ID and OD lapping simplified.

lapping gym it's an interesting word I'll think about it tool makers know what lapping is but there's your dog does lapping doesn't your dog do lapping if the dog sits on your lap or your baby sits on your lap or what if they're licking water is that lapping I don't think so I don't know but anyway lapping is an interesting word we did a primer earlier on on lapping we showed you some of the external and internal laps and we're going to review that again this time we're going to show you in the plant how we do some lapping for both external and internal I can't emphasize enough how easy this is if you set it upright if you don't you're going to have a problem and you're not going to like it it's going to be frustrating it's going to lock up on you it's going to seize it won't work right so it's important that you get it set up properly this is a part that we've already lapped but we're going to take another one back then we're going to show you how we lap it but look at the difference if you look at this difference if you can get a good shot of that Jim this has been ground this has been lapped what a difference in the finish at almost the lap finish looks like Chrome and it's not Chrome folks this is 8620 it's uh it's not a special steel so that's what it looks like when it's lapped we're also going to lap an ID and we're going to fit it to one of these minor diameters again this is the lap for an ID an expandable lap made by American lap has a Hilux in it so and this arbor is tapered so when you tap it it expands so as it wears you just add a little to you tap it a little more and it expands again and you keep on lapping with it it's important you go all the way to the end so you don't wear it in the middle so you've got to go all the way 50% off 50% off back and forth till you get it where you want it one other thing the compound that you use that's important if you use four hundred let's say and keep in mind the compounds like sandpaper 400 600 800 thousand 1200 it's just like sandpaper if you use a 400 it's going to be very difficult to clean the lap and go to 1200 it's not going to be easy thing to do you need to take spirits and wash it out really good and even with that some of it gets impregnated in a lap so if you're trying to get a finish like this this was a finish that we did using 1200 only what we've done is on the external laps if I don't know if you can see that but we mark this fine so we would not contaminate this lap with anything other than a 1200 compound if we're going to use 400 we're going to use a different lab certainly a different insert we can pop that insert out and put this in but generally we just use it different holder so we don't have to waste time doing that and again the beauty of this that lap wears out you tighten it down here and it contracts that's why all these little slits are in here for so it'll contract evenly that plus the helix in here allows it to contract evenly so we're going to go in the back I'm going to show you how to do lapping on an OD and lapping on an ID so let's hit it aback show you how we're going to do it let's go Jim we're back at the old Logan late member that we have that one of the other videos we started to show you about I think we called it a primer of lapping we have a part here then we're going to measure first we're going to show what the size is and we don't want to take off more than a couple of tents at the most so we're going to use a very fine lapping compound in this case we're going to use 1200 so let's go measure this so now we know that it's about a tenth and a half bigger on both ends and it's a little smaller in the middle so we're not going to take off very much so in checking it up I like to chuck it out on the end so if there's a little run out and the really the run out doesn't make any difference but it just bothers me so you can see there's a little run out there there we go pretty true so I'm going to take a little bit of 1200 and I'm going to put it on both ends remember when you put it on it's going to wipe it off it will move it all to one side excuse my cloth so now I need to put some on this end remember I pushed it down to the other end don't need a lot of speed back and forth nice and easy remember we're running at a low rpm I can feel it where it's heavy here and it's not there so again we're just taking off ever so little the black that you see here is coming from the lap itself and a little bit from the part so we'll take a look at that we'll wipe it off see what it looks like I like to wipe it down with Kleenex or tissue you can use a towel if you choose but this is my favorite way of doing it while we can speed it up a little bit and if we do we'll get a little better finish remember the run out doesn't mean anything so I can see that we're starting to take off to see the difference in a texture Jim I don't know if you can pick it up between here and here but there is a bit of a difference so we are starting to remove a little bit of material all right so I'm going to make a little adjustment crank it in just a little bit now I can feel it now it's a little snug and again I'm going to put a little more compound on on each end I can feel a little bit of wobbling which tells me that the parts on a round just slightly it's not going to take much remember we're probably talking we're probably talking millions you know when you're taking off a couple of tents with a lab it's really nothing and again we're using a very fine compound we're using I think it was 1,200 exactly there you go and I'd like to go back and forth it's nothing more than sandpaper like 1,200 sandpaper remember this is a method of stock removal so the first would be machining would be the first step next would be grinding last would be lapping and then when I pull it off I like to go fast that way it doesn't hang up on me so we'll wipe it down and see what we've got I can pretty much tell by looking at it because the finish will be different that's a beautiful finish so most of the grind marks have gone away and what I'm going to do now is give it one more shot and then we'll give it a measure see what it looks like so put a little compound on there there we go be a little stubborn remember when you put the compound on you're wiping it at the other end so you need to put some compound on this end as well put a little more on there and again the black that you see is partially some of the lap itself is sacrificial for the part laughing is not really that difficult but you need to understand the cleanliness you can't contaminate one compound with another if you have 1200 you have to make sure that you clean the lap out if there's anything coarser in there than the 1200 so I kind of like what we've got right here one more pass I can and you can feel it when there's an out of round condition or there's a size different in the middle at the end you can really feel that and we measured I'll show you what I'm talking about exactly and I like to turn the lap around sometimes so we'll give it a wipe and let's see what we've got I think we're ready to measure Jim and there's probably going to be some compound in the schools but for what we're doing is going to make any difference you know I don't like using a rag because a rank could get caught in the Chuck and that's not a good condition the Kleenex gets caught in there the tissue gets caught in there and they're gonna make a difference right Jim put a rag good good could be dangerous so I don't like to use a rag for that look at that finish on there it's like Chrome in it that beautiful just like a mirror I love laughing and again we took hardly I don't think we took anything off to speak up well we'll take it over to the comparator and we'll give it a shot take a look at it see what it looks like but I'll bet you we didn't take off more than more than a couple of tenths because if grind finish on dirt was pretty good now if the grind finish workhorse you'd have to use probably a different compound up front and then finish it with a fine compound but the finish on here was pretty darn good look at that is that cool that's a beauty in that all right so we'll take it over and we'll check it out with a gauge box I'm going to lap it just a little bit more look at that it's a tenth it's on size there and it's a tenth bigger I'm going to lap it again you you you'll notice the Kleenex is good for something else besides blowing your nose now what I like about this finish is that there's no contaminants in there ie no chips in there something that we're left to swirl mark from God dirt or does it was in the air it's pretty darn clean so you don't see any scratches it's a got the same finish all the way through so give it a check so I love this finish it's almost black it's beautiful if you look at this end which is a ground finish in this side which is lap a big difference and we didn't take much off we took a couple of tenths that's it so let's check it for to make sure ha there we are right on sighs exactly in the middle we're about 50 millions under and at this end we're about 25 millions over so that's within 75 million or less than 1/10 of Sighs so remember all we used was 1200 and it's a beautiful part and what did it take it took maybe 10 minutes 15 minutes to do it so if you really need to bring it within 1/10 or 2 or under that's the way to do it using a lamp using this type of a lamp is a helical lamp and you can see it's got a spiral all the way through it so when you tighten on the on the holder it collapses it evenly all the way around instead of having one slot I never liked the one slot there tend to be a little egg shape so this comes out put a new one in when they wear out in the meantime we just continue to tighten until you get it down to the size that you want so this high view is the best lap to use I have used them for years and will continue to use them here at Suburban tool so next we're going to do an IV all right so we're going to do the ID of this bushing the objective is to mate it with this part so we've only got a few tents to take off so again we're going to stay with a 1200 laughing compound which we feel will be more than adequate so again being careful do not use rags around the machine I happen to have a little screw here with an arbor on it that gives me the ability to have some leverage so I'm going to slip that on nice and easy turn the machine on and I'm going to take some 1,200 and just touch it up remember we're only taking off a few tents we're not taking much off it doesn't take much remember you're you're all you're doing is you're getting rid of the grind marks inside the hole so it's you're taking very very little stock off a couple of tents at the most so what I'm going to do now is pop it off I'll clean it out with a brush so clean it out a little mineral spirits I like to make sure that we get all the residue out of there remember there's a good opportunity for lapping compound to get inside the threads of the screws and that's not good so I'm pretty comfortable that we've got a pretty good-looking part there we'll see how it fares on on the mate oh yeah that's what I call a slip fit not too loose not too tight beautiful slip fit so that's all there is to lapping on lapping an ID and remember that this is an expandable lap so you can tap on it as it wears and it will it'll expand so as your part expands your lap will expand you keep putting a little compound on front rear go back and forth a few times take it off and check it and if you've got a slip fit like that that's what you're trying to do so in the event that you want to laugh larger parts of course you can get larger laughs that's pretty Elementary there's a point of no return where you don't want to get too big I don't like laughing beyond say an inch and a half but that's me some guys will laugh bigger than that using an arbor with an expandable lap that's about maximum anyway for more information take a look at our website you'll find our website at sub school comm and check out our other videos remember we had a primer on laughing prior to this one so take a look at that one as well and thanks for watching you you you Oh

Channel: SuburbanTool Inc

Views: 130,914

Rating: 4.9135804 out of 5

Keywords: ID OD LAPPING, Lapping steel, Don Bailey, Suburban Tool, Surface Grinding, CNC Machining, Hand lapping, od grinding, id grinding

Id: H2SeLcbcYkE

Length: 17min 41sec (1061 seconds)

Published: Tue Sep 15 2015

Reddit Comments

[u/guetzli]

Just as with polishing or breaking an edge with a file on the lathe it's perfectly safe if you're paying attention.

[u/Harrybaert]

As others stated, perfectly fine if you pay attention and remove the handle on the holder just like the thread die holder for the tailstock. If ist gets a life of it’s own, just let it go.

Inside and outside honing on an old manual sunnen machine is not that diffrent beside you have a pedal to engage or disengage the belt drive.

If you plan on lapping on a lathe, protect all the ways, all levers, the chuck and all moveable parts from any lapping paste as you can embedd the paste into your ways and slowly grind them down.

If you have a good lathe and are able to produce bores within small longitudinal tolerances you can built aluminium lapping cylinders on your own.

Inner ring with a slot and grooves longitudinal around it as reservoirs for the lapping paste and dust. Outer slotted ring with thread holes and bolts to adjust the size of inner ring. Then some diamond paste and WD40 to adjust your viscosity

[u/VoteForClimateAction]

You'd need to be pretty retarded to get an actual injury from that op

[u/I_Lick_Bananas]

I've got a lot of those laps from collecting old machinist chests, never knew how to use them. Anyone know where I can buy the holder?

[u/dominicaldaze]

Just saw on my YT feed that the master Rob Renz made a youtube video 4 years ago on lapping. This one is on the mill but most everything translates. Had some good tips on "feel" as well as protecting your machines while working with lapping compound. Thought you'd enjoy:

https://youtu.be/AEsaSN4LLU4