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2.2.6 Vacu Installation Increment from O.D. (1/32, 1/16…)

Vacu Installation Increment from O.D. (1/32, 1/16…)

2.2.6   default

 

When fitting a bowler with VACU Grip inserts, Spectre Cloud needs to calculatecalculates the correcttwo hole sizesizes relativerequired tofor the two-tier drill based on the insert's outer diameter (O.D.). The lower hole mustmatches bethe drilledinsert slightly undersizedO.D. so the insert creates a vacuum seal — too looseseats and glues at the base. The upper hole is drilled larger than the insert won'tO.D. hold;— toothis tightis andwhat itgives won'tthe seatrubber correctly.room to expand when the bowler's finger is inserted. This setting controls the increment used when selecting how finelymuch larger that upper hole is drilled above the insert O.D. offset selector steps through available sizes when building a VACU spec.

Note: This setting only appears and applies if your shop uses VACU Grip installation. If your shop drills exclusively STD (glued) inserts, this setting has no effect on your workflow.

Important: This setting requires the Auto Insert OD auto-suggestion to be enabled in order to work correctly. If Auto Insert OD is turned off, Spectre Cloud will not automatically calculate the upper hole size and this increment setting will have no effect. See Settings → Auto-Suggestions to confirm it is enabled.

📐 What Is the O.D. Increment?

The O.D. (outer diameter) increment is the step size used inwhen selecting how much larger the VACUupper hole sizeis selectordrilled relative to the insert O.D. — the amount by which thethat displayed offsetvalue increases or decreases with each click or tap. Spectre Cloud offers threefour options:

  • ✅ 1/32"16" — the fineststandard availableincrement increment.for TheVACU selectorinstallation. stepsGives onethe thirty-secondinsert a full 1/16" of anexpansion inchroom atper side — for example, a time31/32" (e.g.insert O.D. produces a 7/1 1/32", 8/32",upper 9/32"…).hole. GivesThis maximum control overis the vacuumcorrect fit,starting particularlypoint usefulfor most bowlers and the increment most shops will use day-to-day.
  • ✅ 3/64" — slightly less expansion room than the standard 1/16". Used for bowlers withwho sensitivewant gripa requirementsmore orcontrolled when workingfeel with aless brandrubber of insert known for tight manufacturing tolerances.springiness.
  • ✅ 1/16"32" — areduced mid-rangeexpansion increment.room. StepsThe twoinsert thirty-secondsrubber athas less room to flex, producing a timefirmer, (e.g.tighter 3/16",feel 4/16",when 5/16"…).the Afinger goodis all-round choice that balances speed of entry with sufficient precision for most VACU fittings.inserted.
  • ✅ 1/8"64" — the coarsesttightest increment.fit. StepsMinimal fourexpansion thirty-secondsroom at— a time (e.g. 1/8", 2/8", 3/8"…). The fastestsuited to navigatebowlers andwho sufficientprefer forvery shopslittle wherespringiness VACUfrom holetheir sizinginsert follows broad, established size bands.rubber.

⚙️ Changing the VACU O.D. Increment

  1. Open Spectre Cloud at cloud.spectrebowling.com and log in.
  2. Click your pro shop name in the top-right corner to open the Profile menu.
  3. Select Settings from the dropdown.menu.
  4. Navigate to the Spec SheetSystem Defaults section.
  5. Locate the VACUVacu Installation Increment from O.D. Increment field and select 1/32"16", 3/64", 1/16"32", or 1/8"64".
  6. ClickChanges are saved automatically.

SaveNote: toLike applyall system defaults, this setting controls only the change.pre-selection on new spec sheets. The increment — and the resulting upper hole size — can always be adjusted on a per-bowler, per-sheet basis directly on the spec sheet, the same way auto-suggestion values can be overridden after they populate.

🎳 Which Increment Should You Choose?

competitivebowlers verylittle
Situation Recommended Increment Reason
PrecisionMost bowlers — standard VACU fitting,fitting 1/16" The industry standard for VACU installation — full expansion room, natural rubber feel
Bowler wants slightly less springiness3/64"Marginally tighter fit with a more controlled feel
Bowler prefers a firmer insert feel 1/32" FineReduced controlexpansion mattersroom, whennoticeably aless bowler'srubber vacuum fit needs to be dialled in exactlyflex
GeneralBowler VACUwants fitting,minimal mixedrubber clientelespringiness 1/16"64" CoversTightest mostfit practical— sizing needs without excessive scrolling
High-volume shop, standardthe insert sizeshas only 1/8" Fastest entry when insert sizes reliably fall on broad size boundaries
Unsure — newroom to VACU fittings1/32"Start fine; it's easier to work at coarser sizes mentally than to miss a value you needexpand

📌 Important: O.D. vs. Hole Size

It is worth clarifying the relationship between theThe insert O.D. and the two drilled hole sizesizes forwork together in a VACU installation:fitting:

  • The insert O.D. is the published outer diameter of the VACU insert itself — a fixed measurement from the manufacturer.
  • The drilledlower hole mustis bedrilled cutto smallermatch the insert O.D. — this is where the insert seats and is glued at the base.
  • The upper hole is drilled larger than the insert O.D. by athe controlledselected amountincrement so— this gives the insertrubber compressesbody slightlyroom onto insertionexpand andoutward formswhen athe vacuumbowler's seal.finger is inserted.
  • Spectre Cloud uses theThe O.D. increment setting tocontrols lethow finely you can step through that offset value — the difference between insert O.D. andupper hole size —in withSpectre the precision your shop requires.Cloud.
  • ❌ Do not confuse the O.D. increment with the finger hole size itself — they are different measurements.

Tip: If you switch insert brands, check the new brand's recommended upper hole offsetsize specification. Some brands require a tightermore or looserless offsetexpansion room than others — you may find that switching brands is a good time to revisit this increment setting.

  • 2.2.5 — Insert Installation: STD vs. VACU Grip as the Default
  • 2.2.3 — Display in Decimal vs. Fractional
  • 4.4 — Insert Fields on a Spec Sheet
  • 6.1 — Drilling Your First Ball: Step-by-Step Overview

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