router fence adjustment

[BobL]

I've been working my router fence adjuster for a while but only got around to finishing and testing it today.

The photos shows the setup which enables me to adjust the distance between tne fence and the router bit with considerably finer control than is possible using the standard TS fence adjusting mechanism. The adjustment is achieved by the two threaded knurled knobs on a threaded brass rod. The rod is attached to the fence at one end and a wooden block attached to the TS mitre at the other. The number of mm per thread turn of the brass rod was measured to be 1.411 +/- 0.001 mm per turn.

The wooden rod and calipers are not essential but I added them to see if I could use this setup to measure the fence displacement from the router bit. I attempted to measure the consistency of the fence position as a function of distance (comparing where it was, with where I expected it to be based on the 1.411 mm/turn). This is shown in Picture 3. It shows the reproducibility as measured by this system is only about +/- 0.1 mm over a distance of about 100 mm. Because of the flexibility of the timber and various joints used to connect everything up the measuring set up is far from ideal. I should probably just measure the actual distance between the fence and router bit. It would also probably help if I were to replace the replace the timber connections with all metal ones.

[damienhazo]

My hat's off to ya mate for giving it a go but I'm wondering why you didn't utilise the existing clamp on the parallel fence?

Take the fine adjuster on my saw for example:

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The advantage of a fine adjuster on the clamp itself is the flexibility. Because you move the parallel fence into position roughly and the fine adjuster is always moving with it, it only needs a few centimetres of thread at the most...

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Once the fence is within a few millimetres of the desired position, the fine adjuster is secured.

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Positive or negative movement is then dialed in.

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The parallel fence is secured.

Wouldn't an appropriate adaption of this tried and proven method better suit your needs in the long run?


Damien

[BobL]

RE: Wouldn't an appropriate adaption of this tried and proven method better suit your needs in the long run?

Thanks Damien yes I agree, mine is a short term solution to another problem. I have experimented with the method you suggested but the accuracy of driving my TS/router fence using the TS fence drive is relatively poor (+/-1 mm) because my router fence is too wide and heavy (so much for my intended light weight prototype!) and drags too much on the TS top. I added polyethylene strips to reduce friction but I really need to redesign the router fence. In the meantime I had a threaded brass rod left over from another project and decided to experiment with it. Because it pushes and pulls from the middle of the fence it is able to drive the fence more accurately.

[Auld Bassoon]

Hi Bob,

I note that you have the same model T/S as I do. Whilst I have a separate router table, I would comment that the "fine" adjuster on the T/Ss fence is still somewhat crude, and not really suitable for very fine adjustments, so your threaded bar arrangement, so long as it moves the router fence whilst maintaining parallellism, would seem to be a better one.

[BobL]

Hi Bob,

I note that you have the same model T/S as I do. Whilst I have a separate router table, I would comment that the "fine" adjuster on the T/Ss fence is still somewhat crude, and not really suitable for very fine adjustments, so your threaded bar arrangement, so long as it moves the router fence whilst maintaining parallellism, would seem to be a better one.

Hi Auld, Yes definitely agree, "fine" = somewhat crude" ,and with my heavish router fence on top of that, "fine" = "even cruder".
Bob