CleanTop® Double-Density™ is another TMC innovation to the optical table industry. By combining our existing uniquely small honeycomb cell size (0.50 in.2) with our proprietary CleanTop® individual sealed hole technology, we are now able to offer twice the number of tapped holes. Because we use our existing honeycomb core design, which is twice the cell density as our nearest competitor, there are absolutely no changes to any performance specifications. No alterations to the core design were necessary to accommodate the additional CleanTop cups.
• Twice as many tapped holes as conventional 1 in. or 25 mm grids
• 288 holes per ft2, 3,200 holes per m2
• Twice the number of honeycomb cells (0.50 in.2) as our nearest competitor
• Core density unchanged, the highest in the industry (13.3 lb per ft3)
• Hole pattern is 1/4-20 on 1 in. staggered centers or M6 on 25 mm staggered centers
• Available with any version of TMC's CleanTop at a nominal additional fee
• No change to any performance specifications
A handy option to ease replicating an optical setup is our Alpha-Numeric Grid pattern. By electro-chemically etching a coordinate pattern on the top surface, each tapped hole has an address. This is also helpful in documenting a setup for OEM applications.
CleanTop® Tops now include user-friendly rounded corners as a standard feature. We laser-cut a generous, 1-in. radius at each corner of the top.Conventional top construction produces a 90° bend which is subsequently "dulled" by grinding or filing. Though dull, thisright angle often leads to painful hip bruises for those logging long hours in the lab. The rounded corner feature eliminates this inconvenience. If required, conventional square corners are available at no extra charge.
An overhead shelf is an ideal storage rack for equipment and instrumentation used in conjunction with an optical table. Spanning the long axis of the table, the overhead shelf is adjustable in height and free standing, so vibration isolation will not be compromised. It includes a UL-approved electrical strip with two eight-grounded outlet strips in the 6-ft shelf and four eight-grounded outlets in the 8- and 10-ft shelves. (125 V, 60 Hz, 15 A).Optional accessories include a second tier shelf. The shelf includes two rows of holes on a 2 in. (50 mm) spacing to facilitate mounting of fixtures.Built to the same rugged standards you have come to expect from TMC, the structure is formed steel with a non-resonant design, black powder coat finish, and leveling feet for uneven floors. Capacity is 200 lb (90 kg).For custom requirements such as non-U.S. format outlet strips, contact TMC.
Link to Overhead Shelf setup pdfs
As an option on 2 in. (50 mm) thick breadboards with 1/8 in. (3 mm) or 3/16 in. (5 mm) skins, TMC provides a breadboard leveler mechanism (see page 36). The leveler consists of a threaded sleeve bonded into the top, a bushing leveler, and a locknut. An M6 or 1/4-20 bolt may then be used to fasten the breadboard to another top. The leveler is adjusted and locked with a simple Allen wrench.
TMC's earthquake restraint bracket system provides increased safety and stability for optical tables in high-risk earthquake areas without affecting table performance.
The TMC earthquake restraint system relies on top brackets and upper tiebars
to control motion of the table top and, where severe occurrences are anticipated, floor brackets with lower tiebars to secure the support structure to the floor. Under normal conditions, there is no contact between the top brackets and the support structure, so that performance of the optical top and the vibration isolation system are not affected. Clearances are large and brackets are lightweight, stiff, well-damped, unobtrusive and encapsulated with soft elastomer to provide gradual snubbing.
Our earthquake restraint bracket system can be retrofitted to an installed TMC optical table or specified with a new order.
Inferior, competitive designs may depend on large, pendulum-like structures that hang below the table top and connect to the floor. Since pendulums characteristically have low resonant frequencies, these add-on structures lower the resonant frequency of the table top and degrade compliance and damping. In addition, the floor connection creates a potential rigid coupling between table top and floor, which can compromise vibration isolation if it drifts out of calibration.
Top Restraint Brackets encircle the upper tiebar and bolt to the underside of the top. They mount within a few inches of a support post and restrict the motion of the top (see illustration). Normally, four brackets are required for a typical table. Specify brackets individually. On new table orders, the top will be supplied with mounting holes. For retrofitting tables, contact TMC for recommendations.
Floor Restraint Brackets are recommended where quakes are anticipated. They encircle the lower tiebars close to the support posts and bolt to the floor (see illustration). Four brackets are usually recommended. Since standard TMC post-mount support systems are supplied with only upper tiebars, an additional set of four lower tiebars must be specified for both new and retrofitted orders. Specify both floor brackets and tiebars individually. Note that for posts less than 22 in. tall, a special Floor Restraint Bracket is required. Contact TMC for information.
Upper and Lower Tiebars
Standard post-mount support systems are supplied only with upper tiebars. An additional set of lower tiebars is required when floor restraint brackets are used; or, you may want an additional row of tiebars for extra strength. Tiebars must be specified individually – see ordering chart.
Tables made of any commercially available metallic materials are readily manufactured by TMC. Aluminum, non-ferromagnetic 300 series stainless steel, and thermally stable Invar Alloys are among the most frequent requests.
Our multiple new 2,000-watt laser machining centers coupled with our capacity to punch, drill, shear, form, and weld steel makes inclusion of custom hole patterns readily available. Common patterns include notches, rectangular through-holes, laser ports, and threaded bosses.
TMC tables larger than 36 in. x 72 in. (900 mm x 1,800 mm) and supported at least 18 in. (450 mm) above the floor can be fitted with a laser shelf. The shelf consists of an additional undrilled 2 in. (50 mm) thick breadboard attached to the bottom plate of the table. Though such a support system will not match the performance of direct mounting of equipment to the table's top surface, for less sensitive applications this arrangement can save valuable working space on the top. In some cases, our tiebars may interfere with shelf mounting. Contact us if you are in doubt.
All TMC optical tops can be supplied with a laser port, as noted in the laser port and hole pattern suffix chart. The laser port is a 1 7/8 in. (47 mm) diameter stainless steel tube running through the table, bonded to the top and bottom skins.Provisions for mounting a laser shelf underneath the table top are included with this option. See drawing and chart at right.
By welding a precision ground and aligned joiner plate system to the table skins, TMC can provide a rigid coupling between optical tables. In addition to tables coupled end-to-end, we can easily join them in "L" or "T" shapes. (Even relatively small tables are sometimes made in sections to allow rigging in elevators, etc.) In addition, we can provide configurations with two working heights on one table by coupling tables of differing thicknesses. All joined tables are assembled and tested in our factory, shipped separately, and reassembled on site. The tables can, a any time, be separated and supported individually or rejoined.