As far as work went this week, it was a real roller coaster: I've got at least a half dozen projects in various stages of completion, and my priorities were rearranged four times in as many days. At least I got left alone today; that meant that I got to end the week in positive territory
The photos attached show the two hottest job's; the first show's the emergency lathe fixture we need to get production of one series of propellers going again; the black and shiny one with the broken bolt (on the right) is the old one, the shiny one (on the left) is the one I just carved out of the toughest piece of stainless steel I have ever machined. It's made from a grade titled by it's mfg as "Aquamet 22 HS". From what I can see, it's pretty much a stainless steel super alloy. To turn the same part out of 1018 low carbon steel would have taken three cutting edges of a four edged carbide insert. Would have taken ~10 to 12 hour's with the equipment I have. This thing burnt up 5 carbide inserts (20 cutting edge's) and took over 30+ hour's with the same equipment.
The reason I carved the new one out of Aquamet is because it was the toughest piece of steel I could get my hands on; it was part of a shaft that was supposed to have a Nickle Aluminum Bronze rudder blank cast around it. The mold flask blew a clamp ~1/2 into the pour, so we lost that shaft (as well as what was supposed to be a rudder). The old fixture is whatever super high quality steel that Hardinge MFG (Elmira, NY) uses for scary customer applications. The fixture itself is ~18 month's old, but we've been blowing up draw bolts and collets on a regular basis for the last several months...... And that's because the customer renewed the production contract, only at ~3 to5 time's the original volume the old fixture was intended for. And as to why we didn't have a back up? It was because under the old contract, the volumes were low enough that management wasn't worried.
Then add in the final insult: they weren't worried because I had been able patch/bandaid/salvage the
thing for that many month's......
We have not one, but two complete fixture kits on order with Hardinge; only problem is the six week lead time. That's why I got handed the job of trying to make the toughest part I could, just to keep us running. I really hope it works, because I've watched the loadings placed on the fully engineered fixture many times.....
Photos 2,3,and 4 are of a really simple part as far as function is concerned. It's the figuring out how to make it that sucks.
This is the other project that's been riding my
. We see these every couple of year's; the propellers these caps go on are customer proprietary. The cap itself is just a trim piece. The actual propeller has way scary tolerances; the print for this? +/- .010" on the (few) tight tolerances, +/- .030" for the rest. What sucks is just how delecate the
things are.
Photo two show's the first one machined complete; photo three show's it's evil twin Skippy mounted on the machining fixture ready for the whole "OFF WITH IT'S HEAD!!!!!!" set of operations. The final photo shows just how much metal we hogged out underneath, making these things far too close to beer cans.
These would have been pure gravy if we hadn't had that lightning strike that took our program file communication system down last weekend............
