A packaging line builder sent us a drawing that said "cam indexer, 80 mm, as per standard." That line caused a two-week delay, because "as per standard" does not exist in custom indexer work. Our spec sheet was missing the output shaft, the torque, and the seal rating. If you are sourcing an indexer for a dial or filling machine, the difference between a smooth order and a long back-and-forth is in the numbers you send.
Why Buy a Custom Cam Indexer Instead of a Standard Model?
A standard cam indexer is a catalog product: fixed shaft, mounting holes, and ratio. A custom cam indexer starts with the same globoidal cam core but adapts the shaft, the flange, the input orientation, and sometimes the stops to your load. Buyers customize for three reasons: space, when the standard does not fit the frame; load, when the table is heavier; duty, when washdown or dust forces different seals. If none apply, a standard model saves money; if any apply, a custom unit is the only way the machine works. State which reason applies; it changes every later specification.
Torque: The First Number to Define for Your Custom Cam Indexer
Torque is the first number on the sheet; it drives the size of the cam, the output bearing, and the motor. The number you need is the peak torque at the output flange during indexing, not the average during rotation. Include table weight, fixtures, parts, and acceleration in the indexing window. If your machine indexes 30 degrees in 0.8 seconds with a 40 kg table, say so, so the factory can calculate acceleration torque. Give the value in N·m and note whether it includes tooling shock. A unit quoted without a torque value is a guess. State the input speed range too, because the cam profile is tuned for a target cycle. Write torque, indexing time, and input speed on the same line, and the quote comes back faster.
Accuracy and Backlash: How to Specify Positioning for a Custom Cam Indexer
Precision on a cam indexer is stated in arc seconds, and it changes cost more than any other line item. A standard globoidal unit typically holds positioning accuracy around 30 arc seconds with zero backlash. For drilling or press-fitting, that is usually enough, so do not pay for tighter. For laser cutting or vision inspection, ask for accuracy at your working radius, not just at the indexer center. Backlash is normally zero on globoidal units, but confirm it in writing for the custom cam indexer build, because modified shafts and preload can introduce play. Ask for repeatability as well as accuracy, because the same station must hit the same point every cycle.
Shaft and Mounting Options: The Parts Most Buyers Forget
The output shaft is where custom cam indexer orders most often stall. Standard units ship with a straight shaft and keyway, but your machine may need a through-hole, a hollow output, a D-cut, a spline, or a shaft on both sides. Specify diameter, length, and machined features; each changes the turning and grinding program. For mounting, state below-plate or above-plate, frame cutout, bolt circle, and pilot diameter. Define the input side too: motor mounting, right-angle input, and orientation. State whether the indexer needs locating pins for repeatable reinstallation. Every detail defined on the first sheet removes a revision cycle from the lead time.
Seals, Lubrication, and Environment: Custom Details That Matter
A custom cam indexer built for a clean assembly room is not the same as one for a washdown line. State the environment first: indoor dry, dusty, wet, food processing, or outdoor. Wet and food lines need special seals and food-grade grease; dust lines need a different output seal arrangement. Seal choice changes the housing bore and shaft finish, so decide before machining. Lubrication is the second detail. Most globoidal indexers ship with a grease charge and relubrication interval, but a custom unit may change the volume if the housing is extended or the speed high. Ask what grease is used, the replacement interval, and whether the unit has fill and drain ports. Temperature is the third: state the ambient range for ovens or cold storage, since seals and grease suit a temperature window. None of these appear on a standard spec sheet, which is why they belong on a custom cam indexer specification.
Lead Time, Drawings, and Acceptance: How to Order a Custom Cam Indexer
Ordering a custom cam indexer is a three-stage process, and the schedule depends on how fast you answer each stage. Stage one is the spec sheet: the factory reviews torque, accuracy, shaft, and mounting, then returns a drawing for approval. Approve that drawing in writing; verbal approval does not release production. Stage two is machining and assembly, where the cam is ground and the housing precision-bored. This is the longest stage and cannot be compressed. Stage three is testing and shipping: the unit runs a cycle test and the backlash and accuracy are measured. Ask for each stage's lead time separately; the total means little if drawing approval takes two weeks. Before shipment, request the test report: measured accuracy, backlash, and run-in time. On arrival, check the unit against the approved drawing before mounting.
Custom Cam Indexer FAQ
What is the minimum order quantity for a custom cam indexer? Factories build custom units as one-off orders, so the MOQ is usually one, but the price reflects the engineering. How long does a custom unit take to build? Plan on four to eight weeks from drawing approval for a globoidal unit, depending on size and cam profile. Can I change the number of stops after delivery? No, the number of stops is fixed by the cam, so define the stops and the indexing angle before production. What is the difference between a custom cam indexer and a hollow rotary table? A cam indexer provides fixed, cam-controlled indexing with zero backlash, while a hollow rotary table usually offers continuous positioning with a servo. Do I need to specify a motor with the indexer? Not necessarily, but sending the motor type and coupling helps the factory match the input shaft and keyway. How accurate is a custom unit in practice? A globoidal unit typically positions within 30 arc seconds and repeats within a few, verified on the test report.
Putting together a custom cam indexer specification starts with torque at the output flange, indexing time, accuracy at your working radius, and shaft and mounting features. The environment, seals, and test report come next. Send those details through our inquiry page, and the engineering team returns a dimensional drawing and lead time before production. If you are still comparing standard models, our globoidal cam indexer buying guide covers selection, and our list of top 10 cam indexer manufacturers maps the landscape.