Design Advantages of Linear UniSlide Assemblies

• Compact design yields long travel in a short work space
• A simple, reliable design easily adaptable
• Modular components facilitate multiple axis system
• A broad variety of lengths, sizes and feature

Straightness Commencing with a 6262-T6 aluminum alloy extrusion having a straightness tolerance of half the normal commercial tolerance, the subsequent machining and lapping operations are designed to secure a high degree of straightness and parallelism in the dovetail ways. There are essentially three types of deviation from straightness that can occur. Referring to a UniSlide Assembly resting base down on a flat surface with its linear motion or longitudinal direction, X, there can be a departure from straightness in the upward direction, Z, which is designated as the bow error. There can be a deviation from straightness in the horizontal direction, Y, designated as horizontal run-out, or simply run-out. There can also be a twist in the direction of the slide, X.

The upper limits for these three deviations from straightness as determined by our manufacturing processes are:

- Bow* 0.002" per foot
- Run-Out 0.001" per foot
- Twist 1 mill radian per foot

*As installed, bow can be affected by the degree of flatness of the supporting surface and relative tension in the mounting screws.

Reduced straightness tolerances, in the order of one half of the nominal values above, are available. Velmex will select, measure and certify UniSlide Assemblies for the customer at an extra charge of $6/in.

Wear Resistance - The aluminum alloy dovetail base and low friction polymer pads of the slider give excellent performance as a bearing material combination. Under moderate and light loads, the sideways play developed by wear during the first 30,000 cycles of operation is approximately 0.00015 inches. Thereafter, the wear is further reduced, amounting to approximately 0.00005 inches during the next 50,000 cycles. The slider has adjustment screws to compensate for moderate wear. Replacement bearing pads can be laminated to the slider at a nominal cost to recondition the slide after long periods of use, if necessary. For harsh environments and/or a higher number of cycles, UniSlide assemblies are available with hard coat anodized ways. See Options.

Protective Limit Switch Assembly - Velmex recommends limit switches be included whenever motor torque could damage the lead screw or drive nut at the end of slider travel. This includes most applications except those with small stepper motors.

Vacuum Applications - UniSlide linear and rotary positioners can be used in a vacuum to 10-6 torr with modifications. More. We recommend substituting duPont Vespel® for the standard Delrin® AF drive nut in a high vacuum. We can clean the bearings and replace the standard lubrication with a high vacuum lubricant, however, we do not have clean room facilities for ultra-clean applications. In that case, we suggest the critical user reclean the assemblies. Check with us for pricing.

Stall force - The torque requirements of a light load on a horizontal assembly ranges from 20 to 30 oz.-in. and is affected by the pitch of the lead screw. When the maximum motor torque is converted into the direct (thrust) force in the direction of the lead screw axis, a figure designated as the maximum thrust load is obtained. This value is listed in the lead/translation speed tables. The maximum thrust load is limited by the lead screw thrust bearings design.

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Nonmagnetic properties - The regular UniSlide Assemblies are made with Type 303 stainless steel fasteners. Lead screws are made of 303 stainless steel (except W2/P5 and W4/P2.5) and are slightly magnetic. Where an exceptionally high degree of nonmagnetic character is required, Velmex may supply plated brass fasteners and brass lead screws. Rotary tables have several essential steel ball bearing units. Electric motors are inherently magnetic.

Non-standard Lengths - Catalog lengths are those listed, but longer units are also available. In-between lengths are available on special order. Slider lengths are only those listed.

Material Substitutions - Drive nuts: brass, oil-impregnated bronze, Vespel®. Lead screws: brass, in some sizes.

Notice - Failure, improper selection or improper use of the products described herein or related items may cause personal injury and property damage. This catalog from Velmex, Inc. provides product options for further investigation by users having technical expertise. It is important that you thoroughly analyze all aspects of your application and review the information in this catalog. Due to the variety of operating conditions and applications for these products, the user, through his own analysis and testing, is solely responsible for making the final selection of products and determining that all performance, safety and warning requirements of the application are met. The products, including, without limitation, product features, specifications, designs, availability and pricing are subject to change by Velmex, Inc. at any time without notice. ® Reg. T. M. of E. I. duPont

Operating Temperature - Normal temperature range is 40-250°F

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