April Machining Problems

1. April Machining Problems • Vane M1V #1 major damage • Vane M1H#1 roughing mistake • Corrective Action • Impact on schedule and cost Matt Hoff LBNL May 1, 2014

2. Module 1 vertical vane #1 Major damage April 29, 2014 late in the evening. Discovered April 30 at 5:00 AM Tooling Malfunction while being machined on the G&L 450. The end cut back was being rough machined. The operator had set-up and started the cutting program late in his shift and gone home. (This is typical at LBNL shops). Rick Kraft was in the shop until 6:30 PM. Rick remembers hearing the G&L 450 running and it sounded normal. Mark, the operator, came in at 5:00 AM and found the part damaged and the cutting tool laying on the machining bed next to the part. The cutting tool should have been in the tool collet on the machine. It appears the cutting tool slowly worked its way out of the collet during the 8.5 hour long program, eventually falling completely out of the collet. Three of the senior machinist in the shop had never seen that happen before. Rick Kraft says he saw a cutting tool creep a few years ago at a previous job and Jeff, another machine shop manager, says he had heard of it before at other places. LBNL will retire the damaged M1V #1 vane and will start machining a new M1V #3 vane from one of the spare pieces of copper.

3. M1V #1 Vertical cooling passage Cut should have stopped about here Actual cutting tool

4. M1V #1 Comparison of actual part to CAD model CAD model with hidden lines turned on.

5. M1V #1 Other views Horizontal cooling passage

6. M1V #1 Cutting tool in a collet on a bench Extra gouge suspected to have happened when the cutter fully came out of the collet

7. Module 1 horizontal vane #1 Roughing mistake April 25, 2014 Minor damage while being machined on the G&L 450. The end cut back was being rough machined. The operator, Mark, started the cutting program from the wrong surface, which was 3/8 inch too high. Mark did not notice the mistake until the operation had gone into the part 1/2 inch. Since this was a roughing cut and was leaving 1/8 inch of material, the end result is a cut 1/4 inch too high and 1/2 inch too deep. After the mistake was assessed, the rest of the cut-back machining was completed to the correct dimensions. This is the same vane that has the small gouge at the radial matcher. Its possible this cut would have little impact on the RFQ performance and could be tuned out, but LBNL has decided to retire this vane and replace it with the Test Vane. The Test Vane is the same M1H shape, it just needs some re-machining to bring the braze surfaces into tolerance.

8. CAD model of what the vane would look like completed with the extra material removed. M1H #1 Earlier gouge

9. M1H #1 Additional views

10. Corrective Action • PXIE machining problems summary: • 1 minor error because a new program was run untested M1H#1. (gouge) • 2 minor errors because the machinist started a program from the wrong surface. (offset grooves in M1H #2 and the roughing mistake on April 25, 2014 M1H#1.) • 1 tooling malfunction that caused major damage to vane M1V #1 • The project is not quite half way through fabrication. Personal note: I have worked with this shop for 26 years and I have never had this quantity of errors on a part or project. I don’t think anything is wrong with the shop or the machinist, but I don’t have an explanation either. But, with the list of issues we have experienced so far, LBNL feels we must take steps to reduce error in the future. There fore

11. Rick Kraft, the shop manager, has decided to take the following steps to reduce any further problems: • The collet mount system will not be used on PXIE roughing operations and will be replaced with a solid mount with set screw system. • No unattended roughing procedures • The primary machinist for each machine specific operation will document every step taken to set up and machine the vane. Rick will review the list and develop a check list for each specific operation. The secondary machinist (back up) will be involved in this process as a "second set of eyes"  to help verify and to familiarize themselves with the process/project. • All aspects of the machining will be reviewed by both machinists and agreed upon as a best practice . If agreement can not be reached, Rick will mitigate a solution. M1V #2 vane Pete (back-up) Mark (primary) April 30, 2014 in the afternoon, changes already implemented

12. Impact on Cost and Schedule Steve Virostek and Rick Kraft will sit down in the next few days and reassess cost and schedule, so no specifics will be shown here. But there are implications from the two vane substitutions and new machining procedures. Test vane needs to be re-mounted on a stainless plate and braze surfaces re-machined. Time and money A spare vane needs to be machined from scratch. Time and money No more unattended machining will increase cost. (LBNL charges for labor only, not machine time. Unattended machining was mostly at no cost to FNAL.) Time and money Two machinist will be working on each part set-up and review each procedure. (This use to be done by only one machinist.) Money