Replies

1. 
   BG | Oct 12, 2003 05:43am | #1

   Bob,

   I know what you mean about the runners swelling in the summer, it happened to me this summer with oak.  Last year I bought the white plastic stuff and cut strips...did not care for that much either, the screws make it spread and cutting it is messy.  I finally broke down and bought Incra runners and put that on the jigs...they are metal and adjustable and so far work quite well.
1. 
   66wood | Oct 12, 2003 05:28pm | #4

   Thanks for the info. I've seen those runners too in the mags. I read.

2. 
   migraine | Oct 12, 2003 06:00am | #2

   I suggest 1/2"-9ply or 3/4"-12ply for your mitre track assemblies

1. 
   66wood | Oct 12, 2003 05:29pm | #5

   Thanks for the input I may try the plywood

3. 
   beck4000 | Oct 12, 2003 03:59pm | #3

   Hi, UHMW is great stuff if you can get it...I also use plywood for the runners...

   but there again it has to fit your miter slots...

   [email protected]  try here for UHMW,hope this helps you..Oh yeah peeps. this is

   my first Post, (kinda watching what people write)

1. 
   66wood | Oct 12, 2003 05:31pm | #6

   Thanks for the info. I'll try the site you suggest on the plastic.

4. 
   lostarrow | Oct 13, 2003 01:39pm | #7

   I use Corian for my runners. Kitchen/Bath counter top installers/manufacters usually have scrap rips and cutoffs.

   Be not afraid of going slowly.  Be afraid only of standing still.   chinese proverb
5. 
   clampman2 | Oct 14, 2003 02:38am | #8

   Another option is 3/4 by 3/8 cold rolled steel bar stock. It's cheap, stable, and slides well.

   Clampman

6. 
   ian | Oct 14, 2003 04:26pm | #9

   Bob

   you could try orintating the grain on your runners so that the expansion is primarily up and down rather than side-to-side in the slot.  Afterall the runners ride on the sides of the slot not the bottom so with the grain orintated correctly you have some room for expansion.

1. 
   forestgirl | Oct 15, 2003 12:29am | #10

   Oooooh, incredibly good point.  I've been lurking around this thread to see what the thoughts were, as the variation in humidity in my shop is pretty wide.  Excellent point.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

2. 
   66wood | Oct 18, 2003 03:51am | #14

   Have'nt thought of that,I'll give it a try.  Thanks

7. 
   Steinmetz | Oct 16, 2003 01:40am | #11

   Bob, If you can get it ,use Phenolic plastic.

   I use it to make jigs and it is great unlike ordinary plastic, (Which warps)

    The phenolic is quite stable/smooth sliding/ accurately dimentioned and easilly worked with wood cutting blades.

    Drill and tap it counter sink or counterbore it

   Can't beat it. Stein

1. 
   66wood | Oct 18, 2003 03:53am | #15

   I've thought about that before but have not tried it.     Thanks

8. 
   billl6 | Oct 17, 2003 12:38am | #12

   Bob,

   I just made a two runner cut off sliding table and after trying uhmw plastic, I gave up and ripped two maple runners which work beautifully. After finishing with several coats of tung oil I don't expect too many problems with dimension change.

   The plastic spreads when screwed down and flexes too much so I couldn't extend them beyond the front of the jig to ease getting it in the miter slot.

   Bill
1. 
   66wood | Oct 18, 2003 03:54am | #16

   I have used maple on other things and it worked well, I may try it on my runners. Thanks

9. 
   lostarrow | Oct 18, 2003 03:05am | #13

   Bob-

   When I make runners for a jig, either using wood or some man made stuff (I use Corian), I rip them with a slight bevel on the edges,but not out to a feather edge. I try to leave about 1/8" to ride against the sides of the mitre slot. I fit them snug to start with and screw them to the bottom of the jig,bevel up. Then a pass or two with a shoulder plane on that 1/8" edge to get a good sliding fit. Works for me.

   Be not afraid of going slowly.  Be afraid only of standing still.   chinese proverb
1. 
   66wood | Oct 18, 2003 03:57am | #17

   I saw another post about this stuff I went to a web site and may order some,Thanks

1. 
   Justus | Oct 22, 2003 05:41pm | #18

   A good source for UHMW plastic is probably sitting on your kitchen counter. Modern cutting boards are made of various grades of the stuff, some harder or softer, just drop by wal mart or a specialty cooking store. I've been using them for jigs and runners forever.Justus Koshiol

   Running Pug Construction

1. 
   woodaddic1 | Oct 25, 2003 06:42am | #23

   Just as others have mentioned, I tried using UHMW and really didn't like it.  The plastic spread considerably where the screws were sunk and it lacked strength at both ends.  I decided to try something I found on this thread.  I ripped 9 ply half inch birch and they have worked great.  Just thought I'd chime in.

   Ryan

2. 
   wrick2003 | Oct 23, 2003 02:31am | #19

        One afternoon, my saw decided to cut a width of 1x maple that fit just perfectly into my mitre slot. I ripped about a dozen of them, for future use. They rarely need more than a little sanding to glide right.    rg 

10. 
    bsutton12 | Oct 23, 2003 10:07pm | #20

    American Woodworker - June 2003 issue has a technique of using 3/4" aluminum angle for runners that should work well

11. 
    Julmer | Oct 24, 2003 11:17pm | #21

    How come no one has mentioned the method of cutting your runners undersize and screwing two or three flat head brass screws into countersunk holes in one side.

    As the runner contracts or expands you just adjust the screws in/out for a nice snug fit / easy slide in your mitre slot. Usually you might have to adjust once a year.

1. 
   BG | Oct 25, 2003 03:05am | #22

   John,

   I may have done it wrong...but I felt too many loose spots.  I took 3/4 MDF and ran a dado about 1/4" attached the plastic with screws.  I was tough to get even pressure ... and that made the sled slightly askew...

1. 
   Julmer | Oct 27, 2003 06:26pm | #24

   Need to explain my method more clearly. I don't use the screws to "expand" the runner. I use the screws as a contact surface in the mitre slot.

   The runner will have screws to hold it to the fixture/jig (vertical - screwed from bottom up). Next the runner (which is ripped slightly less than 3/4") will have a second set of screws (preferably brass) screwed horizontally along one edge of the runner. (three or four). The screws are adjusted in/out to snug the runner in the miter slot. The heads of the screws contact one of the slots sides

   It generally works only with smaller jigs in which the runner mostly stays in the slot and does not need to be pulled back and forth alot (the screws can "catch" on the slot ends

1. 
   BG | Oct 27, 2003 08:32pm | #25

   John,

   That is fascinating and quite ingenious...I never would have guessed that approach, thanks for sharing. 

2. 
   4DThinker | Oct 27, 2003 10:10pm | #26

   The screw idea might work well unless they tend to rotate as the slide against the slot.  What keeps them from screwing themselves in or out as they are slid down the slot?

   4DThinker

1. 
   Julmer | Oct 27, 2003 11:03pm | #27

   Never had a problem with screws losening. With a proper pilot hole, screws have always been tight enough to prevent. Brass Screws (softer than Cast Iron table) slide easily. If the screws wear over time, you just readjust them.

12. 
    RANGERP75R | Oct 28, 2003 03:46am | #28

    Bob

       I have some jigs built with the U.... the white stuff.. It's OK, but has a tendency to warp in longer lengths. I agree with Stein on the phonelics. They don't warp and as slick as glass.

    http://www.highlandhardware.com

       They have them pre-cut to slightly over  3/4" in several lengths. A gentle stroke or two with a scraper brings them home to "mama" in your mitre slot.

       No expansion or contraction, no warp and no further adjustment.

    Good luck...

    sarge..jt

    
    

    ---

    Edited 10/27/2003 8:50:31 PM ET by SARGE

1. 
   66wood | Oct 29, 2003 05:15am | #30

   Thanks for the info. I think I will give it a try.

1. 
   RANGERP75R | Oct 29, 2003 08:10am | #31

   Bob

      You're welcome. Caution, the pre-cut is not 3/8" thick. They have it pre-cut to 1/4". It is stiff. Don't ask me. I saw them open the doors across the street back in 78'. I figure someone at Highland knew what they were doing going 1/4".

      The good news is I have several jigs set up with it and the extra 1/8" hasn't been a problem. BTW, if you've never worked the phonelic, you can cut it to length with a TS, BS or a hand tool. When you do though, use an old blade. That stuff is murder on blade teeth.

   Good luck...

   sarge..jt

13. 
    IMERC | Oct 28, 2003 03:55am | #29

    Aluminium bars. 3/8x3/4 bars is a stock common size. Too wide? It can be trimmed / shaved to fit. Too loose? It can be slotted and set screwed to compensate.

    Very stable and considerably more rigid than than wood or plastic. Easier to work than steel.

     

    Who ever invented work didn't know how to fish....

14. 
    Steinmetz | Oct 30, 2003 02:02am | #32

    Bob, while wooden runners expand and contract with humid conditions, Phenolic does not. 

    The bigest mistake however, is making the sled of wood. Use 1/4" phenolic and your troubles are over. Stein. 

     If you can't get 3/8" stuff for the runners, !/4" stuff will make-do.