Monday, September 22, 2008

Raising Panels, Not Cain

Now that the glue-ups for the panels are done, it's time to turn them into the 12 raised panels I need for the pulpit. To review, there are three different widths of panels in two different lengths. I need two of each width & length combination; if you do all the multiplication, that's twelve panels.

These are the first raised panels I have ever made, so I was approaching them with a little trepidation. Not a lot, but a little. My first concern was that my table mounted router wouldn't be strong enough to do the job. My second concern was screwing it up & getting huge amounts of tear out that I couldn't repair.

I only have two routers, a Bosch 1617 EVS with a fixed base only and a Dewalt DW-621 plunge router. Both are 2 1/4 HP routers; the panel raising bit I have is a full 3 1/2" in diameter. Most everything I've read says you really need a 3+ HP router to make these cuts. Not having the bigger router or the money to buy one, it was time to give the Bosch a try.

So I chucked the bit into my router. Using my combo square set to 1/8", I set the bit height for the first pass. Next, I set up the fence even with the bearing on the bit & I mounted a feather board on the fence to hold the panel down to the table. And I set the router to its slowest speed.

I made a test cut using one of the cutoffs I had from making the panels. The first pass went very well, better than I expected. The router didn't So I went to town on my panels. And again, the first pass was cake.

Next, I set my combo square to 1/4" & used it to set the bit height for the second pass. After resetting the fence & feather board, I made another test cut on the same piece of scrap. I found that the router struggled a little, but not too much. I was able to find a feed rate that kept the router from struggling & the wood from burning.

This somehow didn't hold true when I started running the actual panels. The router was easily stalled & kept stalling as I tried to feed the first board. I had a feeling that I had the feather board set too tight, so I removed it. If Norm can raise a panel without using a feather board, why couldn't I?

While this did reduce the tendency of the router to stall, I still had to be careful to keep it from stopping. But I was able to finish the pass on all the boards without any tear out or burning.

Time for the third pass. Again, I set the combo square to 3/8". My panels all started at 13/16", so I knew I had to do at least one more pass at 1/16". I set the fence back up & tried a test cut.

And the router really struggled. What I figured was that the increasing height of the bit was also increasing the length of cutter that contacted the wood. The result was increased drag on the bit as it cut the stock. The result was each increase in height would make the router easier to stall. The reason all of those articles called for a 3 HP router for this operation became clear.

I didn't want to lower the bit, so I started cheating. This was probably a very bad idea, but it got me through the next two passes. What I did was I held the trailing corner of the panel against the fence & held the leading edge 1/2" or so from the fence & fed a few inches through the bit. Then I'd place the leading corner against the fence & keep the trailing edge the same distance from the fence & finish the pass. Then I'd do this again, this time with the board about 1/4" from the fence. Finally, I'd make a full pass with the entire board against the fence.

The bit did bit into the wood a couple times, but I had more passes to make & all of the damage came off during the last "all against the fence" pass. At the end of this pass, the boards still wouldn't fit in the grooves I had made in the frame parts, so it was time for a fourth pass.

The fourth pass was made with the bit set to 7/16". It was similar to the third pass -- the router still slowed down a lot & was easy to stall. I ended up making the third pass like the second. At the end of this pass, the stock almost fit in the grooves, but it wouldn't bottom out. So I decided to take a fifth pass at 1/64".

The good news is that I was able to make this entire pass with the stock against the fence, no cheating. And at the end of this pass, the stock fit in the grooves fine.

Below are some pictures of how the panels came out. I only had room to set up half of them for these photos, but the other half are identical.

Next: Finishing the Panels

2 comments:

neil said...

Hey Big T............your panels look great, the coves look real clean. You obviously did some sorting to find your best grain combinations, the follow through of the grain into the upper smaller panels will give an inducation that Tony's Woodshop has some chops!!!!

2 big oak projects in a row.....next we gotta get you into a small project made out of some wormy chestnut.

Tony...you are putting in a really good growth oriented woodworking year.......can't do more than that.

Neil

Tony V said...

Neil:

I'm really happy with the way the panels came out. And if you think they look good raw, you should see them now that they're actually finished. That's the next thing I'm writing about, and there will be pictures.

I'm a little bummed tonight that everything is taking longer than I think it should. So long as everything turns out looking good, I'm OK with it, but I was hoping to have this done before October 6. That's not going to happen at this point. Hopefully by Halloween.

I've been working so steadily on this that I'm beginning to wonder who these other people are that I see in my house every night! ;-) I gotta spend some time with the family.

I was thinking of making my next project a Roubo style bench from Chris Shwarz' book, in doug fir. I haven't done anything with softwood yet. And since it's for the shop & me, I can take my time on it & not feel guilty.

Oh yeah I forgot to mention that I signed up to take a hand cut joinery class at the local BOCES. It starts in January. I'm looking forward to it.

Tony