Bench Sander Blade Grinder MK II
Part 1 (of 3)
I have replaced my Belt Sander Grinder with Mark II. This not only involves a new jig, but also a new machine.
The original machine developed electrical problems (in the on-off switch) and, after one unsuccessful repair, I accepted Carba-tecs offer to return it (at full refund) and upgrade the machine (my cost). Its replacement is the Carba-tec SB-609, a 6”x9” machine. Compared to its predecessor, it is bigger and more powerful. Note that this is not necessary for the purposes of grinding/sharpening blades, as the original machine was satisfactorally specified in spite of being 1/3 hp and 4” wide.
Carba-tec describe the SB-609 as follows: New model features graphite slip pad and dust extraction outlet. Powerful 3/4 hp motor will not stall under pressure. Disc table tilts to 45 degrees. Belt platen swivels for horizontal or vertical sanding. Quick-release lever makes for fast belt changing. Stand and mitre guide included.
I needed to fit a jig to the new machine and, although I could modify the old one to fit, I thought that I'd make a new one – one that included all the features I had previously described in the earlier article.
For original jig see picture below, or go to http://www.woodworkforums.ubeaut.com...8&page=1&pp=15
The other area I was interested in sharing was my efforts in machining metal, in this case aluminium, with the few related metal working tools I own. If I can do it, then others can too!
Below is a picture of my Poor Man’s Metal Machining setup: drill press, 2-dimension vise, drill bits, cheap set of taps and dyes, squares, scribe, digital caliper.
It begins here …
The first step was to cut up a few pieces of aluminium. I did this on a Mitre Saw (cheap GMC) (picture #4), then ground them square on the belt sander (picture #5).
(continued in Part 2) ...
Setting up and using the Belt Sander Grinder
Here is a manual (of sorts) for setting up and using the Belt Sander Grinder. It was developed using Mk II but is equally applicable to Mk I.
Figure 1: Belt Sander Grinder Mk II
Figure 2: Toolrest Setting Jig – loosen height adjusters and slide in the toolrest. Tighten. Use feeler gauge to check that it is set equally on both sides.
Figure 3: Bevel Angle Setting Blocks – these were cut to the three common angles I use, 20°, 25° and 30°.
Figure 4: The bevel angle setting blocks are placed behind the blade with the blade holder pushed up against the toolrest. Note that this must be done on the belt that is used last in the grinding sequence. In this case it is the 1300 grit belt. Once determines, tighten the hold downs on the blade holder.
Figure 5: Bevel Angle Setting Jig (BASJ)
Figure 6: Transfer the blade holder to the bevel angle setting jig. Make sure the blade is square against the side fence. Redo the previous step until both the bevel angle and a square blade is achieved. If the bevel end of the blade is out-of-square, judge where the bevel would end if it were square, and use this mark as the repeated setting.
For the first grind, set the blade against the front fence of the BASJ, grind the blade square, then set it again. Grind only enough that you can feel the wire edge beginning. Then move to the next belt. If you do choose to regrind the full bevel, you will need to reset the blade against the BASJ. Do this again for the last belt as well. In most cases, running through 5 or 6 belts and grinding full bevels will remove about 1mm of the blade length. For plane blades it is expected that you will move at this point to waterstones (or another low-micron grade medium) and grind a microbevel with the use of a sharpening guide, such as the Veritas or Eclipse. The Veritas has the advantage of an in-built adjustment for a 2° microbevel. The Eclipse needs to be adjusted by reducing the length of the blade’s extension (the BASJ is useful here). Chisel blades may just be stropped on the Honing Plate, and this may be sufficient for most tasks.
Regards from Perth
Derek