Miniature Jack planes - Part 1.

For the last few months I have been working on a set of twenty 1/4 scale low angle Jack planes.  I have shared a few of the process photos on Instagram, but I try to keep the descriptions to a minimum.  I have decided to start this blog to elaborate on my photos.  The next few days will be post heavy, trying to catch the blog up to real time on this project. I currently have only one plane completed as a prototype, with the rest about 75% complete.

The Idea.

I was thinking of different tools I could make that had about 20 parts, with a few of them being castings.  I have never done a set of anything with more than 3 parts each, this would be the test.  I also just set up some investment casting equipment I wanted to utilize in my next work.

I have made a handful (literally) of miniature woodworking tools in the past, but never a plane.  A plane was the missing link in my set of miniature tools.  This summer the time came to get started on a plane.  I had to make a set of them because I have to make money to keep doing this.  If money was not a thing I would have made two and moved on.  More important than the money, I wanted a miniature jack plane in my hand as soon as possible. 

I settled on a low-angle Jack plane because it is a standard in most modern hand tool shops. Most miniature makers scale down rare and precious tools. I decided to do the opposite and model mine after a commercially available plane that most have seen.  I like the idea that people are very familiar with the tool before they see the miniature.

I bought a jack plane from Lie-Nielsen to use as a model for my miniature. 

 Plane prototype taking its first shavings

Plane prototype taking its first shavings

Scaling it Down.

I tossed around a few different ideas on how I wanted to make the casting patterns for the sole, cap iron, and adjustable mouth piece. I thought about machining them from wax and inlaying the text as a separate piece, but was skeptical if the time involved would pay off.  I thought about 3D printing and decided it would be perfectly suited for this. I decided to 3D model the sole and the cap iron.  The adjustable mouth piece pattern I carved from wax.

Aside from the 3 main castings, the remaining 14 parts I scaled down on paper. Once I determined the size they had to be, I brainstormed how they would be made, what size stock I needed to start, and what type of special tools I would have to make to put it together.

 A portion of the drawings

A portion of the drawings

Master Pattern.

I took many measurements of the castings and plotted out the curves on paper before imputing them into the computer.  It took me a while to get reacquainted with the software (Autodesk Inventor), but it is pretty intuitive.  I had to build the model as a casting pattern, leaving material on all the surfaces that would be later machined.  Every part of the pattern is drafted so it could be pulled out of sand in the sand casting process. My planes will be investment cast, but the pattern is drafted for sand.  It took me about 16 hours to model the plane sole completely. I had them 3D printed in wax at the local jeweler supply shop. I printed it 27%  the size of the full plane.  The extra couple percent will be lost due to shrinkage in the rubber molding and casting process, hopefully leaving me with 1/4 scale finished piece.

 The Master Pattern model.

The Master Pattern model.

 The Cap Iron Model

The Cap Iron Model

 3D printed wax model. Printed on a 3D Systems Projet 1500 printer.

3D printed wax model. Printed on a 3D Systems Projet 1500 printer.

 Cap Iron wax model

Cap Iron wax model

Part 2 will cover the molding of the master patterns, as well as casting the pieces.