<\/span><\/h3>\nGravity is now a lateral force trying to pull the part away from the fixture face. Clamping must actively pull the part \u200cinto<\/strong>\u200c the vertical datum, not just down. Use step jaws or custom soft jaws with a vertical lip that captures the bottom edge of the part, providing positive location against both the vertical and horizontal planes. The primary clamping force should then be applied horizontally, pushing the part back against the vertical face of the fixture or vise.
\nFor tall or slender parts, support against deflection is critical. Use adjustable heel blocks or live (spring-loaded) supports at the unsupported top end of the part. These supports take up any slack and prevent the part from vibrating or bending away from the tool during cutting. They should be adjusted to just make contact with the part\u2014tight enough to eliminate play, but not so tight that they induce a bending stress. For long parts, multiple intermediate supports may be necessary.
\nThe direction of toolpath engagement is paramount. Program toolpaths so that the predominant cutting force pushes the part against its vertical stops and downward onto its bottom support. For example, when facing the vertical surface, use a conventional (up) milling strategy where the cutter rotation tends to lift the part slightly; this force is safely countered by the downward-pulling step jaw. Avoid toolpaths that create a consistent outward pull, like drilling with a large pecking force, unless substantial mechanical back-stops are in place behind the part.<\/p>\n
\n<\/span>Chip Management and Process Sequencing<\/span><\/h3>\nChip evacuation becomes a major concern in vertical setups. Chips no longer fall clear of the part; they accumulate in pockets, on top of clamps, and against the vertical face of the fixture. This can lead to recutting, poor surface finish, and even part displacement if a large chip gets trapped under a locating surface. Incorporate aggressive coolant flow with nozzles aimed to flush chips downward and out of the work area. Design fixtures with open skeletons and avoid flat ledges where chips can pile up.
\nThe order of operations must account for stability. Always machine the most critical features and tightest tolerances first, while the part is in its most rigid state\u2014typically when it has maximum stock material and support. Perform any heavy roughing on the side facing away from the fixture early on; the resulting stresses and heat will cause the part to warp\u00a0away<\/em>\u00a0from the fixture, and subsequent finishing passes on the fixtured side will bring it back to true. Leave light finishing passes on fragile or unsupported areas for the very end.
\nAfter completing operations on one vertical face, the tombstone can often be rotated 90 or 180 degrees (manually or via an indexer) to present a new face to the spindle. When doing this, use a probe to verify the new position of a known datum. Do not assume the rotation is perfectly accurate; small errors in the indexer or fixture squareness will accumulate. Probing allows for work coordinate rotation or translation in the CNC control to compensate for these minor deviations, ensuring features on different faces maintain their positional relationship.<\/p>","protected":false},"excerpt":{"rendered":"Vertical fixturing, or \u201ctombstone\u201d workholding, reorients a part\u2019s primary datum surface from horizontal to vertical, dramatically increasing the machine\u2019s ability to access multiple faces in a single setup. This method transforms a standard three-axis VMC into a pseudo-four-axis system, enabling the machining of features on perpendicular planes without reclamping. The core challenge shifts from simple [\u2026]<\/p>","protected":false},"author":1,"featured_media":716,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[106],"class_list":["post-1629","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","tag-cnc-machining-services"],"acf":[],"_links":{"self":[{"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/posts\/1629","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/comments?post=1629"}],"version-history":[{"count":0,"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/posts\/1629\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/media\/716"}],"wp:attachment":[{"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/media?parent=1629"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/categories?post=1629"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/reliablecncmachining.com\/fr\/wp-json\/wp\/v2\/tags?post=1629"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}