Blum hardware and LR-32, please check my logic

[Kodi Crescent]

I've never built cabinets with drawers before, so I'd appreciate it if others with experience can check my logic before I begin plowing holes in my workpieces.  My question is about using the Festool LR-32 with Blum Tandem/Solo drawer runners. 

The cabinets will have full overlay doors with the tops and bottoms dadoed flush into the gable sides.  The gables are full 32 mm increments in height for the LR-32 stops.

If I'm reading the Blum Process 32 plans correctly, all the Blum base cabinet plans start the c-t-c system holes at 46.5 mm and 78.5 mm from the bottom edge of the gables.  (37 mm c-t-c in from the gable front edge, and 93 mm c-t-c from the rear edge to match runner mounting hole patterns).  Holes are spaced at 32 mm increments where necessary for shelving and hardware installation.

If I'm measuring my LR-32 hole placement correctly (32 and 9.5 showing on rail underside, 9.5 against workpiece), my c-t-c system holes start at 48 mm and 80 mm from the bottom edge of the gable, a shift of 1.5 mm upwards from the Blum Process 32 plans.

So here's my logic -

When using the Tandem/Solo hardware, the +1.5 mm difference between the Blum Process 32 system holes and the LR-32 holes makes very little to no practical difference during the build, other than to shift drawer divider placement and drawer faces by 1.5 mm from the Blum plans. 

Drawer divider placement adjusts +1.5 mm from the Blum Plan dimensions; bottom and top-drawer face heights adjust by +1.5 mm and -1.5 mm respectively.  Drawer slides mount in the top row of mounting holes, except for the bottom drawer, which mounts in the lower row of holes.

Is this logic correct?

Thanks!

 

[waho6o9]

Practice on scrap first.

Good luck now

I have a test cabinet of sorts that  I try things on. 

View attachment 1

 

[Kodi Crescent]

Practice on scrap first.

Good luck now

I have a test cabinet of sorts that  I try things on. 

View attachment 1

Alright.  I need to buy my hardware before I proceed any further.  Thanks.

 

[waho6o9]

Good idea.

 

[JeromeM]

Practice on scrap first.

Good luck now

I have a test cabinet of sorts that  I try things on. 

View attachment 1

Alright.  I need to buy my hardware before I proceed any further.  Thanks.

That's certainly a good idea, as best practice is to usually to buy the hardware first, so you can easily test your ideas.

 

[jjowen]

[attachimg=1]

It is worth doing your first door on a mock-up with cheap ply. There are a number of things to play with and get right. Don't forget to check your panel thickness before routing and drilling. I do like the Blum hardware, but I have been caught out by assuming that a dimension line on the template on the back of the packet, near the centre of the fitting was not actually the centre line!

Jeremy

 

[Kodi Crescent]

I'll slow down, wait for my hardware to arrive, and make some mockups.  I'm sure there are several other production preparation steps I can complete before I plow any holes.

 

[Jass]

Is there any reason you're bothering with the system holes? I've never used them, just always screw straight into the carcass. Mark your height of screw centreline, square a line back, mark 37mm for first screw then whack in another couple along the line. Just seems like another step of complicating the process.

Sent from my SM-T813 using Tapatalk

 

[JeromeM]

Is there any reason you're bothering with the system holes? I've never used them, just always screw straight into the carcass. Mark your height of screw centreline, square a line back, mark 37mm for first screw then whack in another couple along the line. Just seems like another step of complicating the process.

Sent from my SM-T813 using Tapatalk

That rather depends on if you are using euro screws (you have to drill) and some hardware includes/requires them or regular screws (you can but don't have to)

 

[sheperd80]

Cant help much with your original question but ill just add this. The LR32 is a great system for certain applications, but alot of the time its not worth the effort. On boxes that will have doors and adjustable shelving, its brilliant. But on top to bottom drawer units its not worth it imho. Its so much easier to set dust frames (dividers) and simply set the glides on them when installing. Its simple and extremely accurate as long as the dividers are set accurately using a spacer block.

I have a shop made hinge plate drilling jig that matches the offset of the LR32 so that i can make boxes with and without the LR32 within the same project and still have the same hinge placement from top and bottom of each door.

Sorry if thats a bit convoluted, its alot to try and explain with type. Best of luck with your project!

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[lwoirhaye]

Drawer boxes in 32mm generally leave plenty of headroom.  Drawer faces on the other hand are typically cut in specific increments  so there's no confusion.  The Blum spacing may fuss with the hole positions to make the face dimensions simpler to measure when cutting the parts out.  This may be why the Blum holes are put where they are.  You'll be best off edgebanding before you drill the holes.  For cabinets full of drawer slides it may be simpler to drill the first row with your router and use a drill  jig with a square l to pop in the other holes you need.  5mm shelf pin rods can drop into a jig with 5mm holes like the Align-Rite jig has and into the first row of holes.    I can mail you a few pins if you want to try this approach.  Dave Lers mentions using the Align-rite to do this on his website about 32mm cabinet making.

Google the Kurka Jig manual for a real simple version of a 32mm drawer layout system.  Useful to read even if you don't use it.

 

[sprior]

I've never built cabinets with drawers before, so I'd appreciate it if others with experience can check my logic before I begin plowing holes in my workpieces.  My question is about using the Festool LR-32 with Blum Tandem/Solo drawer runners. 

I highly recommend watching The Poplar Shop's Youtube videos on the LR32 system starting with this one.

 

[jasen]

You also might be interested in a member who created a stop especially for Blum setuphttp://festoolownersgroup.com/festool-jigs-tool-enhancements/3d-printed-lr32-end-stop/20

If you have a 3D printer, quite easy to print. Just another option.

Im about to do some sys drawer cabinets to practice...but first I need to bild work benches LOL

 

[Kodi Crescent]

On the 4 drawer cabinet I'm building, the Blum hole measurements vs. the LR-32 system holes result in drawer front heights that very minimally from the Blum 4 drawer pattern.  Instead of all the drawer fronts being 157 mm with Blum (IIRC), the top one is 155 mm, the middle ones 157 mm, and the bottom one is 156 mm.

I don't know that these height differences are perceptible on the finished build.

 

[lwoirhaye]

That's fine, but I'm sure you can see how drawer face width differences of less than 10mm could drive you crazy in a high production situation with semi-skilled employees putting things together.  32mm is mostly a production way of thinking about things and keeping custom parts like those odd drawer faces out of it altogether.  If it's just you, do whatever you want with it.  Better label those faces as soon as you cut them out.

 

[JeromeM]

On the 4 drawer cabinet I'm building, the Blum hole measurements vs. the LR-32 system holes result in drawer front heights that very minimally from the Blum 4 drawer pattern.  Instead of all the drawer fronts being 157 mm with Blum (IIRC), the top one is 155 mm, the middle ones 157 mm, and the bottom one is 156 mm.

I don't know that these height differences are perceptible on the finished build.

I think the bottom one is going to look subtly wrong with nobody able to say until they know the measurements

 

[Cheese]

On the 4 drawer cabinet I'm building, the Blum hole measurements vs. the LR-32 system holes result in drawer front heights that very minimally from the Blum 4 drawer pattern.  Instead of all the drawer fronts being 157 mm with Blum (IIRC), the top one is 155 mm, the middle ones 157 mm, and the bottom one is 156 mm.

I don't know that these height differences are perceptible on the finished build.

You'll be fine...actually any difference in the gaps between the doors and the face frame will be more noticeable than a 1mm difference in drawer front height.  [big grin]

 

[Kodi Crescent]

That's fine, but I'm sure you can see how drawer face width differences of less than 10mm could drive you crazy in a high production situation with semi-skilled employees putting things together.  32mm is mostly a production way of thinking about things and keeping custom parts like those odd drawer faces out of it altogether.  If it's just you, do whatever you want with it.  Better label those faces as soon as you cut them out.

I can understand that.  This cabinet will be a one-off for personal use.

 

[Gregor]

For cabinets full of drawer slides it may be simpler to drill the first row with your router and use a drill  jig with a square l to pop in the other holes you need.  5mm shelf pin rods can drop into a jig with 5mm holes like the Align-Rite jig has and into the first row of holes.

In case you use euro screws for the drawer rails an only want to drill the front line of holes with the router (and LR32 or whatever you use) you don't need a jig for this should you have the #492525 Self-centering bit ZB HS D 5 EURO CE and a square:
[list type=decimal]
[*]Attach the rails at the intended positions with just the one screw in the front row (to align, don't tighten hard)
[*]Square the rail and use it as a template with the #492525 to make the most backward hole, put screw in and tighten the two screws now in place
[*]Make as much other holes as the template (=the rail) has options (and you see the need for) and put screws in tight
[/list]
Precise, quick and painless - especially when using two drills (one for the self centering, another for the screws).