3-D Printing Follow-Up

My initial skepticism about 3-D printing’s place in the gear industry took a solid hit during a recent visit to a client. I am used to seeing colorful renderings of Solid Works or Pro Engineer files, but nothing prepared me for a complete one-quarter-scale, WORKING model of the prototype product we were meeting about.

Scale models are powerful communication and selling tools. I have built several myself over the years and know the value of putting a physical object in the decision maker’s hands. My first model was for a turret drive mechanism that severely taxed my limited woodworking skills, but it looked fabulous in the mocked-up, full-size mobile howitzer — so good in fact that the vehicle builder “neglected” to return it after giving the contract to a competitor. The project eventually got cancelled, so karma may have been restored to proper balance.

Ten years later, my woodworking skills were slightly better and the resulting model helped secure a nice prototype order. But not before it got bounced on the tarmac at the airport and had its paint job touched up with a felt tip pen!

Some concepts can only really be understood with a scale model. This client took his model to the next level by 3-D printing the internal components too and assembling it with to-scale plastic nuts and bolts. The fit and finish were consistent with the full-size prototype, save for the gear action being a bit lumpy because the bearings didn’t have rollers. Lots of hand-finishing on tooth flanks and splines got the motion close enough that potential customers couldn’t resist rotating the device.

Best of all, the model was made in-house on a low-cost 3-D printer that will get lots of use in the future. I am interested to see if they can throw a shrink factor at the computer models and print their own patterns for the foundry. That savings would more than recover the cost of the printer.

About Charles D. Schultz 678 Articles
Charles D. Schultz is President of Beyta Gear Service and one of Gear Technology's technical editors.