Mill Soft Jaws: The Proper Way to Make and Use Them – Haas Automation Tip of the Day

hello and welcome to this hosta tip of the day today we get to talk all about mill soft just now these soft jaws are like gold so very useful for quick fix train we're gonna be sharing some insights and before the video ends I'll be showing you the number one most useful rule that I know of for fixture design so stick around everything for me begins with my setup so check this out I've got a block loaded up there tightening up those tools by hand this is a common setup for a vertical CNC mill two of Isis of first operation and a second operation if my parts have have long parallel sides to it like this one does then I might as well just hold that second operation in a vise with hard jaws being supported from underneath by parallels I'll also make use of a parallel keeper to make sure those parallels don't go flying out of my my vise when I blow off my parts allowing chips to sell it behind there now we don't typically mill into hard jaws like these because they're a bit pricey they're often case hardened and ground on all sides like a 1-2-3 block for precision if your parts are goofy shaped they can't be held in standard hard jaws no matter how hard you try this is where soft jaws come in soft jaws are just aluminum or mild steel jaws that are meant to be machine they're meant to be fitted for your parts we'll start by making some jaws whenever I have a slow day at the shop or needed some busy work to keep my guys going I'd have them make jaws these are a machinist best friend the cycle time on these jaws is just over a minute and uses only three tools I'll leave the ends saw cut and I won't even machine off these extruded faces by keeping them cheap I'm able to make more of them and they'll be around when I need to use them to save time for setups later I'll just file the edges give them a quick deeper throw them in the tumbler or scotch-brite them and we're ready to go I'm almost embarrassed at how junky these jaws look but I'm here to make money these jobs are gonna be very precise but only on the surfaces where I need them to be we'll want to make sure that our vise is straight now this is always important but even more so if we're gonna cut those jaws if you haven't cleaned your vise in a while now is a good time if there are any chips underneath our floating jaw we want to take care of them and it only takes a few minutes loosen the setscrew pop the jaw making sure to grab our half moon spacer clean everything put a dab of grease on the spacer lightly oil everything and put it back together now this screw is really important you don't want your floating jaws so loose that chips can get between it in the vise tighten the setscrew and this is important back it off just a little so things don't bind whatever vise you have download the manual and do some quick maintenance we'll want to keep our jaws as short as possible to avoid deflection and we need to make sure the vise is clamped tightly before we machine into the jaws clamping on stacked parallels can create the spacing that we need for a taper free part fit we'll want to clamp our parallels as near to the top of the jaws as we can get without machining into them I'll often use empty plastic and mill tubes to hold the parallels and again I make sure the vise is clamped tight me on the parallels just like I tighten the real part I'll often times just grab a piece of stock and clamp my vise on it before I cut my jaws this is fine and it works most of the time 90% of the time I'll use the parallels and keep them towards the top of my jaws when I really want to guarantee a perfect fit when I really cannot have any taper in my jaws now here's an illustration for you that'll show you exactly how this taper occurs if we tried to machine into our jaws without them being clamped on something the floating jaw would just bounce around giving us a terrible cut clamping on stacked parallels creates the perfect spacing that we need now if we tighten the vise with our parallels near the bottom of the jaws they'll cut just fine but it is possible to end up with tapered jaws that don't grip our parts evenly as the vise tightens against our actual part the jaws deflect by some amount with taller jaws the taper can be drastic okay this is an exaggeration but but you get the idea if we try to keep our spacers near the top of our jaws we'll end up with a better part fifth cutting the jaws under this pre-loaded condition will eliminate gaps and jaw taper when it matters when we are firmly clamped on our parts in real life we'll want to keep our jaws as short as possible to avoid deflection but if it can't be avoided keeping your spacers as high as possible in the jaws will give us a firm constant part hold one last check with calipers to make sure our parallels are out of the way of our cut we'll take the profile of our part and cut that shape right into the jaw it's a simple process but there are some pitfalls that we need to avoid when choosing an end mil to cut your jaws make sure that it has sharp corners jaws that are cut with a sharp corner to end mil ninety degrees will allow the part to sit flush each and every time if we cut the jaws with a tool that has a corner radius a bull nose tool the part will be pushed up as the jaws are closed on it even a small corner radius on our tool can cause us problems on some of our parts these pointy corner radiuses can actually grow or shrink in an exaggerated way based on how our tool wears or if we're using tool where offsets this can cause our parts to interfere with our jaws if this triangular part is cut undersized at all it's gonna make this radius smaller when clamping this point to your corner will be crushed by the jaws causing the jaws or the part to deform for this reason I will usually relieve the radius in my jaws to keep them from pinching my parts in the corners watch those radiuses now if we get lucky our part shape will allow it to self align as the vise closes you can see that in this setup the part has nowhere to go oftentimes we'll want a machine our part stops right into the jaw on this part will push our part back and to the left when tightening that vise this brings us to what I think is the number one rule of fixture making it's kind of an open secret with tool and die makers when precision really matters rule number one always always locate on your datums always everytime 100% of the time well maybe not always usually no uh well maybe not always but we should at least try and locate on our datums this is huge this should be foremost in your mind as you are designing any kind of fixture if these holes have a tight positional tolerance off of datums a and B then we should be locating off of datums a and B off of the fixed jaw not them not the floating jaw in this example part my perimeter has a wide open tolerance if the part were to grow or shrink a little bit it would be well within spec still if the overall part size varies on us but but still staying within print our hole positions are gonna be moving around on us unless we locate on our data think about it have you ever spent all day moving your offsets one way or the other to keep a feature within tolerance ask yourself are you locating on your datums are those datum is being located up against a solid fixed jaw as we start winding up here we want to give you some some closing comments starting off it's almost always better to use a steel jaw than an aluminum and there's a couple reasons number one steel lasts longer it's not going to deform over time for high production and beyond that if you do get a chip stuck in between your part and the jaws we want the chip to stick to the part so you only mess up and dent one part instead of having that chip sticking to the jaw where it will dent part after part after part the chip is going to stick to whatever is softest the jaw or the part so harder jaws are better with goofy shaped parts will often drill and then bore a tooling hole making it easy to pick up the work offset on these parts then next time they are running remember boring always gives more accurate hold positions than drilling now if you are reusing soft jaws we can tighten the fixed jaw and just snug the floating jaw then clamp on a part for alignment smack the jaws down with a dead blow and then fully tighten it some of you might have noticed that the holes that we put in our jaws are oblong we've done this to make the jaws reversible I can reuse these jaws just by flipping them over and cutting in a different shape well that is about it for today's tips thanks for letting us be a part of your success and for watching this ha step of the day [Music]

Channel: Haas Automation, Inc.

Views: 294,556

Rating: 4.9346404 out of 5

Keywords: CNC machine tools, CNC machining, Gene Haas, Haas Automation, Haas CNC, CNC, Haas, haascnc, machining, manufacturing, cnc machines, cnc mill, milling machine, cnc machine, cnc milling machine, machine tools, lathes, cnc machining, rotary table, cnc machinery, cnc machine tool, boring bar, cnc machining center, cnc cutting machine, jaws, soft jaws, parallels, mill soft jaws, vise, VMC, fixture, fixturing

Id: 0ppYjZ4So6c

Length: 10min 10sec (610 seconds)

Published: Fri Aug 24 2018

Reddit Comments

[u/erichkeane]

That was a really great video! Setting the parallels as high as possible isn't something I'd thought of before. A couple of other good nuggets in that video, even for non CNC people.

I run a manual mill (hobbiest, have a Powermatic/Burke MVN), but I've machined my fixed jaw a few times to 'true' up my vice better than I can indicate. A few of his suggestions don't matter to me (I always use aluminum jaws, because a chip damaging a few parts is way less likely than crashing into my jaws!), but otherwise a bunch of good info!