We take a look at many different ways to edge find accurately on the milling machine. Some ways are better than others and have both advantages and disadvantages.
I’m a retired tool and mold maker of 40 plus years. I’ve got to say that the paper methods with a live spindle would get you a written warning at the shop I started in. We did however occasionally use a feeler gage and manually turned spindle to get a touch. The only other thing I take exception with is your edge finding the moving jaw side. I’ve always been trained and passed on that in most circumstances you edge find the fixed jaw side. I also prefer to use the edge finder in a collet,i find it’s more accurate. To find the center of a diameter you should edge find in one direction then the other and repeat it as you will not be spot on with the first try. Happy machining!
In the 60's when I started, we put a 1/2 dowel in the spinning chuck. Coated it with the good old "red grease pencil" ( the kind where you pull the string to access more tip. Kept in shirt pocket right next to 6" scale). You slowly touch side of part with spinning dowel. When red wax appears on surface, you're 1/4" away from edge of workpiece.
I teach the paper trick with my new students, who are totally green, BUT i use a bit of spit and stick a postage sized piece to the jaw. Plus I hand spin the cutter with it in nuetral. Personally I run the cutter but thats not a good idea with first timers. The accuracy could be questioned versus more sophisticated special tools but they may not always be available wheras paper is always there. Great video, going to let the students watch it next lesson to show all the other ways you used.
I’ve recently started learning my way around a mill. I’ve used a lathe for a while and have some decent basic skills there. I got a 3 piece edge finder with my mill and have never seen anyone use it like you just did. With no one to mentor me, that was a huge ‘Ah-Ha!’ moment for me. Thanks for sharing that - you just got another subscriber!!
For paper touch off, use a Zig-Zag with a little oil to hold it in place. Works like a champ. The Zig-Zags in the white pack are 0.001" thick quite consistently.
My quick go-to way is to chuck up a centre drill or other short true-running shank and advance it to the edge until I can no longer see light between it. The change is sudden. The paper method I was taught was wet a bit of newspaper and stick it on, wait for the mill to grab it.
For many years I just used a 1/4" piece of silver steel in a drill chuck.....OK so it probably will not be that accurate but good enough and quick for most work.
When I'm in a hurry, I mount a center drill in the chuck, and dial the Y until I'm pretty sure I'm close to the center. Then start the mill, and sneak feed down the Z until I barely touch the work, then move the Y back and forth until the center drill mills a short line on the part. Then I can move to the center of that milled line.
Some random comments for newer folks: The paper techniques with the spindle running are highly discouraged (in many workplaces banned) because the risk far outweigh any benefits; if they even exist. For anyone learning do yourself a favor and turn the spindle OFF. If you have no access to proper XY location tools: use a marker/dykem and rotate the tool by hand grabbing the tool holder. Move in slowly and stop when you just scratch the paint. Make diameter adjustments as needed and wipe/scotchbrite the paint off as required. For the Z-axis set the tool slightly lower than a reference object (gauge block/pin, 123 block, dowel pin, etc) and raise the Z-slowly until the reference object slides completely under; zero Z and adjust for reference object. Both techniques can get within tenths without the risks... Also regarding electronic edgefinders: operation with the spindle off may affect accuracy by way of runout. If your electronic edgefinder does not support spindle on operation, rotate it by hand (please consult each tools manual for proper operation and rpm limitations).
That is a good tip John. I will remember this. My go to thing I use alot for finding the side edge is I took a 1/2" piece of ground drill rod that I milled off exactly .250. then I move it slowly into the work piece until I feel no wobble. It's been good enough for keyways.👍
One thing I like doing for small to medium shafts. Is to use the pointed end of the edge finder. Be sure the quill thumb wheels are locked. Do both side and divide by 2. Also, rather than using thick paper and fingers near rotating cutters. Lick and stick cigarette paper to your work piece. For the top of flat work piece when doing light cuts. Extend quill until cutter touches workpiece, lock quill. Drop table .001 or .002. Or cigarette paper. Black Markers are you friend.
For round stock balance a small ruler using fingers on the top and gently feed down a small bit in a collet until it touches the ruler. The ruler will tip in the direction towards which the bed has to be moved to find centre. Once bang on the ruler will be level. This can be very accurate.
They make an edge finder where the end piece is 0.5" instead of 0.2" so it can find the edge of any diameter rod (just remember to subtract 0.25 and not 0.1)
Yes thank you . that would be a more robust tool for sure , but i am but a simple man lol . The .100 leaves less for me to mess up when it comes to math
Look in the scheme of most jobs. Touching the side or top of the job with endmill is fine. Worked as a maintenance fitter machinist in a toolroom with 8 toolmakers and most just touched the side of job with endmill. I guess experience and a fine touch helps. Note: most jobs
@@Wrighmachining Place the paper between the dowel pin (dowel pin is not spinning) and the workpiece surface (side or top) and slowly advance the workpiece while moving the paper side to side until the paper is gripped between the dowel pin and the workpiece. Subtract 0.25 plus the thickness of the paper.
@@philcook9967 yes in a colit ! I can see how that would work . Thank you i will try that perhaps with a small conecting rod ( new ) that is .500 im sure of it .
Mention should be made of how true the drill chuck holds the edge finder and how square the head is set up as the latter will affect ctr at different positions of quill
Great question, I looked up its official name on Amazon and it's listed as this Fowler 52-577-100 Center Finder with Satin Chrome Finish, 0.375" Mounting Shank 10
@@Wrighmachining If run at the recommended speed of 1000 it will off center itself from vibration and centrifugal force. Besides , you can easily see when it is within .050" or better even without the wobble. I use them so much, that that extra step which has no function would drive me nuts. It's fine if you like to do it but I'd say it is not right to show it as if it needs to be done, for the nubies sakes.
You never showed a dial gauge to find centre for a hole or shaft or bar stock. Without a dro I set the dial gauge minus .100 thou for a .200 thou edge finder (wobbler in the uk) Then advance the .100 thou and you are ready to pitch off.. Started my apprenticeship in 1977
@@Wrighmachining It is a point of what the toolmakers taught me. We used cigarette paper in a pocket operation so would blow the pocket dry tear a piece off damp it and when it picked up you were .002" from the work.
Good informative video, but check your audio. There is a low frequency hum that keeps coming in when your doing things. It’s real annoying on headphones or ear buds.