I'm unconvinced as to the absolute value of a tenon slot on these smaller type 2 and 3 vices for small machines. Better off with separate alignment devices for across the table and parallel to the table mounting. Not forgetting a machinists protractor for angled setting when needed.
Clamping slots down the side for mounting gives more freedom to shift the vice for best position to handle the job rather than being limited by the need to align two mounting lugs and, if fitted, a tenon with the Tee slots. This extra freedom of positioning can be a great help on small machines with short table movements.
The great inherent resistance to moving jaw lift of the type 2 vice comes at the cost of relatively less gripping power. The clamping screw works at around 45° to both work and vice top so the imparted force is divided roughly equally between gripping the job and holding the jaw down. In practice the downwards force probably stops the jaw moving further against the work at a gripping force rather less than that produced by a conventional in-line screw vice. The clamping screw on type 2 and similar style vices is almost always a relatively small caphead. So the maximum force is further limited by the short allen key. Conventional vices have a larger screw and longer handle so more scope for heaving up good'n tight. Whether needful or not.
If you fancy making something for larger jobs consider adapting the jaw layout used on this planer vice to make a simple "endless vice" aligned along the Tee slots, rather than across the table as shown, to hold work direct to the table.
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Forget the base and key. Scale down sizes as appropriate. Simply fix the jaws to the table with appropriate Tee nuts. Perhaps not as strong as the usual commercial and DIY versions, which are too big for your machine anyway, but much easier to make and adequate for smaller work. Its likely that a small cast iron angle plate could be found of appropriate size for the fixed jaw. Or just go crude and effective with a squared off block.
Speaking of creative crudity I recently had to produce a 9 ft long by 3 inches wide light alloy wedge tapering from 6 mm thickness to 1 mm. Fortunately do-able in 4 sections that just fitted into the Bridgeport table travel. To get the wedge angle I set-up a piece of ex-kitchen cabinet chipboard at the correct angle and milled it flat. Creative use of short bolts, tapped holes and wood screws held the alloy bar to the base which in turn was held on the table with clamping kit components. Job went reasonably straightforwardly but the short bolts, woodscrews and tapered base were sacrificed in the process.
Most of we home shop types tend to overlook how many jobs can be made much easier if sacrificial work holding can be employed. I'm certainly far too inclined to try and preserve / hang onto things that "might be useful someday" rather than get value today from a one time sacrifice.
Clive
Edited By Clive Foster on 27/11/2021 20:05:13