Monday, January 2, 2012

The Woodwhisper Guild Roubo Build-Part 7

It seems some parts of this build go quite fast and others, not so much.  The fitting of the tenons is something you really want to sneak up on.  So, I tend to cut everything a little fat, then pare, test, pare, test, pare.  Except for the haunch for the long stretcher that was cut deep enough to accommodate the extruded "V" shape that the deadman runs on, all the joinery was originally cut using my Excalibur for the tablesaw.  That particular cut was going to take me outside of my comfort zone on the tablesaw and the litmus test on anything you do on power tools should be, "if it doesn't seem safe, DON'T DO IT!"  There are many ways to accomplish the same thing. In this case, I got to use my Doc Holliday saw from Bad Axe Toolworks.


In this first shot, you can see I used a flip-stop to enable repeatable cuts and I drew a line on the fence to make it easier judge to where I needed to cut after the initial shoulder. 
           
This next shot is the view of the nibbling out of the waste.  Again, I didn't find the time savings of installing the dado blade to be worth it.  I'd rather cut the shoulders of the tenon with my Freud Fusion blade and so made a series of cuts, broke off the waste and pared with my 2 inch chisel. 

Although I don't want to fill the splits in the legs with epoxy, you can see here that it may prove inevitable.  When I go to glue the ends with the short stretchers, I will use the West System epoxy and make sure they are set to dry with the split upward.  I'll also use some blue tape to keep any epoxy from coming out of the split.  After the glue up, I'll reassess whether I need to fill the cracks.  Most of what I'll be concerned with is the aesthetics.  If I get too much epoxy visible in the crack, I will fill it completely.

Once all the short stretchers were cut and were a snug "slip fit", I did a dry fit and squared them up to enable me to take the measurements of the long stretchers directly from the piece.  
If you are a follower of Marc Spagnuolo's The Woodwhisperer, you'll be familiar with this process known as relative dimensioning.  

These two final shots are a couple views of the base dry fitted.  Although the entire project is built to be "knock down", it is quite the feat to both assemble and disassemble.  The mortise and tenon joints on the long stretchers will be mechanical held together with hardware that came in my Benchcrafted kit.  Therefore, these joints were slightly more loose than a "slip fit".  

After the first assembly, I checked for square and found I needed to slightly move the position of the tenons that let the top sit on the base by about 1/16 of an inch.  To do this, I had to get on the bench and lift each end out of the mortises and carefully slide each long stretcher from the legs, all the while trying to avoid letting anything crash to the floor.

After seeing the piece as a whole, it seemed to me to be beefy enough to not need a fifth leg.  Luckily, there is the The Sagulator.  I entered the dimensions of the bench with 200lbs of dead weight in the center.  Even with that, the bench should only deflect by .003" and the threshold on The Sagulator is .020", so I'm well within engineering tolerances.

10 comments:

Kari Hultman said...

Looking good, Vic! Seems like you're almost done. Have you considered routing out the split parts of the legs and gluing wood strips to fill the channels?

Vic Hubbard said...

No Kari, Because I actually really like the look of the split, especially in regard to the origins of the lumber. I don't think it inhibits the structural integrity. I'm gonna just try to minimize any squeeze out when I glue that section up.

Bill said...

are you going to have any hold fast hole in that leg? They might cause some issues when under stress.

really looking good. I bet you can't wait to start using it.

Al said...

Terrific, Vic! You are ever so close to the finish - I look forward to the bench on the floor, and you using it!!!

flairwoodworks said...

How about some butterflies instead of epoxy for the splits? I think they's be stronger.

If you go with epoxy, anticipate needing 3+ applications to get the surface level as epoxy shrinks as it dries (based on my experience using System Three 5-Cure epoxy filling voids in cribbage boards.

Chris

Vic Hubbard said...

Chris, like I said, if I can avoid doing anything with the split, that would be my preference. I do like the butterfly idea, if I need to reinforce anything. But I don't think I'll need to.

Vic Hubbard said...

Bill - No on the holdfast holes for that leg. It is a rear/backside of the bench leg. The split only goes in a bit, too. I positioned the leg as is because the other option would have the split in the center of the where the hardware goes to hold the long stretchers in place.

Vic Hubbard said...

Al, Thanks again. Yes, I'm really looking forward to having a functional bench. Time issues are why I started The Woodwhisperer Guild build prior to Marc releasing the first of the build videos. I have much to do.

Chris Adkins said...

Wow, looking great Vic! Looks like you are in the home stretch. I agree with the split...it adds character to the bench and as long as it is stable I would definitely leave it. Can't wait to see the completion....and for mine to get this far along. :)

Erik Gilling said...
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