HF 18 inch bender mods

Additionally, HF will send you an extra clamp bar at very little cost. Mine is due to be semented into smaller bits for box work, using same hole pattern that has been drilled and tapped into place on the bender this last week. I'll use an abrasive blade on my new tile saw to cut it into most likely a 5 and a 10 inch sement, and a few smaller pieces.

The tile saw is due for a kerosene fill, a carbide toothed blade, and a router speed control. With those mods, it should cut aluminum tooling plate nicely. That's another article. At about $75 for the saw and control, I couldn't resist. We also have a tile project coming for the home.

I am doing well, and it's taken two years to adapt my work habits to the new apartment. We're sittin' on equity, now. It feels good.

Doug

I'd written:

The modified bender is so much more rigid than before that the amount of *work* needed to make the 18 inch bend in 0.093 inch Lexan is significantly reduced, by a factor of 2 to 4, I 'd say.

I continue to experiment with modifying the bender. I am going to slot or redrill the clamp bar holes some day, but right now I am working at disc-sanding a more agressive bevel onto its edge to allow the bending bar to come over center farther and deal with the high springback of Lexan. I have learned that a bend radius less than 63% of the material thickness is a sharp bend, and propose to round over the tip of the bar at 63% of 0.093, or 0.059 inches, but I suspect this will increase springback and bending work.

The disc-sanding jig is a 1-1/2 x 1/8 angle of aluminum 4 feet long, on the Harbor Freight tile saw I have been writing about, at 15 degrees, backed by a segment of the spare bar, and four magnets on the stainless top. The saw is braced more than 15 degrees upwards, so the work falls away from the disc. It will have to go to 30 later but 15 lets me experiment with setups. I disc-sanded a 4-1/4 inch bar using a slightly different jig and it came out near surface-grinder quality. I intend to use a spray of acrylic microspheres as a surface lubricant during grinding; they are of uniform size and work like tiny ball bearings. In this configuration, I feed the work into the disc from behind, and it drags the work through the setup. That way, with a slight taper on the feed angle, there is no contact as the disc moves up, some through the middle, and most near the edge that is moving down, to prevent a thrown part. I may regulate feed with a thread rotating a paddle in water or some other regulating method for an automatic feed, if the acrylic spheres work as well as I remember. They are part of a powder/liquid plastic repair kit sold by Radio Shack and others.

I had been wondering how to prevent stone work from falling into the diamond blade when cutting bevels. This is part of the solution, bracing the saw off-level. The other part may end up as holes in the top and a slotted bar as an extra fence. Funny saw that way. The whole top doesn't tilt; only the right, and it tilts up, not down, making double cutting necessary, once to length on the square, and once to form the bevel. I have a bit of granite larger than 15 inches and will cut to 15 inches some day to make a plate of length I can use handily.

Doug

Well, I drilled and tapped a hole in the saw's tilting top, drilled and countersinked (countersunk?) a hole in a length of angle, screwed them togther, and braced the saw so the work was level. I ran the work past the disc sander and increased the bevel to 15 degrees. Nicely done.

The result is sheet bows in the middle. I have to switch to the rated

Small samples bend nicely to 90 degrees with the new bevel.

Doug

I have two rows of holes in the base bar now, allowing the clamp bar to be screwed to it with the five M6 screws in two different ways. (Four, actually, two of which are never used) This allows for a deep throat, a shallow throat, or the use of holes in the work clearing the screws.

Doug