The three partners contributed their diverse production and processing experience and their last initials to found SPR Machine in 2002. This Hamilton, Ohio machine shop has grown from 2,500 square feet to 78,000 square feet, with 14 mills covering the floor, as well as lathes, welding and inspection equipment, all designed primarily to service the aerospace and medical industries. quality blanks from 60 inches to 0.0005 inches.
All of this talent, experience and entrepreneurial energy make SPR Machine an open store that embraces new growth challenges with enthusiasm. SPR jumped at the opportunity when one of the challenges of converting steel to brass part materials arose and needed to see how much cycle time SPR could save with high speed machining.
This eventually led the workshop to new equipment, intuition, staff qualifications and a renewed respect for the versatility and machinability of brass.
The opportunity came when co-founder Scott Pater was an off-road and RC car enthusiast, and he combined those passions with friends to race off-road RC cars.
When this friend created a redesigned version of an RC part and started offering it in hobby shops, Pater showed him that SPR would be a better supplier than a Chinese supplier, especially since ordering overseas means months of waiting to receive the parts.
The original design used 12L14 steel, which corroded and expanded, making it difficult to remove after use.
Aluminum solves the problem of corrosion, but lacks the strength and weight to provide stability in a small car with a low center of gravity.
Brass combines both with an aesthetically pleasing appearance that makes the piece appealing to customers and reinforces SPR’s quality-focused approach. Also, brass doesn’t produce the same long and sticky SPR bird’s nest debris as other metals, especially in almost 4″ long drilled parts.
“Brass works faster, chips come out smoothly, and customers like what they see in the finished part,” Pater said.
For this job, Pater invested in the company’s second CNC lathe, a seven-axis Swiss-style Ganesh Cyclone GEN TURN 32-CS with two 6,000 RPM spindles, 27 tools, linear guides, and a 12-foot static bar feed press. .
“Originally we machined this concrete part on the SL10 lathe. We had to machine one side, take the part and flip it over to finish the back,” says Pete. “On Ganesha, the part is completely finished as soon as it comes out of the machine.” With a new machine at their disposal, SPR needed to find the right people to better understand its learning curve.
Operator David Burton, formerly of SPR’s deburring department, accepted the challenge. A few months later, he learned block coding and G-code for a two-axis machine and wrote the source code for the part.
SPR’s partnership with Cincinnati-based machinability consulting firm TechSolve gave the store a unique opportunity to optimize this segment in partnership with the Copper Development Association (CDA), which represents copper, bronze and brass manufacturers and users. .
In exchange for TechSolve directing production parameters to the SPR, the shop floor will receive the final optimized parameters from the machine and material experts.
In addition to turning, the part initially required ball milling, drilling many deep holes, and drilling bearing surfaces on the inside diameter.
Several Ganesh spindles and axes saved production time, but Burton’s original production schedule resulted in a part cycle of 6 minutes 17 seconds, meaning 76 units were produced every 8 hour shift.
After SPR implemented the TechSolve recommendations, the cycle time was reduced to 2 minutes 20 seconds and the number of parts per shift increased to 191.
To achieve this optimization, TechSolve has identified several areas where SPR can reduce cycle times.
SPR can replace ball milling with broaching, joining parts and machining five slots at a time, which most likely won’t work when making stainless steel or steel parts.
SPR saves even more time with solid carbide drills for drilling, more aggressive feeds and depths with fewer retractions and greater depth of cut for roughing. Balancing the workload between the two spindles means that neither waits for the other to complete a process, increasing throughput.
Finally, the absolute machinability of brass means that the process can be carried out at high speeds and feeds by definition.
SPR allows TechSolve to streamline the process so that the shop can see the benefits of using brass in other manufacturing parts.
Burton’s original production plan provided the starting point, and SPR’s own optimizations reduced cycle times even further.
But being able to see the entire process from analysis to production optimization is a unique opportunity, as is the use of brass itself.
As SPR realized, brass offers many benefits, some of which stand out in this project.
With high-speed machining of brass, you can quickly drill deep holes, maintain accuracy and increase tool life during long shifts.
Since brass requires less machining force than steel, machine wear is also reduced and higher speeds create less deflection. With up to 90% scrap brass, SPR is able to profit from mechanical chips through recycling programs.
As Pate says, “Brass offers huge productivity gains. Your equipment is your limiting factor unless you have advanced tools that can really do high speed machining. By upgrading your machines, you can unlock the true potential of brass.”
SPR’s Lathe Division processes more brass than anything else, although the entire shop also processes aluminium, stainless steel and specialty materials including plastics such as PEEK. Like much of the work that SPR designs, engineers and manufactures, its brass components play a vital role in space exploration, military telemetry, medical instruments and other applications that often involve non-disclosure agreements with client lists, many of which are clients. SPR results are not allowed. be named. The type of work the workshop does means that the tolerances divide the SPR workflow into about half in the three-thousandth range and the rest in the three-tenths range.
Adam Estel, CDA’s Director of Bars and Bars, commented: “Using brass for high-speed machining helps mills justify investment in new equipment as it increases revenue and productivity and opens up new business. We are very pleased with what SPR has achieved, which should inspire other shops to be more aggressive with brass.”
George Adinamis, Senior Engineer at TechSolve, praised SPR for being open, saying, “It’s a great compliment that SPR shares information and trusts us, and the whole process is one of total collaboration.”
In fact, some SPR clients rely on Scott Pater for help with part development, part design, and material advice, so SPR can use brass on other projects and see their clients follow his advice.
In addition to designing and manufacturing parts for other clients, he became a supplier himself, creating a tombstone that allows four-axis lathes and mills to machine round and flat workpieces and castings.
“Our design gives us higher performance and is lighter in weight, yet very strong so a person can mount it on a machine,” Pater said.
SPR’s sophisticated experience fosters project innovation, collaboration, and an approach to success, with brass playing an increasingly important role in her workflow.
With this combined experience highlighting the benefits of working with brass, SPR Machine will look to other parts conversion opportunities to improve efficiency and profitability.