Harold Hall

Workshop Projects

First Page

If you already have a four jaw chuck then facing the ends whilst in this will be the easiest method to adopt, if not, then doing this on the milling machine is the only option. Photograph 12 shows my method of machining the four at the same time using my engineers sash clamps but machining one at a time in a conventional vice would be an acceptable method.

Whilst there is no essential order for carrying out the remainder of the machining operations I think that making the 10mm web along the base of the jaw is a good starting point. I say 10mm but there is a possibility that the slot drill if not running perfectly true will have cut a slot slightly oversize so measure the slot before machining the web. However, this is not a moving jaw like those in a four jaw chuck so a very close fit is not a requirement. Photograph 13 shows my method of carrying out the machining having one fence to set the height and one to assist with opposing the cutting action, one clamp is therefore more than adequate. Still with this set-up, also mill the 1mm deep recess the purpose of which is to permit the jaws if required to be compressed by a small amount when holding larger rectangular items.

Drill, tap and counter bore the holes leaving just the jaw to be slit and if you have a large slitting saw then do this on the milling machine. Photograph 14 shows my method , the angle plate is just giving some added support to oppose the machining force though this was probably unnecessary but it does serve a purpose with the next part so arrange to machine the slots in both whilst this set-up in on the table. Whilst not seen, a similar thickness piece of steel was placed between the jaws at the other end as holding a component at the end of the jaw without this being done is definitely taboo, even with a quality vice.

If you do not have a suitable slitting saw then it is a task for the band saw and failing that a manual operation with hack saw. Whilst neither of these methods will be visually as elegant they will function equally as well.

Thin Piece Larger Diameter Clamp (6)

This is a straight forward part but have included a shot of my method of facing the ends. In this, Photograph 15, the lower member packs the part up to keep the cutter clear of the table's surface and a fence is clamped on top enabling the parts to be positioned so as to machine their ends square. The head of the screw that secures the two parts to the table also acts as packing for the clamp that holds the workpiece. The fence in front sets the position of the workpiece enabling a consistent length to be achieved with ease on the second end. This method was much easier than fiddling around within a vice's jaws particularly when making a number of identical parts.