Customer Problem | Pain Point:
Electrical conduit is widely used to run electrical components in the buildings and infrastructure throughout of the world. A manufacturer of steel EMT (electrical metal tubing) contacted Proto-1 with a new problem. When steel EMT is used in the field, the 10 or 20 foot sections have to be assembled together. This assembly process, when repeated in large numbers, was inefficient for contractors in the field who were installing conduit in large structures. The manufacturer of the steel EMT wanted to supply contractors with steel EMT that came with pre-installed set screws or compression couplings, but they lacked a solution that could turn the raw material into the final product with one process.
Engineering A Solution:
In order to accommodate to the customer’s requirements, Proto-1 would have to build its largest custom tube end forming cell yet. The customer required a machine/process that was fully automated that could form raw material into both of their two steel electrical tubing products. To start, Proto-1 designed an auto feeding magazine for 10 & 20 foot tube sections. This magazine would feed tubes to the station transfer line which would not only transfer the tube to each station but it would hold the tube in place during each end forming operation. There were 5 stations of varying operations in total for both types of steel EMT product. The compression coupling style of steel conduit utilized 4 out of the 5 stations. The first station involved an expand operation which expanded up one end of the tube. The second station was another expand operation to expand the tube to its final diameter. This station was needed since the whole expansion couldn’t be done in one operation due to material splitting and flaking. From there, the tube skipped the 3rd station and moved to the 4th where the fitting was delivered and then pressed into place. Once in place, the tube would move to the 5th and final station where a crimp was applied on the outside of the tube, between the two o-rings on the fitting. This operation was completed using an RFM rotary style end forming setup. From there, the tube moved to a dock where it can be lifted out and placed for shipping.
After the tooling was changed over, the machine could then produce the steel EMT utilizing the pre-installed set screws. This style utilized 4 out of the 5 stations as well. The first station was an expand operation on the end of the tube but the 2nd station was a punch and flatten operation which would punch two holes and then flattened the area around the punches. From there, the tube moved to a 3rd station where the set screw assemblies were dropped into the two holes on the tube. Prior to being dropped in the tube, the 3rd station would assemble the set screw to the crimp nut. Once the screw assembly was in place, the tube would move to the 4th station where the crimp nuts would be crimped in place, finishing the tube. The tube would then move to the dock.
Final Tube Forming Solution Delivered to Customer:
In the end, the conduit end forming cell was a success. The product that it was able to create in one process eliminated the need for other processes for the manufacturer, increasing overall efficiency. Not only did the machine save time for the manufacturer, but it also was able to deliver a product that would save contractors time in the field.
