"I Know this seems like it takes alot of time but it's much more better to spend the time and not screw up the part..." Very nice explanation, Peter, when the tolerance is that close, we avoid alot of headaches doing as you teach on yours videos.
When finishing I have great luck taking my first finish pass, and then taking a spring cut immediately before adjusting for my remaining cuts. At least for me it seems to eliminate a lot of fluctuations in sizes when creeping up to finish size. Great video
Great video, dude. When I first learned to run CNC machines, they started me out with boring gear bores on steering housings. We had one bore that had a close tolerance of +/- .0005" and when I had to change the insert, this was the exact method they taught me. I found myself following the exact train of thought as you down to the adjustments and everything. It's really validating to know that I had a good teacher and see the same thing done in other shops even on completely different materials and parts.
What a lot of people don't understand is boring bar/tool deflection. On extreme stick out boring bar (10x stick out vs boring bar diameter) i had deflection change size ranging anywhere from 0.5 to 1 mm. It's a very extreme example but it showcases that depth of cut adds more pressure on tooling so it will cut a lower size than what you specified. On the other side of the spectrum taking too small of a cut can rub material and quite often take more material than what you specified (0.01 mm taking 0.03 mm easily). Speeds, feeds, depth of cut, material, CNC repeatability, clamping method etc all play a factor which is why for tight tolerance work Sandvik recommends the 3 pass finish method which Peter demonstrates in this video.
Whenever I come across a machining operation that's new or challenging, your channel is one of the first places I turn to for insight. Videos like this one have helped me navigate many of the complexities of my career in the industry. Thank you for being such a reliable resource! Your willingness to share your expertise with us through the years is something I value and appreciate.
Good evening, and thanks for your reply. I agree that you can’t just drill and ream but, if you drill, bore and then ream it seems to me to be easier. However, every machinist has their own rational justification like every Doctor treats patients differently. I enjoy your video’s and you are very talented. Thanks again for the response.
I really liked the explanation on the programming side of things - I use GOTOs every once in a while, but I've never thought of using it to loop and repeat something. Very cool!
Thanks for this Peter, it's very useful to follow your thought processes, as always. I try to do the last three or four cuts on bores with critical dimensions using an identical DOC, at about a third of the nose radius of the tool. I try not to take spring cuts, to avoid the risk of resonance chatter in deep holes without the tool being properly engaged. Useful tip about backing the adjustment off a long way before setting it each time, and keeping a consistent torque on the locking setscrew. I'm tempted to use my little adjustable torque driver, so the tension is identical each time. Your videos have been a big influence on how I approach my very manual, very amateur machining projects. Keep up the great work.
I purchased the itsbore kit solely because your videos, I see your work and can tell your level of thought that goes into tooling and just trust your opinion man and it has worked beautifuly for everything I needed
I need to be careful to say Amazing, because I know you don't like to be seen that way. But what is Amazing ? Is your never ending devotion to posting so many videos. Just for the sake of helping others. I am always a little concerned that all this time you spend on RU-vid is keeping you away from other things in your life you enjoy doing. Boring Heads, are a must for machining parts accurately. Sneaking up on the finished size is definitely the way to go. But many rush this part of the job because they are concerned about using too much time to get the job finished. Only to run oversize and completely wreck the part and usually their day as well. Big Thumbs Up, to your continued enjoyment of posting videos here on RU-vid. 👍
Great video. I frequently have to work diameters to that tolerance but not with such a complex part. But I do the same thing when it can't be scrapped. It's best to take the time and make it right.
Currently running bore +.0005 -0.0, what I like to do is set two boring bars. Semi finish and a finish one. And leave only .002 for the final cut which is pretty consistent all the time.
@12:54 you nailed it, take the same cut, keeps the same depth of cut on the tool so the system will distort the same amount allowing you to predict the final pass
The comments seem geared to CNC machines. What I saw was a process to achieve an accurate bore. This method is the same as a non-CNC machine. When I ran DeVlieg we had to fit bearings in our parts. Short bores with extremely tight tolerance. We had to sneak up on the final size like you did in the video. The difficult part is consistency in every adjustment, tighten the head to tight and you lose size. Luckily for use, if we cut oversize we could plug or use other methods to correct the problem. Your videos remind me of the struggles we went through in the machine tool industry that the person on the street cannot fathom.
In the past I’ve used Komet boring bars to bore a rocker arm bearing to 1.375/1.376. Used the G85 boring cycle also and it would hold .0002 all day. Stock was about .005 to .008. Also did the same for the bearing bore both in ductile iron and 4140 steel. But I don’t blame you for being cautious with those high dollar parts. We tried using boring bars that were offset like the one your using and found they didn’t hold in a production setting. We had to buy boring bars that spun on center and only the cartridge would move.
I couldn't agree more on the N#'s! I have my HAAS post set up exactly like you do there. One N# corresponding to the tool number immediately after each tool-change. I wish I could turn them off in my BROTHER machines. But, I have not been able to figure out how yet. Great video as always Peter! Thanks for sharing! -Bill
Do you make the programs at your brother machines? That should be the function of the cam software's post. If you want to strip the N sequence numbers you could export the program from the machine, to a editor and use that to strip out the N sequence numbers. If the size of the program is to large this will save on the memory required in the control.
@@EdgePrecision Yes, I use FeatureCAM. I can post the code without N-numbers just fine. The Brother control (C-00) ads them when the .nc file is imported. I don't think it is possible to defeat this function either.
My goodness man. I may do something like that in the cooperate shop I work at. But I have worked in fast paced job shops, that do that on the lowest bid.... Such a nightmare... And the minute they sent me jobs like that while riding my ass to go faster, I left for more pay and less pressure.
This is quite helpful, a systematic way of approaching the final dimension. This actually seems more accurate than taking a spring cut in between tool adjustments. What are your thoughts on making spring passes before adjusting. For our work, we don't usually have production type operations. We do much more one part only prototyping projects. Sometimes two or three but usually only one part. So a lot of times we don't have the opportunity to get that much experience with a hole. Sometimes we will use scrap material and practice and that sure does reduce the pucker factor. Thank you so much for this video....very helpful.
I have done spring passes in other materials. You increase your chances of getting chatter in the finish with spring passes. I usually only do them on the last pass if necessary. Usually in tougher materials like titanium or heat treated materials. Also I would not do a boring cycle that fed back out in tougher materials. A bore orient cycle G76 would be better.
I have no CNC experience whatsoever but this would be my approach too in my conventional world. The reversing with a boring head is a tricky n can screw a person around, especially considering that you're working with a rather long boring bar so tool pushback is definitely something to remember. I would go through the hole, stop spindle, back off on the boring head, withdraw from the bore to be extra careful but in softer materials not always necessary. Taking those few minutes extra is always worth it, scrapping is wasting.
It's so weird to see someone who has the same thought process as I do about things. Like purposely developing a process and never changing it once it's proven . I do this with alot of things, even changing tools or doing setups, or flipping inserts every thing has to be done the same way to keep track to notice flaws and deviations and things that don't conform to the standard.
Sandvik are gonna bit a bit pissed Peter, Capto, not accurate enough?. LOL. I agree that repeatability is not guaranteed, but its the real world variability that we all have to deal with, and I concur with your process. Best wishes , Mal.
Yes I find it helpful, it is good reminder for me, thank you for the video, I see your GOPRO coolant proof case in video is that the same one you made like 3 years ago?
Thank you, Peter! Your videos are ALWAYS appreciated! :) Btw, still waiting to see something on the force applied by your custom toe clamps....... no pressure, just waiting.
@@EdgePrecision Thank you! You should make those toe clamps to sell. You'd probably sell them faster than you could make 'em! I think they'd be a huge money maker...... :)
@@EdgePrecision You mentioned in the video that coolant would puddle up making it messy to measure a part. Then you mentioned possibly having an angle or radius for the coolant to run off. I just meant you could fab up some blocks that have recessed pockets underneath for magnets to be glued in or pressed. That way they can easily be used in that situation.
I’m sure it’s an optical illusion (probably just for me)… but, the spindle seems to be running the wrong direction. Great procedure and nicely instructed video
Hello, Piter. Thanks for video! Надеюсь, что Гугл переводчик переведёт правильно) Мне кажется, что для такого большого количества деталей, эти отверстия целесообразно делать развёрткой. В качестве охлаждения - лучше использовать керосин + масло. Конечно перед этим нужно развёртку доработать до нужного допуска. И испытать на болванке. Если это амортизаторы от военного самолёта, то там 100% допуски завышены. Военые люди любят так поступать)))) Стаким подходом как ты делаешь эти амортизаторы можно в космос запускать))))
По поводу цикличности отдельных блоков в программе - удобно. Ну и с выбором метода выхода в координаты путём выборки люфтов твоего станка тоже всё понял. Спасибо
A question please. How do you anticipate the customer will measure the entire parts for QC? Will it be soley with a CMM, or will there also be manually taken measurements of certain features as well? Just curious as I've never been involved in such high dollar parts. Do you ever find yourself second guessing the necessity of some of those tolerances on the prints your receive? You don't have to comment on that, but I sure find myself often thinking such things. Thanks as always for sharing your knowledge and journey!
They will use whatever is necessary to get the dimensions. I think on these parts they will use a Romer arm for the overall dimensions. And a bore gauge like I show in this video for these bores. And various other gauges for the threads.
Lets say the material isnt aluminium but something harder that requires a good surface finish. Taking so small DOCs I would think hitting a good surface finish will be extremely complicated. I think my worst tolerances has been +- 0.0004" (or 0.01mm). It would be stressful having to deal with tolerances like yours Peter. Not only that, but your part is also quite complicated to begin with. Thank you for showing us your way =)
Lol. I saw 0.01 mm or 10 micron tolerance on a bore. With clapped out 2axis lathe, spindle and just using carbide boring bar. And i think we clamped on raw stock. Cherry on top? 0.01 mm Mitutoyo 3 point micrometer with like 5-10 micron repeatability or even more depending on how strong you ratcheted. And the lathe couldn't even properly repeat the parts without ruining surface finish with awful scraping (sometimes the chips just got in there). Plus we had to add like 20-30 microns of taper for the G1 move itself... All in all 8 micron tolerance sounds crazy but on Peter's machine, spindle, tool holding, tool itself, clamp rigidity, proper measuring instruments etc just make the job 1000 easier imo.
Are you referring to the / GOTO line? If so, in a G code program. When you have a / (forward slash) at the beginning of a line. There is a button on all controls called either Block Skip or Block Delete (or it can be a switch on some Fanuc controls) (Or labeled /BDT on Toyoda)(Or a soft key like I showed in this video). Anyway whenever this button, key or switch is on in the memory/auto mode, the control will skip any line with a / as it's first character in a line/block (Hence the name block delete). Now as I showed in the video my Mazak has nine soft keys for block skip (They call them). Each with a number. So if the / is followed by a number (No space), it will only work with the soft key of that number. This is especially useful if you have different block skips in a row going to different N sequence locations in the program. So the line would look like this /1 GOTO4; (next line or block) /2 GOTO5; So with the Block skip #1 key enabled the program would skip that line and go to N5. With both both keys #1 and #2 enabled it would just continue reading down the program. You can see how you could use this to do many things in a program. For instance you could specify witch sub programs to go to and run would be one thing. Or to start or skip specific areas in a program.
Peter you are amazing! I willl look you up next time I am in Mexixo. I would Love to meet you and my pinoy wife. She has. O friends from homein Oz. . She may know why. Regards and good luck Phil
What you said at 2:15 is exactly what I do for these small parts I make hundreds of that are +.0003 Minus nothin. But I’m givin setup material. Also, I run mazak mills at work, I hate mazaks mazatrol so damn much😂but they’re more good machines
I have my program structure very similar to you. I hate N numbers on every line. The only time I do that is if I'm roughing a large part that I may need to change an insert mid cycle so I can do a program restart on the line I need to go back to.
Looking at the program unless I’m blind you rapid to the start position not feed. On several of my Fanuc machines there are different tolerance parameters in the background for each. For precision like this you should rapid and then run a G1 to the same coordinates to increase positional accuracy How do I know this? I was doing engraving on my Doosan Swiss lathe and it looked like it was drunk and everyone was different. Turns out as it was a showroom machine it had been fiddled with to make a faster cycle time on the demo part to impress customers. Accuracy positional for rapid should have been 5 micron and it was set to 300 microns🤦♂️ fast but wrong🤣 Hope that’s interesting. I don’t know anything about Mazak controls but I’m sure there’s lots of hidden stuff like that.
I've worked with Mazaks for a bit. I know there are all sorts of dec/acc motion control parameter adjustments, especially for their "shape compensation" feature (g61.1) but as far as I know there are no simple accuracy settings like that. Newer Smooth controls have something kind of close with a series of sliders where you can optimize for accuracy, speed, or smoothness.
I enjoy your work. You are very talented. I do have a question? Couldn’t you have run a cycle with the boring head leaving 0.10” then finish to size with a Reamer? I know that’s a bit “old school” but, I’ve never had a Reamer fail me if used properly. Any how, just a thought. Take care.
Yes that is possible. But if you are going to start with a boring head. You might as well finish it. The thing about just drilling and reaming is the reamer will just follow the drilled hole. With reaming you never know the exact size they will cut without testing in the actual material. In different materials the same reamer will cut different size and finish. So if you want to be absolutely sure of size, finish and location every time bore the hole. One reason boring gets a sort of difficult reputation is cheep boring heads. This makes it difficult to adjust them to the exact dimension when using them. But good ones are expensive. But once you use one you will never go back to a cheap one.
Great explanation, I appreciate all the detail and watched every minute. I've never done any roller burnishing but wonder if this is a good application for it?
Roller burnishing does work. But to make it work the best. You will have to either ream or bore the hole first. And the finish has to be rather coarse on that prep to make it work the best. I have done burnishing before. The tool is expensive and is usually a certain size. Not a universal as boring. Boring a hole would be my first choice. Unless it could not be done for some reason. Than I have run a burnishing tool.
Wow, this particular video had an ad ever 15 seconds to 1:00min. Made it super hard to stay focused on what’s going on, rewinding prompted another ad. Hope your getting the pay for it!
Sorry I don’t have to much control over how adds are played. If you watch a lot of RU-vid it may be worth it to you to subscribe to Premium for $12.00 a month. Than you see no adds.
@@EdgePrecision More or less making sure they are actually giving you the credit, sometimes monetization can play a lot of ads for a user and then not assign it properly, not a dig on your content. You do a great job and appreciate it, which is why I’d say check into the backend and see if the statistics match, you may be getting the wringer.
Great video. I'm sure there's a reason why not, but could you just grind a reamer? Bore for center and ream? Long tools in your tool changer may be a problem dunno.
Gortteswinter talked about a kind of 'binary' approach to final size, like you're doing, measuring the actual amount removed in a cut, so knowing just how much is the *actual''* removed material, so that the next cut can be, essentially perfect ... btw, on the coolant problem..could you cut a piece of ptfe with a flat on one side, radius on the other, and just clip it/clamp/magnet attach to the 'gripper'?
14:55 wouldn't do that, right before boring to finish... Any backlash/inaccuracy in the ballscrew, encoder, servo, droop, whatever..... in the machine and you'll get overlapping 8 shaped bores. I'd much rather write a simple boring program for that, that keeps everything fixed, except the boring axis.
As a matter of fact, I accidentally scrapped a fixture at work today because I didn't give the tool enough positive comp to bring it to size slowly like you mentioned. I'm a mill guy, but the premise is obviously the same. I loved the block delete/skip tip you talked about. Do you happen to know if the code is the same for a machine with a Fanuc control? Awesome video! Isaac
@@isaacmcmillen9246 The GOTO has to be letters not any numbers. Immediately followed by the sequence number no N. So in my example /1 GOTO4; if you only have one block delete, omit the 1 after the forward slash. Like this / GOTO4; Any line in a G code program with a / slash in its beginning will be skipped when the block delete button is enabled.
I remember you saying you use Esprit for your cam. Will it output the N numbers and block delete where you want them or do you have to manually edit that in after posting? Charles
@@EdgePrecision Thank you, I used Esprit about 14 years ago and you could edit the post to do custom things sometimes. Thinking about getting it again, I know it has added a lot of features. Charles
@@465maltbie I now use Esprit TNG. With TNG you can no longer edit the post. But it is so much better than the regular Esprit. Their support has been very good for any problems I have had so far.
👍 do those inserts have a small TNR and positive rake in order to take shallow depth of cut? I know someone inserts will rub if not enough chip load. What if you did a long retract in z between cuts to measure instead of running the whole sequence? Thanks
Why 4-4-3-1? Wouldn't it be better to do 3-3-3-3? That way, the only difference between cuts is surface footage. And you have 3 chances to see how close to size the tool cuts under similar conditions.
This is what I normally do. I back the head off one revolution on the dial. On this ITS head that is .004". Take a cut. Measure it then advance the cut half of the .004"or .002". Take a cut measure then Half Of the .002" Or .001". Take a cut and measure. Then adjust based on how much the measurement requires to hit the middle of my tolerance. You need to reduce the pressure on the bar as you get close to the size. or you will overshoot your dimension. Generally the first cut is deeper from the rough hole then all the others. This is why I back off the head for the first cut. If I just ran the boring head without backing it off each time it will cut oversize because these bars inserts have a negative lead angle. This will tend to deflect the bar outward on the first cut with these long overhang tools. So what you will find is the first cut should be -.004" on the diameter but it isn't. Because it was cutting deeper from the rough drilled hole. So then I go .002" out for the next cut. Now this may actually cut very little. Then I go .001" just to verify that the head is cutting where I think. The difference should be another .001" Larger. It is only then I have the confidence I can make my final adjustment to my dimension. This is with less then .0005" tolerances. If the tolerances are larger it can be done in fewer steps. I suppose you could cut in even steps as you describe but I don't see any better advantage in doing so. Also the change in size is so small that any surface speed is insignificant and doesn't make any difference.
Thanks for this, 1 thou sounds like a small final cut, is that what you set for all materials? (is this aluminium by the way is that why you can make it so small?) Thanks.
This was aluminum, but I have made small cuts like this in many materials with good success. Only in soft steels where you need a good finish. A small final pass may not leave as nice a finish. Unless you can run the proper surface speed for that.
I'm interested in why you are using the G85 cycle which G01-in -> G01-out, instead of using a more "modern" pattern, which does G01-in -> spindle stop -> orient boring bar -> back off slightly of the wall of the hole -> G00-out.
You are referring to a G76 boring cycle. In this aluminum part I chose this because I wanted to drag the bar back as sort of a spring pass on the bore. I would not do that on a tougher material. I would use the G76 bore orient and retract cycle. Like you mention.
It is possible but you can never be sure what size a reamer will cut without testing it in the material you are cutting. Also the finish and location could not be what you want. The reamer will tend to follow the drilled hole. In this case these holes were drilled with long tools which could contribute to location issues that the boring would correct. So to be an absolutely sure and not risk previously done, very expensive material and machine work I chose this way.
If your suggesting just run the tool without backing off the head. Then running it again as a spring pass. What I have found on these close bores is that will tend to cut oversize. On an expensive part I don’t want to chance it. If they were many less expensive parts. It could be possible to get the setting just right for that to work.
Don't you wanna take the same depth and make tiny adjustments? Now you took 4, 3 and 1. If it was 1 thou bigger you could 3x 3 thou. After the first cut you know how much the second should become etc. Objective is to keep everything the same tool pressure which depends on the cutting depth?
This is the way that has always worked for me. I backed the head off .008. Took a cut. Then went .004 bigger then .003 and finally .001. Or looking at it this way. I basically almost split the depth of cut in half every pass. It may work the way you say also. But I like to reduce the depth as I go.
@@EdgePrecision may be your method makes more sense when the error gets proportional smaller. I just want to understand the logic behind each approach. I really appreciate the effort you put in into making the excellent video's and genuinely answering these questions.
For only a few parts like this strut, I can understand using your method. But if you had a good sized quantity of them to machine, would you go to a precision reamer?
Do you think you might ever switch to a clear coolant so that you can see better? Might be able to hire someone else to do it for you while your programming a part.
A reamer could work. But there are couple things. It will require a test part to be sure of its size. To get repeatability the hole needs to be drilled accurately. Also a reamer will follow the drilled hole. Not as accurate as boring for location.
@@EdgePrecision petter . Why i menchiond this procedure is your abilities on makeing your own tooling starting with a precision bore and use a piloted Carbide reamer pilot to fit the bore and make a test on some matching forged aluminum.
@@EdgePrecision So bore twice for position and size then ream once? Seems a reamer would be far less likely to blow the hole oversize than sneaking up on it with a boring head. This of course only seems practical because you can grind and size your own reamer. The odds of having the right size reamer for most shops is very low and they aren't cheap so we bore holes.
@@bcbloc02 I agree on this! Drill for material removal, bore for location, ream for size. Reamers are dirt cheap. You can get +.0001/-.0000 reamers from Triangle in any size in two days, albeit in high speed steel, but I prefer HSS when it comes to reaming aluminum anyway.
