SNS 209: Measuring Lead Screw Backlash, Chasing Acme Threads

[Music] hey guys welcome back to the shop another week of Saturday night special and I think I got a lot of good stuff for you again this week for our machinee we're gonna get back on the Genie shaper work and we start with the tool slide the lead screw and the nut and what I what I do is we set the nut up and the screw and we measure how much backlash is in the screw and I was actually kind of surprised at what I found there so I've got some interesting content there for you and we do a little bit of machine work there to try to correct the tool slide correct any kind of backlash that's in the tool slide lead screw that's not affiliated with the actual nut and you'll see what I'm talking about we get all that we get all that going and try to get that finished up it didn't have enough time in this video to put all that footage in there so I've got the rest of that edited and we're gonna do a midweek video after SMS so we'll finish all that out midweek okay there's plenty of stuff that I mean to do on the genie I got plenty of parts there oh by the way you might be seeing some extras over here just today I got all the parts in from Tim one of my viewers that found that 24-inch D and he in the scrap yard and he went and he pulled a bunch of parts off of it because they were scrapping it and I just got that pallet in the day and I got all this stuff over here so I'd like to go over there and show you that stuff and show you what I got and because I wasn't sure if a 24 inch and a 32 inch was the same but judging by the pictures they looked the same because both machines were of the same generation of the machine okay they were identical other than the stroke and mine being a universal but I think the parts are interchangeable anyway so we'll measure that out and I got some extra goodies in the box there we're going to check those out real quick and see what we got all right I want to go over one thing that's uh that I've been dealing with sort of personal stuff that I've been having to deal with you remember my 2018 goals that I talked about you know property goals and my we got the patio done and my next goal after that was to try to get my garage built or at least get it ordered and and get that kind of like on its way before springtime and I had to put that to the side and put that on hold because I had other issues that were more important that at the 10/2 and I had to replace the roof on my house and I'm thankful to say that that was finished this week the guys finished up and they did a great job on replacing the roof and I'm I hope that I never have to deal with that again on this house I just I don't think that I'm going to be living in this house for that kind of period of time where I'm gonna have to replace it again but I wanted to talk real quick about the type of roof that I put on my house I would have loved to have gone to a metal roof but my wallet wouldn't afford that it was it was quite a bit more expensive being going with what was what I needed on there so I have a low pitched roof of my house I believe it was like a 112 pitch so they recommended going with a modified roof system so the roofing that is up there is is a GAF Liberty modified roofing system you can look that up on YouTube they have a video that shows how its installed if you're curious but this is a couple of the samples of the material that was put up on the roof and I find this kind of interesting because we're always learning right roofing is not my trade you know I don't do roofing and just like carpentry is not my trade you know but we're always learning about things so I tried to take in what I could and learn about this and you know what it does so this is I mine is a two ply system I believe they do have a three ply system it's more it's more expensive but this is a 15-year roof and I have a five year warranty on workmanship for my roof so the first layer is it's it's a peel-and-stick system right here so this is the first layer that goes down like where your tour paper would go alright one side is a peel and stick and it is sticky alright so it's a peeling stick right here it's very very sticky and once this is applied down to the wood it is there it's bonded they don't have to heat it unless they don't have to heat it here but this is you not to heat it but they roll it they have rollers that they they push it down on and once this layer is stuck down to the wood it's sealed it's good it's very flexible so it moves it's self-healing and you've got a very good leak proof roof by the way they did do wood repair there was some decking that had some wetness that got wet it had some rotting issues here and there so all of that was fixed including the soft fit and the fascia boards that the areas that were bad I had to do it all while they were doing the roof so all that's done and now I'm working on paint we're actually getting it all repainted now that the outside of the house there anyway that's the first layer that's sticking that's what it looks like right there it's a mixture of rubber asphalt polyester and there's probably some other stuff in there too that I don't remember so that gets down first and then this would be the actual top layer right here that gets rolled out all right and it's also peeling stick sticky on the back there alright you got a little bit on the top side there where I believe the overlapping piece gets stuck there I know they tar all the sides where everything overlaps it's a very nice system this is also rubber asphalt polyester and it's very thick it's very pliable it's very rubbery and it moves it moves okay so we got a new roof on the house and I'm very happy about that I just kind of wanted to share that with you that that kind of gives me a peace of mind now that I'm not having leaking issues because I've been dealing with leaking issues for quite some time and I've had guys come in and do patchwork repair work to stop it okay it stops leaking here starts leaking over here so it was time for a roof they just told me that like you just you're chasing your tail you need a new roof so that's what we did so what I was getting at was I had to put my garage on hold which is okay because I need to take care of the house so now we're going to be kind of like working towards getting my garage and privacy fence I want to get that up too so some of those property goals that are still within sight just push back a few months and hopefully I can get through that okay so with that let's go ahead and check out these new shape reports over here alright so this is some of the new parts the new duplicates this is a tool slide that we're going to be working on in this episode right there and apparently I haven't done any measuring yet but it looks like they're exactly the same here's the clapper and the clapper box this is mine this is off the 32 this one's off the 24 again appears to be the same this unit right here was one of the items that I was very interested in to see if this one is going to be any better than mine so I don't know yet got to take it apart do some measuring and see how it feels alright this is the tool head off of the 24-inch and then this is my tool head there off the 32 inch and the one thing I do like about mine is that it the outside of it appears to be cleaner this one has been hit on several times on this side right here they some more of those it's more those hammer guys it's got it just gorilla all and everything just doesn't make any sense but it does have a clean casting right here look at that it's good for mining and you see where mine's busted probably happened you know somebody operating this and they actuated the RAM that came out and bam hit that hit something to either the vise or the workpiece or something that's probably why that got broke right there so anyway that one's good so you know I don't know I just wanted to I wanted to have all this stuff since he took it off that's the clamp right there that holds that in the backing plate the shim the bolts and then we have the tool slide right here and then that's the nut that was in this one right here so I'm not sure if somebody made that if that's factory Jeannie I don't know mom was cast iron and I'm sure it was factory that's what it looked like to me will do I tell you what I got some I got my 12 minutes calipers and I just wanted a real quick reference this see if I can get him out with one hand there all right so it looks like ten and a quarter let's see if my original just hitting a quarter and it looks like it is look at that alright and in our clapper box it looks like it's gonna be all over six six inches 100,000th and this one looks like it's going to be about the same so I think we're in luck I think we got some actual spare parts for the machine very cool let's look at the tool slide six and a quarter on the width there that's the first time I've ever measured that actually any of this stuff and then that one is six and a quarter as well I think that we have identical parts so here's the box of goods right here and let me show you what is really cool and that I don't even know if this is uh yeah there's the cam plate that's missing off of mine looks like some breeze has been put on the top of that so let's see something real quick well I just put this stuff in the way there's the one that I borrowed and you can tell they're different let's check this out alright so it goes right here did you look at that freaking kidding me man that is the that is the cam plate right there see the other one that I had borrowed must be off of maybe an older older vintage shaper it goes back too far and actually hits the bolts right there but that is an exact match perfect that's what I was betting on whenever I seen the pictures whole lines up just like it's supposed to and it has the proper height this is the height that I had measured I remember when I changed the height this put this about 3/4 of an inch so that looks about right right there so we got a good replacement part that is just awesome thank you very much Tim and this is all the other stuff that he pulled off too that's the top clamp right there you got the tool tray in these boxes you have that is the little cam for the auto down feed here's the bevel gear this is the bevel gear that goes right up in this area right there the one that's missing the key funny enough is that this machine was the same exact way the keys missing out of it but you can see the brass pins there so must be a weak point that many of the machines dealt with that's the bevel gears it goes through the cool head the same exact tool holder that I have for mine the Armstrong number 42 look at that they didn't have it they even have it set up backwards all right we got crank handles there is the automatic down feed mechanism right there alright but he had taken a couple of the parts off the back right there that's this guy right here all right top that's the handle off the top of the RAM for the RAM adjust and then here is one of the crank handles that was missing that ones see well there it is it's a little loose a little bit loose but it's a crank Amal and syringe and it fits in there too very cool all right okay I think that's about it as the that's the lock for the tool slide there was one of the piece oh yeah okay so here's the there's the t-bolt and it's dirty so I don't want to screw it in there yep this is the t-bolt that goes right there alright so very cool again Tim thank you very much nice to have some spare parts for this thing and on this weekend I plan on getting back on the the project I want to get back on to the nuts so I am still planning on making a new nut for this tool slide right here hey guys welcome back so this is the lead screw and the nut out of the tool head off the genie shaper so we're gonna go ahead and and start on this this is the this is the very beginning of the repairs modifications and the cleaning up of the tool head for the shaper and I wanted to kind of give you a little bit closer look at things just being the lead screw here and I mentioned it in a previous video that there's visually there's very little wear in the screw but obviously there's going to be some amount of wear in these threads and this is you know this video all these videos are also for guys that are you know learning this trade as well so you know not only am I just sharing my journey with what I do here we try to apply this as a learning experience for others who are watching and trying to learn the stuff themselves so this is a Acme thread this is a five pitch Acme thread the diameter is one in 1/16 so it's one in a sixteen five so five with a five pitch with each revolution of the screw you get two hundred thousandths movement two times five is two hundred times five I mean that will equal one inch so five pitch personally I prefer five I'm not a five but a four pitch I like the four pitch better because you get 250 thousands per revolution and I think it it spaces out the lines on the dial where it's a little easier to read but anyway we're not really here to discuss that we're just I'm just kind of talking about what this is so here's the nut and I believe that a lot of the where is in the nut which is okay this is I have no doubt that this is an original nut and it's been in that machine a very long time that I believe that machine dates back to the very early 50s so we're talking about a machine that's at least 65 between 65 and 7 years old so you're going to have a little we're in this is to be expected so we're gonna replace the nut I've got a new piece of ductile iron ordered I've actually got it so we've got a piece inch and AB ductile iron I've got a foot of it so that I can make another one if I mess up or if this one if I need to make another one because I don't cut the pitch right you know I've got some extra there so I'm gonna go ahead and screw this on here now I was going to mention we're gonna set this up tonight and I'm gonna go ahead and clean the end of this this rod up right here we're gonna clean these very first threads because they have been hit and rubbed on a little bit so it's it's tight going on this end just because these are marred up the end of the shaft is marred up and the center has been marred up because it's been hit on just like other things it's been hit on there's no reason to hit the end of this screw right here I've no idea why somebody would hit that but anyway we're gonna go ahead and get it started and we'll look at the backlash and it's like I said it's a little snug right there on that end there we go we got it on so the issue that we're dealing with this backlash now when this thing is together and it's in operation most of the time that nut is going to be in that general area right there if you look at the keyway there's a little bit of a keyway show and that's the general area that the tool head likes to rest them because you don't want a bunch of excessive overhang by bringing this down but this is built to where it allows you to have a lot of travel for different operations that you might be doing but for heavy cutting it's going to be in this general area now the backlash is the space that's between the male and the female thread that's gonna allow that rod to move now looking at it like this doesn't look like a whole lot but that's your backlash right there and what we want to do is eliminate that backlash as much as possible so we'll measure it we had a lot of people that suggested how about measuring it so what we're going to do is we're going to set it up probably put it in a lay so it's a little you know we can hold one and we'll put an indicator on this and I'll move it to see how much backlash we have and we'll also we'll run it up here because typically on the ends of your lead screws on no matter what machine you're on if it's a mill or lathe the ends of the threads are very seldom are not used at all your nut is going to be in the middle during all the motions so we would expect to run this nut up to that point right there and measure the backlash and it'd be less than what it is down here in the middle so we'll do that we'll do that check we're gonna get the end cleaned up right there and what I'm gonna attempt to do is I'm gonna try to set this in a lathe and possibly chase this thread I have to make a tool bit grind up a tool bit and if I can get this thing running straight I'm gonna attempt to cut it now if this thing is bent warped we may not do it because I don't want to mess it up any more than it already is but we will attempt to chase it to clean the thread completely up and make it uniform the same size all the way down and then if we get to do that then we'll make the new nut to match the new thread and I'm going to try to machine the new nut so that it is an extremely close fit on the thread alright so we'll go ahead and let's go to the lathe I have a hardened gentian a 16 collet that we'll use to hold it on the thread to clean the end up and also had this thread pitch gauge here I was going to show you now this is one I borrowed from work this is one that we have there and I actually placed in order for one from KBC today so that I would have one in the shop as well I really like this that you're it's built like a regular thread and thread pitch gauge except this is for Acme and I believe it has 16 Leafs in it for all of your different size Acme pitches so we want 5 that's gonna be a five by the way there's your if you in case you're interested in this is a spi it says it's made in Japan really nice tool five pitch and this tool might even this gauge might even build be useful to look at it and see a little bit of where in those gaps there and move it back and forth but anyway I wanted to have this here to verify my five pitch so I brought it home to borrow for the job all right let's go ahead and go to the lathe we've got to slide it onto the collet or through the call at first because of the collar diameter there we're going to start with cleaning this end up right here it looks like it's running nice and true there we're going to face it we're going to clean this up we're gonna clean them threads up recut the center just touched off there that's looking better and we'll put a good chance on that in there too let's go ahead and face the end here I was like tools hi-yah rather than just a bit a little bit fast I'm trying to let it dwell just a bit also God spindle over the quill lock lightly lightly engaged to help keep it from moving around alright that'll work I gotta set up in a fifteen sixteenths collet here on this end we got our new Center on a live live Center there and I just spun it up it doesn't look good to me okay I've got 1,000 right here that's that's not bad that's to be expected I'm usually getting about that with this collet Chuck right here is the turndown area mm right there but this screw right here that knock is the handle of the Chuck by the way it doesn't look straight it looks like it's got a little bit of a snake looking effect going on to it it's got to like a little bit of a kink in it let me see if I can get a an indicator tip on this thing and we'll see what kind of run-out we're looking at I put my wide flat stare at tip on the indicator here let's just come in here now this works good for bridging gaps you can skate right past that key it doesn't mess with it but you can see that we've got a little bit of crook to it there five five six thousandths right there not too bad see it's only mm right there within mm right there so I think down here on this end where most of the use is at you've got some a little bit of a little bit of bending that's been going on that's out quite a bit I'll put it back in the 1 and 1/16 collet and tighten down on this on the end that we know is should be pretty good see how it's running without the center in it it appears to be pretty straight so I don't know if I had it in a bind but I can still see that vent area it's got a very slight vent area here where the most where is yep so we definitely got a bend in it right there let's forget about the screw for now and let's go back to our back last what we were wanting to check see you can see it a little bit easier right there so what we're going to do is check it there in the middle right about in that spot was where it usually lives now you can see it a little bit better maybe you can see it now but we're going to put an indicator on it and I'll move it to see what how much back last we got we'll check it on all three ends we're going to use my steric number 671 right angle attachment that's not bad that was that's less than what I thought was there ten thousands eleven thousands that's changing because I turned it some see so that's about eight okay one more in will go to the backend and check it looks like seven yep got about seven thousands on that in right there so you know it's a lot closer than what I thought it was going to be honestly so I believe the reason why it's got more backlash once it's installed is because of this end right here this this shoulder widths acts like a you know a thrust area that goes up into the casting of the tool slide you've got there's a gap right there so as you're moving that screw there's a gap right here that is that it's compiling that that backlash so this is something that we need to address so here's our tool slide and this is where the screw fits up in there so this is one of the areas I'm talking about and you've also got a bearing area on the other side as well and there's actually you can feel where in there from where this shaft was rubbing so it goes through like this all right and that's where it pulls up when you're making your movements it's going to be applying pressure between these two points right here so I believe one of the things that I had going on that I didn't realize at the time I'm seeing it now is we had a little bit of slack right here whenever you turn the screw it's gonna try to take up any slack in this screw before it moves in the nut there or moves the tool slide so this is your friction dial and you can see it's a little bit worn on that side right there our little spring doodad goes in here and that's what applies the pressure to your friction collar all right so this is gonna go up on this side right here it's got a close fit on that shaft but you see this is this is what I'm talking about now this is a little bit of an exaggeration you got your hand wheel that goes on there all right and it's tight and then there's a lock nut that goes on the back end and you snug that up until you get you can't tighten it up to where it doesn't spin because it'll bond up right there so you got to have it just enough you got to have a little bit of in play there in this area but now I'm wondering do I need to we probably need to face this just to clean that up there clean that face up and I mean just a little bit because we'd have to do it all for this one - that's a close fit probably face this shoulder so that we have a good clean machined area it's got a sharp edge on there where it's been rolled up and maybe make some shims some brass where shims like a thrust bearing to go on at least this side right here so it's got a it's got a bearing surface and it's not rubbing you know the the steel shaft on this cast right here so this may be something that we look at doing right here here's the other side right there and you can see the you see the where this is where the the collar goes and there's an oil groove there as well so I still got to clean that out it's got I missed it there's still got a little bit of gunk in there so we need to make sure that we addressed this whenever we go back together and make sure that there's very little in play here to help eliminate any kind of backlash because this is going to add to any backlash in the screw and nut I went into my granddad's toolbox and this particular drawer is where the Acme thread pitch gauge always stayed and my dad and he'd done a lot of these it's got several tool bits in here that are already ground these are all acne thread tools and that's this is the place that he always kept them right here so there's several mixed in right here but most of them are right there so I found a piece of Rex 95 that dad had ground up no telling how long ago and this is for a number five it fits and I checked the angle you check the angle there and you got another gauge there that you can check it with as well but whenever you do a an ACME you have to thread it I mean you have to grind it to fit the gay properly there so we're gonna use this tool to chase these threads hanging on this in these first few threads are actually rolled over there's an edge it's rolled over and that tool won't go all the way in there so we're gonna set this up and we're just going to chase those first few all right that's all we're not going to go down the whole thing we want to clean these up that's a three eighths tool bit so we're using my 3/8 Armstrong tool holder so I have got this thing squared up to the gauge right here we got the gauge pressed against the threads and we've got that edge pulled up I got everything tight so our tool should be nice and square to our thread everything's locked down so we can go ahead and start and I need to we'll get it going we're going to be on a 5 pitch and I need to adjust the center let's do that real quick alright that looks pretty good a couple of notes here I've got the compound set I've got two set on 15 degrees that's the easiest number to set that on so we've got our compound in feet at 15 degrees there and as far as the number that you can hit on your threating dial right here we're cutting a 5 pitch which is an odd size on this machine you can hit every other line so in this case you would hit you know 1 2 3 or 4 now I know that confuses a lot of people so the best thing to do if it confuses you and you're fresh this kind of stuff is just pick a number and stick with it you know so you put you a little dot or something on whatever number and hit that every time and you can't go wrong but you can hit every other line whenever your once you're lined up and you're going to be chasing your thread ok let's see if I can get you a shot of everything at one time we got our tool and we got our compound and stuff like that so what I'm going to do is go ahead and engage it I'll just come on around here to the number one mark and we'll just use number 1 all right so I got engaged I'm gonna go pass those threads just a bit I want to get into where I know it's a good thread we're gonna run this in so I'm using this to be able to line up that tool bit right there to come back in a little bit more I'm using the cross slide to come in until the right side of that tool bit touches right about there I want to set to zero on the cross slide that'll be our zero that we go back to and now you can just use your compound to feed in all right so we're just trying to clean up the roll though over area right there and you could just reverse it if you want to you only have an app disengage that so we reverse it all right I'll move the camera so you can see the cut in action right there stop it and we're going to come back to our zero right there feeding the tool in there some I'm gonna back out reverse it [Applause] totally unnecessary exhaust they're going back to our zero see how it's hitting that right side and I still got a little ways to go its feet in there just a bit it's back out I'll bring it back I engaged it on number three [Music] zero I went back too far I got a full another revolution here to that zero right there we just about got it right there and then just bring it out [Music] I'm gonna go ahead and run that in until I feel it touch all right I run the compound in I'm gonna zero that one all right so zero see what that does [Music] you see I was touching the bottom there all right well I tell you what I'm gonna do I'm gonna make one more pass let me come back into my zero and I'm gonna keep my hand on the hand wheel here to try to put a little pressure to try to cut the right side of the thread again back off 1,000 waiting on my number to come around will hit to this time alright I got a little bit of pressure on the hand wheel you see it just scraped a little bit right there okay well I think that'll work I'm gonna go grab the nut and try it on that end right there didn't bind up there didn't bind up there so I got done what I wanted to do there I got her cleaned up I do need to polish it a little bit it's got some sharp edges on it still our thread is chased I still have some sharp burrs on these these last or the first couple threads anyway so we're gonna file though that's what I'm going to do right now I'm just making sure that there is there's not any burrs [Applause] okay that's much better than it was and the rest of our thread I believe is going to be good I feel a few up here this is the area that's usually kind of sticking out of the tool slide so probably gotten touched a few times just kind of very lightly touching okay that'll work I got the lead screw flipped around in the collet and this face right here where this journal is the space that's where it backs up against the casting so it's a thrust face and it's got a little where I'm gonna face this off it's got a sharp edge there so we're gonna break that and this is the area there what I want to do is I haven't decided what method I'm going to use yet but I'm going to make a brass washer or a bronze washer that's going to go on this face right here and I want one that's going to go on each side so the collar the friction collar is going to be on this side goes up on the other side of the casting so I want a washer for each side I don't think I got enough room to incorporate an actual thrust bearing I'd like to but I don't think adding a thrust bearing I'm gonna have enough threads out here for the nut so I'm just gonna go with some thin bronze washers on each side so we want to clean this up I didn't run it too bad I stuck a little piece of Emery right there in the center to polish that out get the rust out of it using a dmg insert so that I can get all the way up in there without hitting that this diameter right here just touching it probably took a couple thousands there I touched it that's okay what I'm gonna do will probably take like ten thousands right there [Applause] looks like there's still a spot there huh where's that grease no let's do another five and see we can clean that spot up [Applause] all right yeah that looks good right there so we'll take this tool out we got our razor edge there put in our MC HNN and just break the corner Gus just wanting to clean them up a little bit this would be considered a bearing surface right here just runs through the housing got clearance there and of course this is your thrust face right there all right I think that's that's good on this [Music] you

Channel: Abom79

Views: 113,673

Rating: 4.969902 out of 5

Keywords: abom79, shaper, metal shaper, lead screw, lead screw backlash, lead screw nut, lathe, metal lathe, engine lathe, indicator, starrett, starrett 671, indicator attachment, backlash, acme threads, thread chasing, single point thread chasing, chasing acme threads, tool slide, tool head, shaper tool slide, machine shop, machinist, job shop

Id: 6IQ1e4aEvKM

Length: 49min 6sec (2946 seconds)

Published: Sat Mar 24 2018