for the Aerospace & Instrument Industry. We design tooling that is appropriate to the job. Our minor size broaches (Dwell Teeth) allow for near perfect concentricity from the pitch diameter to the broached minor diameter. This feature allows for later tooling points or spline qualification. Ground fillet radius are standards. Our broaches are designed and made with the key elements of the part in mind. Hex, Square or D-D Broaches may have side shaver teeth if the tolerance requires. They are designed & made with a purpose - The success of the end user. Because of our flexible dress system we are able to convert quickly to profile modifications. (I.e. Plus Tip, etc.) Using Diamond Wheel Dressings, we program exact points of tooth Geometry. All spline & gear parts are element checked and charted on our state of the art Klingelnberg P26 Gear Analyzer.
Our specialties include holding good concentricity from pitch diameter to location diameter. If the part is processed correctly, this can save future truing operations and reduce costs. Blind Hole Broaching Internal Splines, Squares, Hex's in Aerospace materials. This operation (done at Broach Masters) is very competitive with shaping on parts under 3/4 inch P.D. It is clearly the best choice for Splines under 3/8 P.D. for both quality and price. Blind Hole Broaching (done at Broach Masters) is an economical and efficient means of internal Spline production. This operation offers good concentricity to ground location Journals and good surface finish when part material is hardened to Rc32-36, it is competitive with shaping parts under 3/4 P.D. and the best choice for splines under 3/8 P.D., for quality and price. The main advantage is that it is very repeatable in size and does not have any variance because of cutter deflection.
Why use U.G.C. Shank Shaper Cutters? Because Performance = Profits
The cutting of internal gears and splines presents an interesting challenge to the designer and manufacturer of shank type shaper cutters. Deflection (of the cutting edge by cutting forces) increases by the fourth power with the reduction in shank diameter -- and also increases by the third power with the increase in length. It is therefore very important to make every effort to control the design of the cutter in such a way as to reduce the deflection as much as possible. Standard norm for the maximum number of teeth that can be used in a cutter is between 7 and 9 teeth less than a fillet root internal spline (with 30ö P.A.). Example: Assuming a 12 tooth 24/48 DP. 30ƒ P.A. full fillet internal spline starting 1/2" below the face of the part and 1 inch long, requires a fluted cutter with a cutting length of 2 inches. 1-1/2" to reach the end of the spline plus 1/8 inch for overstroke plus 3/8 inch of cutter life. The accepted rule would be to use a 5 tooth cutter. This cutter would have a shank diameter of approximately .250. Applying 10 lbs. of load radially at the cutting edge would cause a deflection of over .004 (.00464 to be exact). An 8 tooth cutter designed by U.G.C. to produce the same part would have an approximate shank diameter of .355. Applying the same 10 lbs. Load at the cutting edge would cause a deflection of .00114 inches ‚ less than 1/4 the deflection! It does not require much study to understand that the durability of the cutting edge will be greatly improved by using an 8 tooth cutter vs. a 5 tooth cutter.
Another point to consider is how many times each tooth of the cutter gets used while cutting one single part. Assuming the part will rotate 2-1/2 times in order to rough and finish cut, each tooth of a 5 tooth cutter will be used 6 times (12/5 x 22-1/2 turns) while each tooth of an 8 tooth cutter will be used 3-3/4 times (12/8 x 2-1/2 turns). Considering the difference in deflection and the number of times the teeth are getting used -- our calculations and tests show that an 8 tooth cutter will outperform a 5 tooth cutter by at least 6 to 1. Adding in the time required to sharpen the 5 tooth cutter more frequently, there should be little doubt that the 8 tooth cutter in this scenario would be a far better investment, even at a slightly higher acquisition cost. For over 25 years we have continually refined our shank cutter design software to allow us to use the maximum number of teeth without trimming interference and while maintaining the utmost in geometric tooth accuracy. This is but another example how we at Broach Masters / Universal Gear (U.G.C.) continue to devote our efforts and resources to provide our customers with superior quality gear cutting tools that provide not only the utmost accuracy, but also the highest value for the dollar.
Experience the Difference!