This is a file of various hints and mini-projects that are too small to merit a diagram, lengthy explanation or a full blown article in a magazine. Most of the ideas would require tailoring to your own situation so a detailed diagram would be a waste - although, in many cases, I've suggested the dimensions I used to give you an idea.
Items are arranged in no particular order - I simply add to the file as ideas occur to me.
I welcome suggestions for additions to this file. Email me at mklotz@alum.mit.edu. If I add your hint, I'll be sure to give you credit.
The two nuts that came on the threaded depth stop rod on the milling machine were not only hard to adjust but they tended to slip. When I use the depth stop it's generally to prevent drilling through something into which I put a lot of time. I want to be able to trust it. I made about four different designs that weren't very satisfactory before I hit on one that works for me.
Knurl a slug of brass and thread it to fit on the depth stop rod. Split it into two separate nuts. On one of them drill six holes (3/32" diameter), equally spaced and parallel to the threaded hole. On the other drill a 3/32" hole on the same radius and loctite in a short length of drill rod. Now bore out the one with the pin so it's a smooth slip fit over the depth stop rod. Make sure that with both nuts mounted on the rod the pin can engage any of the six holes in the periphery of the other. Cross drill the one with the pin and thread for a small, knurled, finger-operated locking screw.
In use the threaded nut is threaded on the rod first. The second follows with the pin pointing down. Now, it's a lot easier to spin one nut than two in order to make the adjustment. Once the threaded nut is adjusted the one with the pin drops down and engages one of the holes. Tightening the locking screw against the flat on the depth stop rod absolutely guarantees that the bottom nut will not go anywhere. Six holes gives me a fine enough adjustment for the less than precise use I make of the depth stop rod. (I have a dial indicator mounted for really precise measurements.) One could use more holes if desired. By considering the thread on the rod, one can pick a number of holes that gives a convenient size nut advance for one angular hole increment. With a 20 tpi depth stop rod five holes would yield an advance of ten thousandths per hole.
Take a 3-1/2" length of 1" diameter aluminum rod and form a hemisphere on one end (see BALLCUT.ZIP). About 1/2" from the end opposite the hemisphere cross drill a hole to match the diameter of the arms on your 3-jaw chuck wrench. Center drill and tap the flat end for a suitable setscrew. Mount this on one of the chuck wrench arms so it touches the central rod with the square tenon that goes in the chuck hole. A flat filed on the bottom of the wrench arm where the setscrew seats helps to keep the hemispheric end pointing vertically away from the square bit. Now put the wrench in the chuck and put the palm of your hand on the hemisphere. By rotating your hand in a small circle you can crank the wrench rapidly to move the jaws in or out. The beauty of this design (versus a crank used separately from the chuck wrench) is that the device is always there where you need it and the chuck wrench arms are available for extra torque when you need to dog the jaws down.
Even though a lathe chuck crank isn't the greatest idea for adjusting the jaws when the chuck is on the lathe, it's very useful when the chuck is sitting on your workbench. I generally remove my chuck to change the jaws because it's more convenient and reminds me to clean the scroll and chuck jaws. Mill a short piece of HRS to a square tenon that's a close, smooth fit in the chuck holes. Turn the opposite end to 3/8" diameter for about a 1/2" and mill a flat on it. Make the bar of the crank of 1/2" x 1/2" steel. It's length should be such that the crank can be conveniently turned with no knuckle banging when the chuck is sitting face up on a bench (protect the register with a cork pad). Mount the square key in a 3/8" cross-drilled hole in the arm with a setscrew coming from the end to hold it in place. Although it could be soldered/brazed in place the setscrew arrangement gives you the option of making another square key to fit the holes in your 4-jaw (or other chucks). The spinner is a one inch length of 3/8" diameter brass - nicely polished. Drill 1/4" to take a 3/4", 10-32 shoulder bolt. Carefully counterbore for the head of the bolt so that, when the bolt seats in a tapped hole in the crank bar, the spinner is just free to turn smoothly.
A hint. After you've removed the jaws from the chuck, insert a toothbrush in one of the jaw channels with its bristles in the scroll threads. Turn the crank so that the toothbrush is moved toward the chuck periphery. It will sweep all the swarf out of the scroll and drop it over the edge of the chuck and onto the bench.
I don't like marking out and I'm not very good at it. One of the many things I don't do well is get the prick punch on the point where the two mark out lines cross. Even a magnifying glass on the punch doesn't give me consistent results. Try this. Take a 1" length of 1" diameter brass and drill/ream a 1/8" hole as close to center as your facilities permit. Put a 60 degree (included angle) point on a 1-1/4" length of 1/8" drill rod. Harden and temper the point as you would for a prick punch. (It only took me three tries to get this right.) Mount the brass slug in the milling vise and, as precisely as possible, carve away one-quarter of it so that the resulting shape looks like a one-quarter eaten wheel cheese.
Push the drill rod prick punch into the hole. In use one sets the device on the work and aligns the two edges of the cut away portion with the (usually perpendicular) layout lines. This automatically places the prick punch over the intersection of the lines. Tap lightly with small hammer and then apply the center punch. Works for me! I've made some of these for friends as gifts and they've been well received.
Mount an aluminum (or any non-magnetic material) handle to a small, high-strength pot magnet. Pick a magnet diameter that's a nice fit in a piece of PVC tubing (or machine a piece of plastic to fit the magnet). Close one end of the PVC with a thin (important - magnetic field strength decreases as 1/r2) plastic cap or a thin piece of plastic cemented in place. Use this to remove ferrous chips from whatever. Once the chips are caught, hold the unit over the waste bin and withdraw the magnet from the PVC. Chips will fall cleanly away and the magnet will require no cleaning.
The drawbar on my mill-drill requires a LIGHT tap with a hammer to loosen it after it's been used to draw in a tool. Make a (H)ammer-Wr(ench). Mill a 3/8" square tenon on one end of a 2" length of 3/4"(AF) hex steel. Mount a (commercial) 3/8" socket that fits your drawbar on this tenon with a screw-washer combination threaded into a hole in the center of the tenon. Attach (solder/thread/interference fit) a 1/2" thick slug of hard brass (so you won't damage the drawbar nut) to the other end. Cross drill and tap the hench body for a length of 3/8" steel rod. Mount to a file handle. Now after loosening the draw-bar nut with the socket you need only flip the tool in your hand to have a safe way of tapping the drawbar loose.
I would like to make a set of spacer blocks. I want them primarily for their convenience - not their accuracy. A one thousandth tolerance will be good enough for the purposes I envision. The question is what sizes to make. With blocks of 1,2,3,5 units I can construct all the integer unit lengths up to 1+2+3+5=11. A better solution is to make the blocks according to the binary system, i.e. each one has a length which is an increasing integer power of 2. In this case it would yield 1 (=2^0), 2 (=2^1), 4 (=2^2), and 8 (=2^3). This combination of four blocks will produce all the integer unit lengths up to 1+2+4+8=15. I don't want to bore you with a mathematical proof, but, for a fixed number of blocks, you will always get a broader COMPLETE range of unit combinations if the blocks are made in lengths that agree with the binary numbering system. It's not a general proof but you might try (as a puzzle) finding a four integer combination (other than 1,2,4,8) that can be combined to yield all the unit sums up to 15.
Anytime you want to make up measuring sets make them according to the binary system and you'll get maximum range for minimum fabrication effort. Obviously this applies to making weights for a scale as well. I did this with a small beam scale I made and it worked out very well. It seems simple to me because I'm intimately familiar with the binary number system via my computer work. Others may have a short period of adjustment but, what the heck, a little adjustment for the sake of elegance is always well advised.
An added benefit is that, once you've made them, you can decide which ones to use for a given size by expressing that size as a binary number and choosing the ones corresponding to a 'one' in the binary number. Suppose you need a 10 unit item. Many scientific calculators (an essential shop tool) will tell you that:
10 (decimal) = 1010 (binary) = 1×8 + 0×4 + 1×2 + 0×1
So, you need the 23 (=8) item plus the 21 (=2) item to make a 10 unit item. (I know, you could have done that in your head, but once you make a set with fifteen blocks, you may find this approach a time-saver.)
Battery powered devices that are used intermittently tend to get left on either via laziness or forgetfulness. There's a way to save yourself the effort and expense of constantly replacing batteries. Mount the device to a sturdy, weighty base. Depending on the application, the weight of the base can be achieved with the batteries that power the unit in question. Screw a small micro switch to the base in such a way that when the base is set on something the switch is depressed. Wire the power circuit of the device in question through the switch. Now when you pick it up it will turn on automatically and when you set it down it will turn off automatically. I've done this with pulse detectors, modulation detectors and such and it's worked well.
There must be a company somewhere manufacturing high-intensity oily dirt which is sold in large quantities to every metal supply house. Commercial (STP is only one brand) carburetor cleaner in aerosol cans is the only thing I've found that will cut this and virtually any other kind of persistent oily dirt INSTANTLY and with no rubbing effort. The stuff is flammable as hell and not fun to breathe so use it outdoors if possible. In the shop don't spray it on the surface to be cleaned. Spray it onto a rag held against the spray tip. Discard rag safely and immediately in a sealed container.
This is a great way to clean parts before using loctite. Most loctite products won't hold worth a damn on oily parts. Make sure the part is dry before applying the loctite.
I made an aluminum collar that clamps onto the tube on my tailstock. A setscrew on the bottom fits into the tube slot that prevents the tube from rotating when it is advanced. On the top is a small block that holds an adjustable sliding rod parallel to the tube and about 1/2" above the (flat in the case of my tailstock) top of the tailstock. In use a dial indicator is attached to a low profile magnetic clamp and placed on the top of the tailstock. The sliding rod is used to communicate the motion of the tube to the dial indicator. [The neat thing about dial indicators (I have them mounted on everything!) is that they are virtually backlash free.] I don't use this attachment very often but it's sure nice to have when I do need it.
One of the handiest devices I have is two small IDENTICAL (that's important) vises that mount on a length of 3/8" square steel rod. I made the main bodies of the two vises as one piece (V-grooves as well) and then split the parts. A milled 3/8" square groove in the main pieces serves to align and secure them on the mounting rod. The movable jaws are blocks of aluminum mounted with 1/8" guide rods and stock 1/4-20 machine screws fitted with small knurled knobs for tightening. I originally made this unit to hold awkwardly shaped model ship hulls on a Panavise base. Then I discovered that it was ideal for holding long slender rods on both sides while sawing them. Other uses will immediately suggest themselves. Butt soldering parts is easy. The 3/8" rod is easy to clamp in the bench vise. The extension that connects to the Panavise base can be made hexagonal in shape so that it may be grasped at different angles in the bench vise.
This device came into its own when I added a second 3/8" square rod perpendicular to the first rod. They are joined with a half-lap joint secured by a recessed machine screw. This joining ensures that the vises are in alignment when mounted on each of the two arms. Now soldering and gluing at a right angle is easy. I used the 90 degree arrangement as a test jig while building an "elbow" engine. It was secure enough to let me test the device under power. Try one - you'll like it. BTW, it makes a really keen fly-tying vise. You can add all sorts of attachments to hold thread, small tools, etc.
If you're into fishing you might appreciate another variation. Making leaders, tying knots, etc. in the field can be trying at best. I took a 6" length of 1" diameter aluminum and turned five 'U' shaped grooves (3/8" wide and 1/4" deep into it. I wind various test leaders in these grooves and secure the free ends with finger operated lock screws. I bored most of the body out to form a cylindrical cavity 1/2" in diameter and made a knurled brass plug that screws into the end of the cavity to (O-ring to prevent corrosion) seal it. The cavity holds the needles, tweezers, and knot formers I use to form fishing knots. I made a tiny brass (won't rust) machinist's clamp (roughly 1 x 3/8 x 3/8) with a threaded stud that holds the vise in the end opposite the cavity plug. In use in the field, the body of the unit can be easily held between the knees with the hook secured in the mini-vise. The correct test line can easily be unwound, attached to the hook, forming knots with the tools available from the cavity. When done, throw the whole thing back in the tackle box where it will await the next big catch without everything coming unraveled or lost. Screw a piece (or several) of spring steel to the mini-vise and they'll operate as friction "catches" to secure ends of line while you reach for a tool or a beer.
The speed vs pulley setting chart on my Taiwanese milling machine seemed to be inconsistent - a given belt change led to different speed ratios according to the chart. This seemed a physical impossibility so I set out to measure the speeds for myself. (I was vindicated - the chart was indeed wrong.)
Now this idea isn't for everyone. One of my other hobbies is electronics so I have an oscilloscope and counter - the latter essential to the process. I made a 1/2" thick by 3" diameter aluminum disk and in the center of the circumference cut a 3/32" inch rib that projects out 1/4" from the body. Imagine an oversized hamburger sticking out of its bun on all sides. Into the hamburger I drilled sixty (important number) 1/16" holes. I mounted this on a shaft in the milling machine vise with my trusty Brinkman flashlight shining down through the holes. Beneath the holes I mounted a small phototransistor connected to the scope and counter.
The rotating device chops the light and the output is a square wave. The scope is used as an aid to adjust everything so that the square wave is clean and achieves its maximum amplitude. The counter counts the pulses. With sixty holes the frequency displayed on the counter is one-for-one identical to the mill speed measured in revolutions per minute - no mathematical conversions are required.
The phototransistor type is not critical - any Radio shack generic type is probably OK. The circuitry is trivial - two resistors and a battery are all that are needed. Hobbyists who lack the counter (the oscilloscope is nice for making adjustments but not essential) might be able to locate a friend who has one.
If you're electronically clueless, email me and I'll send you the circuit diagram.
It's difficult to check the progress of the work when using a pinch type knurling tool because the tool obscures the workpiece. I mounted a mirror behind the tool at an angle so that I can see the backside of the work while setting the initial knurl pressure and watching the progress of the knurl. Long ago I made a mount for the back of the carriage to hold a dial indicator and so could adapt this to hold the mirror. Lacking this, a simple triangular frame bent from sheet metal (looks like a book holder) sitting on the cross slide might be used.
Speaking of mirrors, one mounted on a finger dial indicator makes centering work in the milling machine much easier. I happened to have a small gimbal mounted microscope mirror lying around. A light aluminum arm about two inches long was cobbled up with a clamp fitting that holds it on the indicator with the mirror at the end of the arm facing the dial indicator face. Now when the indicator is turned with its face away from you the mirror can be easily adjusted so that the dial is visible. When the dial indicator is facing you the two inch arm length offsets the mirror enough so that it's easy to "look around it" and view the indicator directly. Since indicator motion is reversed when viewing through the mirror, I put a small piece of adhesive label on the dial face to serve as a positive indicator of which way the pointer is moving.
I had an intermittent problem with recurring "rings" on workpieces when using the automatic carriage traverse on long turnings. I was standing there in front of the lathe watching this happen one day when I straightened up, stopped leaning on the tailstock and started pondering the problem. Magically the rings stopped occurring. So I leaned forward to observe more closely, bracing myself against the tailstock gently, and they started happening again. It only took me five or ten minutes to come to the astounding conclusion that maybe, just maybe, leaning on the tailstock might have something to do with the problem. Somehow it never occurred to me that even the gentle pressure of my hand could affect the cutting action on such a massive tool. I also found that leaning on the handle of the backgear cover (conveniently placed just where your hand wants to be when inspecting the work closely) could affect the cut. I know this makes me sound an awful dummy but I wanted to pass it along so that if you encounter the "ring" problem you'll be sure to get a cane to lean on when taking long cuts.
Working from an open book is generally a pain because, unless spiral bound, the book wants to keep closing. A commercially available bookweight gave me the idea for something that solves the problem nicely for me. I took a 1"x14" length of 1/8" thick clear plexiglas and cemented to each end a flat plastic petri dish (the disposable kind). I filled each of these with bird shot and then cemented the covers on so spills were impossible. This lies easily across the open book, you can read through the plexiglas, and the weights are outboard enough so that they don't obscure anything on all but the largest books. If I build another one I will mount a hinge in the middle of the plexiglas bar so that the unit can "bend" more closely to the profile of the open book. This will make it less likely to tip off very small books and will also allow it to be folded for storage. Obviously the petri dishes aren't critical - any small flat container that can be filled with a weight of some kind will work. One could get exotic and turn some fanciful low-profile shapes out of brass to serve as weights.
Whether or not you hand-load shotgun shells, a bag of bird shot is a great shop asset. Get your wife or girlfriend to sew you a leather bag about 4 x 4" - heavy canvas will probably work. Fill it about 7/8 full with birdshot and you have the ideal "third-hand" for holding odd-shaped work to the bench. "Nestle" odd-shaped pieces into the 'self shape conforming" bag (as metal engravers do) while you do precise filing or marking.
Bird shot is also very consistent in weight. Borrow an accurate scale and weigh a (counted) hundred shot and compute the average weight. Now throw a random number on the scale and calculate how many using the average weight. I'll bet, after counting, the error is +/- only one shot pellet. I don't think I need to explain how this fact can be exploited in many weighing applications.
Speaking of leather. Jeweler's know that when working on tiny assemblies, a minute part, if dropped onto a resilient surface, can achieve incredible velocities and launch itself into impenetrable recesses in the shop environment. They use a leather sheet, slung loosely below the working surface to catch dropped parts. The loosely slung leather is very 'soft and lossy' and the part will not bounce when it is dropped onto it. You can achieve the same effect by placing small mechanisms on a thrice folded, soft cotton flannel baby blanket while you work on them. I've dropped damn near microscopic watch screws onto such a surface and they seldom get more than a half-inch from where they fall. Choose an unpatterned baby blanket - white (for maximum visual contrast) is the best color. Avoid anything with a deep pile or the part will lose itself in the pile.
When my daughter's cheap desk chair broke, the five-arm base with rollers was still in fine shape and, hating to throw anything away, I thought about how I might use it in the shop.
I bought a 6' closet rod (one of those ~1 & 1/2" diameter wooden rods one uses to hang clothes in a closet), turned the end down (get an outboard support) to fit the chair base and mounted a crossbar to the top. The result looked for all the world like the sort of IV stand one sees in a hospital. I happened to have a circular piece of plywood left over from a cable spool. I cobbled up a clamp to grip the closet rod and support the plywood as a shelf at about 8 inches above waist height.
Ok, so now what do I do with this monstrosity? First I mounted two photo flood light lights in aluminum reflectors to the crossbar with the junction box and switch that controls them bolted to the shelf. Now, when I want to work under the hood of the car I roll the IV stand close to the radiator and can 'really' see what I'm doing. On the far outboard ends of the crossbar I mounted some hooks on chains so I can easily alter the hook height by slipping it into different chain links. I hang both my Dremel tools (one with flexible shaft, one not) from these hooks. When I need to use the Dremels, I wheel the IV stand next to my workbench and everything is close to hand.
Anyone with an ounce of ingenuity can probably think of other ways this idea can be adapted to their needs.
I wanted a depth gauge for setting the bit depth on my router. I didn't want to have to mess with a scale to measure the most common values - namely multiples of 1/16" - I wanted a tool that had all the most common measurements "built-in".
Take a piece of 1-1/2" diameter aluminum rod stock and machine it so it's 2-1/8" long. Bore it out to 1" ID. Now, on the mill, machine into the wall a series of eight, equi-angularly spaced flat-bottomed slots 3/8" wide and at depths of 1/8", 1/4", 3/8", ..., 1". The result will look like a crennelated castle tower built by a bunch of drunken masons - each crennelation is a different depth. Machine a slug of aluminum or whatever to 1" length and 1" OD - a nice sliding fit in the ID of the drunken castle tower. To one end of this slug, bolt a piece of 3/8 x 1/2 x 2-1/2" brass so that when the slug is dropped into the central hole of the tower, the brass arm can drop into each of the crenellations (slight trimming of the 3/8" dimension may be required to get a smooth fit). Now, it should be obvious that, with the base of the crenallated tower sitting on a flat surface (e.g., the router base), and the arm dropped into the 3/8" deep crenellation, the bottom of the arm will be 2-1/8" - 3/8" = 1-3/4" above the flat surface. A router bit run out to just touch the bottom of the arm will be projecting 1-3/4" beyond the bottom of the router base.
In the very tip of the bottom of the arm, cut an accurate 1/16" deep step. By measuring to this step you'll be able to get all the 1/16" steps between 1" and 2" of router bit projection.
Ok, you're as scared as I am at the idea of having the bit project over one inch (unless you're incrementally making a very deep cut). Drill the bottom of the brass arm to accept a (1/4" dia.) rod that's accurately machined to be 1" long. Now you've got all the 1/8" increments between zero and 2". Machine a 1/16" step into (half) the end of this auxiliary rod and you've got all the 1/16" steps from zero to 2".
A further refinement is to drill and tap the end of the arm so you can mount a threaded rod that's infinitely adjustable with a locknut (I used a 1/4-28 piece of brass rod). That allows you to "remember" an oft-used depth setting for future use.
Obviously, the tool will only be as accurate as your care in manufacturing it. Strive for perfection since, I think, once built, you'll find yourself using this more often than this description might suggest. You can engrave the body of the tower to suggest the measurements capable at that crenallation. I like mystifying my friends by using it with no visible markings.
Also, makes a great xmas gift for any woodworking friends. I haven't given this to anybody who hasn't come back with two friends in tow waving money in my face to build them one.
I had an odd-shaped workpiece that I wanted to bore on the lathe. It had to be clamped to the faceplate - wouldn't fit in the four jaw. I normally do a rough alignment by bringing the tailstock close to the work and use the tailstock center as a guide to roughly locate the work center on the spin axis of the lathe before switching over to a proper center-finder used with a DI. In this case, the tailstock was really in my way as I tried to juggle the workpiece and its four clamps against the pull of gravity.
So I tried something I'd thought of a while ago. I have a small laser pointer - the kind used to give the impression of importance in content-free management meetings. I moved the tailstock out of my way near the end of the ways and stuck the pointer (which fortunately has a cylindrical body) in the tailstock chuck. It's beam made a nice, obstruction-free reference point for the rough alignment - the reference mark is on the work, rather than 1/2" or so away and I don't risk scratching my hands on the sharp tailstock center.
It wasn't perfect, of course. I quickly discovered that the laser beam wasn't accurately aligned with the body of the pointer - not surprising since it's hardly marketed as a precision tool. The solution would be to machine a small "chuck" to hold the pointer, equipped with two triplets of alignment screws that would allow small adjustments of the laser beam angle relative to the reference surfaces of the chuck. A lot of these pointers have a normally-off push-button - adding a screw to the chuck to hold the button down when in use would be a good idea. The dimensions of the chuck should be such that the device can be gripped in the milling machine chuck, as well.
Commercial laser levels exist. They're ideal for projecting a height across some distance - a task once reserved for water hose levels. If the chuck had a flat that allowed it to be placed on the level or the surface on which the level sits, that would be nice too.
There are probably lots of other ways to exploit this idea. A laser pointer height gauge for work with recesses that can't be reached with the marker arm might be nice.
Doing a very accurate alignment of the beam to some reference on the chuck seems to be a tricky proposition. Offhand, I can't think of a good method that doesn't involve a lot of optics not likely to be found in the home shop. Maybe someone out there can think of a clever way and let me know.
Update 08/19/99: A recent article in Model Engineer suggested making a necked down fitting for the hole in the business end of the laser. Since the "spot" on mine was more of a "short line", I tried this. Made a short brass rod to fit under the (interchangeable) screw-on head, aligned by a shoulder that fits into the back of the head. Drilled most of the (0.3" long) rod out to 3/32" and then drilled the very tip with a #75 drill (surplus carbide circuit board drill - get some!). Now the spot is truly a "spot" of tiny dimensions. The rod is held in place by the screw-on head so it's removable, should I want to go back to the "as purchased" configuration. It's so much better than before, I'm motivated to make the alignment jig I mentioned above!
Update 03/12/00: Some folks on the Usenet news group rec.crafts.metalworking have toyed with the idea of using a laser pointer as an optical "lever" to maintain the alignment of the head on a mill-drill that doesn't have a knee. Attached to the head, the laser beam is bounced off a (first surface) mirror on the other side of the shop and back to the mill head. Note the spot location, raise/lower the head and then rotate it until the spot lines up again. I haven't tried it so can't speak to its utility but it's something to think about.
I needed a benchtop holder for my jeweler's screwdrivers. My first crude attempt involved drilling some holes in a block of wood. Trouble is, all the handles are identical and it wasn't easy to determine the size of the blade (or type - Phillips or slot) when they were all hidden in the holes.
I made a wooden revolver cylinder with (through) holes sized to accept the handles of the screwdrivers. I mounted this on a 1/8" steel rod threaded into a piece of scrap steel the same diameter as the revolver cylinder. The mounting is a loose fit so the cylinder can rotate. With the screwdrivers stuck into the holes in the cylinders the blade tips are exposed in the gap between the bottom of the cylinder and the base. Makes it real easy to select the one you want. I expect the same idea can be adapted to other small tools with similar handles.
I needed a lead hammer to seat stuff in the milling vise after tightening raises the part against the movable jaw. Since I make tiny parts, I often have the mill head lowered pretty far so there isn't much clearance under the chuck - a low-profile hammer was in order. I considered cannibalizing my lead brick (part of a radiation experiment in grad school - don't ask) but decided that the risks of melting lead were beyond my threshold of tolerance. At the local fishing supply store, I found what they referred to as a "rock cod" weight. About 1.5" long, it has a square cross section and one end is formed into a hemisphere perfect for a hammer head. I drilled it for a 0.375" steel rod, held in place by cross-drilling and pounding in a 0.125" steel roll pin. Put a file handle on the end of the steel rod and now I have the perfect "low-profile" lead hammer for seating stuff in the milling vise.
Another fishing related item. Outfits like Cabelas sell cheap, imported fly tying vises. Buy two of them. Clamp them to the edge of your workbench (you DID allow overhang for clamping things, didn't you?). They're perfect for holding really tiny parts for all sorts of operations. Just as a test, I secured two paperclips and butt-joint soldered them without a problem. The "collets" that came with mine are cheap enough to justify filing them to shape for one-off jobs. With a lathe, making special purpose collets from 0.5" diameter steel is a piece of cake.
I use an edge finder regularly on my full-size mill/drill for accurate locating. When I use my Unimat for fine work, I'm out of luck - the 1/4" chuck won't accept conventional 3/8" or 1/2" edge finders. It annoyed me until I read about using a ball bearing as an edge finder. I found a tiny one - 0.25" OD, 0.125" ID. Mounted it on a piece of scrap 0.125" drill rod. Stick it in the chuck and bring it up to the work slowly. When the outer race stops spinning, you're half the diameter of the outer race from the edge. It helps to put some layout dye on part of the outer race - makes it easier to detect when it stops spinning.