Australian/New Zealand Luthiers Forum

HI, I found putting the radius on a bridge base to suit the top radius more time-consuming than I liked, so I made this tool up.

I used to use scrapers with bridges held in a special jig, then I used the sanding block you see here, but now it takes less than a minute to do the same job.

I have a number of these belt sanders [collected over the years] so I could afford to reshape the sole plate under the belt of one of them, making a dedicated tool to give the required radius I needed. What I did on the Makita sander was to put a shim under the sole plate that the belt ran over that was shaped with the desired radius, this made the belt run over the radius instead of flat.

The job did not worry me until I started doing a few bridges at a time. I also use it to remove old glue and reshape bridges during bridge replacement repairs. it saves a bit of time there, also.

I sanded a piece of ply in the photo to show the timber removed, not shown is the block that fits onto the bridge to give me a better grip whilst sanding. Cheers Taff

Looks good. I would worry somewhat about taking too much off. I guess you would use a fairly fine grit...?

I shaped blocks on the lathe for my various radii and stuck abrasive to them. Works well but does take some time. I do get a good fit this way.

Thanks for the tute Taff.

I profile the bottom of my bridges by running them over a convex sanding board that I radius in the same radius dish I use for the tops. I then fine tune by sticking sandpaper to the top in the bridge area and moving the bridge over same to get the fit perfect.