Steve Rowe
06-18-2010, 3:40 PM
With all the interest in shapers as of late, I thought I would do a review of the Leuco adjustable groover. I have been extremely impressed by the quality and versatility of these cutters. I use this particular cutter primarily to cut spline grooves, slots for drawer bottoms, and for milling stock for dust panels in furniture.
An adjustable groover is basically a two (sometimes 3) piece stacked dado cutter set with shims to adjust the cutting width. Some larger cutters will also permit arranging the cutterhead to cut a tenon to fit in the same groove with minimal hassle on setup. The advantage of using this cutter on the shaper as opposed to a dado on a saw is that you are not balancing what could be a large piece on a narrow edge which challenges the quality of cutting the groove. This cutterhead design gives me four different cutting edges so I expect it will last me a long time prior to needing to replace cutters.
I like to use plywood for splines since it has grain going in two directions and offers a stronger joint (at least in my view) than a solid wood spline. Plus, it is relatively inexpensive and readily available. The problem with using plywood as splines is that the fixed width cutters never match the thickness of the ply. This is where the adjustable groover excels. The Leuco cutter I have is 130mm diameter, has a width range of 4 - 7.5mm with a maximum depth of cut of 30mm (just under 1-1/4"). You can get cutters to do deeper cuts but need a larger diameter cutter (also included is the larger price tag).
Now, don't get turned off by metric on this because it really makes adjusting the cutter much easier than using imperial measurements. Here is my procedure for setting up and cutting spline grooves:
Measure the thickness of the spline using digital calipers in millimeters. For my example, it is 5.27mm.
Since the minimum groove width for this cutter is 4mm, I need to add 1.27mm of shim thickness between the 2 cutterhead pieces. I always add about 0.1mm additional shim thickness which makes it easier to insert the spline with glue in the joint.
I have pre-measured the shim thickness and marked them with a Sharpie but, I don't really use this to do the math. I grab some shims and measure the thickness with the digital caliper. I then add to, take away or replace shims based on the markings to achieve my desired shim thickness. You don't need to achieve the exact thickness to achieve a good joint but it obviously needs to cut a slot of greater thickness than the spline.
Set up the shaper cutter with the shims, adjust the depth of cut and height of the cutter and mill away. I get perfect thickness cuts first time and everytime using the technique above.
An adjustable groover is basically a two (sometimes 3) piece stacked dado cutter set with shims to adjust the cutting width. Some larger cutters will also permit arranging the cutterhead to cut a tenon to fit in the same groove with minimal hassle on setup. The advantage of using this cutter on the shaper as opposed to a dado on a saw is that you are not balancing what could be a large piece on a narrow edge which challenges the quality of cutting the groove. This cutterhead design gives me four different cutting edges so I expect it will last me a long time prior to needing to replace cutters.
I like to use plywood for splines since it has grain going in two directions and offers a stronger joint (at least in my view) than a solid wood spline. Plus, it is relatively inexpensive and readily available. The problem with using plywood as splines is that the fixed width cutters never match the thickness of the ply. This is where the adjustable groover excels. The Leuco cutter I have is 130mm diameter, has a width range of 4 - 7.5mm with a maximum depth of cut of 30mm (just under 1-1/4"). You can get cutters to do deeper cuts but need a larger diameter cutter (also included is the larger price tag).
Now, don't get turned off by metric on this because it really makes adjusting the cutter much easier than using imperial measurements. Here is my procedure for setting up and cutting spline grooves:
Measure the thickness of the spline using digital calipers in millimeters. For my example, it is 5.27mm.
Since the minimum groove width for this cutter is 4mm, I need to add 1.27mm of shim thickness between the 2 cutterhead pieces. I always add about 0.1mm additional shim thickness which makes it easier to insert the spline with glue in the joint.
I have pre-measured the shim thickness and marked them with a Sharpie but, I don't really use this to do the math. I grab some shims and measure the thickness with the digital caliper. I then add to, take away or replace shims based on the markings to achieve my desired shim thickness. You don't need to achieve the exact thickness to achieve a good joint but it obviously needs to cut a slot of greater thickness than the spline.
Set up the shaper cutter with the shims, adjust the depth of cut and height of the cutter and mill away. I get perfect thickness cuts first time and everytime using the technique above.