Adding CNC Gear Hobbing Capacity: What to Ask Before You Buy a Machine
Shops come to us for hobs and, increasingly, for the machines that run them. In 2026 CTI-USA became the North American distributor and service contact for Eifco CNC gear hobbing machines, and most of the conversations follow the same path: a shop has an aging mechanical hobber, or is sending gears outside and wants the work back in-house, and needs to decide what to buy. Here are the seven questions we work through with them.
1. What is the real part envelope?
List every gear you expect to hob in the next five years, not just the ones you cut today. For each, note outside diameter, face width, module (or DP) and material. The machine's maximum workpiece diameter and maximum module in steel must cover the largest part with margin, but buying far beyond your envelope costs money in the machine, in floor space and in the larger hobs it needs. Eifco's CNC hobbers cover workpieces from 90 mm (horizontal HOBBER 150H) through 630 mm, which spans most job-shop and OEM gearing from small precision components to industrial gearing.
2. Spur only, or helical and more?
Helical gears need a differential (electronic on a CNC machine) so the blank rotates slightly faster or slower than the index ratio to produce the helix. Splines, sprockets and worm wheels each add requirements: splines are routine on any hobber, sprockets need the right hob and a machine stiff enough for the coarse pitch, and worm wheels need either a tangential feed slide or a radial-infeed cycle. Eifco's CNC range is designed for spur gears, helical gears, splines, sprockets and worm wheels; confirm the specific capability you need is standard on the model you are quoted.
3. Direct drive and dry hobbing?
Modern machines use direct-drive hob heads and tables rather than gear trains. The benefits are higher hob speeds, less backlash and quieter, more accurate indexing. Direct-drive spindles, together with the hob speeds they allow and proper chip evacuation, make dry hobbing practical, which eliminates coolant handling and lets you use coatings such as TiAlN and Altensa at the speeds they are designed for. If you plan to hob dry, confirm chip evacuation and guarding are designed for it.
4. Which control, and who knows it?
Ask which CNC control the machine carries and how the hobbing cycles are programmed. A conversational hobbing interface (enter module, teeth, helix, feed, shift) is faster for a job shop than G-code. Also ask who in your shop will be trained, and whether the supplier trains on your floor at installation.
5. Who answers the phone when it stops?
This is the question that decides most imported-machine purchases, and it should. Before price, ask for a written answer to each of these:
- Where are spare parts stocked, and what is the shipment commitment?
- Who performs service in North America, and what is the response time?
- Is remote diagnostics available on the control?
- What is the escalation path to the factory's engineers?
CTI-USA is Eifco's North American distributor: the US-based point of contact for evaluation, quotation, tooling and coordination of installation and training by Eifco technicians, and the party that puts those commitments in writing before a purchase order.
6. What tooling does it need on day one?
A hobber without hobs is a very expensive table. Budget for the hobs, arbors and fixtures for your first parts as part of the machine purchase. Match the hob bore and length to the machine's arbor and hob-head travel, and decide the tool steel and coating for your materials and volumes before the machine arrives. CTI-USA supplies the hobs (module 0.1 to 40, DIN 3968 class AA, A or B) and will specify them from your part prints while the machine is on order.
7. What does it cost per gear, not per machine?
Compare options on cost per gear produced: machine payment, floor space, labor, tooling and resharpening, and the value of bringing work in-house. A new domestic or premium European machine, a new competitively priced import with a written support commitment, and a used machine with unknown history will land in very different places on that calculation, and the right answer depends on your volumes and your tolerance for downtime.
Talk to us
If you are considering adding gear-hobbing capacity or replacing an older machine, we are glad to walk through these questions against your actual part list, with no obligation. Email sales@cti-usa.co, call 330-962-8160, or use the request form. For a quick feel for cycle times on your parts, try the free hobbing cycle-time estimator.
Adapted from posts first published on LinkedIn, August 2026.
Richard Potesta is the founder of CTI-USA, the North American sales, engineering and support partner of Capital Tool Industries and distributor for Eifco machines. Questions about an application? Contact CTI-USA or call 330-962-8160.
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