Let's Make A Slitting Saw Arbor!

ah this is not gonna work i hate this thing so much hello internet my name is quinn and this is bloody hacks long time viewers will know that i've complained exactly 58 times about this crappy budget slitting saw arbor that i use for small slitting saws i've got a job coming up where this thing is not going to cut it so there won't be a 59th time i'm finally going to make myself a decent slitting saw arbor so let's go let's take a look at the problems that we're solving this is a so-called universal slitting saw arbor you can buy these things everywhere and they have this little stepped cone in them and whatever diameter your slitting saw uses sits on that particular diameter and then the other diameters are spring-loaded and compress into the arbor which seems clever but as you can see there's a lot of moving parts here and so there isn't a lot of concentricity or rigidity in this thing and well it's not very well made either however the real faustian bargain with this is because of that collapsing step cylinder business you have to have this big cap that goes on the bottom because it has to have the diameter and the depth to encompass all of those steps and so you lose all of your reach with the slitting sauce i've only got 300 or so thou here of reach with this saw but if you look at the saw itself it's quite large i should have maybe up to 600 thou of reach with this saw and this is a very steep limitation that i encounter quite a bit and the other big one that gets me constantly is the thickness of the underside of this arbor what this means is that you basically can never make slits above the vise because the part is going to be sticking up so high because of that arbor that you lose all of your rigidity and so you have to do all of your slitting operations off down to the side of the vise which is frequently inconvenient here's my design that i hope is a little better so the arbor there in yellow goes into the spindle and then the cap shown in teal screws into that and the shoulder on the cap registers on the slitting saw keeps it concentric and then that shoulder also registers on the counter bore of the arbor to keep all three pieces concentric and then the thread draws that shoulder in as needed to take up different thicknesses of slitting saws this is my little collection of small slitting saws most of these were donated to the channel so thank you to my viewers and they seem to fall into two main categories but luckily percent of them have the same arbor size they're all about 510 thou which is a strange size but i'm pretty sure these are metric i think that's probably supposed to be 13 millimeter so this arbor is going to fit these saws and that's going to cover 80 of my use cases but i'll show you how to adjust it for smaller saws if needed i've got a scrap of steel here that i'm going to use for this and this happens to be 12l14 steel but you could make it out of just about anything it's not a very high demand application this happens to already be machined but i am going to put a center in there and then get some tail support going now i'm going to turn it down to whatever is a convenient size for the size of saw that you're going to run and the collet that you want to put this in so in this case with a 510 thou hole in the saw 625 was kind of the closest collet size that was also going to leave sufficient material gripping the center of the saw to provide enough friction to keep it from spinning in the arbor so that's kind of the goal is you want the arbor to be as small a diameter as you can get away with to maximize the reach of the saw but still fit in a collet and still have enough friction on that saw so i'm going to leave the od a little bit large for now you'll see why here in a minute and but this is also the point where i realized i forgot to face the end as is supposed to be tradition so i went back and did that as well next up is the tapping drill size for the thread on the cap and that's going to vary depending on how small of a saw you're trying to hold here but you can check out my drawings to see what i used for this arbor after this i'm going to be boring out the counter bore that holds the shoulder of the cap and thus keeps the saw concentric you typically would see me start this with a two flute end mill mounted in the tail stock to create a nice flat spot for the boring bar to start but a viewers recently sent me these dewalt pilot point drills that have a flat grind on them and so he suggested i try these out and yeah actually i can say that worked very well so i went up in two sizes and that was less of a good idea i think you want to go to your final size right off the bat because of course after the first size there's no longer a pilot hole for the point on this drill so it wanders a lot as it engages the material but that's okay i still left it under size to finish up with the boring bar now the larger drill did chatter in the bottom of that hole you'll see some chatter marks here later so you do need to run them quite a bit slower than a normal drill but i think you can run them faster than the two flute end mill so i think it is still a faster way to do this so give this a try i'll link to these drills down below but of course you can also just grind a regular grill to have a flat profile like that if you are so inclined next up is the boring bar to bring this to the final dimension needed for the cap shoulder that holds the saw so i'm aiming for 511 here a one thou clearance slip fit on there this worked out okay but it would have been better if i'd started with the cap because you always want to start with the part that is the least mutable the hole in the slitting saws doesn't change and i have to fit that perfectly so i should have made the cap first because the cap has to fit that and then made this counter bore to fit the cap but with that counter board done i'll go in now with the tapping size for the cap and i went in with a taper tap and then chased it up with a bottoming tap as well just to make sure i have as much thread depth in there as possible lastly i'm going to come in with the chamfering tool and clean up some of the edges this inside edge i just want to break it just make sure there's no burr on that because i need that to register well on the shoulder and then i'll chamfer the inside of that hole there a little bit in case there's a shoulder on the thread and i did not jam for the od because we're not done with that yet i am however going to set up to part it off now so the length here is pretty flexible because it's going in a collet so yeah whatever feels good to you you can look at the drawing if you want to see exactly what dimension i felt was going to work and we just have to part this thing off and with that remaining material i can just slide it back into the right length here for the cap place off the end to get rid of that parting detritus and now i need to turn down the rest of this od to match the smaller od that's left over from the arbor there a clever person would have turned both of these parts in one set up instead of doing it two separate like i'm doing here but well you're stuck with me for the finishing pass i just very carefully touch off on the existing small diameter and then finish it down again this doesn't have to be perfect because we're going to do one more pass on both parts here in a minute anyway to mark the final length of the cap i'm going to blew up the area there and because i'm a terrible human being who doesn't deserve to exist i'm going to make a light mark in that ink with my calipers i look forward to deleting many colorful comments on this topic and the actual length of this part is not super critical so i just turn a light pass up to that line by eye and then i set an indicator and zero it on the carriage that i can do subsequent passes up to that same point and get a nice clean shoulder but the actual depth doesn't matter now see here how far i have to go so now i'm turning the shoulder that's going to hold the actual saw so this is the most critical dimension so i'm taking my time here to make sure i get this right when i think i'm close i deburr the end there with a file just to make sure it doesn't interfere with my fit if there's a bur it could make me think that the diameter is too large because the saw doesn't fit but the saw does in fact go on there it's very close so you have to get the saw very straight but that's a good sign that's what we want and that seems like a really good fit so i'm happy with that i'll try a different saw just to make sure that they're all consistent and they are indeed so so far so good so that's the shoulder that shoulder should also be a good fit on the counter bore in the arbor so i'll check that now as well and that's pretty good i ended up with about a two thousand slip fit there instead of one thousand so not as good as i was i was aiming for but it's still definitely going to work and i'm still a bad person so i marked out the length of the thread the same way and i turned that diameter down and then on the final pass i lock the carriage wind out the cross slide to face off the shoulder and end up with nice finishes and good dimensions on both surfaces looking pretty decent so far and i'm going to come in with my chamfer tool and put a very generous chamfer on that because this is going to be the threaded area and it'll help the thread start it's kind of a quality of life thing when you're using the arbor and it also helps the die start on the diameter there to start cutting the threads speaking of the die i can bring that in now with my tail stock die holder you could single point cut these threads if you were feeling fancy but i am not feeling fancy i just want to cut some threads and this will be quick and easy now i didn't do any kind of undercut at the base of these threads so that means that this shoulder won't seat tight against the inside shoulder on the arbor but that doesn't actually matter because there's always going to be a slitting saw in there but you could if you wanted to we've got enough parts here to test everything together so put the saw on there thread the arbor on there and let's see if that tightens up on the saw properly and it does so that seems quite good well i can't resist spinning it up and seeing how it looks and it looks good you can see some run out in the arbor there and that's because we haven't finished turning the od of this thing yet and these two parts were made in different setups so we're going to correct that here right now so i take the saw off and i tighten the arbor on as far as it'll go you can see again there's a little gap there because of that shoulder on the base of the thread but that's okay it's going to suffice for this then i just do a very fine cut all the way down both parts because the stock hasn't moved from when i turned the shoulder on the cap that holds the slitting saw then that shoulder is now concentric with the od of the arbor because i've now cut them both in one set up that's the key here to make the slitting saw arbor as concentric as possible so i'm just checking the dimension now in three places make sure there's no taper and it looks good but i am a few tenths large i'll test fit it on the collet here and it does fit but it's a little snug a little snugger than i would like so for quality of life here i will polish it down a few tenths and just make it a nicer slip fit in that 5 8 collet now i can put a nice chamfer on the end of the arbor i'm doing that with a file instead of a chamfering tool because this setup here is not rigid this arbor is long there's a lot of stick out and it's only being held in by that threaded shaft there on the cap so low tool pressure is the order of the day which means a file and i'm also going to file the parting nubbin off there so i don't have to try to turn that again i don't have a rigidity for that either over to the mill now with the cap before i part it off i want to use the excess stock to hold it here in the middle and i'm going to put some wrench flats on this cap the key to achieving a really low profile cap here is wrench flats rather than trying to put some kind of bolt or other fastener in the cap that would add a lot of thickness to it to calculate the depth of cut for wrench flats on a part you can do a lot of math to figure out exactly what it should be or you could do what i do which is i go over to my wrench drawer and measure all the wrenches and i find one that's a little bit smaller than the od of the round stock subtract that size from the round stock divided by two that's your depth of cut on each side and then a collet block makes it easy to index 180 degrees and then just a test fit with the wrench now the secret here is you want to end up with sufficient surface area on the flats that the wrench will have a good purchase so you don't want to go too small with those flats or else the wrench is going to round them over immediately and then on the fit you want just a couple of thou of clearance again if you have too much clearance the wrench is going to tend to round off the corners of the flats but if you have too little clearance that's a quality of life problem it's fussy to get the wrench on and off so there's a balance there and now back over to the lathe to part off the cap since we no longer need that extra stock there to hold on to it okay the parts are done let's give this thing a little test drive here so the slitting saw goes on the cap like so you can see the registration shoulder there and then the whole thing threads into the arbor and then we can use the wrench flats to snug it down with whatever wrench happen to be a good size in this case it's a 14 millimeter wrench flat on a 5 8 arbor because i am a monster all right well it's shiny but does it actually do the job let's go head-to-head with the commercial arbor here's the commercial arbor spinning up and look at the run out in that thing now slitting saws always have some run out in them that's how they're made but that is excessive i mean even the arbor itself has run out in it that you can see there especially the cap and there's very little saw exposed now let's spool up the new one and look at that i mean there's still a tiny bit of perceptible run out in that saw but the arbor is running perfectly as far as i can tell and it's just night and day and look at all the real estate there on that saw that we have access to now and then of course the other huge win here is the clearance underneath that arbor you can see this close setup here that i had recently on a job and that just would not have been possible with that old crappy commercial arbor so that's my little slitting saw arbor i can make another one of these now for my smaller saws but i hope you will make one of these too it really is a huge quality of life improvement for these little saws makes them so much more useful thank you very much for watching i hope you enjoyed this little project again drawings and models are on my patreon and if you like what i'm doing throw me a little love over there not just for the drawings but because love thanks for watching and i will see you next time you

Channel: Blondihacks

Views: 99,106

Rating: 4.9583683 out of 5

Keywords: blondihacks, machining, machinist, abom79, this old tony, vintage machinery, steam, electronics, making, maker, hacking, hacker, lathe, mill, woodworking, workshop, shop, model engineering, engineer, engineering, live steam, machine shop, metal lathe, vertical mill, metalworking, metal shop, diy, home improvement, resin casting, how to, do it yourself, do it yourself (hobby), mini mill, mini lathe, tutorial, slitting saw, slitting saw arbor, saw arbor, milling machine, joe pie, joe pieczynski

Id: -COjawgu32k

Length: 15min 3sec (903 seconds)

Published: Sat Jan 02 2021