Finishing up the desk

Re: Finishing up the desk Porn Alert....

Barry Irby

Back in the day before we became civilized and all PC those were called Sex Bolts.

I would have made two drill guide blocks, Identical, except one would have the smaller hole and the other the larger hole. By drilling them on the drill press it would have been fairly easy to keep the holes lined up, using a fence and stop blocks.

Or, you might have been able to find connector bolts that have the female part longer, just short of the total thickness and then you would only need one size hole.

Re: recent ladder used these.

Henry (Raleigh NC)

The ladder I recently built used these barrel bolts, implementing the strategy that Barry mentioned (full length female portion). The difference is that in my case I was attaching a metal plate to a single wood piece. The male portion of the connection was a washer head screw.

Henry

Re: Finishing up the desk

Ellis Walentine

Not sure why you'd need to enlarge the female side with a progression of bits instead of just one. Otherwise, the drill guide is a fine way to keep the hole perpendicular and located where you want it.

Ellis

Re: Finishing up the desk

Bill Tindall, E.Tn.

Not sure why you'd need to enlarge the female side with a progression of bits instead of just one. My experience in wood is that sticking a 3/8" bit into a 1/4" pilot hole would result in a 3/8" hole not centered in the pilot.

Otherwise, the drill guide is a fine way to keep the hole perpendicular and located where you want it.

Here is the problem to solve: 8 holes have to have their centers perfectly aligned such that when the 3 units are assembled the bolts easily pass through their holes and the top unit is in registration with the side units. This problem is complicated by the fact that the hole in the side unit must be 3/8" and the hole in the horizontal top unit must be 1/4". I can assemble the three parts. Then with a drill guide drill a 1/4" hole through both units, as shown, ensuring all the holes are aligned. I don't see how I can use a drill guide to enlarge the hole on the vertical units. How would I replace the 1/4" guide with a 3/8 guide and be sure of alignment?

Re: Finishing up the desk - hardware choices?

Henry (Raleigh NC)

Bill

I think I would drill the smallest pilot hole that would penetrate from one side into the other, then use that as a guide to fully penetrate the second side. The point of this is to mark hole location (centers). With these starting points, I would then drill out each hole to it's appropriate size in one shot (using a guide/template to maintain perpendicularity to surface). The grain of ash may make this strategy more problematic than the maple I was using. The sharp point of a brad point bit (or even a smallish forstner bit) may help maintain 'concentricity' compared to a normal twist bit.

Also consider using a longer female potion to extend into the 2nd piece (i.e. about 1/4" into the second piece, or maybe 3/4 of total depth of the two pieces of wood). I think this would add 'beef' to the load carrying ability, as there is a lot more metal in the barrel portion of these than there is in even a #12 screw (clearly depends on what available to you). The barrel would be load bearing and the screw simply simple draws them together. In fact this thinking can be extended: depending on location and aesthetics, using a full length female barrel nut (through both pieces of wood), and a 'decent size' washer or washer-head screw would also work (methinks).

Just presenting options that you did not ask for... take or leave as you see fit. You may already have hardware in hand.

Henry

Re: Finishing up the desk

Brad Chenoweth

Hi Bill,

Seems like you could have done just what you did, except drill just deep enough to leave a drill point for a center on the second piece, then use that to precisely locate the larger bit for the second hole. Maybe even make a second guide for that operation, but I'll bet you could have drilled it straight enough by eye, or with aid of a small square. Just my (sometimes rambling) thoughts:>)

Re: Finishing up the desk - hardware choices?

Sgian Dubh

Henry, you've beaten me to making a very similar suggestion. The technique you've outlined is pretty much the one I've used for aligning M6 connector bolts. To wit, align and clamp together the two parts that need to bolted together.

Because I work in metric, I put a 1.5 or 2 mm drill bit in a drill, preferably a pillar drill (drill press) but a hand held drill will do used with care, and bore right through the two parts. Next, the two parts can be separated and a Forstner type bit is installed (13 mm diameter if I remember the head size correctly) and the recess for the heads is bored.

Next, depending on the configuration of the male and female parts I use a combination of 6mm and 9 mm (again, if I'm remembering the sizes correctly) spur drills, aka brad point drills, to create the clearance for the parts.

In each case the centre point of the larger drill bits are guided by the original 1 mm or 1.5 mm bore hole drilled through both wooden parts at the beginning. If boring using a hand held drill, all that's really needed is a means to bore to the right depth when using the secondary drills, i.e., the 13 mm, 9 mm and 6 mm drill, and I usually just either eyeball it or use a bit of masking tape as a flag. Slainte.

Concentric holes

Jack Dover

My experience in wood is that sticking a 3/8" bit into a 1/4" pilot hole would result in a 3/8" hole not centered in the pilot

This is an interesting problem indeed. Have stepping 1/32" worked acceptably?

I think that the most sure way to drill two strictly coaxial holes is a stepped drill bit. While some of us might have access to machining facilities or have a machinist friend, most of us can't fabricate a stepped drill of arbitrary diameters at home (btw, will appreciate any pointers on how to find anybody in NJ willing to do odd machining jobs every once in a while)

After some thinking I could come up with maybe two options.

1. There's a jig sold everywhere: a clear plastic base and a set of bushings with different diameters holes. Something like this could work, except the jig is awkward and flimsy (and therefore cheap) and most probably holes in bushings aren't very accurate. But I could make a bigger wooden base that holds bushings snug, find drill bits that are also snug in bushings and just hope bushings are coaxial.

2. I would sacrifice one fastener and drill a nut all the way through. I would use a diameter that matches a threaded part of a bolt for a good fit in wood. If this fastener is hardened, I would probably just cut a threaded part off a nut and use it. A 3/8" hole would be drilled in one part of the desk, then this nut would be used as a bushing to drill a 1/4" hole into a second part. So it's like the previous option, except one part is holding a bushing and there's only one custom made bushing.

t's just a theory though. In practice it could be as good as stepping with 1/32".

Re: Finishing up the desk

Paul Leuba

How about using a brad point bit to drill the larger hole for the barrel first, drilling only deep enough to accommodate the length of the barrel. Then, drill the smaller concentric hole with a brad point bit centering in the small penetration left by the point of the larger drill. A drill guide for each of the sizes of the bits can still be used to ensure straightness of the holes.

Paul in Hunt Valley, MD

Re: Finishing up the desk *LINK*

Mark Hennebury

You can always make one out of a regular drill bit. or lots of styles are readily available. you can even get them custom made. Check the Link WL.Fuller inc

Fuller

Re: Finishing up the desk

Don Stephan

I was having some difficulty following some of the replies, but liked the suggestions to use a brad point drill just into the second piece, and use the cebnter point to locate the 2nd bit. The idea that came to my mind is not elegant at all. Trying on scrap woods, drill the larger hole through both pieces and then find or fashion a hollow sleeve to enter the smaller diameter hardware in the larger diameter hole.

My experience with woods like oaks and ash is a drill bit tries to follow the easier drilling parts of the wood if using a hand held drill.

Re: Finishing up the desk

Bill Tindall, E.Tn.

I had considered the bushing idea. I could have made bushings on the lathe. I decided carefully enlarging the smaller hole on the mating piece was going to be successful. I will know if it was when I assemble it.

What about....

Mark Hennebury

One hole and this type of fastener.

Re: machinest method

Larry Clinton At Frankfort, (Central) Indiana

Hardened drill bushings are sold at almost all industrial supply housings - these are very accurate. Cost is $10 to $15. You can buy in almost every size (custom sizes are a more expensive). These are concentric, OD to the ID is less than .001" Common drill sizes fit within .001" for cheap ones.

A little expensive for a one time use but they will last a woodworker forever! Google them and you will find a large list of suppliers - Even the Chinese ones will be far more accurate then needed for this application.

Re: What about....

Henry (Raleigh NC)

Similar to what I was suggesting above , or attempting to, but of course pics show this sooo much more clearly than a bunch of words.

Thanks Mark

Henry

Re: What about....

Bill Tindall, E.Tn.

Had this connector been available from my supplier I would have used it.

Couple things

Ellis Walentine

First, a step back... How far out of alignment could this assembly be if you just drilled 3/8" holes all the way through? What would this affect?

Second, and in keeping with the idea of keeping it simple by drilling just the larger diameter hole.... How about using a forstner bit to create a concentric recess for the head of the male part of the bolt? Then, even though the shank of the bolt is smaller than the hole by 1/8", a tight fit on the head would center the shank in the hole.

And, back to my first suggestion, have you tried chasing out a 1/4" hole with a 3/8" bit? If so, what were the results? I may not be fussy enough, but I'm betting that the results would be acceptable, unless there's some critical alignment issue I'm not seeing here.

Ellis

& THE winner is

Buck

Mr. Mark Henn?????? !!! Good show - ps. never heard or seen

THOSE kinds of fasteners!!!

Re: machinest method

Jack Dover

Oh, I keep forgetting that nowadays one can buy almost anything online, just need to know the right keywords and where to search.

Yeah, hardened drill bushings will work wonders, they're also useful for all other types of applications. They will most certainly match the fastener OD, they're also made standard. A 0.001" of slop is actually good, or a handheld drill is going to bind.

Multiple drill guides

Pat Evans

Since your drill guide is just scrap wood, you could have used your drill press to make multiple guides.. one for each hole. Drill the small hole all the way through the guide, then without moving the guide, drill the larger hole part way through. Use the guide by drilling the small hole first, then the larger hole which would of course remove the small hole portion of the guide. Thus the need for multiple guide blocks.

Re: What about....

Mark Hennebury

Ones with the longer nut sleeve would seem to be the best if you could find them. So that it would go through both pieces. I used a bunch of the Murakoshi brand joint connectors many years back, I just checked their catalogue and they don't seem to have any with long sleeves that would go through both pieces of wood. It seems that lots of them are made.