Saturday, August 16, 2008

Making the Shelf Supports

Last time, I had finally done a dry fit of all of the parts I'd made to that point. Everything was being held together with eight 24" K body clamps. To make this assemblage of parts free standing, its time to make the shelf supports / stretchers.

Because of the way this piece is designed, with 2" x 2" posts in each corner, and because I'm not using plywood for all of the sides, I couldn't cut dados to hold fixed shelves. So I designed the piece with stretchers that fit between the posts and that support the fixed shelves on the top & bottom, These are to be attached to the posts using pocket hole screws, one on each end. The shelves will be glued & screwed to these pieces at the final assembly.

The stretchers are to be as wide as possible, so they align with the inner faces of the posts. More or less. And they have to be long enough to fill the space between the posts they fit between. And here's where I made a bit of a mistake.

I knew I wanted to use relative dimensioning for these parts, so instead of placing each piece of stock where I wanted it & marking it, I measured one of the spaces & cut the parts for both boxes on that face to that measurement. Turns out I measured the smaller of the two boxes. The too short parts threw the bigger box out of square when I put it together. I ended up having to make these parts over, which didn't take too long but was a pain.

When I put the shelf supports in place, I knew it was important to get them all at the same height. In addition, the spacing at the bottom of all three boxes is the same, but the spacing on the top of the two outer boxes differs from the spacing at the top of the center box, and none of these are the same as the bottom spacing.

To do this, I cut spacer blocks the correct length. I carefully aligned the bottom of the block with the top or bottom of the post & clamped it in place. I then placed the shelf support in the correct orientation and clamped it to the spacer. I then drove the pocket screw home. As a picture is worth a thousand words, or so they say, the following two pictures show what I'm trying to say.

It was while I was trying to drive these screws home that I found that my Makita 12 V cordless drill is too big to use in this application. It just can't get into the tight space well. So I posted a question on WoodNet about cordless drivers for tight spaces. The clear winner of the informal poll turned out to be the Bosch PS10-2.

Next thing I do is to do a search on Froogle to find a decent price for the driver. I found a site that was selling it, new, for $110. I go to the Tool Nut, where they have a "price match" policy. In actuality, they don't exactly match the price for Internet sites. They take shipping into consideration, as well as their margin. And they have to charge sales tax, which I'm required to pay on Internet sales in NY state now, anyway. They came in pretty close, $118 with tax. So I bought it.

The Bosch PS10-2 made short work of driving the pocket hole screws home. And when all of the screws were driven home, the three boxes were able to stand on their own for the first time.

At this point, I've completed pretty much everything down to step # 8 under "Shelves" on my punch list that was posted in my post, "How Am I Going to Make a Pulpit?" Time to get started on step 9, "Cut blanks for all shelves from ply stock." We'll cover that next time.

Saturday, August 2, 2008

Finishing the Posts & Rails

To recap where we are now: The joinery for the posts and rails has all been cut. The frames have been dry fit. Sounds like we should be done making the posts, huh? But there's actually lots more work to do before the posts are finished.

I went back to my check list & finished the items on it for the posts. That is,

  1. I cut all of the rabbets that will accept the ply partitions. I had to cut 6 rabbets 1/2" wide x 3/4" deep, more or less. These were cut on the table saw using the two pass technique.
  2. I cut the grooves for the center box's ply partitions in the two center front posts. This was done with a stacked dado cutter.
  3. I cut the rabbets on the bottom ends to receive the matching rabbets that will be cut on the base pieces. These rabbets are 3/8" deep by 2 1/2" wide. I cut them as though I was making a tenon. That is, I made a shoulder cut 3/8" deep 2 1/2" from the end of the post, then put them in my tenonning jig to make a cheek cut.
  4. I cut all of the posts to final length (Yeah, I know the steps in "How Am I Going to Build a Pulpit?" call for me to do that later, but I got the top rails to line up perfectly with my layout line for those cuts so I figured I could do it now).
  5. I cut a 3/8" x 3/8" groove on the center right front post for routing the power cord for the lamp I will install.
  6. I drilled all of the shelf-pin holes.
  7. I counter bored, drilled, and epoxied the t-nuts for the leveling feet in the bottom of the posts.
  8. I even installed the leveling feet.

After all of that was done, I cut the ply partitions from a sheet of 3/4" red oak veneer plywood. I needed two partitions 11" wide and 44" long and two more that were 15 1/4" wide and 44" long. So I set my table saw's fence to rip 11 1/4" and I went to town.

This is when I found out that the outfeed table that came with my 22124 isn't long or wide enough to rip a whole sheet of plywood without additional support. It works for most of the cuts I make, but when a full sheet has been pushed through to the other side of the blade, it just doesn't sit on the table saw the way it should. The off cut wants to roll off the saw to the left, while the keeper piece wants to do a swan dive to the floor.

I can't do anything about this now except to use a helper or roller stands the next time I do this. Another item for the "dream workshop" list. In any event, the first rip was done without too big a crash & I can still count to 10 without having to take off my shoes.

After finishing the first rip, I reset the fence to 11" & fed the 11 1/4" wide piece through the saw with the edge I'd just cut against the fence. This removed the factory edge & gave me a nice crisp new edge. Next I set the fence to 15 1/4" & made one more rip cut for the center box's partitions.

Luckily, both of these boards were narrow enough to fit in my cross cut sled. Unluckily, its fence & the tape I have installed in it only go to 30". I needed to cut these to 44". So I attached a straight piece to the outside of the sled with a couple of 6" Tradesman clamps & I cut three ply blocks about 2" wide from some scrap. These blocks would form a make shift stop block. I needed three pieces because the fence is a lamination of 2 pieces of 3/4" plywood, so one piece wouldn't stick passed the fence.

I then measured & marked one of the 15 1/4" pieces at 44" & drew a square line across the board. I placed the board in the sled & aligned the square line with the kerf in the fence of the cross cut sled. I then clamped the three ply scraps to the straight piece I clamped to the fence so they would act as a stop block. This let me get all of the pieces exactly the same length without having to measure again. I had to stick a piece of scrap under the right hand side of the work piece on the first cut for each piece, as it needed some support, but the cuts went well.

The next thing I did was to glue the ply partitions to the posts. This went well and as expected. I have grouped the rails for each wing with the post / ply partition assembly for it, so I can sand the rails smooth at this point. In fact, I will did just that so and then did one more dry fit. I'm pretty much going to leave everything together until I get to the panels, just so the units can free stand and not occupy space on my work table.

Below is a picture of the parts I'd made to this point dry fit together, being held together with clamps. I actually went out & bought an additional (4) 24" K-Body clamps to do this dry fit.

It looks pretty good from this angle, but there are a couple of problems. One of the side boxes is fairly close to square, but the center section is a little torqued & the other side box is noticeably out of square when you look down through it. These were assembled free standing & not on a flat surface, so I'm not too worried about it at this point.

Next time: Making Shelf Supports