Welcome to the second issue of PRODUCTIVITY TIPS, a series of three e-newsletters dedicated to helping professional woodworkers improve productivity, quality, safety and ultimately, the bottom-line of their businesses.

PRODUCTIVITY TIPS is specially presented by the Wood Machinery Manufacturers of America in collaboration with Wood & Wood Products and Custom Woodworking Business magazines. Each issue features a compendium of valuable how-to tips, delivered in a Q&A format. Answers are supplied by resident experts of WMMA® companies.

As an added feature, the tail-end of each answer includes a hot-linked e-mail address of the expert responding to the question. This handy feature allows you to directly "ask an expert" any questions you might have on a related subject.

PRODUCTIVITY TIPS is complemented by PRODUCTIVITY BOOSTERS, a series of three e-mail newsletters featuring new products that WMMA members will display at the AWFS Fair in Las Vegas. Together, Tips and Boosters form the WMMA’s 2007 PRODUCTIVTY MASTERS campaign.

This month’s questions:

Q. What can I do to improve panel saw productivity?

A. One of the easiest ways to improve panel saw productivity is through the use of stops. There are typically a couple different options from which to choose.

The first method is utilizing a quick stop gauge that consists of a metal extrusion with an embedded scale and an adjustable stop block. This type of system provides an easy-to-use method of making repeat cuts at any length.  This system also has an optional digital readout that mounts on the stop block adding digital precision and repeatability.

The second method is to use a stop bar gauge. This is a multiple stop system for production shops. It consists of a metal extrusion with an embedded scale and multiple flip stops. This method makes it very easy to set up a variety of stops at different lengths, thus eliminating the need to take multiple measurements.

Ask an expert: e-mail Tom Houska, Marketing Professional of Safety Speed Cut, at t.houska@safetyspeedcut.com

Q. I get checking in some hardwood face veneers when hot pressing three-ply panels with a particleboard core. How can I prevent this?

A. Veneer checking is a moisture problem particularly in more porous veneers such as red oak. It results from excessive moisture in the panel that tries to escape during hot pressing. If the moisture content of the core and face is OK, the problem may be with an excessive glue spread. Check the squeeze out on the panel edges. If it is excessive, the spread should be reduced. Less moisture is then added to the panel and checking should reduce.

Three-ply panels are more susceptible to checking than five-ply panels with crossbands under the face and back. The crossband tends to keep the face from moving across the grain, thus reducing the panel’s tendency to check. Of course, be sure that the crossbands are in the recommended moisture content range of 6% to 8% along with the other panel components.

Ask an expert; e-mail Kent Pitcher, President of CP Adhesives, at kpitcher@custompak.com

Q. What’s a simple, effective way to clean sandpaper?

A. Try putting your clothed-backed abrasive paper in mineral spirits over night. Most foreign deposits will dissolve away leaving you with a clean and fresh abrasive.

Ask an expert: Bill Schroeder, President of SuperMax Tools, at bills@supermaxtools.com.

Q. What are the best material handling methods on a CNC Nested Base Manufacturing work cell?

A. Material handling is more important than ever for optimizing productivity on a CNC machine. Over the last several years there have been major advancements in tooling, software and CNC machine tools for Nested Base Manufacturing (NBM). These advancements, combined with the demand for lower production batch sizes, lower inventory levels, more customization of products, and increased flexibility on the manufacturing floor, further validate NBM as the right solution for today's panel processing woodworkers. The "bottleneck" high production NBM has today typically has to do with material handling. A few of the methods of material handling that will increase the productivity of a NBM work cell include:

• Manual Material Handling - Staging tables allow two spoil boards to be in process at once to facilitate pre-loading the next panel. One spoil board is on the machine table in process; the other spoil board contains the completed nested parts and is pushed onto a receiving table to be unloaded and reloaded with a new sheet. This second spoil board is ready to be reintroduced to the machine as soon as the current sheet is complete.

• Twin-Table Operation - Either a true twin-table CNC machine or a long travel stationary table machine can be used to allow the operator to unload/load on one table while the machine is operating on the other table.

• Automated Unload System - The CNC machine has a device to automatically "push" the completed nest onto an offload table for part labeling and sorting. The operator then has to simply load the next panel to be machined.

• Automatic Material Handling - This system automatically unloads and loads the panels from a stack or unit of material. This system truly paces the production through a NBM work cell and is tied into the CNC with a scheduling interface to allow the operator to easily coordinate jobs through the work cell. 

Note: An additional benefit of the Automated Unload System and the Automatic Material Handling System is that they also get tied into the central dust collection system to help eliminate airborne dust created from blowing dust off spoil boards prior to loading fresh sheets.

Ask an expert: e-mail Steven Mehr, Manager of Applications and Training of Komo Machine Inc., at smehr@komo.com

Q. What RPM and travel speed are optimal?

A. There is no easy answer. There are a wide range of variables to consider -- the RPM, the depth of cut, the diameter of the router bit, the material, the chip load, etc. Each variable affects the feed rate.

There are some basic guidelines to keep in mind when calculating your feed rate. A greater depth of cut requires a slower feed rate. The deeper the cut the more material removed and the more heat and side pressure that is generated.

Smaller diameter cutters should be fed at a slower rate than larger diameter cutters - although smaller diameter cutters require faster RPM. Don't get attached to a magic number. Each combination of factors gives rise to a unique situation.

Ask an expert: e-mail Linda Wyant, Vice President of Her-Saf Products, at linda@hersaf.com

Q. How can I prevent wood pieces from shrinking and swelling? I’m constantly having to adjust machine settings to compensate for these problems.

A. Wood shrinks and swells depending on how dry or humid the air is. A simple solution is to maintain a constant humidity at the plant and the raw wood warehouse to prevent wood from absorbing or releasing moisture.

Ask an expert: e-mail Michael Fonzo, Sales Manager of American Moistening Co., at mfonzo@amco.com

Q. How can I extend the life of my sanding belt and the components on my widebelt sander?

A. It is very important to use the full width of the abrasive sanding belt whenever possible. Simply feed the stock in alternating areas of the conveyor table to evenly wear the abrasive sanding belts.

On earlier passes with coarser sanding grits, pieces can be fed into the machine at an angle up to 45 degrees. When sanding with finer grits, or finish sanding, you should run the wood straight through the sander in the direction of the grain. This method will also give longer life to the components of the machine such as the contact roller, conveyor belt, and conveyor table.

Ask an expert: e-mail Tom Houska, Marketing Professional of Safety Speed Cut, at t.houska@safetyspeedcut.com

Q. When should I consider using a thin cutting frame saw to produce my veneers?

A. The frame saw uses saw blades with a saw kerf as thin as o.036 inch. With the thinner kerf, lumber yield can be increased up to 40%. This is especially important when cutting expensive lumber species. If you are producing veneer slats that will be further processed, i.e. face-glued, additional labor-costing steps can be avoided because the surface produced is smooth and highly-conducive for gluing.

Many companies that manufacture engineered flooring, doors, stiles and rails are able to take the veneer slats directly out of the frame saw and face glue them to a core product.

Ask an expert: Karl Ogden, President, Ogden Group, at sales@ogden-group.com

Q. Many manufacturers offer cutterheads for moulders, planers and jointers that use reversible two-sided knives that reference off a center groove of some sort during installation. Is there a way to sharpen two-sided knives?

A. As long as the reference groove is not on the "face" side of the knife, in many cases these knives can be sharpened, usually one time. The knives are placed in sets on a special magnetic bed surface grinder and the "face" or flat, non-groove side of the knives are re-surfaced, removing only a small amount of knife thickness. The center reference groove is not modified during sharpening, so they reinstall in the head with the same accuracy as before sharpening, just a few thousandths of an inch shorter.

Check with your sharpening professional or with the cutterhead manufacturer regarding the feasibility of sharpening your specific knives with this process and for the maximum amount that can be safely removed. Since many of these heads use a centrifugal knife clamping system, you need to be sure the gibs still hold the thinner knives tightly in the cutterhead.

Ask an expert: Jim Coon, Regional Sales Manager of Terminus Technologies Inc., at terminusjimc2@comcast.net

Q: Is poor alignment the main problem people face when seeing a poor finish from their widebelt sander?

A. Achieving the best possible finish from your widebelt sander requires a number of variables to perform simultaneously. Alignment is a key, but often people forget the importance of using the correct abrasives or the proper abrasive sequence needed for their specific application. Not all belts or minerals are created equally, they are different for very specific reasons, and if you utilize the wrong belt, the finish you achieve and the life of the belt may be drastically affected.

Belt and machinery manufacturers are great references to help you “tune in” your abrasives to a level that satisfies both your finish expectations and the life of your abrasives. Don’t forget, the machine is simply driving a tool; it’s the tooling that determines the finish. Following are some general guidelines to get you started:
  
• There are basically four “types” of belts, heavy abrasive planning belts (24-60 grit), light calibrating belts (80-120 grit), finishing belts (150-240 grit) and polishing belts (280-600 grit).  Each of these has a specific stock removal and scratch depth associated with them. If you push them beyond that limit they will load up and fail prematurely, resulting in a poor finish and higher than needed abrasive costs.

• The abrasive belt sequence you use is directly connected to your results. Since each grit leaves behind a specific depth of scratch it is imperative that you use the proper belt in the next step to assure that you have completely removed the previous scratch. In addition you need to keep in mind the stock removal capabilities of each belt and incorporate that into your sequence. A general rule of thumb is that you can skip two grit sizes in the heavy abrasive belt category (from 36 to 60 grit for example),and you can skip one grit size in the light calibrating belt category (80 to 120), but if at all possible, try NOT to skip grits in a sequence in the finishing belt category.  Once you enter the polishing category (lacquer sanding for example) the sequence will have to be determined by experimentation as there are too many variables that can affect the outcome (type of lacquer, thickness of coatings and such). 

Ask an expert: Tim Mueller, Marketing Manager of Timesavers Inc., at tmueller@timesaversinc.com