Thread: Table saw runners

Don’t shave the entire length.
Using a lead pencil, draw all over the side of the runners and then put into the tracks. Push the jig a few times and where the runners rub on the tracks, the lead will be smudged or rubbed out. This is where you shave the runners only


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It sounds like there are some tight spots in the table's T-track slots.

I'd be tuning up the slots by making up another set of runners a whisker under the size of the ones on you jig. Then tightly wrapp one layer of 400g wet and dry paper around the new runners and adding a couple of large screws to hold them in place and to give you something to hang onto. Then soak the table slot tight spots with kero and work the papered runners back and forth until the slots loosen up. Stop periodically and check the fit

A few years ago I make a mini metal cutting table saw and used the above method to get a really close fit for the dovetailed mitre slide.
It worked a treat.
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This sounds reasonable but it's a puzzle why this has to be done when I make the runners cutting both sides alternately several times.

Are you sure you have the runners parallel and at the correct spacing. Do they run freely when not attached to the jig?
If they run freely then they are not attached right.
The easiest way to do it is place the runners in the slots and then attach the jig.

Just a thought - is your jig using two parallel runners?

Perhaps its simply changes in the humidity in your shop that is causing the problems. If your sleds / jigs are made from timber and the runners also timber then they naturally will move with changes in humidity as it affects the moisture content (EMC) of the timber, swelling or shrinking accordingly. If so, shaving the timber runners is only a partial solution.

Even "stable" materials (ply or MDF) used to construct the sled / jig bases will move to some extent.

If its happening on the one day, then changes in EMC is unlikely to be the cause, so look towards milling QA issues in the mitre tracks & follow BobL's tips; or your own QA issues in constructing the sleds / jigs..

I have struck the same problem in the past and found that the mitre slot varied in width from what I guess was bad machining.