HOW TO POSITION HOLES ACCURATELY ON A MILL WITHOUT USING A DIGITAL READOUT, MARC LECUYER
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- Опубліковано 22 сер 2024
- This video looks at how to use the graduated collars on a milling machines lead screws to accurately position multiple holes on work parts on milling machines not equipped with a digital readout. I produce these shorter than usual videos to answer viewer questions about machining. As for all thatlazymachinist videos, this video is aimed at the novice machinist who wishes to develop proper basic work skills. MARC LECUYER, thatlazymachinist.com
9 years later and this video is still helping people new to machining! Just got a 1965 Bridgeport mill myself
I can't believe !!! a pen mark on the table solve all my problems.. thank you !!
Thanks Marc, I don't have a DRO on my 1964 Bridgeport yet, and this is very useful information for me!
Awesome, you are true master and a full of heart and brains dedicated teacher, a gold star for Canada and the human race. Thank you very much for making and posting this video, and ... of course, ...we want more from you.
another video that answers a specific question I had regarding an upcoming project, the building of a tool post grinder.
new, they are unrealistically expensive, whilst used versions retain their price levels all to well.
I already had a precision arbour, and a nos dumore motor with pulleys from ebay at less than the shipping cost offered a potential solution to my dilemma.
a good friend has a machine shop and has offered the use if his Bridgeport, but I was lost pondering how to locate the holes precisely as it has no dro.
and eureka!! thanks to you i am ignorant no longer... at least regarding that question....
thanks again for you shop and training videos. they are helping this late in life beginner immensely.
I am pretty new to machining and this was a great video. Thank you for explaining how to deal with backlash all without a DRO that so far, I can not afford!
Excellent video as always Marc, Although very helpful, it would have been nice to see a more complicated set-up like a 5 or 6 bolt pattern on a given PCD for a square or round flange. I think I could do it taking into consideration moving past your required gap and then winding back always keeping the same direction of movement for measurements. But would be nice to see and keep as a reference. Thank you.
Hi Bernie, here is a video that I produced some time ago about producing a 5 hole circle on the round column mill. I hope this helps, Marc ua-cam.com/video/SrS2VtDf7IE/v-deo.html
@@THATLAZYMACHINIST Thank you Marc, I am amazed you replied, good show. Bernie
Thanks Marc, very informative. Who doesn't a quicky anyway.
Always so well explained! I like the Legere Engineering poster in the background, I go there a lot!
Dear Marc, Nicely done. I'm sure you remember jig boring machines, using calibrated rods and inside micrometers that allowed even more accurate positioning of a table on a jig boring machine (those were the days). Meilleures salutations, mon ami.
first off: that a-hole bit was pretty darn funny :D
….great videos. glad i found thee, fellow canuck
Been learning about machining from videos like yours and I thank you for them. The question in my mind at the moment is how high relative to my own anatomy the bare table top should be mounted. Anyone? Everyone?
Thanks Marc, Love the quicke vids i can sneak them in while on lunch break
Good little quickie. I have no DRO so I'm wading in the "remember where you were?" quagmire. The grease pencil mark is an excellent idea for me and my memory (or what's left of it). Wish I could give thumbs up every time I watch one of your videos, but I can't. Here's a thumbs up in words.
You should always have your Y axis reference point against the solid jaw of the vice. That way, you don't have to turn your screw backwards, and that surface doesn't move, removing the necessity of re zeroing your Y for each part. Also, when you pick up an edge and resetting your dial, compensate for the radius of the tool by setting the dial back by that amount. That way, when you turn the dial to zero, you are right over the edge and you don't have to reset the dial a second time. By resetting your dial only once, you cut that source of error in half.
Thanks marc... nice explanation
Thanks man , really l got a lot of tips . l wish can come from Kuwait to get some practice lessons in ur class
Good explain. Very good. Thanks to teach us....
Digital readouts and calculators, take them away and watch the young'uns run around like lost puppies. I don't have alot of gray hair in teh machinist trade, but i did at least learn to count manually before I got readouts.
Really enjoying your videos, even with some experience it's always good to pick up some new stuff.
Great video Marc! Thanks for sharing!
Nicely explained but I am damn glad I splashed out on a DRO, all I have do now is save up to put some on the lathe too.
ATB
chris
I agree, readouts are very handy. At the beginning of my career readouts were not that popular (very expensive in the seventies) so the graduated collar technique is second nature for me. That being said I still prefer the readout. Marc L'Ecuyer
Happy 2019, Marc.
Very informative. Thanks
I am enjoying all your videos,very informative, i am pretty much a novice i try ,i make mistakes but im learning,
i wonder if you could explain in easy terms how to measure & machine dovetails on the vertical mill? many thanks, Garry.
Hi Garry, that would make a great little quickie. Do you need both male & female and is the dovetail 60°? Marc
Hi Marc, if you could explain both male&female, the dovetail is 60deg.
Thanks Garry.
thank you Marc !!!!
thank you that is very helpful :)
Would it be beneficial to lock the table each time after positioning before drilling. I. E. to reduce the risk of accidentally bumping the table out of position because of the backlash?
an edge finder helps...
Marc, apologies if I keep having questions lately. One thing I was wondering, if you drill Hole A, and then movie directly to Hole C, will you get some "cumulative error"? For example, I know the machine is probably pretty accurate (I am not familiar with how accurate it truly is, up to .0005?), but if you are slightly off on the first hole, then that Hole C really is being moved to from Hole A's reference, isn't it? So you can accumulate error if say, you had 10 holes. Is there any situation you would have to start to account for cumulative error (I think it may be called progressive error in machining?), or is that mostly dependent on the tolerances in the part specification?
Each hole will have error, the best way to avoid accumulating it is to refer back to the original zero. When I move from one hole to the other I do not reset my zero, I use the zero I set at the start. Lets say I had a first hole at .375 in x and a second hole at .500 in x. I would set my zero on the reference surface then move .375 and drill my first hole. Then I would count from there, I was at .375 so next zero on the collar will be .400 and the next one after that will be .500 . If however I reset my collar to zero after the first hole (.375) and then counted .125 I would also be at .5 but I would have doubled my chance of error. I hope this helps, Marc
ok, I understand now. Even though after Hole A, you continued from that point on and added to get to Hole C, you were still referencing the same zero point. I mistakenly was thinking you were referencing Hole A in some way to get to Hole C, but actually you were referencing Hole A's current position, which was already based off the original zero. Ok, that makes sense. Thank you for responding.
Hello again, one thing that should be mentioned is that some times the tolerance that separates two holes is important. If hole A is positioned from the edge of the part with a tolerance of +- 0.005" and hole B is positioned from hole A with a tolerance of +- 0.002" it is necessary to indicate (find hole A's actual center) the completed hole A and set its position as zero and then move from there to produce hole B. That way the positioning tolerance of hole A does not affect the tolerance of hole B. An example of this type of dimensioning can be seen on holes of the vice jaws of the machinist vice project. You can download all my project drawings for free from the first page (big red button) of my website THATLAZYMACHINIST.COM
That is a great point on relative positions, Marc. Thank you very much from someone who's both lazy AND very amateur as a machinist.
I was wondering about the Kennedy clip at the ends of your videos, until I happened to stop this one at 13:18. I'm assuming that's your father since it was at least 50 years ago. Geez you look alike!
Hi Rex, many speeches have had a great influence in my life but three in particular: I have a dream (King), ask not (kennedy) and we will never surrender (Churchill). The Kennedy speech was the easiest one to put myself into because there was an empty seat next to J.F.K. (his seat). As I have said, I do this for fun and this video modification is a tip of my hat to these great men. Marc L'Ecuyer
looks like you were using a center drill- did you go back with a regular drill to do a thru hole?
Hi! No I didn't, it wasn't a useful part, really just an excuse for the demonstration. Thanks for watching and for taking the time to write, Marc
why can't you just backup if you go past 0? oh... to compensate for play?
Ooops!
Complete and total waste of time
Did it ever occur to you that maybe the fella who asked the question was smart enough to realize that
THE DIALS ARE GRADUATED?And perhaps he was asking how to compensate for backlash - thus the word in his question - ACCURATELY?
U could have condensed this video down to the amount of time it takes to say "use the dials' graduations"
Hi Becky! Thanks for a great comment, it is good that you helps us focus on the fact that the dials are graduated. Thanks for watching and for taking the time to write, Marc.