1. Jig for drilling drawers for false fronts

[Cheese]

A sister thread:https://www.festoolownersgroup.com/...ed-lights-using-the-mfs/msg576988/#msg576988I

I need to install some false drawer fronts on 20 drawers. There will be 4 holes/screws in each drawer so I figured a jig was mandatory. There will be a pair of holes on the LH & RH of each drawer.

However, because each drawer is lined with aromatic cedar, the screw head holes need to be counterbored into the rear of each drawer.

[attachimg=1]

[attachimg=2]

The OD of the screw head is .500" so if I want to have .06" (1/16") adjustment in each direction, I needed to counterbore a .625" (5/8") diameter in the rear of the drawer. A .250" through hole would then also allow .06" movement for the screw body.

Not being able to readily find a 5/8" x 1/4" counterbore I decided to use a Series 3 Zobo bit. Unfortunately, a 5/8" diameter bit is not available however a 16 mm (.629") bit is available.

If you're not familiar with the Series 3 Zobo bits, they have the ability to use different size guide pins, centering points and pilot drills.
https://www.timbertools.com/System-3-Accessories/
https://www.timbertools.com/Zobo-Central-Drilling-System-3/

Unfortunately again, they do not offer a 1/4" diameter pilot, 6 mm is the closest they come which is not up to the task.

So, the plan is to purchase 4 each 1/4" drill bushings, a section of 12L14 tight-tolerance 1/4" rod and a 16 mm Zobo bit. One end of the rod will be turned down to 6 mm so it fits into the Zobo bit while the other end fits into the drill bushings.

[attachimg=3]

 

[Svar]

Unfortunately again, they do not offer a 1/4" diameter pilot, 6 mm is the closest they come which is not up to the task.
So, the plan is to purchase 4 each 1/4" drill bushings, a section of 12L14 tight-tolerance 1/4" rod and a 16 mm Zobo bit. One end of the rod will be turned down to 6 mm so it fits into the Zobo bit while the other end fits into the drill bushings.

Isn't it easier to take 1/4" bit and turn/grind its shank to 6mm?

 

[Cheese]

Here's a photo of a 20 mm Series 3 with a 6 mm pilot. I made my first MFT by drilling a field of 6 mm holes and then inserting the pilot/Zobo bit and enlarging each to 20 mm. A centering point is also shown.

[attachimg=1]

Here's a shot of the standard 6 mm pilot on the top and the new 6 mm/1/4" pilot I made on the bottom.

[attachimg=2]

And here's a shot of the new pilot installed in the 16 mm Zobo bit with the 1/4" end in the drill bushing. Nice fit...

[attachimg=3]

The 3rd section of this thread will deal with the maple jig itself which hopefully, I'll have time today to start.

 

[rvieceli]

[member=44099]Cheese[/member]  you should be able to readily find a 5/8 inch counterbore with an interchangeable pilot that you can put a 1/4 inch pilot on at most industrial supply houses. MSC has them.

Ron

 

[butzla]

I must be slow today, I haven't the foggiest idea what you are asking or what you're trying to do..  Please forgive me.

 

[rmwarren]

[member=44099]Cheese[/member] you obviously need a Shaper Origin for this job. [poke]

RMW

 

[Cheese]

Ya, unfortunately I own one but I’ve not yet spent the time to figure out the process.  Old habits die hard Richard.  [smile]

However you’re exactly correct. Drill a 1/4” thru hole and then bore a 5/8” diameter counterbore .100” deep.

Forget the drill bushings, forget the $100 Zobo bits, forget the wanky counterbore diameters and the custom arbors.

There’s only one problem.. this all needs to be done within the confines of an already assembled drawer...from the inside of the drawer.

Aye...there’s the rub.

 

[Cheese]

I must be slow today, I haven't the foggiest idea what you are asking or what you're trying to do..  Please forgive me.

No Jim mea culpa...

Sometimes we all get too nerdy in whatever endeaver we consider to be important.

This thread was a response to a [member=297]Michael Kellough[/member] inquiry as to what I was doing with drill bushings and drill rod.

To give you a Cliff’s notes synopses, this is a simple maple jig with 1/4” ID hardened drill bushings that will allow me to drill 1/4” diameter thru holes thru the back of a drawer and will the allow me to drill 5/8” diameter counter bores that are .100 deep and that are still concentric with the original thru hole in the drawer.  The jig will allow all of these holes to be within  010” or less of their desired location.

 

[Bob D.]

"There’s only one problem.. this all needs to be done within the confines of an already assembled drawer...from the inside of the drawer."

Think outside the box, or maybe that's work from outside the box.

Will this work?

*Drill your 1/4" through hole.
*Insert the bit through the hole from the outside.
*On the inside place a 5/8" countersink collar but facing the inside of the drawer.
*Run the drill in reverse (so the countersink is running in the correct direction) and withdraw the bit to engage the countersink.

I'm thinking of something like this but of the appropriate size.
https://www.mcmaster.com/3309a49

 

[rmwarren]

"There’s only one problem.. this all needs to be done within the confines of an already assembled drawer...from the inside of the drawer."

Think outside the box, or maybe that's work from outside the box.

Will this work?

*Drill your 1/4" through hole.
*Insert the bit through the hole from the outside.
*On the inside place a 5/8" countersink collar but facing the inside of the drawer.
*Run the drill in reverse (so the countersink is running in the correct direction) and withdraw the bit to engage the countersink.

I'm thinking of something like this but of the appropriate size.
https://www.mcmaster.com/3309a49

That is quiet ingenious Bob. Perhap drill rod rather than reusing the actual drill bit to prevent enlarging the hole.

Filing that one away for future use.

RMW

 

[Cheese]

Think outside the box, or maybe that's work from outside the box.

Will this work?

*Drill your 1/4" through hole.
*Insert the bit through the hole from the outside.
*On the inside place a 5/8" countersink collar but facing the inside of the drawer.
*Run the drill in reverse (so the countersink is running in the correct direction) and withdraw the bit to engage the countersink.

I'm thinking of something like this but of the appropriate size.
https://www.mcmaster.com/3309a49

Hey Bob I need a counterbore so the flat washer head on the screw can be easily positioned for proper drawer/front alignment.

However, taking your idea one step further, I could turn another 6 mm/1/4" arbor and make the 1/4" end long enough to go through the drawer front and also be chucked up in the drill. Then I'd place the Zobo bit on the inside of the drawer, pass it through the 1/4" hole and chuck the end in the drill and drill in reverse mode.

Thanks for pointing out those countersink heads though, you never know when something like that will save your bacon.  [smile]

I'm pretty confidant I'll have enough space inside the drawer to use the CXS drill with the C 15 chuck because the Zobo bit has a 9 mm  shaft. The drill fixture will space the thru-holes 1.25" from the drawer side and the drawer bottom. It'll be tight but doable.

 

[Michael Kellough]

Okay, sounds like a plan, but what are the other 122-1/2” of drill rod for?

 

[Bob D.]

"Perhap drill rod rather than reusing the actual drill bit to prevent enlarging the hole."

Good point Richard, much better using a piece of rod.

 

[StevoWevo]

Ok please excuse my ignorance cause sometimes things go right over my head. I’m very curious why you would not drill the counter bore with a short Forstner bit first and then drill the through holes? I am assuming the ceder linings will slip into the rabbets and cover the hardware?
Don’t get me wrong, I’m learning and  I like your approach for super accuracy but seems like a lot more work.

 

[Cheese]

Ok please excuse my ignorance cause sometimes things go right over my head. I’m very curious why you would not drill the counter bore with a short Forstner bit first and then drill the through holes? I am assuming the ceder linings will slip into the rabbets and cover the hardware?
Don’t get me wrong, I’m learning and  I like your approach for super accuracy but seems like a lot more work.

You're right, it is more work and if I was doing only 1 or 2 drawers I'd likely follow your lead and just eyeball the thru-holes.

Unfortunately, there are 20 drawers to assemble and adjust for alignment. The total amount of adjustment is only ±1/16" (.06") and there are 6 holes in each drawer to present potential tolerance issues. I think it's reasonable to assume that it would be easy to drill the thru-holes off center by 1/64" (.015") and if that happened in only 2 holes the amount of adjustment would be cut in half. Worse yet if all 6 thru-holes were off center you could have the condition where you no longer had any adjustment.

If I had constructed the drawers myself, this wouldn't have been an issue because I would have machined the thru-holes and counterbores into the drawer fronts before the drawers were assembled and glued.

I purchased the drawers already made and would do it again because for $52 per drawer, I can barely purchase the lumber needed for a 28" x 21" maple drawer, 5/8" thick, dovetailed, assembled and machined for Blumotion undermount slides.  [smile]
http://www.fleetwoods.net/media/pdf/STANDARD_DOVETAIL_DRAWER_BOXES.pdf

 

[Bob D.]

"I purchased the drawers already made and would do it again"

I built a custom kitchen island a few years ago and because of the time constraint I did the same. Owner had specific wants so for the 6 drawers the drawer sizes varied and had 3 different depths (front to back) so no two drawers were the same except for the height. Part of this was because the drawers had to fit around the cooktop and the popup downdraft vent and associated ductwork inside the cabinet. While the drawer box's were being built and finish applied I was busy building and installing the island. When the drawer boxes arrived all I had to do was install the fixed half of the Blum undermount soft-close sliders in the cabinet and pop the drawer boxes in. Then align and fasten the drawer fronts to the boxes and install the pulls. Saved me a couple days and cost wise I think it probably saved me a little. Different vendor than Cheese used but a quality product delivered on time and well packaged with no shipping damage encountered. Everything fit like a glove.

 

[greg mann]

Bob’s reverse countersink is cool but you need to buy the shank too. It is a bayonet style of mount that allows the quick attachment and also drives the tool. They do make counterboring styles as well but 5/8 on a 1/4 shank is probably not in the cards.

 

[junk731]

Very entertaining, I love the way you guys try to reinvent the wheel. Why not become familiar with the existing system from Blum to install drawer fronts on an assembled cabinet. Its extremely easy, low cost and extremely accurate. Here's a little hint.
https://www.richelieu.com/ca/en/cat...-standard-front-adjuster/1007144/sku-29510012

 

[StevoWevo]

Ok please excuse my ignorance cause sometimes things go right over my head. I’m very curious why you would not drill the counter bore with a short Forstner bit first and then drill the through holes? I am assuming the ceder linings will slip into the rabbets and cover the hardware?
Don’t get me wrong, I’m learning and  I like your approach for super accuracy but seems like a lot more work.

You're right, it is more work and if I was doing only 1 or 2 drawers I'd likely follow your lead and just eyeball the thru-holes.

Unfortunately, there are 20 drawers to assemble and adjust for alignment. The total amount of adjustment is only ±1/16" (.06") and there are 6 holes in each drawer to present potential tolerance issues. I think it's reasonable to assume that it would be easy to drill the thru-holes off center by 1/64" (.015") and if that happened in only 2 holes the amount of adjustment would be cut in half. Worse yet if all 6 thru-holes were off center you could have the condition where you no longer had any adjustment.

If I had constructed the drawers myself, this wouldn't have been an issue because I would have machined the thru-holes and counterbores into the drawer fronts before the drawers were assembled and glued.

I purchased the drawers already made and would do it again because for $52 per drawer, I can barely purchase the lumber needed for a 28" x 21" maple drawer, 5/8" thick, dovetailed, assembled and machined for Blumotion undermount slides.  [smile]
http://www.fleetwoods.net/media/pdf/STANDARD_DOVETAIL_DRAWER_BOXES.pdf

Gotcha, didn’t realize this was a large bank with all the drawers together. Also see how not getting all six dead nuts would cause a big headache in your scenario. Thanks for the clarification.

 

[xedos]

I purchased the drawers already made and would do it again because for $52 per drawer, I can barely purchase the lumber needed for a 28" x 21" maple drawer, 5/8" thick, dovetailed, assembled and machined for Blumotion undermount slides.  [smile]

Couldn't you have ordered them unassembled ?  Likely would have been even less expensive, and the shipping been about half the cost.

You would have had the best of both worlds. 

I have been advocating outsourcing drawer production for decades for the reason you've noted. Most shops or guys can't touch the material price of a dedicated drawer operation unless they are getting free wood.