Winding Dimensional Control Plan for Modular Coil Assembly

1. Modular Coil Winding Dimensional Control Plan Peer Review B. Stratton May 13, 2005

2. Thanks • This plan is the result of much useful input from: M. Anderson, S. Anderson, A. Brooks, J. Chrzanowski, M. Cole, P. J. Fogarty, M. Hause, P. Heitzenroeder, B. Kearns, B. Nelson, S. Raftopoulos, W. Reiersen, F. Terlitz, D. Williamson, and M. Zarnstorff

3. Charge • Is the overall structure of the plan adequate to ensure good dimensional control of the coil windings? • Is a trail winding needed in order to achieve good dimensional control? If so, is a trialwinding needed on the first production winding form, or on the first winding form of each type? Why?

4. Outline • Assumptions behind dimensional control plan • Dimensional control steps from start to finish of winding process • These will form the basis for procedures • Justification for trial winding

5. Assumptions • Strategy: wind “into the box” without shims and with an extra turn (compared to original plan) for each coil type • Type A and B coils will have 11 turns and type C coils will have 10 turns • Twisted racetrack (TRC) coil experience shows that compression required to fit in extra turn is achievable • Preset side clamps to positions chosen to achieve desired height of completed winding pack • Adjust height and width of completed winding pack to place the current center of the coil at the design location • This strategy assumes uniform compression of the winding pack during winding and adjustment to achieve the correct overall current center of the coil • We will see if this is a valid assumption when the TRC is cut up

6. Winding dimensional control plan-1 • Written for first winding of each coil type (either trial winding or production winding) • Measurement steps that could be eliminated on subsequent windings of a given type are in green • Areas requiring further work are in blue • Problem areas are in red • Mount winding form to support ring and install in Station 1 • Mount measurement monuments to inside surface of winding form • Prefer conical seats over tooling balls: quicker and more reliable to measure • Preferable to have vendor install some monuments on inside and outside of winding form • S. Raftopoulos has designed two types of “pucks” that can be welded on at PPPL: one with a conical seat and the other with a ¼” hole for laser tracker monuments • Need to finalize number of monuments, their locations, and which ones will be supplied by vendor

7. Measurement monument locations Precision ¼” holes on both flange edges, 6-8 holes per flange Vendor supplied Conical seats distributed around the winding form in this area; 6-8 seats on both sides of T Vendor supplied or PPPL installed

8. Winding dimensional control plan-2 • Set up Romer arm and check calibration against NIST-traceable standard • Make point-cloud measurements of machined winding surfaces, flange surfaces, and flange bolt holes • Can Romer arm reach both sides of winding form from one location? Probably OK for type C coil. Will make CAD model of arm to determine this for all three coil types. • Fit CAD model of winding form to point-cloud data • Measure monuments and incorporate them into CAD model • Are our measurements consistent with vendor-supplied data? • Re-measure monuments • Measure winding surfaces in same pattern as will be used for measurements taken during coil winding. Necessary to determine component stack up from measurements during winding. Use same pattern as on TRC. Make a measurement fixture that can be installed at each clamp position to define these measurement points.

9. Block 1 Block 2 ... Clamp 2 Clamp 1 Clamp 3 4 4 8 8 12 12 3 3 7 7 11 11 2 2 6 6 10 10 1 1 5 5 9 9 Point Groups 1 2 3 Point Groups 1 2 3 Shim 3 Shim 2 Sim 1 Measurement pattern Tee Side Measurement Points Outside Winding Direction Block 1 between Clamps 1 & 2 Similar pattern on sides of winding pack A. Brooks

10. TRC Side B: Clamp Location Numbering Scheme 20 25 19 30 18 35 17 40 16 15 14 13 12 45 9 8 11 7 6 5 4 3 2 10 1 50 A. Brooks

11. Winding dimensional control plan-3 • Re-measure monuments • Based on our measurements and vendor’s measurements, are winding surfaces within tolerance? If not, two cases: • If deviations are smaller than reasonable range of adjustment of winding pack (<±0.080”) do nothing at this point. Compensate for deviations later during setting of side clamps. • If deviations are larger than range of adjustment of winding pack, shim low places to improve uniformity. Use glass cloth tape underneath chill plates to shim. • Install clamp studs • Clean and mold release winding form • Install winding clamps and lead blocks • Install cladding, minimizing glue thickness between cladding and winding surfaces. Bend cladding tabs individually to ensure that cladding conforms well to winding surfaces • Measure cladding surfaces on base and septum using standard pattern. Check that dimensions are consistent with winding surface measurements and cladding thickness (0.040”) plus any shims

12. Winding dimensional control plan-4 • Move winding form to station 2 or 4.(delete 3) • Install ground wrap, trimming as needed in bends to achieve uniform thickness. • Measure winding surfaces on top of compressed ground wrap using standard pattern. Check that dimensions add up to nominal thickness of cladding and compressed ground wrap plus any shims. • Cladding: 0.040” • Compressed ground wrap: 0.045”-0.010”=0.035” • Total buildup: 0.075” • Measure cross sectional dimensions of conductor under gentle compression for spools that will be used to wind side A. Use these conductor dimensions in subsequent prediction of desired winding pack dimensions. Fit set of calipers with wide jaws for this measurement.

13. Winding dimensional control plan-5 • For side A, set side clamps parallel to septum at desired width of winding pack using gauge blocks. Use washers to shim side clamps. • Where winding surfaces are within tolerance (<± 0.010”) set side clamps to measured width of four compressed conductors adjusted by TRC experience to make predicted height of winding pack correct. On TRC, final height of pack was low compared to expected value in straight sections and it was high in some regions of high torsion/curvature. Use A. Brook’s fit to TRC side A layer 10 height measurements to predict clamp settings. • Where winding surfaces are out of tolerance (>±0.010”) set side clamps to positions calculated using expressions in section 1 of M. Zarnstorff’s memo, plus prediction based on fit to TRC side A layer 10 height measurements. Note: these expressions assume that the winding form septum surfaces are straight, perpendicular to the base, and in the desired orientation. More general expressions are needed if these conditions are not satisfied, e. g., if the septum is tilted or if the T is rotated.

14. Best Fit of TRC side A height using layer 10-base measurements before adjustment InP=in-plane curvature (1/in) OOP=out-of-plane curvature (1/in) Tors=torsion (rad/in) dW=dH*(W/H) can be used to predict initial clamp settings assuming constant cross sectional area of winding pack A. Brooks

15. Calculation of side and top clamp settings from M. Zarnstorff’s memo-1 • Assumptions: • winding form T is straight, perpendicular to the base and in the desired orientation • Assumes turns uniformly distributed in winding pack, so that location of current center is determined by winding pack boundaries • Covers two cases: • Positioning the clamps to compensate for deviation of the winding surfaces from the design CAD model • How to adjust the clamps where the desired clamp positions can not be achieved x1, x2 (y1, y2)=deviation in horizontal (vertical) locations of winding surfaces w1, w2 (h1, h2)=deviation in horizontal (vertical) surfaces of winding packs W, H= design width (height) of winding pack

16. Calculation of side and top clamp settings from M. Zarnstorff’s memo-2 Case 2: Case 1: The ~ denotes the achieved values of the height and width

17. Winding dimensional control plan-6 • Continued • Make a set of 10-20 gauge blocks that covers the range of possible settings in 0.010” increments • Radius edge of clamps so they conform better to the winding pack in regions of high curvature or torsion • Use silicone rubber under pads in these regions • Wind side A to complete winding pack, reforming conductor by tamping as was done on TRC. • Set top clamps to specific torque value during winding. Value of 35 in-lbs used on TRC was probably too high. Use 30 in-lbs. Use torque wrenches for which this value falls in the middle of the operating range • During winding, measure top and sides of first, fourth, and seventh turns using standard measurement pattern. Check that these dimensions are as expected.

18. Winding dimensional control plan-7 • Measure top and sides of completed winding pack using standard measurement pattern • Use Romer arm to set top clamps to desired height of winding pack. This will either be the design height in regions where the winding form is within tolerance (step 21a) or the value from section 1 of M. Zarnstorff’s memo (step 21b) in regions where the winding form is out of tolerance. In places where this can not be achieved, get as close as possible without exceeding 30 in-lbs torque on clamps. • Measure height and width of completed side A winding pack. • Reposition casting in turning fixture to wind side B • Repeat steps 20-27 for side B of coil.

19. Winding dimensional control plan-8 • Adjust height and width of both winding packs starting with side A. This adjustment attempts to keep the current center of the coil within tolerance of the design position in places where setting of the top clamps to the calculated values can not be achieved. Work systematically in regions of 3-5 clamps. Start in regions of high torsion/curvature. Need to define a pattern for adjusting each coil type. • In these locations, set top and side clamps to values from expressions in section 2 of M. Zarnstorff’s memo using measured height and width of winding pack to evaluate these expressions. Use Romer arm to set top clamps and adjust shims to set side clamps. • Do these expression need to be generalized to account for more complex deviations of the winding form from ideal, e. g., tilting of the septum? • Measure top and side of side A winding pack • Readjust side A winding pack to put height and width within ±0.10” of predicted values where possible. • Measure top and side of side A winding pack

20. Winding dimensional control plan-9 • Continued • Use expressions in section 2 of M. Zarnstorff’s memo to calculate adjustments to side B winding pack required to put overall current center of coil at design location. Use measurements of adjusted side A winding pack from step 30e as input. • Adjust side B top and side clamps to calculated values. • Measure top and side of side B winding pack • Readjust side B winding pack to put height and width within ±0.10” of predicted values where possible. • Measure top and side of side B winding pack • Perform final analysis to make sure design position of current center of coil is achieved. Use final measurements of both sides as input. • If current center position is not satisfactory, repeat adjustment of both sides (steps a through k)

21. Winding dimensional control plan-10 • Perform final measurement of height and width of winding packs after adjustment is complete • Use Romer arm to measure positions of top and side clamps after adjustment is complete. Need to define measurement points on clamps. • Go around coil, completing ground wrap and installing chill plates in sections of 3-5 clamps each. In each section: • Remove minimum number of top and side clamps needed to complete ground wrap and install chill plates on both sides in one section of the coil. • Complete ground wrap on both sides of coil, keeping thickness as uniform as possible in top and side clamp locations. Thickness variation elsewhere is OK. • Install chill plates, ensuring that they are in good contact with the winding pack, especially in clamp locations • Re-install top and side clamps to positions measured in step 31 minus compressed ground wrap thickness plus chill plate thickness. Use Romer arm to set top clamps. Use shims to set side clamps.

22. Winding dimensional control plan-11 • Measure top and sides of chill plates in standard measurement pattern. Check that dimensions are consistent with final measurements of winding packs in step 31 plus thicknesses of compressed ground wrap and chill plates. What tolerance to set on this measurement? • Install cooling tubes and solder them in place, removing minimum number of clamps required to work in a given area. Re-install top and side clamps to positions used in step 33d. • Attempt to maintain winding pack dimensions while bag mold is installed. We do not yet have satisfactory plan for doing this. The present plan is: • Measure surfaces of top and side clamp pads using Romer arm. How to do this? The top pads appear to be accessible with the small Romer arm tip but the side pads are not. Can they be made a little wider to provide a measurement surface? • Remove minimum number of clamps necessary to work in a given area.

23. Winding dimensional control plan-12 • Continued • Replace top and side clamp Delrin pads with G-11 pads and install bag mold. Maintain constant bag mold thickness (two half-lap layers) on top of pads. Variation in bag mold thickness elsewhere is OK. • Replace clamps. • Use Romer arm to set top and side clamp pad surfaces to values determined from measurements in step 36a plus nominal thickness of compressed bag mold and difference between thicknesses of Delrin pads and G-11 pads. Two half-lap layers of bag mold compresses by 0.005” (after initial compression and release) so compression of bag mold should not be a major source of error. Is this reliable? • An alternative is to set the top clamps to 30 in-lbs torque instead of trying to compensate for the bag mold thickness. The chill plate and cooling tube structure is reasonably rigid so it will help hold the winding pack in place as clamps are removed to install the bag mold. • Complete coil

24. Justification for test winding • It would be very useful to do a trail winding on the first winding form of each coil type. The lead blocks and chill plates would be installed but the ground wrap would not be installed to save time. • After the trial winding is complete, adjust the winding packs to put the current center of the coil at the design location. Then measure the positions of the top and side clamps. For the production windings of each coil type, set the side clamps to these positions. Set the top clamps to these positions after winding. This would have several benefits: • The correct amount of conductor would bewound onto the form in a “relaxed” state. Less deformation of conductors leading to more uniform distribution in winding pack. • Minimal adjustment (possibly none) of the completed coil would be required. Saves time. • The six coils of a given type should be very similar to each other • Drawback: cost and time • Reminder: the first production winding is de facto a trial winding