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My first project... a bookshelf!

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Project by rivox1 posted 04-30-2013 09:33 AM 856 views 0 times favorited 18 comments Add to Favorites Watch

Hello Jocks,

Well, to be 100% honest, this isn’t my “first” first project, but it’s the first one I’m willing to share ;-)

I’ve dabbled in ‘practical’ wood projects in the past, but it is not until recently that I’ve really taken woodworking as a serious hobby.

This shelf is nothing in comparison to the other projects I see on this site, but as a beginner woodworker it seemed like a logical choice to build a shelf.

My goal was to make something that was simple and elegant. I tried a floating shelf that didn’t have any visible supports, but it was TOO simple and lacked style, so I re-designed it with the small supports that you see in the pics.

I’m a stickler for details, so one of my requirements was that there were no visible screws, bolts, etc. I hope I succeeded! If my math is correct this shelf should support 106 lbs before it fails.

A background in applied math and engineering certainly helped with the design and installation, but I can see there is still a lot of honing through sweat and wood dust before I can make something truly remarkable.

Thanks for looking! Comments and suggestions welcome!

-- Cheers and Safe Woodworking!





18 comments so far

View Monte Pittman's profile

Monte Pittman

14569 posts in 1024 days


#1 posted 04-30-2013 10:24 AM

Good job. Plenty ways to hide screws and hardware.

Welcome to LumberJocks

-- Mother Nature created it, I just assemble it.

View stefang's profile (online now)

stefang

13262 posts in 2020 days


#2 posted 04-30-2013 10:55 AM

Nice work. It is elegant. You don’t have to be a math genius to do work working, but it helps!

-- Mike, an American living in Norway.

View helluvawreck's profile

helluvawreck

15959 posts in 1553 days


#3 posted 04-30-2013 03:42 PM

Nothing short about that shelf. Nice work and welcome to Lumberjocks.

helluvawreck aka Charles
http://woodworkingexpo.wordpress.com

-- If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away. Henry David Thoreau

View LookingGlass's profile

LookingGlass

76 posts in 794 days


#4 posted 04-30-2013 07:49 PM

Great job….

Love the color and wood grain pattern…

Keep up the nice work.

-- Take care.....Ed

View Fishinbo's profile

Fishinbo

11289 posts in 862 days


#5 posted 05-02-2013 04:36 PM

Simple design but looks classy. Like the stain and the grains. Well done!

View Sanding2day's profile

Sanding2day

979 posts in 533 days


#6 posted 05-08-2013 06:11 PM

Very nice… Hate to ask when I’m not sure I would understand the answer but… 106 lbs before failure? Would have suspected a much more substantial weight given its appearance. How was this determined? Thanks for sharing

-- Dan

View rivox1's profile

rivox1

30 posts in 542 days


#7 posted 05-08-2013 07:27 PM

SANDING2DAY: Thanks for the question. The rating of 106lbs is at the tip of the shelf (furthest away from the supports) this was calculated based on the tensile strength of the glue, and the upwards pressure on the support by the lever effect created… Notice how the top of the support is much thinner than the bottom, as such it supports less weight.

If the weight is placed closer to the wall, the rating goes up to around 280lbs or so… I hope I explained to your satisfaction… If not, let me know and I’ll try again!

Thanks!

-- Cheers and Safe Woodworking!

View Dallas's profile (online now)

Dallas

3032 posts in 1173 days


#8 posted 05-08-2013 08:06 PM

I’m not totally certain, but I think your math is off a bit.
The grain running up and down on those cleats is problematic.
They will snap off at the grain line with very little pressure.

-- Improvise.... Adapt...... Overcome!

View rivox1's profile

rivox1

30 posts in 542 days


#9 posted 05-08-2013 08:18 PM

DALLAS: well, I’m an applied mathematician and I work at NASA, so for the sake of my employment I hope my math is right.

There are two hidden bolts that attach the shelf to the supports, the fail rating of the bolts is taken into account for the overall rating of the shelf.

I put 2 40lbs sandbags on the shelf and it didn’t bulge!

Thanks for commenting!

-- Cheers and Safe Woodworking!

View Sanding2day's profile

Sanding2day

979 posts in 533 days


#10 posted 05-08-2013 08:58 PM

Lol “I’m an applied mathematician and I work at NASA” 106 lbs it is :)

Certainly not arguing the point and appreciate the clarification but as I see it weight would be distributed both down the angle and into the wall, and as you state to a greater extent the upper portion of your bracket depending on load location. The bracket appears relatively tight requiring the shelves lever action to tear off the top of the bracket before failure. Not sure where glue came into play.

I am personally unsure at what weight this would happen although I am tempted to physically test it out. The addition of a screws holding them to the wall and shelf within the bracket seem to make this the only likely failure point. Thanks again…

-- Dan

View Dallas's profile (online now)

Dallas

3032 posts in 1173 days


#11 posted 05-08-2013 09:22 PM

rivox.
Due to some physical disabilities, it’s difficult for me to describe what I’m seeing.

Let me try to explain. Look at the top of your brackets. The grain runs perpendicular to the shelf. where those grain lines run on the brackets is weak. This is provable by cutting a similar slot in a similar piece of wood. Take another piece of wood, slide it into the slot and lever it down sharply at the junction of the two cuts of the slot. I would almost guarantee that using wood with the grain as loose as your shelf is that it wouldn’t take much to snap the upper piece off.
Maybe as an applied mathematician it looks good on paper, but as an inbred, country raised, back woods, 8th grade graduate, I can tell you that it is inherently weak.

Now, as an almost 60 year old dimwitted engineer, who has had multiple brain traumas, the easiest way to to add some strength to those joints is to radius the corners of the slot.
You do this by drilling a clean hole at the junction of the cuts. Then you roundover the edge of the board you are using as the shelf. This spreads the load out across the grain so each of the growth rings has less stress on it.

Wasn’t it mathematicians that came up with the Challenger?

-- Improvise.... Adapt...... Overcome!

View rivox1's profile

rivox1

30 posts in 542 days


#12 posted 05-09-2013 02:08 AM

DALLAS: thank you for sharing your knowledge! I took into account your point. The bolts I mentioned are not holding the wood from the top but rather from the back 6” into the shelf. The amount of weight being supported by the top of the brackets is not what one would logically assume by a simple visual inspection!

In regards of your comment regarding the Challenger, I don’t know if it was supposed to be a joke or what. If it was a joke, I must say I don’t find the loss of the life of seven of my colleagues a matter to joke about. If it was a serious question, over 2,000 scientists collaborated in creating the amazing machines that comprised the Space Shuttle program, many of them mathematicians.

SANDING2DAY: lol! I hope I didn’t come across as arrogant by mentioning my background… It was more of a joke! If meaning if I can’t do this simple calculation, then I should reconsider my career!

But you are absolutely correct, the point of the design is to transfer as much of the weight to the wall as possible! This is achieved by enlarging the surface area of contact with the wall (in this case roughly 26 square inches) as well as all of the hidden bolts both onto the shelf and into the wall!

Thanks for your comments!

-- Cheers and Safe Woodworking!

View Sanding2day's profile

Sanding2day

979 posts in 533 days


#13 posted 05-09-2013 02:15 PM

Rivox, I took the comment as a joke and not arrogance. No worries… Thanks to both you and Dallas for making me give some thought to the dynamics of this project and again way to go on your new shelf…

-- Dan

View Dallas's profile (online now)

Dallas

3032 posts in 1173 days


#14 posted 05-09-2013 05:27 PM

No, I was not joking about the Challenger. I watched the failure in living color while on the road.
You are correct, there was nothing funny about the failure of 2000 scientists, many of them mathematicians making a major mistake and then denying it.
Don’t get me wrong, I’m one of the guys that thinks politics should be taken out of the space program. NASA rested on it’s laurels when it landed on the moon and really hasn’t extended itself since.
I was very proud of America when Apollo hit the moving target in 1969. I thought that America would continue to excel. Too bad it hasn’t. And it get’s worse.
Houston didn’t get one of the Shuttles?

I think you did come across as arrogant with your degrees, background and the need to show off your abilities. Too bad you couldn’t wait and accept that many of those here have as good or better credentials than yours.

Then again, I think your project looks extremely good, xxx x xxxxxxxx xxxxxxx. (x’s denote deleted letters). I truly think that soon you will surpass my abilities, although that is no real goal in itself.

Have a great day and never be so arrogant that you cannot accept criticism.

-- Improvise.... Adapt...... Overcome!

View rivox1's profile

rivox1

30 posts in 542 days


#15 posted 05-09-2013 06:10 PM

DALLAS: I’m not sure where you’re coming from with your comments, I think I’ve accepted criticism just fine. I am new to woodworking and I accept that, but you’re not criticizing my project, you’re criticizing nasa, the space program, the government, and ultimately my math, which I know is accurate by the way. I think that you are engaging in a Byzantine discussion that makes no sense for this particular forum… at the end of the day who really cares how much weight the shelf supports? I put that as a foot note without the intention of having it turn into the main discussion point of the conversation. Much less offend anybody!

In regards to your comments about my personality, you don’t know me, and I don’t know you, so they don’t mean much!

In any case, this is not a forum for discussing politics, or space travel, or personalities, it’s a forum to discuss woodwork! If you don’t like my project or my comments, there are plenty of others to look at, nobody is forcing you to look at mine!

I thank you for participating in the conversation! Have a pleasant day!

-- Cheers and Safe Woodworking!

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