MINIATURE X & Y CROSS SLIDES

FOR THE MICRO MARK DRILL PRESS

 

The Micromark drill press is a very nice unit that will deftly handle bits from #80 to 1/4" with a nice little 1/4" Jacobs chuck that seems to be pretty darn good. The spindle thread will take any chuck with a 3/8-24 thread and will handle a 3/8"capacity chuck but I doubt that it has the necessary power to drive a 3/8" bit.

This little drill press has been designed as a low cost clone of the very expensive, $2000 plus, super high speed miniature or jeweler's type of drill press I've seen in several tool catalogs. But in this case, looks are deceiving. Nevertheless, I do love my little machine and use it extensively. The modifications that I have done on my drill press allow it to also double as a miniature milling machine to mill and drill many of the very small scale components dealt with in the field of model engineering. The base of the drill press is a fairly good aluminum casting with a ground surface, diagonal clamping bolt slots and a central 1/2" hole. Normally, a small machine vise would be bolted to the table but only fairly coarse positioning of a workpiece to the spindle axis was possible. You would either place the work under the drill bit by hand ( not recommended ) or by shifting the vise around before tightening it down.

To further strengthen the column of the drill press, I made a 2" diameter 4" long stiffener out of aluminum rod, drilling and boring it to a slight over size diameter and slipped over the column with the drill head removed. The hole thing was epoxied to the base and the gap left between the column and the brace completely filled with epoxy and the whole thing allowed to cure.

The Taig lathe basic cross slide mechanism is used throughout in some of the extra gadgets available for it. The compound slide is nothing more that a slide unit with a rotating "T" slot adapter so it can be slid onto one of the two "T" slots of the cross slide to provide compound angle movement. The vertical milling attachment which slides through both " T " slot of the cross slide also utilizes the very same slide. By purchasing two ( $71.00 for two ) of the compound or "top" slides and crossing one over the other to create a milling machine table, you can then attach it to the drill press table and you'll have instant X & Y movement. The first thing to do is to unscrew the slide to disengage it from the 1/4-20 drive screw. The bottom of the slide with the male dovetail needs four drilled and counter sunk, rectangularly spaced holes into the base so it can then be screwed, centered to a 1/2" thick 5" x 3" piece of flat aluminum plate. Insert and screw the top portion of the slide again. The dial handle would be oriented to the right side of the plate in the traditional position for the X advance. Take the second slide and unscrew it as before, layout, drill and counter sink a second set of four holes with a #20 bit to form a 1-3/4" square hole arrangement for 4-40 screws on about the mid line of the base. These holes need to be larger than the normal #33 needed for the 4-40 screw to allow plenty of play for squaring the Y slide to the X slide. Lay some double stick tape on the top surface of the X slide and using a good accurate machinist square, orient and stick down the Y slide base and right angles to the X slide and without moving it, transfer punch the four holes positions with a # 20 punch. Drill the resulting punch marks with a #43 bit to a 1/4" depth and tap with for a 4-40 thread. Screw the top slide base onto the top of the X slide and set the Y slide base at a perfect 90o to the X slide with a good accurate machinist square and tighten the screws. Check again and re-adjust if needed. Attach the whole assembly to the drill press base by drilling four diagonally placed holes on the base plate and bolt it to the base. There will be plenty of play to squaring up the base plate to the drill press table although it isn't really necessary to do so as long as the X & Y slides are square to each other.

Workpieces can be clamped to the top slide by using the "T" slots or by bolting a small vise, like the one made by Sherline for their milling machine. End mill diameters should be kept small with the 3/16" shaft sizes being ideal to use with this size drill press. The stub length being better than the double ended ones. Another very good miniature source would be Dremel cutters or carbide 1/8" shank cutters. The Micromark drill press has three pulley speeds but realistically speaking, it doesn't have the torque at the highest speeds to do any heavy work. The smaller mills, i.e., 1/16" diameter tip could be driven at the highest speeds but very light cuts need to be taken with these small and fragile bits. An electronic speed controller such as the kind now offered for routers is a very good addition to the mini milling outfit so you can fine tune any given speed setting to any particular situation. Keep it mind that this outfit would only be used for super miniature work on very fine precise type of job not suitable for the larger drill press set up. Special mini size holding fixtures could also be designed and built to fit the "T" slotted "X" slide for just about anything miniature holding job you might ever require.