This news article was originally written in Spanish. It has been automatically translated for your convenience. Reasonable efforts have been made to provide an accurate translation, however, no automated translation is perfect nor is it intended to replace a human translator. The original article in Spanish can be viewed at Torbellino, una solución para roscas difíciles

Vortex, a solution for difficult threads

15/10/2004

The growing demands of increased productivity, high quality assurance, all this together with the reduction of the price per piece, are a constant in the industry today. The situation is complicated further when it comes to complex parts that require long hours in the development of the process, preparations of machine and cycle time. This increased demand even more narrow profit margins... It must be machined parts with the highest precision and minimum time without spending time or money on costly second operations.

Comparative test published in Tooling & Production by Mr. Steve Rose, President of the RTSI, Solon, OH.

Threading by Vortex is the most effective way of producing threads, being a solution that minimizes the time of production, allowing shorter cycle times. It is a specialized process that provides spectacular results. It is a proven fact that screws and threaded parts machining comes to be up to 9 times faster that traditional methods and, as appropriate, without the need of finishing operations, sometimes reaching similar to the grinding process qualities.

The process of threading by Vortex has been always with machines designed for this purpose, requiring a large and costly installation.

Madaula are working in porta-herramientas designed to be mounted on motorized turret (lathes, Star, Citizen, Okuma, Mori Seiki, Mazak, Miyano, etc.) while preserving their ability to multitask.

Areas of application

In all production areas are manufactured pieces with threads, but more especially in the dental, optical, biomedical, electronic, telecommunications, automotive, fasteners, precision turned parts, watches, etc.

Also applies to parts for dental implants, screws of bones for surgery, screws for hips, for maxillofacial surgery... even screws of lower diameter 1 mm can be tapped.

When comes to machined threads in difficult materials (stainless steel, titanium, temperate materials to 65 Hrc, etc.), few processes are so fast and efficient as the threaded by whirlwind.

While the process is not new, its popularity goes spreading capacity for coupling devices of vortex in CNC lathes and precision turned parts, still a solution really cheap and alternative investment on unique machines of threaded by whirlwind.

Advantages

Threading without turning prior.
You can be any kind of special profile.
Without distortion on the piece, due to low shear forces.
High-quality threads. Without inflections in the pieces.
Very small shavings, without problems of shavings.
Without burrs.
Long life of the tools.
Possibility of up to 40 reafilados before replacing it.
Little effort to court. Little solicitation of the machine.
Low power required.
Thread "whole", no way out of thread.
Implementation in a single pass.
High practical rotation, that no real machine.
Less downtime due to the long life of the tools.

Application machinery

Although the system can be applied to any lathe with motorized turret, it is a fact that the most popular implementation is carried out in the so-called "mobile head" or "Swiss" type lathes.

Types of threads that can be obtained

The flexibility offered by the threaded by whirlwind enables cost reductions by simplifying preparations and speeding cycles. The different available sizes include in addition to the normal and special profiles:

thread thumbnail
thread extra long
variable pitch thread
conical thread
threads of multiple entries
deep profile threads
"buttress" (deep support of Helix)
visinfines

Principle of operation

Consists of two components: the cutting head and the head of whirlwind, which is mounted on the rotating station of the lathe.

The Vortex is essentially a threaded process whereby the porta-herramientas head rotates the piece. The porta-herramientas is equipped with multiple teeth in court for the carving of the thread as "orbits" around the piece.

As shown in the drawing, the head has three blades that contact with the piece in movement, generating the thread into a single past and generally without turning prior. The cutting depth is around 2.3 mm maximum.

The piece revolves about 10 RPM, while the head porta-cuchillas does to 2400 RPM aprox. With the 3 tools by contacting the piece hundreds of times at every turn, the Court effort is minimal and finish quality is maximum.

The blades have to adjust to the angle of the propeller of the thread. This is easily done by means of an ingenious device. Also, the angle provides free space for turning the blades.

Shape of the blades

The circular shape provides excellent resistance of the tool and sufficient space for the evacuation of shavings. Economic performance is higher, given that every cutting edge can Threading hundreds of pieces and many reafilados can be completed before the end of its useful life. The reafilado is easy and can be done in any flat grinding machine.

Comparative

By way of example we transcribe a comparative test (1), published by a builder of lathes, which makes evident the superior performance of the vortex in the execution of a thread in a bone screw.

Piece:

Bone surgery of taper screw

Geometry

Thread length:	100 mm
Diameter of base:	4.27 mm +/-0.05 mm
Passage of thread:	3 mm
Height of thread:	1.5 mm, radial

Machine tools:

Citizen M12

Material:

Steel inoxidable316 L

Results

	No Vortex	With vortex
Spindle speed	1,000 rpm	10 rpm
Speed of the Vortex	n/a	2,400 rpm
Depth of cut	1.5 mm	1.5 mm
Number of passes	63	1
Cycle time	9 min 30 sec	4 min 15 s

The M12 Citizen with whirlwind reduced the duration of the cycles in the piece of evidence of the half, without turning prior in a single pass and to comply with the tolerances.

Advantages of the whirlwind Madaula

The whirlwind Madaula heads offer a "turnkey" solution which includes the head of Vortex can be adapted to each type of machine, the porta-cuchillas head and adapted to the geometry of the thread carving cutting blades.

They incorporate the latest technological advantages, fruit of a receptive attitude to the demands of customers, designed to facilitate further implementation to point and to ensure a consistent quality in threads.

No less important is the economic aspect, as the whirlwind heads are offered at prices never seen so far, increasing its attractiveness.