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Galvanometric and Resonant Scanners
Published in Gerald F. Marshall, Glenn E. Stutz, Handbook of Optical and Laser Scanning, 2018
The most successful removable clamps are a form of collet that provides isolation of the mirror substrate from clamping stress. A disadvantage of the collet approach is potential loosening of the collet clamping forces, with a resulting drift of catastrophic failure. Collet clamps, if not overtightened, induce only compressive forces that produce no bending movement and thus no distortions in the mirror facesheet. One collet clamp technique is to mechanically isolate the shaft by relieved regions so that the distortions imposed by the clamping screw are not transmitted.
Toolholders and Workholders
Published in David A. Stephenson, John S. Agapiou, Metal Cutting Theory and Practice, 2018
David A. Stephenson, John S. Agapiou
Types of collets include single and double angle collets (Figure 5.57). Single angle collets are generally superior. There are several single angle collets with different cone angles; the most popular are the Rego-Fix ER style 16° (DIN 6499) included angle and the Erickson TG style 8° included angle. A lower included angle results in higher grip power (rigid tool grip) for the collet (e.g., an 8° collet provides twice the holding power of a 16° collet). The number and width of slots around the periphery determines the collapsibility or size range for the collet. A larger number of slots around the collet results in a larger collapsible range, better accuracy, and higher gripping power. When possible, a shank size equal to the nominal size of the collet should be used [60]. Collets with fewer slots designed to clamp only nominal diameter tools provide the highest concentricity. A light film of oil on the collet chuck socket cavity can increase grip power by as much as 40% and 50% using a steel and carbide tool shank, respectively. Carbide shanks generally grip slightly tighter than steel shanks. A double taper collet with one slot that does not extend through the wall thickness has low collapsibility (roughly 0.07 mm as compared to 0.3–1.0 mm of standard collets) but very high gripping power.
Advanced Autonomous Welding for Refabrication and Follow-On Testing of Previously Irradiated Nuclear Fuel
Published in Nuclear Technology, 2023
Justin D. Yarrington, Jason L. Schulthess, Spencer H. Parker, Jordan M. Argyle, Clayton G. Turner, John D. Stanek, Cad L. Christensen
Fuel was then removed from both ends of each rodlet in preparation for press fitting new endcaps. The fuel pins contained fuel with low to medium burnup [approximately 9 GWd/tonne heavy metal (HM) (Ref. 22)] that had bonded to the cladding intermittently and had the potential to shift if a force was applied. The fuel was mechanically removed using a modified precision mill (Wabeco F1210) with an additional fourth axis, as shown in Fig. 3. The fourth axis used a lathe chuck and collet combination that securely held the rodlet. The mill spindle was rotated 90 deg to align coaxially with the fourth axis. The alignment of these were checked using height gauges and high-accuracy indicators and were set to be within 0.0254 mm. An in-cell vacuum system was used to collect fuel and cladding particulates during milling operations.
Ultrasonic assisted nano-fluid MQL in deep drilling of hard-to-cut materials
Published in Materials and Manufacturing Processes, 2022
Tien-Dat Hoang, Quoc-Huy Ngo, Ngoc-Hung Chu, Thu-Ha Mai, Truong Nguyen, Ky-Thanh Ho, Du Nguyen
In Fig. 1, a drill bit with internal coolant through holes (1) was clamped by a collet (2) located directly on the ultrasonic horn (3). The horn was designed to guide and amplify the ultrasonic vibration generated by the ultrasonic transducer (4). The cutting fluid, contained in the tank was supplied onto the end of the drill bit by a plastic tube (5) using its self-gravity. The ultrasonic transducer (4) was fixed inside a sleeve (7), which was internally fitted in a couple of bearing (6). The arm of a thick disk (8) acting on a load cell (13) via a ball join (14) allows getting the tangent force generated when drilling. A preset force Fs was applied for the load cell to ensure that the arm is always in contact with the load cell and enhances the system stiffness. The residual force measured by the load cell, induced when drilling, was used to calculate the drilling torque, as similar to the one in.[8] The outside tube (9) of the bearing (6) was then fixed on a commercial bearing slider (10), which is constrained by a load cell (12). This arrangement allows to measure the thrust force.
Eccentric-weave FSW between Cu and AA 6061-T6 with reinforced Graphene nanoparticles
Published in Materials and Manufacturing Processes, 2018
D. Jayabalakrishnan, M. Balasubramanian
Experimental work was carried out in 3-axis vertical milling center with the FSW tool attached to the collet of the spindle. Aluminum AA6061 T6 and pure copper plates of dimensional parameters as shown in Fig. 2 were joined through FSW process. The mating sides of the plates to be joined were elliptically grooved at its median for the preinjection of graphene nanoparticles as shown in Fig. 2. This was used as reinforcement to MMCs at the welding joint. Two types of tool with and without pin offset as shown in Fig. 3 were used in this process. The stirring process was carried out in four different conditions. The linear weld movement of tool was done with and without pin offset. The second type is the eccentric motion of the tool with and without pin offset. The photographic view of the FSW machine setup is shown in Fig. 4. The welds were processed using the parameters such as welding speed, tool pin plunge depth, and rotational speed of the tool. Details are shown in Table 1. The chemical composition of the AA 6061 T6 is shown in Table 2. The weldments of four various FSW joints fabricated using the tool (with and without pin offset) along the linear and eccentric weld path are shown in Fig. 5.