My last blog concerned project management and the problems of staying on schedule. I thought it only fair to pass on some techniques I learned along the way to get projects and parts moving again.
1.Be open to alternate materials.
Sometimes the start date of a component gets delayed because you can’t get the material required. It might be the size, chemistry, or pedigree that causes purchasing to come up empty. Can’t find “aircraft quality?” Read the specification; perhaps you can improve the rating of a commercial grade with extra testing or lab analysis. Blank size an issue? Re-examine those stock allowances or re-design the gearing to reduce the finish diameter enough to make what is available work. Chemistry limits are established to get core properties; sometimes an alternate grade will get the same results if you reduce the critical section with webs or a hole through the middle.
2.Be open to alternate processes.
We once had a project with such a tight deadline we couldn’t get hobs made in time. It was more expensive, but we learned wire EDM could cut the rough teeth just as well in a matter of hours — not weeks. Blew the budget, made the customer deadline, and got more business. Can’t get a fabrication in time? What about milling the part from a big chuck of steel or iron?
3.Be flexible with your design.
It isn’t as much of a problem today, thanks to CNC hobbers, but once upon a time we had a gear that none of our machines could cut due to change gear issues. An hour of playing with the geometry was all it took to develop an alternate tooth combination that we could cut. A similar situation often occurred with rolling element bearings before we wised up and located bearings earlier in our design process. That “alphabet soup” in a bearing number can blow up on you if aren’t careful.
4.Rework is your friend.
A wise boss once opined that “Anyone can make a good part the first time; it takes real craftsmanship to salvage one.” No matter how careful you and your crew are, parts will be damaged in manufacturing or come up short of acceptable at inspection. Good engineering can often get that “defective” item reworked into something better than the original requirements by chrome plating, repair welding, thread inserts, or re-heat treating. Remember that scene in Princess Bride about whether Wesley was “dead” or “dead-dead?” Don’t give up on critical components until you consider the rework options. Very few are “dead-dead.” Give your local Miracle Max a chance.
(We’re always looking for good project stories to share; the comments traffic has been light of late. CS)