Installation Archives

T2K has been informed by a number of customers that scratch resistant "siliconized" machine window are offered as a replacement option for machine windows surfaces which become badly damaged due to chip activity. Bonding Visiport or DiscAir spin window systems to such siliconized polycarbonate is not recommended for several reasons.

1) Material Compatability Issues
The 3M VHB+ material used on all mounting systems for Visiport and DiscAir products is based on an acrylic carrier closed-cell foam. A window material with a silicone-based coating is fundamentally compatible only with other silicone products. While the edge sealing material T2K supplied is compatible, the VHB+ material, being acrylic based, is not. As such, bonding is somewhat compromised in theory.

Based on our testing, however, any T2K spin window bonded according to the instructions laid out in the Installation documents will bond adequately well, as the area required for bonding is many times greater than that required to hold the unit onto the substrate. (Keep in mind that the secondary purpose of the bondset is as a gasket.) The installation instructions are available for download from each Visiport product page and supplied with the product.

2) Poor Cost-Benefit Ratio
As we hear it from the customers actually buying these products, the cost factor is much higher than for the simple, plain optical grade polycarbonate commonly used in the industry. If, however, the point is to increase the life of the window in a machine tool application, then this money is by and large wasted as the extra life provided by the siliconized surface is only marginally longer than for polycarbonate without it.

Truly, if you have a machining application that has sufficient chip activity that the ability to look through the polycarbonate window is destroyed, then you would be far better served either installing a Visiport and allowing the rest of the polycarbonate window's view area to degrade as before, or replacing the polycarbonate window with a safety window incorporating a glass surface on the inside of the machine to resist the chip activity of your application. The use of either window type, of course, does not impact your ability to bond the Visiport on, although a better bond is achieved in practice with glass due to the difference in surface energy this material provides.

3) Downtime and Availability
When the time comes to replace the window, either due to chip activity affecting visibility, metalworking fluid replacement guidelines (which at two years is no different than standard polycarbonate), cracking, or damage due to tool impact, a siliconized window may or may not be available from your OEM as quickly as standard polycarbonate. Certainly it will be more expensive.

T2K can provide you with either a new mounting plate or offer our factory rebonding service to replace the bondset from directly mounted spin windows. With our factory pre-mount service, we can send your Visiport clean, refurbished, and mounted so that you can minimize the downtime switching the old window for new.

For additional information, contact T2K.

Electrical Hookups
Final connection to a machine power supply must be made only to fully regulated 24±1 Volt D.C. auxiliary power connections, which is the same supply that drives the machine hydraulics and most proximity and interlock circuitry.

Some customers mistakenly feel that hooking up to the tool changer power supply, for instance, will extend the spin window's operational life because it is not running constantly. This actually hinders operation because the brushless DC motors can take from 3 to 30 seconds (depending on Visiport model generation) to ramp up to full speed with power interruptions. With heavy coolant spray, this will affect visibility.

In addition, power interruptions of this type will shorten the life of the electronics. The load on the motor from heavy coolant spray on the unit during its ramp up to full RPM's may trigger the unit's overload protection, which turns the unit off to prevent damage to the motor and electronics. T2K spin windows are engineered for continuous duty operation, and are designed to be on whenever the machine tool is on and producing chips.

Please be aware that failure to hook up the power supply as required will void the warranty on the unit.

Power Supplies From T2K
In order to provide a matched power supply of the appropriate type for customer and distributors, T2K offers the 100 Watt PS24-100 (Visiport VP220A Series and before) and the 120 Watt PS24-10 (Visiport VP220.B5 and VP220.C Series) power supplies as optional equipment with every new unit purchase. Fully enclosed, compliant to UL-508, DIN-rail or enclosure mountable, these power supplies ensure adequate amperage for each installed Visiport at all times of machine operation. T2K also offers a slimline version of the 120 Watt power supply (PS24-120S).

Contact T2K for pricing and availability.

Internal Visiport Venting
Visiport's patented design incorporates the ability to vent ambient or "clean" air from outside the machine cabin to prevent internal fogging of the Visiport. The most common method of providing this air flow is throught the use of flex conduit, which is a steel wire braid over a PTFE (teflon) tubing material. With the new B-type units, T2K also provides PUR (polyurethane) tubing as an alternative conduit material. [Shown as PUN on parts list and price sheets]

Venting and Air Flow
Improper installation of the flex conduit can block air flow to the unit. This can allow the Visiport spin window to fog up and can possibly lead to electrical and/or mechanical malfunctions.

Improper restriction of air flow can be caused by (a) over-tightening the fittings, (b) accidentally putting a crimp in the flex tubing, or (c) inappropriate placement of silicone sealant during installations. Please note that adequate air flow to the unit through installed flex conduit is necessary for the unit to function properly. The flex conduit protects the wiring harness between the Visiport unit and the external bulkhead assembly the on/off switch and/or motor electronics, but it is air flow that is the primary purpose behind the use of the flex conduit, PUN tubing, and STK-Steel Tubing Kit (for discontinued Visiport VP210, VP215 and VP220 models) sold with the product.

Custom OEM Wiring Harness / Tubing Designs
Customers incorporating their own tubing scheme to route the wiring harness between the Visiport and the external bulkhead assembly or the machine tool's electrical cabinet should note that it is extremely important to ensure adequate air flow is accommodated in their custom tubing designs.

If aesthetics or integration concerns demand a customized routing scheme, air flow considerations cannot be overemphasized. Due to the necessity to prevent fogging and internal moisture problems that may cause premature product failure, T2K can easily supply flex conduit for new or currently in service Visiport units. In addition, T2K is happy to provide technical support to customers who require custom installations. Contact T2K for details.

The typical Visiport® retrofit installation to a new or existing machine tool consists of specifying 4-6 discrete parts, and evaluating optional connection fittings, disc coating, and the machine tool window itself.

Discrete parts required for complete installation

1. Visiport® Base System

Includes Base Unit, Standard Mounting Plate Assembly, Bulkhead Assembly.

2. Conduit
Goes between "Installation Point" on window and "Bulkhead Point" on sheet metal.
Required not just to exit the conductors from cabin, but also to aspirate the Visiport.
Aspiration required to prevent fogging and overcome any disc pumping action.
Comes standard with matched length (conduit+8" prox.) of 2-conductor wire harness.
Sold in unit lengths, i.e., 1.5-m takes 2.0-m price point.

3. Fitting
Attaches conduit to Visiport base (and bulkhead assembly).
Priced as 1 part (T2K supplies 2nd matched fitting for Bulkhead Assembly end).

4. Power Cable
Goes between "Bulkhead Point" and "Power Supply Point".
Robotics-grade 3 conductor (2+ground) cabling.
Sold in unit lengths, i.e., 1.5-m takes 2.0-m price point.
Also sold in legacy 10-m length (Code P or P/N 220A7015).

5. Power Supply [option]
Required if machine does not have 5 amps, 24VDC to dedicate to unit.
Visiport® consumes only 200mA under no-load conditions.
When used with high-pressure coolant, Visiport® draws up to 4.8 amps.
T2K power supply is UL508 compliant with UL/TÜV/CE approvals.
Alternately, customer may supply own fully-regulated 120W power supply.

6. Installation Vacuum Pump [option]
One-time purchase for installers of Visiport & DiscAir systems (reusable).
Used to quickly and completely adhere standard VHB adhesive to substrate.
Helps installer identify color-shift in adhesive that had 'made' to substrate.
Comes with 4-40 & M4 thread adapters for T2K Mounting Plates/Bases.

Additional options and installation evaluation steps:

Optional Connection Fittings
When considering the necessary parts to make connections between the "Installation Point" and "Bulkhead Point", and between the "Bulkhead Point" and the "Power Supply Point" span distances, there are 90° Strain Reliefs and Adapters available for the Terminal Box bulkhead assembly that allow you to modify the plane that the Conduit and Power Cable will drape in, to allow for smooth opening of doors and windows to which the Visiport® system is installed. Please refer to the price sheet for price and part number details.

DLC
Diamond-like carbon (DLC) coating is an option for the glass disc supplied with the Base Unit. The few atoms deep layer provides exceptional scratch resistance and lubricity to the regular chemically strengthened glass used. This coating is popular with aerospace machining operations, but it sufficiently costly that T2K advises customers to evaluate the standard disc's life under operating conditions prior to making the 2X cost to 5X plus wear calculation. Please note that the coating does not impart any additional impact resistance to projectiles, as the coating is only several atoms thick.

Machine Tool Window Evaluation
Finally, there are several issues regarding the condition of the machine tool window that must be considered by the Visiport® installer in order to ensure a successful installation. The window must not be so scratched as to prevent proper viewing through the window. The Visiport® does not replace the existing window, it augments the window that is already there. Merely installing a Visiport® system over a scratched up window will not provide the desired visibility.

Secondly, the windows installed into machine tools are of two types, namely polycarbonate plastic or a multi-layer machine tool safety window composed of a glass layer on the wet side of the window for scratch resistance to chip activity together with a polycarbonate plastic layer for impact resistance, either with an edge seal or metal frame for containment and mounting. Machine tool safety windows that meet clarity requirements can be easily cleaned up to allow very successful bonding of the VHB adhesive that is used in the standard VHB Mounting plate.

Polycarbonate windows are another story, in that chip activity and oil contamination are typically such that the window found on a machine tool in use cannot be cleaned sufficiently to accommodate bonding of the VHB adhesive. While 3M's VHB adhesive is tremendously strong, it needs to bond to the window substrate rather than to a thin film of oil on the surface of the substrate, and due to the wetting action of modern metalworking fluids, together with the scratches and pitting common to chip activity, a used window must be considered contaminated and should thus be replaced at the same time a Visiport® installation is done.

As a customer service, T2K can easily provide you with a replacement polycarbonate window of any given size and thickness, with or without a hole pattern, and can also provide premounting of the VHB Mounting plate in a specified location to speed the installation process. Given the necessary dimensions, T2K can also provide custom aftermarket machine tool safety windows from SEGE, the world's leading manufacturer, with full CE Mark impact class requirements, at an extremely competitive cost.

With machine tool windows having been classified as a wear item in some countries that should be periodically replaced to prevent metalworking fluid embrittlement over time, T2K would strongly recommend that customers consider replacing any machine tool windows that are blind, cracked, severely pitted, or over 5 years old. Research has found that over 8-10 years, some polycarbonate windows had as little as 10-15% of their original impact strength, due to the exposure to metalworking fluids, and that it was impossible to visually determine which windows had been embrittled simply by visual inspection. The ease of replacing these windows, and the ease of maintaining you Visiport® installation on your machine tool window, should help to improve operator safety and productivity at the same time. Please contact T2K for more information.