Undermount slides

[Erik Christensen]

I have a number of dovetail drawer boxes I am making that will use Blum undermount slides. I have used these before and know that they require you to cut a notch in the back of the drawer for the slide mechanism. In the past I cut that notch on the table saw with a dado blade AFTER drawer assembly as I was afraid that the back pin board might fail if it was notched without support. I was not really happy with the process of trying to cut the notch in an assembled drawer – lots of tearout and much more difficult to position accurately.

So the question is for those of you with more experience with this – do you cut you notches before or after box assembly? If before – any tips or suggestions? Did you have any failures of a pin board?

If it matters in your recommendations the drawer box is ¾” hard maple with a ½” maple ply bottom.

Thanks

[frank shic]

i just use a handsaw and chisel to cut the notches out after assembling the drawer. the notches don't have to be pretty.

[Paul Murphy]

I like building drawer boxes where no notch is required, i.e. the bottom of the drawer back is level with the top of the groove cut for the drawer bottom. I screw the back of the drawer bottom to the drawer back. I like this method for a couple of other reasons, one being I can finish the drawer without the bottom installed, and also it works well with solid wood drawer bottoms by simply slotting the screw hole.

[David Giles]

After every drawer box construction project, I make a note to self, "Always cut notches before assembly." Then I forget to do it once again.

[Jamie Buxton]

I like building drawer boxes where no notch is required, i.e. the bottom of the drawer back is level with the top of the groove cut for the drawer bottom. I screw the back of the drawer bottom to the drawer back. I like this method for a couple of other reasons, one being I can finish the drawer without the bottom installed, and also it works well with solid wood drawer bottoms by simply slotting the screw hole.

That's my standard method too. I cut the dovetails with a router jig. I cut the drawer box front sides and backs all the same height, and then cut the dovetails. Then I cut the dados for the bottom, and rip the drawer box back the right height. Save the offcut. It has the pins for the back lower corners of the box. When you glue up the box, cut those pins from the offcut and glue them in place. I generally put labels on the offcuts so I can associate those fake pins with the back they came from, so the end-grain pattern seen in the assembled box is continuous. Yeah, yeah, nobody but me will ever notice.

I've also made a simple jig to position the holes in the back. I use a plunge router to make the holes. The depth stop on the router never slips. And the template guide on the router fits precisely in the guide.

[John P Clark]

I built a jig for a router and router out the back of the drawers after construction - last step prior to installing hardware and drawer. Works well and does not take much additional time for construction. I have built about 50 drawers in the last couple of months using this method.

[John Morrison60]

Erik
I have done both, but prefer the before assembly notching for time saving.
I like John's method of building a jig for routing, think I will try it next time.
John, do you have a picture of your jig?

Erik, Are you using the blum guides that are made for 3/4 thick drawers?
The normal hardware will handle 3/4 backs & fronts, but will not work with
3/4 sides.

[Jamie Buxton]

Here's a drawing of the jig I made to cut the backs of drawers for undermount slides. (I don't have the jig any more. I now make the drawers a different way, so the jig was surplus, and a friend grabbed it.) The jig uses a plunge router, a 1/4" straight bit, and a 5/16" template guide. With the depth stop set at 3/8", the hole for the pin gets bored. With the depth stop set deeper, the cutout on the bottom edge of the drawer gets made. Notice that the jig registers against the bottom face of the drawer bottom, and the inside face of the drawer sides. This means it can be used with any thickness of drawer side, drawer back, or drawer bottom.

[Karl Brogger]

for those of you with more experience with this – do you cut you notches before or after box assembly? If before – any tips or suggestions? Did you have any failures of a pin board?

I cut them after the drawer is assembled, and sanded. Its the last step in the process for me other than mounting the locking devices.

I do it on the tablesaw with a dado head. You have to make two passes, which gets old. There is some tear out, but honestly, who cares?

I have am older 2hp Rockwell shaper that I bought specifically for cutting the notches. I finally ordered a cutters so I can set it up. I'm a bit nervous about whether or not the material will explode doing it this way. I did order 5, 1/4 tall cutters hoping I could stagger them enough so it wasn't just one big cutter slamming into it.

[Jeff Wright]

I'm currently making a dozen drawers for a new kitchen I'm building. They will all have hand cut dovetails. Like Paul, I like making them where the bottom can be installed after finishing and glue up. I have used my router table in the past to cut out the notch for the Blum devices. I adjusted the cut by creeping up on the final setting. Worked great and looked good too. While no one other than me will see that area, I still want it to look good.

[Mike Tidd]

I use the Blum undermount slides just about every week. I have found that making the cut out before assembly saves me time and produces a cleaner finish than the dado method. I gang them up for cutting on the bandsaw. Quick & simple.

Mike