Lightening my Coulter 8"

I've been using my 8" F/4.5 scope more, because I just haven't been having the energy to pull my 13" out.

The 8" weighs in at around 40 lbs. I wish it was lighter. I shifted the bearings a couple of months ago so it wouldn't need a counterweight at the bottom of the tube.

And today I finally cut out big triangular holes in the sides of the rocker box.

I sketched out a template in Inkscape, and printed it out in three pieces (it didn't fit on an 8.5x11 sheet), glued them together, and transferred the locations to the wood with a punch.  I used a 2.5" hole saw for the corners of the triangle, and joined them up with a jigsaw cut. It was my first time using my fancy (reconditioned) Bosch 1590 jigsaw. I was pretty pleased. I used a Bosch T234X blade. It cut the tough OSB very nicely, and pretty smoothly (though the hole saw smoked a lot and there was a lot of tearout). The dust blower wasn't strong enough to keep the cut line clear, which was unfortunate (since I was wearing a dust mask, I couldn't blow dust away). Then I painted the exposed wood (with an approximately 1:1:1 mix of acrylic black paint, Titebond II and water). The cut out portions weighed in at a total of about two pounds. Not a big difference, but I find that at around 40 lbs, every pound makes a difference.

Bosch Progressor U234X blade

My super-cheap Harbor Freight jigsaw used to cut horribly crookedly and non-squarely. The recommendation I was hearing was to get a circular saw, but I was scared of kickback. So I decided to try a good blade in the jigsaw.

I ordered a Bosch Progressor sampler pack from ebay, and loaded a U234X blade in the jigsaw. While I was at it, I noticed the jigsaw's shoe wasn't square and fixed it. I set medium speed, and turned off the orbital feature, and made a sample cut of 1/2" baltic birch ply against a guide. It cut very slowly, but once it was done the cut was quite straight and smooth. And only a touch of sanding would be needed. The squareness was off by about 0.3 degrees. (Maybe the shoe isn't quite square enough?)

All in all, it's good enough for me. No need for using a router or circular saw.

In the photo, the test cut I did is the front cut (the photo shows both sides of the cut). The side cuts were done with a friend's table saw. Those cuts are slightly straighter and perfectly square (as far as I can tell), but have a lot more tear-out.

The U234X (T234X is the T-shank version) blade is cool. It's 0.05" thick and has two alternating rows of teeth, one against each cutting surface, which smooth both sides of the kerf.