One secret to productivity on the mill is to use as much of the envelope as you can. The more parts you pack onto the table, the more it can get done without assistance while you work on something else. When it comes time to pack a bunch of small parts on, the ubiquitous vise is not the right tool. Instead, consider something more like this shopmade pallet system as seen over on Practical Machinist:
16 parts all neatly held by Mitee-Bite’s “Pit Bull” clamps…
The Mitee-Bite Pitbull’s have a sharp edge that jams the part against a stop on the other side as you tighten the socket head. They’re prefect for this kind of work. Mitee Bite offers a whole line of different edge clamping products worth checking out.
This particular fixture is also part of a shopmade pallet system. A pallet is an interchangeable plate. There is a base mounted on the table, and one or more of the pallets. By using pallets, you can drop a bunch of parts on the mill table, machine them, and them remove them all as a unit. Putting parts on or off the pallet can be done while the machine is working on another pallet, which keeps the machine productive a greater portion of the time.
Here is another pallet plate for this system:
This one is set up for machining the firearm rail system…
Here’s the underside of the pallet as well as the top of the base…
The top of the base has two locating pins that match bushings in the pallets. These bushings are press-fit into precision bored holes. The pin and bushing system is the secret to making the pallets repeatable. Just drop them on their pins on the base, tighten down the 4 socket head cap screws in the corners, and your pallet is positioned to a known location on the machine. Note the cutouts on the underside of the pallet so you can get your fingers in to lift the pallet up.
Here’s another good trick: these pallets are using one round and one diamond head pin for location. The diamond head minimizes problems of misalignment in the Y due to slight inaccuracies but keeps high accuracy in the X dimension. This makes installing and removing the pallets much less finicky. The link provides more information on diamond head pins.
A shopmade pallet system like this can radically improve your shop’s productivity.
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