How can I repeatably position OF1010 with guide rail?

[Julie]

I am experimenting with the MatchFit system of dovetail grooves.

I will have to use the guide rail instead of the edge guide for most grooves because they will be too far for the edge to use the edge guide.

Each groove requires two passes: one with a relief bit to remove most of the material and then a pass with the dovetail bit to create the proper groove profile. If I position the rail for each groove, use the relief bit for the first pass, change to the dovetail bit, then do the final pass, I will have both passes in exact alignment. However, this will require a huge number of bit changes. Bit changes on the OF1010 take time, and each time the bit is changed the bit depth also has to be re-calibrated.

In order to streamline the process and only change bits once, I would like to route all the grooves with the relief bit and then go back and repeat the process with the dovetail bit. Festool makes a big deal about their routers having a witness mark where the center of the bit is so it can easily be lined up to a center line. That works well enough when the location does not have to be precise and when the guide position does not have to be changed. It does not help when the router is being re-positioned to cut the dovetail when there is already a groove there from the relief bit.

Does anyone have a suggestion for repeating a previous position for the guide rail/router guide?

 

[tjbnwi]

Cut a pair of stepped block with the bottom the width of your relief groove. Bore a hole the diameter of the major radius of the dovetail bit. Set the block in the groove, with the router on the rail eyeball it close, “shimmy” the rail so the bit will fall into the hole, set rail, repeat for other side. This will give you the most accuracy.

Other option is to place a witness mark along the rail opposite the splinter guard side before moving the rail to the next slot. Eyeball the rail onto the witness marks, cut the dovetails.

Tom

 

 

[jeffinsgf]

Tom's second approach would be mine. Just mark the back side of the guide rail for each of your cuts. Alignment of the dovetail cut with the clearing cut needs to be close, but I'm pretty sure you have .010" to .015" to play with. You put the guide rail back on a pencil line, and you'll be plenty close.

 

[Julie]

My first project was just the top of a cabinet, where I am going to use the Matchfit hardware to hold benchtop tools in place. I used my parallel guides with the rail. It was very awkward using a 55" rail with 30" parallel guides on a 16x18" cabinet top.

I am planning to set the router bit center at a known distance from the back of the rail and then mark positions from the back of the rail in the future as recommended by [member=7266]jeffinsgf[/member]

I really wish that I had a short rail section for times like this, but the price for the Festool 800mm rail is just too high for my budget.

 

[jeffinsgf]

Do you have a couple track clamps? (Festool, not Micro-Jig) Clamping your rail down will go a long way toward making the long rail easier to work with on shorter material.

 

[Willy Eckerslike]

Two routers - one with the clearance bit the other with the dovetail.  The gain in productivity soon makes up for the cost of another router.

 

[Crazyraceguy]

Two routers - one with the clearance bit the other with the dovetail.  The gain in productivity soon makes up for the cost of another router.

This is absolutely the best way to go about this, but may people just will not (or cannot) do it.
As Tom and Jeff have suggested, careful marking should get you close enough. Your initial clearance-cut should not be so close to the final size as to make this that big of a deal.