Making a part: Stainless Steel Guide Frame

[Music] hey welcome back today we have an interesting little project we need to make three of these parts this is for a university project i will talk about that later but let's start with the part itself you can see we have technical drawing top view side view in a section section bb that's through here looking against this cut surface here gives us this cross-hatched surface which is this part here and we have bottom view also we have a section view through uh yeah uh cut cc that's this one here cutting all the way through here and looking against from this direction gives us this arched top surface with a radius of 16.5 the part needs to be machined from stainless steel 1.4305 or a similar steel uh 14305 is a free machining quality of stainless i don't have this one at hand but i have a 1.4301 here which this is the iso material number in the antsy world that's a 304 stainless and the 4305 is a 303 stainless since i have a very good fittings piece of stock 1 4301 six millimeter thick final part is 5.56 so i have some allowance on here i will use that it's a little bit less nice to machine than the 14305 or 03 but it will do fine when we look at this part at the overall shape we see in the top-down view that we have this c-shape here in this large long slot here and my experience tells me that we will get problems with warping if we cut the slot and finish it the part will warp definitely so what we're going to do is we're going to slice some material off oversized final part is 15 millimeter we'll cut it to 17 millimeters that gives us one millimeter of allowance on each side then we will rough out the slot which will be four millimeter on the narrow end and rough this out to three millimeter we will just run a three millimeter end mill down the middle and take out all the tension of the stock and then we will go from there otherwise um i think we will end up with with something that looks like a very much bent oh c shape which we don't want we have fairly loose tolerances here we're going by iso 27 68 medium that's an m m for medium and you take your trusty uh tabenberg metal and you look up up here iso 2768-1 tolerance class m for middle or medium a dimension plus a dimension point five to three can be plus minus point one three to six millimeter can be plus minus point one six to thirty can already be plus minus point two thirty to 120 can be plus minus 0.3 so this is a system for standard tolerancing on on parts that you don't want to tolerance but you want to give the machine shop an idea how how critical a dimension is and if you put something like iso 2768-m on a drawing he knows to stay within those tolerances anything that's more important will be toleranced separately when we look at the drawing again um 4 30 all these are nominal dimensions that's for birth discounts if we have a dimension like 38 minus 0.2 like this one up here this is this is different so we have 38 minus 0.2 this can be anything between 37.8 up to 38.00 whatever we don't write tailing series of course so good practice would be to machine it to center of tolerance so center of tolerance would be 37.9 this would be the target dimension that we would shoot for and that gives us 0.1 millimeter of tolerance to both sides makes it very easy same for the width here 15 minus 0.2 and looking at this makes me already know and i also have the assembly drawing that this needs to fit in a cutout because the dimension the outset they tolerance the outside dimensions minus here we have a slot nominal width is four millimeters plus point one that tells me that there probably needs something to fit between those two sides of the slot something will be sliding in so they go on the safe side they put a plus tolerance on it and the matching part probably has a minus taller but overall nothing crazy everything is well within 0.1 millimeter taller overall this would be a function related dimensioning if you put if you take this dimension and you write there instead of 38.38 minus 0.2 you write there 37.9 plus minus 0.1 both of these mean the same but this is easier for the machine shop and this is easier for understanding the assembly in conjunction with the other tolerances so it depends on what you want to do i started to slice down the length of the material to get my 40 millimeter width before milling it to size i can already see that there's something wonky this is my regular saw kerf down here that's the width of the saw blade plus the set of the teeth and it's a little bit it's about three times that down here so this material has definitive some tension in it and we're releasing that when we cut through it like this so next we'll be cut here [Applause] [Applause] ah this blade is a little bit there is somewhere at least a bunch of teeth missing by the way it behaves means very rough i laid out four pieces two lines and saw between the lines before i cut those four individual parts one spare uh i'm going to mill it a little bit over size um to width just run an end mill over both sides to clean it up we're over at the mill parallel device this is the [Music] cold drawn side called round finish goes on parallel 3000 rpm four flute carbide end mill [Music] you saw me do a climb clamp cut pass down there and the climb cut pass up there that means i get virtually no burr on the outside instead of moving one time over it with a slightly larger end mill and have a heavy burr on one side i prefer to do a to do two cuts i always have to love when i see people use a face mill in a single pass and then file a ridiculous burr on one side of the part that's very ineffective to me and the little bird creates can be wiped off a finger so there is no real burr present uh just breaking the edge a little bit and now we will do something that will save us some time drop the part flat in here and square off both ends just just do a light cut on both ends do one cut flip apart and do another and the reason will be obvious in a [Music] second one side quick deeper and when you file for deeper i like to file towards the surface we just milled like this and then take the file and run it flat over the surface to remove the secondary burst from filing yes secondary bursts exist and are a real thing there we go now we will slice off one part and take the larger piece go back to the mill vice and re-cut it just do the same cut again that we just did and do the same on the other side and that way we will end up with four parts that are already milled on three sides square and straight so makes it easy i call this technique the self-squaring salami [Applause] okay there we go two parts three side three sides milled and squared and we have a piece large enough to be held again in device like this and mill side milled okay here we're back at the middle with the piece that's sawn on both sides dropping back in the vice the vice jaw will do a perfectly fine job of squaring it up and i have a one of the cutoff pieces three sides square out here to balance out the wise jaw otherwise it would crook by a lot or it would clamp the part but it's not good for the vice so that's good practice here i'm going a little bit much into detail this time with squaring up the stock and how i how i'm processing the stock because i noticed that for example my the apprentices that we get at my day job when they come from the apprentice shop this is stuff you don't learn in the apprentice shop usually this comes from a little bit experience and or you have seen it somebody doing it that was the case in my uh what that was my case i saw this and it made totally sense so that's why i'm showing it too also notice that i did do when i take like cups like this i take primarily climb cuts because finish is nice and it's easier on the machine and easier on the cutting tool on on heavier cuts you better are careful what you're doing the second side now we can split this piece through the center and also have two pieces like these two that are square on three sides we can cut all four pieces now to the same width by dropping them on on parallels i have parallels here horizontal that are slightly narrower than the four pieces stacked together these four pieces are 24 millimeters in total stacked up and these parallels are 22 millimeters so i don't pinch the parallels in the vice and i raise them up with two additional parallels down here we tighten this down a little bit and because we cannot trust them to be down on these parallels all four by themselves we will take a copper drift and seat them properly onto the parallel probably shouldn't be moving by now and give that twice a little bit more grunt there is no high precision required at this point and for measuring the width we don't we're taking the quill with the end mill we drop the end mill down onto peril careful not to damage the end milk deaths zero out the dro this is now our zero and we move up by the desired width of the part [Music] four parts just need a quick deburr on the belt sander or a file then we cut the slot in the center i have my diode test indicator here in the spindle we need to find the center of the stock to rough out this law i'm going to make contact with the fixed jaw first like this sweep for the high spot and crank it to zero on the dial of the dti zero out my dro spin this thing 180 degree without bumping the indicator make contact sweep for the high spot crank to zero half of the dro measurement crank to zero and now we can double check by moving the indicator in position like s find r0 find the high spot zero out the dial here zero and zero so we're exactly on center here that's perfectly fine and you just saw it's very quick using the dial test indicator for this kind of operations let's drop down on the work to get our zero when you do this be super careful not to crack the end mill corvette emblems tend to lose their front cutting edge if you do this careless so i want to rough out the slot to three millimeter of width and uh 31 31 millimeters length so i'm going to drop down and just touch the work with the end mill okay just scratch the work with the end mill and and zero out the dro in this position now i can just drop down and take my repetitive cuts to final depth or in this case until we ordered all the way through okay this end mill is not behaving very well but we will go with it we'll increase the rpm to 3000 and use cutting oil this could help in this case [Music] so i took point five million in a depth increments and used the cutting oil this is yokish alfa 93 heavy-duty cutting oil let's see let's see if the part yeah the part seemed to have moved a little bit i zeroed out the calipers back here where it didn't move and now we're checking the front here and it's not crazy it's only 0.1 millimeter that the part opened up that's i expect a little bit more we might have gotten away without roughing it out this the way i'm doing it now but better be safe than sorry so yeah the slot is also kind of on center it's it can't be precisely on center because i took a fairly heavy cut for such a small end mill and this and the end mill just bends away and the cutting force but here we go not not too much off of deflection here so let's rough out the other three ones i'm cutting the parts to final width now as i have seen that the the warpage is minimal okay there we go checking my dimension here nominal 15 and we're minus 40 micron so overall tolerance would be 15 minus 0.2 millimeters but uh i have to it's rather bad habit but i like to stay close to nominal minus a little bit in this case so the part is still close to normal i know that's a bad habit but that's just me at least i know it's a bad habit and also notice that when i put it in here in the wise on parallel and clamp down on it i didn't hammer it down onto a parallel because that would bend the part most likely in this area and we don't want that i'm skim cutting the back side just to clean it up a little bit then i'm going to cut the front to final length this has to happen very carefully because this is like a tuning fork now light skin pass with six millimeter end mill gives nice finish we skim cut the first side now we can flip the parts around and hold them like this and climb cut them to size and there we go 50 micron under size very nice it's the next day and somehow overnight the spindle of my mill changed from merced 4 to iso 30. so now i'm running these super nice small iso tool holders number 30 taper in this mill i will talk in a separate video a little bit more about the spindle exchange and why i did it the change itself is very easy you can buy the whole quill assembly with a number 30 spindle from kami machine tools here in germany costs about 350 euros and is pretty much ready to go and this allows me now to use these super nice side lock holders which has just a set screw to hold the end mill in place some people don't like them very much i love them they have an excellent run out tool change especially on a manual mill where you're changing tools all the time because you're doing some crazy stuff and you don't have an automatic tool changer it's very easy because you just use a t-handle allen wrench here loosen the set screw pull out the end mill put another one in and you're ready to go again without having to change the whole tool holder it's very quick and the run out on these is just uh spot on it's like three microns on the shank of the end milder up here so that's good enough for what i do but here we are continuing on these parts and now i'm finishing the slot to size it's a stepped slot so first we will cut it full depth to four millimeter and then we will put in a step with five millimeter width i balanced out the vise jaw with gauge blocks back here don't use your good gauge blocks for this use some scrap ones i was yes i have scrap gauge blocks i buy very cheap gauge block sets that look awful on ebay de-rust them with scotch-brite and use them as blocking material on mill and lathe or grinder so here we are with our three millimeter high-speed steel end mill in this case i roughed out the remaining material in one millimeter depth increments and now i will finish it at full depth to width so i'm stepping over 0.3 millimeters for a first pass and i do this all climb milling because when you do conventional milling the end mill tends to get pulled into the work with client milling it tends to get pushed away from the work we will probably need a spring pass here check with a four millimeter gauge block yeah four millimeter gauge block is still no go so let's take a spring pass here high-speed steel cutters tend to get deflected more because high speed steel is three times less stiff than carbide so spring pass will always be necessary there we go that's four millimeter gauge block looking good to me now we cut the step at full depth to size roughing in two side side steps and then finishing let's check with a five millimeter gauge block should be on the very tight side yes indeed so we're opening up two two to twenty microns per side okay here we go yes that's a nice that's a nice five millimeter gauge block fit this is 505 and this doesn't fit anymore so we're nice on the on the tight side very close to nominal but very free fit exactly what i want the part comes out and here a quick look at the sidewall finish and the step we machined in there also five millimeter gauge block fits in all the way to the bottom of the slot when you cut some a feature like this always make sure that your end mill is not worn tapered and the mating part can can go down all the way very common mistake with slots and pockets have them taper to the bottom and the meeting part only goes in with a hammer now we're doing this milling operation on the back which just leaves those two strips and takes down all the other material around it for that make sure the part is clean we drop it in the vice up against our stop here make sure it's nice and seated lock it down and we get the tool out of the spindle because we need to change tools one nice thing about the i-30 that's also the main reason why i switch it need extremely little height above the table to change tools only like 10 20 millimeters of clearance to get the tool up because the taper tapers down more than a more steep before if you compare it to a milst tip before which has about the same gauge diameter here not only is the moisture before about twice as long it doesn't taper down as much that means that you can't tilt it to the side to get it out of the spindle to clear it this one doesn't need as much height and can tilt it out the side way easier let's let's take our height this is a six millimeter carbide shank i drop down the two like until i cannot get my end mill under it then i retract the spindle slowly using the fine fine feet of the quill there we go put in the diameter of our carbide shank and we're good to go now we picked up the height without damaging the tool drop it down 1.4 millimeters final that will be 1.5 but i'm roughing out everything at 1.4 in case something weird happens and i'm just stepping in from the side now we change tools because we need to open the slot in this position here too to have the same height level as the step we just machined around the part this is a three millimeter two flute mitsubishi carbide end mill since all the milling is done i'm drilling the holes now and for that i'm holding them in device like this clamping parallel and i use a gauge block stack that's close fit in the slot here to prevent the slot from getting crushed and i'm also clamping in the center of the vice so we don't put unbalanced load on as you can see the counter bores go very very close to the edge of the part for that reason i'm i'm centering each part or at least double checking each part with dial test indicator in the spindle of the mill so i make sure i don't break through the side of the part with the cardboard because that looks stupid as hell drilling 2.2 millimeter drilling the counter bore with a 4.3 millimeter drill and then following with a flat bottom 4.3 millimeter drill to remove the drill co these still look but ugly because this top surface has still 0.5 millimeter of allowance that will get cut into a radius in a large i think six and a half millimeter radius something like that this is a 3d printed dummy of the mating part it doesn't really fit but it goes in this position on the real part and create somewhat of a guide in here where a part is sliding back and forth also before we cut the radius we need to trim these edges down here to 45 degree and also chamfer the outside edges one by forty five so port goes in the wise i have some very narrow spring steel parallels these are out of pre-hardened spring steel or spring hard spring steel which comes rather straight and i just abrasive cut strips out of it and ground in parallel to act as parallels they are very useful when you need to drill close to the edge of a part part goes in against stop don't crank down on the on device like like a madman we start but with a 3mm carbide drill that i'm just using to spot drill corvette drill is very rigid it doesn't doesn't tend to wander off and also they are usually grind in a way that they cut very freely usually they have a four facet grind and they drill on point just putting a very very minute mark on there using the carbide drill uh 2.2 millimeter high speed steel drill with a four facet grind [Music] drill all the holes now we change to a 4.3 millimeter drill to do the counter bores these go to a certain depth so i move a little bit over touch the top of the part of the drill and zero out my dro okay last tool same drill diameter but shortened with a small abrasive cutoff wheel and then ground flat with about five degree clearance on the d bit grinder i'm going to use this to clear out the drill cone the other drill is 118 degrees tip angle and we need to get rid of this because there is a regular screw going in there with a cylindrical head touching off on on sea height adding some cutting oil we don't need a huge amount here there you go when drilling stainless especially a grade like three or four stainless that tends to work harden on the pressure when the drill only erupts you need to keep a steady feed just keep the cutting edge in contact with the material in the material cutting and not have a drop have a drop and you will kill the cutting edge and also don't go crazy fast that's why i did run this at 300 rpm four beautiful countersinked holes counterbored and we did not not blow out the ends here or here or the sides which is a good sign that's my setup to cut the chamfers on the edge of the part and this is a little bit weird setup because you will see in a second why i have a magnet plate here in device small hundred and twenty five millimeter magnet or 150 150 millimeter magnet tool makers wise on top set with a 45 degree block to my desired chamfer angle and now you're saying uh why don't you just put the part like this in a vice and cut the chamfer with a regular chamfer end mill you're right that would be perfectly fine it also needed to chamfer these corners here and you cannot do those with a chamfer end mill you need to come in with an end mill from the top and cut it at 45 like this or the other direction and that's why i have it set up like this and i'm reusing this setup to cut the the outside chamfers too because it works so nicely i have a stop here on the side of device which is just a strap clamp part butts up against it sits on two parallels parallels are held in place with a uh with a spring between the pair uh parallels so they don't fall out park goes up here gets clamped and now my position of this this vertical edge is defined now i can just side mill with the three movement carbide angle my chamfer and i do not have to to pick up this position each time there we go first one i don't want to take super crazy heavy cuts on this chamfer because we are only holding the wise on a magnet but for these light cuts that's perfectly fine okay now we can flip the part around to the other side and the last one is on this side there we go all four sides chamfered gauge blocks that can go out the very last step is to cut this large radius here this is a r 16.5 millimeter radius that gives a diameter of 30 33 millimeters i made this ring with bore of 33.02 millimeters aimed for 33 but uh too stupid to read the two-point internal micrometer and i'm using this against a light source to check my radius but how do you cut this radius i could 3d profile it on the cnc router without a problem but the cnc router is currently set up for a completely different project and i don't want to tear it down or mess with it we could do it on a lathe with an arbor and have it rotate at the diameter we need and just turn it but this part is rather fragile with those two prongs sticking out here we could do it on the surface grinder cylindrical grinded with a spin fixer or on the tool and cutter grinder also just rotated under a grinding wheel or we can mill it and the last option is what i choose mill it on the manual i use the indexing head as a fourth axis and i turned the part like this under an end mill and just the surface finish i got with a little bit of scotch brite there's a little bit of a line i need to do a little bit of blending on it but it's really it's really okay that's my setup i have my walter gta 80 dividing head in one of my vices and i made an aluminium arbor it's held in the three charge chuck and it's milled to accept the parts just like this the slot is in when it's vertical is in y direction on center and has the correct depth to the center of rotation to give me the radius i need at the height of the part i need it it's a little bit tricky but i i sketched it out and it worked right away well on a second try this uh this other feature down here is first try which i fortunately enough realized soon enough so park gets screwed in with four m2 screws tiny screws screws go in like this yeah these screws are partially milled away because they stick out the real screws that will be used with this part are slotted head screws where the head is only 1.3 mm high and the idea now is we just move with the end mill x back and forth and we rotate the indexing head a little bit more each pass how much i'm not sure i'm just eyeballing the the crank handle [Music] so okay this took about four minutes to cut the result is really nice i i'm not i can't complain about this i'm really happy how this looks take it off the fixture see if we can get these screws out i'm going to take new screws for the next one because the heads of these are already pretty mangled up and i'm worried that i might not get them out if i take another pass on them they cost like two cents a piece so that's okay here's finished part that's really a decent surface finish so shiny uh keep in mind this is 304 stainless so usually if you get a decent surface finish on it it looks okay these are the parts after some uh deburring and finishing and finish is quite decent i'm pretty happy with how these came out that's the backside and my trick for a good finish that i found out is a scotch brite wheel not the giant one that you know that you put on a bench grinder but a tiny one like this one i think you can buy them but these are easy enough to make yourself and pretty much no work at all you take a regular orber for a rotary tool that you would also use for a cutoff wheel like this one take the arbor and you take some scotch brite take scissors by the way i used these scissors only to cut abrasives because cutting abrasives is fairly hard on scissors as you might expect then you cut two squares clip off the corners rid of the abrasive dust on your table place them on top of each other kind of kind of center to each other take a punch punch kind of centered a hole and you come in with your screw other side of the arbor and if you don't have to explain it on camera or show it on camera you get a nice scotch-brite finishing wheel that's almost running true it's self-truing in use after a few minutes in use they look like this they don't last very long but on small parts they work excellent they give a really nice edge on corner round over and clean up surfaces very nicely a very satin like finish so and don't run them at crazy speeds i i run them at 10 000 rpm max otherwise otherwise they start to sound a little bit dangerous this is at 10 000 rpm that's very reasonable and the idea is you take your part or the machining you take a good carbide burr and you run it across all the edges create a little chamfer and then you come back with this and blend everything just over that gives this one piece look let's do one when doing deburring or edge breaking with a carbide burr in a die grinder don't get greedy take light passes always climb cutting if possible and after each pass evaluate what's happening also when you go into corners take the corners slowly and orient the part so you can for example take an internal radius in in one sweeping motion same applies for long continuous edges like like these outside ones light passes evaluate what's happening after each pass and don't get greedy even convex edges like these work very well changing to the scotch brite wheel and with this you cannot do much wrong just just hit all surfaces and edges and also constantly evaluate what's happening looking at the result and correcting your the application of the wheel if not if necessary this is to me the most fun part of making a part getting rid of of the majority of the machining marks getting getting the edges and corners right and just make it look nice here are the finished parts two of them i need to ship three i made four because one is in case i messed something up packaged up and ready to go so i hope you enjoyed this rather thorough walk through to these parts thank you all for watching and i'll be back [Music]

Channel: Stefan Gotteswinter

Views: 20,989

Rating: 4.9795918 out of 5

Keywords: stainless, steel, edelstahl, fräsen, optimum mb4, milling, part, four axis, vierachs fräsen, 4 axis milling

Id: utpzlwockzc

Length: 51min 20sec (3080 seconds)

Published: Sat Jul 31 2021