Unofficial FLL FAQ06-c - Table
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Q18.1) My shop light fixture has a plastic diffusion lens. Should I use it?
A) No. The specification for an FLL table uses a shop light without a lens.

Q18.2) How can I be sure the lighting on my practice table will be the same as at competition?
A) You can't! You must allow for variations in your mechanical or software design.

Q18.3) Using construction 2x4 for the table borders seems 'rough'. Would it be better to make the borders from a better wood?
A) Yes and No. A beautiful border of ebony would be very pretty. But at competition you will be using tables of rough and crooked lumber. Best to practice and learn to deal with those problems early! I would take a little sandpaper to the edges just to keep the splinters down.

Q18.3.5) Where are the instructions for putting together the field models?
A) The building instructions are found on the CD that comes with the Challenge Set. The Challenge Set should not be confused with the Robot Construction Set. The Challenge Set changes each year and includes the LEGO to make the field pieces. The Robot Contruction Set (a jazzed up Mindstorms set) includes the critical parts you will need to build your robot.

Q18.4) Now that I have made all the LEGO field pieces how do they stay in place?
A) You should have received a sheet of 3M Dual Lock self adhesive material. This material is similar to Velcro. Pieces of this material are applied to the field pieces as well as to the mat to hold certain elements in place. Detailed instructions will be provided by FIRST at kickoff. Not all elements are held in place. Some may be lose to allow the robot to manipulate them.

Q18.5) What color should the table border be painted?
A) The border should be painted black. FLL does not specify the type or manufacturer of paint nor the texture (gloss, matte, ...). This choice is up to you. Consider carefully relying on an exact color as the tournament tables may differ. In fact, some local tournament tables may not be painted at all!

Q18.6) How can I make a duplicate of the mat for off site practice?
A) This is a tricky problem. It will be nearly impossible to make a true duplicate. The texture of the mat is bound to be different on the copy. For some robots this may not be an issue. Most robots though, will behave differently since the friction will be different. Some teams paint the features on plywood, some transfer to paper. Some teams cover the paper copy with clear adhesive shelf paper. Others find that Tyvek and magic marker works well.

Q18.7) I have heard that the mat is fragile. Could you explain?
A) The mat is made from some kind of vinyl with a clear plastic coat over the top. The bond between these layers is what is fragile. A sharp bend or kink in the mat will cause the clear plastic to delaminate and bubble. A dropped robot can also dent the mat and start a bubble. Bubbles in the mat change the surface color and may render the mat useless for line following.

Q18.8) Is it possible to repair a delaminated mat?
Most mats can be mostly fixed. If you use a normal house iron and a piece of printer paper, you can remove most imperfections. Follow these steps and your mat will be good as new:
  1. Lay your mat out on the table and put books on the corners to hold it down.
  2. Set your iron to low, turn off the steam (steam is very bad), and wait for the temperature to stabilize. Test the iron setting by touching the bare tip of the iron to the mat in a non visible area. Pick an area under a stationary mission model in case you melt the mat! It should not distort the mat or stick to the iron.
  3. Only touch the iron to the paper, never the mat.
  4. Work from the middle of the mat out to the edges.
  5. For bubbles, poke a hole with a pin in the edge of the bubble, work your iron towards the bubble in a sweeping motion side to side slowly and only with the tip.
  6. For edge bubbles start at the most inside area and work to the edge.
  7. For creases, make sure your paper is bigger than your iron and put the whole iron down over the crease with a bit of weight and move it slowly back and forth as if you were attaching an iron on to a T-shirt. Check your work often.
  8. For edge de-laminations, turn the iron up just a little and using the paper, press really hard. Keep an eye on the edge, if you see it stretching , turn the iron down a little.
This may take you some time and you may need to adjust your iron to a hotter setting to make it work well, but you will have a batter mat, not perfect, but better.

Q18.9) How am I supposed to attach the mat to the table?
A) You probably do not need to attach the mat at all. After a few days, the mat will flatten out and stay in place. If your mat needs a little convincing to stay flat on the ends, try double sided carpet tape. If you need to store the table vertically, remove the mat each time you use it, or use a staple gun to tack it down along the edges and in out of the way places (like under stationary mission models).

Q18.10) Any suggestions for a detachable light assembly?
A1) Use wing bolts. A2) Use the preformed metal table assembly parts that fit 2x4s. They are sold at Home Depot and Lowes and are less than a dollar. They mount to the table and provide a place to slide the 2x4 in.

Q18.11) Our mat does not fit in our table!
A) Make sure your table dimensions are correct. The inside dimensions should be 45 +/-1/8 inch in width and 93 +/-1/8 inch in length. Then trim the mat to fit. FIRST normally provides advice in trimming oversize mats. If not, the guiding principle is to leave the edges adjoining the base alone and trim the opposite edges.

Q18.12) Will the tournament tables be exactly like our table?
A) Tables are likely to vary considerably based on the skill of the builder. As such, tournament tables vary in quality. I have seen tacky paint, massive unfilled knot holes, light supports in the wrong locations, warped surface and borders, and out of spec dimensions. Come to a tournament prepared to make last minute corrections. For veteran teams, focus on ways not to rely on exact placements. Missions should work even with placement errors of up to 1 cm.

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Disclaimer: This FAQ is not an official FIRST document. It is an accumulation of knowledge derived from six thousand messages posted to the FLL forum over three seasons. It has been reviewed by numerous people, but may still contain errors. Use at your own risk.
Readers are encouraged to submit errors, suggested wording changes, new topics, or comments to Skye Sweeney at skye@fll-freak.com
Copyright 2003-2006 Skye Sweeney; Last Updated on 10/28/2006