Shars Boring Head v. Criterion

hi everyone I just got this in the mail yesterday and I'm just getting around to opening it up this is a boring hit that I got from chars and I thought it might be interesting to show kind of a side-by-side comparison between this which is an imported boring head and my criterion boring head which is the kind of the name brand that everyone clones for those of you not too familiar with boring heads the way they work is this part slides right here and you've got three holes that you can use you have these two so for smaller holes you can put it right there in the middle larger holes you can do that and for really big holes you can have it sticking out of the side so for even a two inch boring head like this you can actually bore a pretty large hole with it I wouldn't take very heavy cuts if you had a boring bar sticking out that far but you could easily do a six or seven inch hole with this boring head so this is actually their combo set that they sell that has everything that you're gonna need to get started with a boring head it's got the boring head itself it's got the shank it's got all of your Allen wrenches it's got these indexable carbide inserts boring bars that come with inserts and each one and then you've got the Torx wrench to change out the inserts if you need those one thing you should be aware of is the shank is actually loose in the package I don't know if that's normal or if this one was just happened to be loose so you can see the boring head screws on in the action of cutting the boring head is actually going to be tightening on this shank but you should still probably put a little bit of retaining compound on there and maybe put this end in and your mill spindle use your spindle lock and then use a strap wrench on this to try to tighten it up as much as you possibly can let's talk for a minute about all these screws that you see on the boring head these three right here are just for tightening the boring bar in the holes so obviously the boring bar goes in like that and you would tighten that again you use this middle one for smaller bores you can put it through there for larger ones and then with this boring bar I would actually have to be on the other side the insert would have to be on the other side otherwise you'd be if you had it like this you'd have to run it in reverse and it might unscrew from the Arbor you've got another size of screw for this this is the Gib and you can see the boring head is split right here by the dovetail so these two side ones are used to just adjust the tension on this Gib so that it feels good the the tension is not too loose or too tight so once you get your tension adjusted you don't have to move these screws at all now the middle one is what you use as a lock once you've made your adjustments on this dial then you would go ahead and lock down the middle screw so the dovetail can no longer slide and that keeps it as rigid as possible under the force of a cut each mark on the dial is one thousandth of an inch it does not say on diameter on this boring head it usually does say one division equals one thousandth of an inch diameter so I'm going to have to actually test that undercut and see if this reads on the diameter or the radius if it reads on the radius then that means if you moved it one division one thousandth of an inch it would actually take two thousandths of an inch off of the hole I'll test that out and let you know later in the video the adjustments are all made right here and in general what I do when I'm boring something is I've already got this set at zero and I'll just get it where it's it's gonna actually take some material off and it's at a convenient number that way I can make my pass measure it from there I can say okay well I've got a hundred thousands to go for my diameter and I'll be able to move my dial accordingly it's a lot harder when you start on some some random tick mark in between numbered lines so if possible I'll I'll start my cuts on zero or at least on some numbered line this is what I was talking about earlier this is my criterion boring head which again this is the one that everyone seems to copy and it says one division equals one thousandth on diameter that does not say that on my chars boring head but basically what that means is that if I move one division here it actually only moves it over a half a thousandth so it actually removes one thousandth of the diameter that's very handy when you're dealing with a bore because you're measuring the diameter of the bore and if you've only got twenty thousands to go it's super convenient to be able to just move twenty thousands on the dial and know that you're going to be right there as far as a side-by-side comparison to my criterion head the criterion is maybe slightly slightly smoother in doing the adjustment with the dial but it's really not by much I mean this is very smooth I've run it back and forth a few times and it feels really nice and that's a pleasant surprise because usually you would think cheap import it's gonna feel like it's got sand all in it and it really doesn't it's it's very smooth and I'm quite impressed by that so the set comes with four different lengths of boring bars all the way from a little short one that's maybe about two inches long up to this guy which is about maybe three this is a two inch head so it takes half inch boring bars of course if you get a three inch it would take different size I think that one's five eighths I think it's really nice that the set comes with these indexable ones because the brazed carbide ones eventually they're going to chip and you're going to either have to resharpen them or buy a new one especially if it chips really badly so this is really nice I think that's a nice touch so like I said I'm going to do a side-by-side comparison between this one and criterion boring head so I just popped a couple of holes I think these are fifteen sixteenths holes in a piece of scrap and I'm going to use the same boring bar in each head and go ahead and bore out these holes a little bit different depths of cuts and hopefully you'll be able to see in there enough that you can see what the surface finishes like and I'll give you some extra little tidbits there about things I'm experiencing that obviously you're not going to be able to experience through the video okay so here we are I'm about to take my first cut and I just wanted to show you a little bit of a setup on this bar and the size hole that I drilled is kind of in a sweet spot of crappiness here because it's you get at it said really far over one way for the middle hole and really far over the other way for the side hole so I'm just going with the middle hole either way the the mass of the bottom is going to be offset quite a bit for this reason in particular you never really want to run boring bar super fast I'm gonna run this one at 660 rpm the lowest speed in the high range on my mill since my stock is only 3/16 of an inch thick and I'm just going to use the shortest bar that's in the set and again I'm going to use the same bar in each boring head so what I've done is adjusted this so that the the boring bar should actually make a light cut and I've also placed it to where zero is is that the witness mark on the dial that way when I take this cut and I measure I'll be able to say okay I'm so many thousands away from whatever my goal is and remember after you make your adjustment you need to make sure to tighten up this middle screw again that acts as a lock on the Gib that just keeps it a little bit more rigid now I know there's a lot of mills out there and not all of them are going to be bridge ports or Bridge port clones so I'm not going to get into the mechanisms of how to set up for power down feed because that's going to vary by machine and people with mill drills or other brands and mills may not have the same control so that's a little beyond the scope of this video in the interest of full disclosure though I will say that the power down feed mechanism on my Bridgeport doesn't in the strictest sense work anymore what I mean by that is I screwed something up and I haven't gotten around to fixing it yet so what I'm going to be doing on this is feeding the knee up in order to make this cut and I'll use the power feet on my mill so that cuts really nice and smooth I like that finish and what I'm gonna do now is I'm going to take a measurement on that hole and then I'm gonna test to see if this cuts on the radius or on the diameter because that's a that's a big difference and it's one you'll need to know so I used a telescoping gauge and a micrometer to make the measurement on my bore and I came up with 970 thousandths and two-tenths now I used a telescope in gauge because it's a lot more accurate than using a pair of calipers so if you've got any kind of tight tolerance whatsoever you really don't want to use calipers they're just not very accurate on the inside some force if you don't know how to use a telescope in gauge I've got a video of that and I'll put a link to it in the description so what I'm gonna do now is move this dial 10 thousandths of an inch and this is going to tell me after I take this next cut whether this dial reads on the diameter or on the radius because it's not marked if it reads on the diameter it would usually be marked with the diameter symbol which is a large Oh with a slash through it I'm going to loosen up the lock there that middle screw right there and I'm just going to move ten thousandths of an inch on the dial er now if this actually reads on the diameter then I should only take ten thousandths off of the entire diameter so only five thousands off of each side if it reads on the radius meaning that that 10 thousands actually moved the tool over ten thousandths of an inch I'll be taking ten thousands off of this side of the whole and ten thousands off of that side and increasing it by 20 thousands so let's take a peek that is a really nice smooth cut I like the finish that I'm getting quite a lot I had to move over so I can actually get the telescoping gauge in there but I have the whole location set on my digital readout if you don't have a digital readout then you probably don't want to be doing that you want to just drop the knee down as far as you need to that's just a little more time-consuming so it looks like the dial actually reads on the radius on this head because I'm just shy of 990 thousandths right now and before I was at 970 and I had moved ten thousands on the dial that's a consideration you'll have to take into at the radius reading dial because if you were going for one inch on this bore and you were at 990 thousandths well you've got ten thousands to go but that means you have to divide the difference by two so you would only have to move this five thousandths it should work equally well as a diameter reading dial it's just it's an extra step you're gonna have to break out calculator you should honestly have that out anyway I'm actually going to go ahead and take one more cut on this and just to see how easy it is to get to exactly my target dimension so I'm going for one inch I moved the dial accordingly and we'll see how close I get all right again even on a light cut it's a very nice finish by the way what I'm doing here is I'm going to move the table over just a little bit since this is my last pass and then move the knee down that way I'm not going to get a drag mark on the bore all right and I got pretty much right on one inch I might be 1/10 under yeah so that's not too bad at all it shows that the head actually cuts what it says it's gonna cut so that's very nice and this wouldn't be a very thorough video at all if I didn't try a heavy cut so I'm going to take 50 thousandths off the diameter so it's actually only gonna be 25 thousands on the dial and don't forget to lock your Gib still got a really nice finish in there and typical for a roughing cut with the boring head so overall this is performing quite nicely so I'm going to take one last clean up pass on this just to get a good surface finish again so it's fair to compare between the char's head and the criterion head after everything's done well it's pretty decent let's go ahead and switch over to the criterion head so I'm going to do the same test with the criterion head so its side by side I have the same boring bar in the interest of fairness I've went ahead and switched the insert to a fresh corner because that could definitely affect your surface finish and I'm going to do the exact same thing I've got a light cut first just to establish where I am and then I'll measure and see how far I need to go to one inch and I'll see what I can do to get this right to one inch just like I did with the chars head then I'll also go ahead and take some heavy cuts and compare the two surface finishes and then lastly I'll take one light cut just like I did over here that way hopefully I can get it on camera what the surface finish looks like after half a dozen cuts with the same insert the surface finish between the cuts looks pretty much identical and honestly that's less to do with the boring head and more to do with the fact that I have the same boring bar in there so that's not really much of a surprise so let me go ahead and take a measurement and see where I am and I've only got about nine thousandths to take off so this will be another really light cut before I get to one inch just like the chars had this screw right here is your lock you don't touch the other ones and then we'll take my adjustment here now one big advantage to the diameter reading dial is you can just go right to the mark that you you need for your final cut in this case I needed about eight and a half thousandths and it's very easy to split that thousandth and get reasonably close when you're dealing with the radius diameter dial that gets to be a little trickier because of course you're already dividing your cut in two in order to get there and then it's not as easy to split hairs with it because the adjustment is coarser so I ended up maybe 1/10 over here yep that looks right so they perform equally well in that regard of course that could just be me so let me take some heavy cuts this be 50 thousands off the diameter just like I did with the shark's head so again the surface finish on that roughing cut was pretty similar to the chars head and again same cutting tool so that's not that much of a surprise hey so that's three roughing cuts I'm gonna do two 20 thousands finish passes here okay last finish pass here so here they are side by side you may or may not be able to see it on camera I'd say the criterion surface finish is slightly better but I'm not entirely sure that's got anything to do with the head more than by the time I finish these cuts the insert had a bit of a built up edge going so I'm not real sure that's uh that's conclusive the insert corner on the criterion head doesn't seem to have that built up edge going on overall I'd say I'm pretty happy with how the chars had performed I mean the cuts were smooth the surface finish was nice there's no chatter as far as everything else the fit and finish on the head is quite nice and it's a it's a nice little kit to buy I mean you've got everything you need there's one thing that I find slightly annoying with this again it's not a deal-breaker but the dial the numbers on the dial go the wrong way when you're adjusting this head of course you've got your holes right here so you're adjusting the head outwards this way so in order to do that the numbers really should go up counterclockwise so we should have 0 10 20 30 40 and 50 and instead we have it the other way around so you're counting backwards on this dial which again it's not a deal breaker and it's definitely something I can live with but it's one of those things that just makes the tool slightly difficult to use it it adds a mental step in there if you know what I mean you know the numbers are just laser engraved so maybe when they contact their supplier and order the next set they can have them flip that around so the numbers go the right way anyway I hope this helps with any questions you've got on the chars boring head and thanks for watching I'll see you next time

Channel: Stuart de Haro

Views: 34,522

Rating: 4.8506875 out of 5

Keywords: Machining, Machine Shop, Machinist, Milling Machine, Metal Lathe, Machine tools, boring head, boring head setup

Id: yU_xQElcHVc

Length: 19min 1sec (1141 seconds)

Published: Sat Sep 02 2017