Tuesday, 12 January 2010

Shooting Board - The Bird's House - Part 2...

One of the things I would like to see this Shooting Board have is an Adjustable Bird's House so to that end, here is the first-off design of what I have in mind.

To control the angle of the working platform, I came up with a simple scissor jack that works by a screw. Turn the screw one way and the two scissor arms come together and the end of the platform rises. Turn it the other way and the opposite happens. Easy Peasy.

Where the problems arise is in the fence to register the work square to the Shooting Board. If the fence is cut at 45° at its working end, when the platform drops, that angle reduces as well, resulting in it not fully supporting the stock being planed. This, I believe, will result in tear out, so it was an issue that had to be addressed.

To overcome this, I came up with the idea of fixing a vertical piece to the base, a piece that wouldn’t move when the angle of the working platform is changed. When I first came up with this, I discounted it because I thought with it only being fixed at the bottom it wouldn’t be able to take the pounding of the plane blade. I then realized, after a bit more thought, that the Bird’s House will be clamped (how, I don’t know yet) to the Shooting Boards fixed fence, so by adding that support, I think this idea will work.

Then the issue of keeping a two-piece fence registered with each other came up. The adjustable fence will not be supported by the Shooting Boards fence, and while there will not be a lot of pressure on this part, I figured something should be done to ensure a square register of the stock at all angles.

My plan for this calls for cutting a 1/8” slot in both parts of the fence which will accommodate a 1/8” by 3” piece of brass plate. The plate would be fixed to the adjustable part and float in the fixed part, registering them together, I hope, when things start to move.

This project is starting to look like it is going to be a blast as now not only does it involve woodworking, but also some rather cool metal work as well.

What Is It?

Here are the plans for my “What Is It?” challenge again...

I’ll give you a hint. If you are into the latest technology as well as old tools, this “thing” will be right up your alley.



1 comment:

  1. Hi Mitchell

    Nice idea for the scissor-adjuster. I like this (may try it out), but in practice mine is set at 45 degrees with a fine adjustment that can tune it a couple of degrees each way (simply screws as feet).

    The issue for comment, however, is the apparent need for a fence that backs up the workpiece to prevent breakout. This type of fence is actually unnecessary. It is better practice to add a chamfer to the back of the piece, and plane to the end of this. The chamfer not only prevents breakout, but it gives one a visual guide for planing.

    See: http://www.inthewoodshop.com/ShopMadeTools/ShootingforPerfection.html

    Excellent blog.

    Regards from Perth