I posted these in the accessories forum,but they'd be better seen here. KEEP CHECKING this long list. I'm adding to it as I remember useful stuff that might not be common knowledge,or easily found in books. These are to be used at your OWN DISCRETION. I cannot be responsible if you have an accident!! If you must hold and end mill in a 3 jaw lathe chuck (not the best idea,but I used to have to do it),it can slip out when cutting. Wrap a piece of brown paper bag around the shank of the end mill,just 1 thickness. Brown paper bag has no clay(which is your enemy). Let the ends of the paper meet between the jaws. Non clay paper will hold like crazy. I use non clay paper in my SMOOTH jawed milling vise to hold slippery metals like brass or aluminum. It never slips,provided you clamp the part with decent force. To check drill bits for straightness when buying them at the local store,place them on the counter and roll them back and forth under your finger tip. Look for wobble on the ends of the drill. Even good,USA made drills can be curved. If your drill ,especially larger size ones,leave scratches in the hole,the drill is curved. You can partially remedy this by grinding rounded edges on the lips of the drill,but if too bent,the drill will still leave scratched spirals in the hole. To start a drill in the lathe without first drilling a hole with a center drill(which is the best thing to do), with the cross slide,bring the blunt end of a lathe tool up to the drill carefully. If the drill starts with a wobble as they most always will,carefully advance the blunt end against the drill until it drills into the metal without wobbling. Remove the blunt end when the drill is seated into the hole. Be careful to not push the drill past center. I have heard that some Chinese drill sets are only hardened in the common fractional sizes such as 1/8".3/16".1/4",etc.. They think that most users just use these common sizes,so beware. I only use USA drills. They aren't that expensive unless you buy the premium brands like Cleveland. You can more accurately sharpen small drill bits by hand,using a hand held stone. I used to sharpen #80 drills like this,using 4X drugstore reading glasses: Hold the stone vertically in your good hand(I'm a lefty). Present the drill to the stone,carefully mating its angle to the stone. Move the stone(a fine India is good) straight up and down,while rolling the drill to also grind the relief angle which you mustn't lose. Rotate the drill 180º and repeat. This is more controllable than using a bench grinder as it is slower and less likely to ruin your drill point. One day on a Sunday,I was drilling a LOT of #80 holes,and the bit kept breaking. I stoned the bit to a flat end using a pin vise to hold it,and re sharpened it about 5 times that day since I needed it THEN. If you have a tool post grinder,you can accurately sharpen up large drill bots that are really screwed up: Chuck the drill in your lathe,and set the compound to the angle you wish to grind the drill's tip to. Turn the lathe on in reverse. Grind the tip until the tool post grounder has fully ground the CUTTING EDGES of your drill. The rest of the tip doesn't matter. Remove the drill,and with an India stone,or a bench grinder,carefully relieve the drill's cutting edges to very near the cutting edge itself. USE the hand held stone,and carefully continue to home the same relief angle on both sides(takes a little skill,yes). Hone until you reach clear to and including the cutting edges. A correctly ground drill will throw equal chips on each side. I have done this on 1 1/2" drills and have drilled cannon out 2 feet deep quite accurately after reconditioning the drill this way. Repeat: properly sharpened drills throw equal chips on each side. When using Dykem blue lacquer,carefully wipe the surface WITH ACETONE before applying it. If there's any oil on the metal,your Dykem will tear when you try to scribe it. Do NOT lean on your smaller size lathe when using it. It can cause the lathe to deflect enough to mar the surface finish noticeably. I don't even lean on my 16" lathe. Before you try to level your lathe,put a new,sharp center in both the spindle and the tailstock. Better yet,TURN a center in situ from a bar of steel in the chuck and leave it there. Bring them together,point to point. Look straight down on them with a magnifying loupe,about 10X is fine. Adjust the tailstock sideways till it's center is perfectly in line with the spindle center. If you level the lathe well,it should turn a true cylinder. If the tailstock is out,you will not get a true cylinder,and it is wrong to keep adjusting or twisting the bed to get the lathe to turn true. While you have the centers nose to nose,look at them sideways,too,to make sure the tailstock is the same height. If it's not,you will need to place shims between the top casting and it's base(hopefully you have a 2 piece tailstock.) After you do this,run an indicator along the top of the tailstock spindle(incorrectly called the ram,often) and make sure it's parallel. On old lathes,the tail stock spindle will often point down hill. It is also useful to check the spindle from the side. I had a NEW lathe that had a spindle which wasn't parallel in either direction. It had to be scraped in true. It is common to have a tailstock that is a few thou. too high,but the tailstock needs to be parallel to the bed in all directions. Most new Asian lathes have headstocks that can be swiveled a bit. The larger ones,like 10" swing and larger,have headstocks that rest on precision ground flat areas,rather than on the V ways. They have bolts that can be loosened to adjust the headstock. Often there are 2 bolts behind the headstock that you can use to make small adjustments. Take a light cut across the face plate. Adjust the headstock till it faces flat,and ALSO turns a true cylinder. MOST lathes,when adjusted to turn a true cylinder from a bar of steel not supported by the tailstock,will face about 1 1/2 thou. hollow,which is within gov't. specs,so that flanges turned will not rock against each other. Luckily,my 16" Taiwan lathe turns both cylinders and facing cuts true. That's only luck,though. If your gear head lathe creates harmonic "waves" when you're turning bar stock,place oak blocks under the feet if the lathe sets on concrete. This magically stopped my new 16" lathe from making these harmonic vibes. I discovered it accidentally when leveling it. More expensive gear head lathes likely don't do this,but my 16" Grizzly did!! Three flute end mills are a PITA to measure,especially re grinds,unless you have a special mike with a Vee anvil for checking such. I avoid them,and only buy 2 or 4 flute cutters. NEVER,EVER maker a brass bushing to hold an end mill in an oversize holder with. The end mill will suck out of the brass bushing with even moderate cutting. I found this out over 45 years ago when I was a newbie. You can ruin a project and possibly break the end mill. Use only steel for such bushings,and MAKE SURE there is no oil on the end mill or in the bushing. You can see .0001" (a tenth of a thou.) of light between a surface and the blade of a square. Tilt the work and check it against a light source. When you are trying to carve or sculpt an accurate curved or flat surface on ,say,a model airplane,or other object,darken the room and look at a low angle at light from a distant window across the surface to see bumps or dips. I did this all the time when making violins. I taught this trick to a company making wind tunnel models of aircraft in Hampton,Va. Some of their models were sculpted of solid wood. They were glad to get this tip. Even very small bumps or hollows are easily seen in this type light. Edit: They used to drill holes in armor plate in the 19th. C.,with carbon steel drill bits using soapy water as a lubricant. Still perfectly good,but don't leave it on your machines! NEVER,EVER slide your tailstock dry on your lathe. The bed may be hardened,but the tailstock and the carriage are not. Squirt some oil just in front of the tailstock before sliding it if you want to keep it parallel to the ways. Lube the carriage,too. If your carriage has an open back side,be sure to lubricate it,too. Asian lathes and mills seem to make everything from cast iron,even when they should be steel. These axles that gears turn on can and will break off if not oiled. Use WAY oil if you can buy it in less than 5 gallon cans. I go in with a friend to divide a 5 gallon bucket of way oil. It is stickier and tackier than regular oil. If you must use normal automotive oil,use NON DETERGENT OIL ONLY. 30 weight is o.k.. If you use motor oil on your lathe,use NON DETERGENT. Better,use the maker's recommended oils. In the headstock of a gear head lathe,HYDRAULIC OIL is best. You can effectively made a good reamer in an emergency out of drill rod,preferably 01(warps less than W1.)Polish the drill rod after turning it to just over the desired dia . Grind a longish FLAT angle on the front end of the reamer-to-be,about 30º is plenty. Turn down the shank,leaving,say,1"or less bearing surface on the side of a 1" reamer. Too much bearing surface will generate friction that can seize up the reamer. Harden the reamer. It will ream a hole drilled just previously drilled undersized beautifully. This is a reamer used in the 18th. and 19th.C.,and they still work just fine,but run the lathe SLOW. Carbon steel will not stand higher speeds. That's why HSS was invented. DON'T reverse the lathe when backing out this type of reamer(or any other reamer,either). It can break hunks of hardened steel off their cutting edges. I make MANY,MANY special form cutting lathe and milling cutters from 01 or W1 annealed steel. I've made dozens of wire drawing dies for drawing special shaped "wire" for making silver and gold bracelets the museum sells,etc. using these tools. I made ALL the wire dies for the bracelets they sell in Colonial Williamsburg,and many special molded shape wires for the PGA trophies. Carbon steel works just fine. It needs to be run SLOWLY,though. I do not recommend the CUTTERS for production,of course,but for 1 off or small runs,they work just fine. Dies last a long time for silver,gold,copper,etc.. Harden them,and draw them to a light brown. You can make perfectly good special taps from 01 or W1 steel,too. Turn your thread on the drill rod,and grind the cutting end to SQUARE or TRIANGULAR. The leading edges are ground or filed to just below the thread depth. Grind the angle at about 30º. You can grind the angle shorter after tapping if you need a bottoming tap for a few holes. Harden them and draw to purple(just before blue). They will tap steel quite well. Another centuries old type of tool that still worked fine. They made taps this way in the 18th. C. commercially. No reason they will not work today for special use. I make missing parts for mechanical antiques which often have non standard or special shaped threads,many left handed. These taps work like magic for limited use. I even make Acme taps like this. You do have to know what you are doing to tap acme threads,though!! The commercial sets should come in sets of 3 to allow progressively deeper cutting. For bronze,you will be o.k. with one. Some taps have all 3 sets ground in one. To drill brass,sheet metal,or plexiglas without the drill grabbing,or cracking the plastic when coming through the exit end of the hole,grind or,if the bit is small,hone vertical cutting surfaces on the lips of the drill. Brass is treacherous to drill. I got a block of brass sucked right up out of a smooth jawed vise when the drill broke through. I thought the vise would hold it!! The brass cut my finger pretty badly. It took 10 years to get the feeling back into the end if the finger. Plexiglas is easy to destroy when the bit breaks through. Simply grinding the cutting edges vertical will eliminate this,and the drill seems to drill just as easily when in a machine. I have some old brass drills. They look like spiral drills that were never twisted. Sort of like the old blue drills that came in the handles of eggbeater drills,except these are HSS.bright,and in larger sizes. Too bad you can't buy them anymore. The vertically ground ends of drills are also needed for SHEET METAL,which is treacherous stuff to drill. A vertically ground drill tip will not grab the sheet metal and spin it around when it breaks through. CLAMP SHEET METAL OR PLASTIC DOWN anyway when drilling. The correct type of center drill to use for turning tapers has a shape that looks like a bugle seen from the side,rather than straight angles. This drills a hole that will stay 100% in contact with the tailstock center when work is presented at an angle to it,rather than the 2 point contact that you normally get from the regular configuration of center drill. To saw thick foam rubber in a WOOD cutting bandsaw,if you don't have a special blade,try putting a SHARP blade on UPSIDE DOWN. This helps keep the blade from grabbing and sucking the foam down the throat plate. I mean a wood cutting blade with 4 to 6 teeth per inch,not a hacksaw blade type metal cutting blade. To drill a NEAT hole in foam rubber,make a drill out of pipe. Grind the end of the pipe sharp like a leather punch. Add a shank to it so it cuts through the foam rather than making a mess trying to drill it. This trick stumped a company in Norfolk tears ago when they needed to neatly drill 4" foam rubber. They were glad to get the tip. When I am making a cannon,and need a very neat hole that doesn't have to be an accurate size,just somewhat larger than the ball is to be,I have a bunch of old drills that have had long shanks welded onto them sometime in their past. I have made some of these drills(which I only use for drilling cannon) drill amazingly smooth,reamed looking holes,by chucking their shanks in the lathe,and taking a light,kissing grind down their flutes while they rotate backwards in the lathe. Use a tool post grinder for doing this. This makes a perfectly straight,perfectly aligned drill that leaves a very smooth hole. The chuck I've done these in is an 8" Bison that had only .001" runout. Any off centered welding has been eliminated by doing this. Fortunately,the drills I've done this to were quite accurately welded onto the shank,and just a little grinding was needed. I have made holes that look like automobile engine cylinders like this,believe it or not. Scoring and scratching in holes is due to drills not quite being straight. Before I ground the edges of the drill,I had previously ground the ends with the tool post grinder and relieved them as described above. If you are using a gas furnace for melting metal,the type furnace where you have to pull the crucible straight up to remove it,before you light it up,place a piece of brown paper beneath the crucible. The paper is large enough to extend beyond all edges of the crucible. The paper will burn up,but it leaves a layer of carbon that will keep the crucible from getting stuck when you try to pull it out. Freeing a stuck crucible full of molten metal is very dangerous. You don't want to break the crucible or get splashed when it gets freed. Run your tool post grinder for 1/2 hour before you use it to grind surfaces that you want as perfect as possible. This is recommended by Themac(one of the best tool post grinders made. I love mine). This gives time for the bearings to get warmed up so their desired tolerances are reached. This is only a tiny amount of difference in the tolerances,but t makes a big difference in the performance of the grinder. You can see imperfections only 1/250 thousandths deep in a smooth surface. Therefore,you need to get those bearings properly warmed up,even if it is an inconvenience. In case I have not mentioned it,to use a steady rest without marring a smooth surface,such as a finished rifle barrel,use cardboard. I mean the gray cardboard that is about 1/32" thick from the back of a writing tablet. Cut a strip long enough to go around your workpiece,and have 3 or 4 inches left over. Open the steady rest. Wrap the cardboard ONCE around the piece. Bring the 2 loose ends to the hinge point of the steady. Pull it snug and clamp the ends of the cardboard in the hinge of the steady rest,screwing it down firmly. Adjust the fingers of the steady to touch the cardboard firmly,but not too tightly. Oil the cardboard WELL with fairly heavy NON detergent motor oil. KEEP the number of revolutions you must make to accomplish the work to an absolute minimum. Do not let the lathe run idly. Turn it on,make your cut efficiently and turn it off asap. More tips will follow as I recall them. P.S. just edited Nov. 15,2013.