Recent project

[beacon14]

Not wanting to hijack the thread about table surfacing, here's a few pics of a dining table I had the pleasure of machining recently. Unfortunately the customer wanted a brown stain, so the finished photo leaves a lot to be desired, but the table top is 40" x 102" x 1.75" thick, and was machined from a 58" (!) x 120" x 2" slab of Bubinga. The "inlays" are 3/4" steel and are bolted through the wood and a 1/4" steel sub top.


8406

8407

8408

[mikejohn]

David
Brown stain or not, I like it a lot!

..............Mike

[rustnrot]

How dimensionally stable is this wood as the humidity and temperature change? .... And I gotta ask how heavy is it?

[beacon14]

I suspect the Bubinga is as stable as wood gets, i.e. you'd better allow for wood movement or you'll end up with firewood. The steel butterflies anchor the center edges of the two table halves securely to the steel subtop...the outer edges are secured with 1/4" lags through 1" slots using nylon washers, and only gently snugged up - enough to be able to lift the table by picking up the corners of the top, but still allow the outer edges to move up to 3/8" in either direction. And the two halves were finished all the way around including the undersides before the table was assembled.

It's heavy - two people could barely lift it. The steel base weighs as much or more than the top.

[bleeth]

FYI- There is an article about large bubinga slabs in this months Woodshop News.
For those who use; it note that the color tends to lighten and yellow even with a UV protectant finish under direct sun (as in constantly through a window).

Dave

[bleeth]

By the way: Beautiful job Dave.

[joe]

David,

My complements on such beautiful work.

How hard was it to make the keys and did you have to manually charpen the round corners left behind in the table?

Joe

[srwtlc]

Nice work Dave!

Due to the fact that you have a riftsawn slab, expansion and contraction and the tendency to warp will be minimal. Finishing all sides also slows down the intake and expelling of moisture which balances the wood.

Stain on Bubinga, that's just wrong. No offense to you Dave.

What's the trestle made from (looks like Walnut)?

Keep up the good work.

Scott

[gerald_d]

Could we please have a moment of silence for that Bubinga tree that grew to 58" in diameter, and then had to end up wearing stain. It is an endangered African tree (African Rosewood).

These are the jobs for which one wants a very solid table.

[beacon14]

Yes, I know about the stain, but that was not my choice. I felt honored to be able to work with this piece of God's Earth and enjoy its natural beauty before it got painted and shipped off to L.A. to grace some celebrity's mansion. And I did struggle some with the ethical issues of using such precious resources, but in the end I decided that the issue was bigger than me, the trees are being cut and used regardless of my inconspicous little life, I do what I can to conserve resources (working out of my home, for one thing), but in the end I'm just making a living and someone was going to use that slab for something, at least I could try to make something lasting and useful out of it. It is my hope that some future owner with better taste (or at least a more appealing color scheme) will sand that table down and make something else useful and lasting with it.

The steel work was done by a metal worker. I probed each dovetail (they were each "unique"), offset the resulting vectors in DesignCad, then imported into PartWizard for the toolpaths. I used a 1/8" bit to Profile the opening and used Area Clear to clean out the pocket with a 1/4" bit, and since the corners of the steel were ground back except at the very tip, I only had a tad of hand chiseling to do in each corner.

I haven't been so nervous cutting a piece of wood in a long time, but I don't work on too many pieces that would take two month's mortage payments to replace (not to mention 300 or so years of slow growth). I did a lot of testing in scrap pieces, and in the end it was pretty easy to do the actual machining. I ended up leaving around .01 clearance so the butterflies could be placed and removed easily without having to be pounded in, and I relieved the sides of the butterflies for ease of insertion and to ensure a tight fit at the top where it matters (an old trim carpenter's trick).

The trestle is bubinga (from the same slab), you can't tell from the photo. The part between the panel ends is wrapped around a 2x2 square steel tube, the "ends" that stick out past the panels are just stuck on there to complete the illusion of a trestle. Another detail not readily visible from the photo is the steel trough let into the center of the top - for flower vases I guess.

Thanks for the compliments
David B.

Butterflies hot glued to table for probing, outline being cut:

8409

Test fitting - almost there:

8410

[Brady Watson]

David,
I know zactly what you mean about being nervous with the cut. I had to make some eyebrow-shaped table tops with a 45° full-depth edge around 3 of the sides. The material was 6/4 X 11' 6" X 30" Honduran...naturally it was old growth. Needless to say it wasn't as costly as the piece you did, but enough to make me check everything 42x before I even screwed the piece down. All of that was of course after I spent a day or 2 just admiring the plank and how special it was in this day and age.

Here's a shot I took after brining it home:

8411

[mikejohn]

I see I'm not the only one to drive around with lumps sticking out the back of the truck

[t_fiddler]

Looks great!!!

Now did I zero to the top of the Table or the top of the TABLE.....?

[stickman]

And I thought I was bad, when I got sweaty palms, cutting into 3/4" oak plywood... Whew...

[Newbie123 (Unregistered Guest)]

Whoa, you surfaced the entire rough slab using the CNC? Incredible. What size bit did you use and which motor/spindle setup are you using? How long did the entire process take (not including computer setup time)?

I'm new to this forum and am heavily considering the PRT96. I have a Minimax 410 Elite combination machine, and my 16" jointer suddenly seems very weak in comparison.

[beacon14]

Well it was just a little too wide for my 6" jointer or my 15" planer. I thought about hand planing - for a millisecond. I did the final sanding on a 36" wide-belt sander, but needed the slab to be flat and smooth first. I used the same setup as I use to surface my table: PC "3hp" router, 1.25" diameter surfacing bit from Onsrud (it has slightly rounded corners to miminize ridging), light passes ranging from .18" deep at 2.0 ips to .1" deep at 4.0 ips. I only needed 2 or 3 passes per side, and ended up taking the 2" rough slab down to just under 1.75".
A typical pass would take approximately 1 minute per square foot, or 30-40 minutes, while I did something else. As for computer set up time, I wrote a short program where I only have to enter the length and width of the workpiece, the cutter diameter and stepover, and depth of cut, and it makes a pass, and gives me the option to do another pass at a new depth until I'm done.

here's the file (http://www.talkshopbot.com/forum/messages/29/7427.html?1113769932)

[ron brown]

I use a 1-3/8 Her-Saf bit for the same operation. It has replaceable index bits. One real advantage a rotary bit has over planer/joiner knives is it handles squirrely grain better than straight knives do and usually has less tearout. Releiving the point on the cutting edges of the indexable also helps - this is only a few thousands of modification on each tip.

Ron

[Newbie123 (Unregistered Guest)]

Thanks for the info, David. Which spindle/motor are you using? I'd imagine that 30-40 minutes of constant cutting would not be good for PC router, so I assume you're using the Columbo(sp)? Thanks for the code as well. It looks a lot like assembly. What software do you use to process that code? Or does the controller recognize it on its own?

Ron, where you purchase your bit? I use spiral cutters with four sided index bits in my shaper. I would love to use one for routing. Thanks.

[beacon14]

I dream of owning a spindle, but alas, I run the PC router all day if necessary. It's not as hard on the router as it is on my ears - I'm not taking a very agressive cut. 30-40 minutes on the PC is better than 6-8 hours of hand planing.

The code can be written with any word processing program, or even in the ShopBot File Editor - it must resemble more than one rudimentary programming language, but I don't know that many (or any, really) so I can't say, but as far as I'm concerned it's ShopBot code - it was written for the ShopBot and is nothing more than a series of ShopBot commands with a few IF...THEN, INPUT, and LABELs thrown in for navigation.

[gene_marshall]

Hey dave,
Have you tried the "worktunes" avial at the depot
or on amazon

A radio in the hearing protection.
I tell ya, this has made my shop enjoyable again
and we run 5 PC's

I reccommend them highly
Gene

[beacon14]

gene, I may have to try them out - I've always worn earplugs so I'm not used to a headset. The big question: can you get them with XM radio?

[gene_marshall]

Don't think so.
I'm just happy to have a radio again.

I am very suprised that the receive the radio signal so well in our shop.
block building, cell tower a halk mile away, 5 pc routers, 3 dust collectors
flourecesent lighting.

But they work really well.

I must look silly playing air guitar.
Gene

[propellers]

Dave, In our shop we have a product called Advent Wireless. Purchased at Best Buys. This unit is a transmitter that plugs in a radio, computer, cd player any audio device.
This unit will transmit to the supplied headsets. We have one hooked to our shop radio and another to the computer. The employees tune into either channel. Whats cool is on the computer we subsribe to coast to coast and other talk shows or tune in to net radio.com and listen to late night radio or on radio.net listen to radio stations all over the country with live bradcast, today we are listening to Hawaii local stations.
These units work good, I would like to see a little more noise reduction but not bad.
Another good thing about these is our employees do not waste time talking to each other so much and production seems to be better than not using them.

[gerald_d]

Lonnie, I suppose you could also talk to your guys if you plug a mic into the computer? Like a paging/PA system?

[bleeth]

That would probably cause an epidemic of dropped headsets!

[gerald_d]

Most of the time they need to be called is because the current girlfriend is on the phone.

[propellers]

Gerald, We could do this but like Dave said all the employees would hassle the poor paged person so right now the employees really think I splurged for their benefit so they are happy, if they knew it was to keep Workmans Comp down and to keep them from carrying on long conversations lowering production they would probably go on strike...now if I can use the paging idea to insert subliminal messages...hmm. I do not want a raise, I will work my butt off without whining..I will polish the shopbot during my lunch break..you get the picture. Technology is wonderful.

[oddcoach]

I GOT A PAIR OF BOSE NOISE CANAELING HEADPHONES FOR CHRISTMAS. I USE THEM WITH AN MP3 PLKAYER IN MY POCKET, RUN THE WIRE INSIDE MY SHIRT. IT WORKS GREAT. THE BOSE HEADPHONES ARE WORTH THE MONEY. VERY COMFIE. I CAN HEAR SOMEONE TALKING IN A NORMAL VOICE WHILE THE PLANER IS RUNNING.

[oddcoach]

sorry about the caps lock