 Greetings, calculator friends. This is taking apart a 1920s Monroe mechanical calculator. Part 14, episode 14. So when last we left, I was trying to take apart the carriage mechanism. And we had loosened this end of the smaller digit wheel axle thing, I guess. What are we going to call this? Well, so this is actually the totaling mechanism. This is sort of the item count mechanism that you use during multiplication and division. This actually displays the total. So let's just call this the total axle. So anyway, so we had loosened this end, but I couldn't get into the other end here because the center axle was in the way. And so I determined that I needed to take the central axle out. The central axle has this screw over here and a nut over here that I was having a little difficulty removing. I just got myself a thinner set of pliers and I was just able to reach inside there and turn the nut. So that worked out well. So now let us continue. I will hold the nut in place and then remove this holding thing. So what I did was I left the adjustment set screw in there. I'm probably going to do that for the other ones as well. There's no real point in removing the set screws once we've already measured one and determined what size it is should we choose to replace it. So this will go in bag 14, but before I do, because these two parts look the same, I'm going to measure them. So this was the one that I took off of this opposite end over here. It measures in length 0.403. Its diameter over here on the outside is 0.565. So now I'm just going to look at this one. It's 0.417 and its diameter is 0.562. So basically they are the same and the set screw is going to be the same as well. Alright, so I've removed that nut. So now the question is can I remove the central axis? And it doesn't look like I'm going to be able to. Well, yeah, boy, these parts must have been put into their locations in a very specific order. Because I thought I'd be able to get this out. But it doesn't look like I am going to be able to. Nope, okay, let's see what else I can loosen. Well, maybe I can loosen this end of the total axle as well and maybe lift it out as one unit. That's a possibility. So again, I'm going to take my really thin pliers and attempt to turn the nut. Turn the nut. It's a little bit difficult, but I'm sure it can be done. That's difficult to do. Maybe I can loosen the screw on the side. Okay, so after fiddling around with this for a while, I've determined that maybe the middle part, the middle axle cannot actually be removed unless this totaling axle is actually removed. And the reason for that is that this central support seems to totally prevent this middle section, this middle axle from being removed. So if I can't remove the middle axle, I absolutely have to remove this part. So what I did was I took the really thin 9-16 inch Crescent wrench and I was able to reach in here and undo this nut over here. Which means that I can now remove this screw from the end. Yeah, it would help if I held on to the nut. So I'll remove the screw from the end. Turn this now. I'm pretty sure this measure is the same as the others. Yeah, .395, which is pretty close. And .560, which is also pretty close. It also has a set screw, so that goes in there. So now I should be able to simply lift out, well, maybe not simply, but with some manipulation. Ah, there we go. So I can just lift this out just like that. There we go. I'm going to set carriage aside. Focus out a little good. So here's the entire thing. So we have, number one, a nut. And the flat end of the nut faces outwards like this. And there's a little bit of a, there's a little bit of a lip on the side if that faces in towards here, towards this end of the axle. Manuring. We can measure the thickness. And that's .158. I suppose we can measure the inner diameter as well. .393 or so. So that can go in the bag. And what else can we loosen from this end? Nothing. So from the other end, we have also a nut. This appears to be just an ordinary nut that fits onto the screw. So this is .187 or so. What I'm going to do is I'm going to go and find that original screw in the bag. And I'm just going to screw the nut onto it so that I know that it's a pair. So the other thing is that there's this lock here. Now the lock has a sort of, yeah, the lock has a sort of tab on it and there's a sort of a cam that turns around inside. So it can raise and lower this. And what this has the effect of doing is it sits on the axle and it actually drops into a hole in the other axle, the other digit axle. And it prevents it from moving. So in that way, I guess the central wheel can control whether the axles can move or not. So I'm going to put that in the bag. And now we can see that we have something attached with a taper pin, which is our nemesis on one end. On the other hand, we do eventually run into something that has a taper pin. So what I'm going to do, and this end right over here, there's actually a clip that holds this part in. I'm not going to bother taking this apart. Essentially the way it works is that we have a whole bunch of digits. These wheels are actually made out of plastic and they were formed with the gear, the metal gear. And there's a little spring between each digit that serves as a detente. And some of these wheels are extraordinarily hard to move. So I think that means that I really, really need to clean this up really well. Because ideally you would want it to spin nicely like this. But see this one spins nicely. This one sort of spins nicely. This one barely spins at all. So obviously this needs to be cleaned somehow. So I think I am going to be forced to remove the parts that are on taper pins for this. So in order to prepare for that, I am going to remove this clip. So it's just a simple clip with just a little bit of force. All I have to do is take the small pliers and insert them on either side of the clip and then just sort of push out on it to get it out. That's the idea in any case. I can actually do this. Surprisingly difficult, like most things. Well obviously that's going to have to take a little bit of thought to get that out. So I'm just going to set that aside. So a quick update. So I found that this part, which was sitting on here, was held in by this clip. And I did manage to remove the clip simply by prying at it. Basically with this tool, the dental pick, which is a useful thing. And behind it I found this really thin washer over here. So it's really, really thin. No, okay, sorry. That wasn't actually the washer. I picked out the wrong one. This is it. Yeah, here we go. This is a really, really thin washer. It's almost, almost like foil. Well, maybe not quite like foil, but it is point. It looks like it's about point on focus, focus. Why don't you focus? There we go. It is about 0.012 inches, which is pretty small. But anyway, that was sitting here right over there. And then the clip was on top. So that was that. The next part is this part, which has a taper pin. As you can see, I was able to tap the taper pin out after several iterations of heating with a heat gun and spraying it with penetrating lubricant. And then I just tapped and tapped and it came out. So that's a good thing. So I'm going to remove that right now. Okay, so there is the taper pin. Aren't you focusing? Okay, there we go. Taper pin. And now I can just remove this part. So, and we, again, we have to look at the orientation. So if we look down along the shaft, if we look at the front part, we can see that there is this little cutout on the surface. And on the other side over here, there is a gear, but focus. One part of the gear here actually meshes with a circle. So if we look down the shaft like that, we can look at the orientation and see that this notch is basically on the same side as that sort of surface. So if I remove this, we'll be able to remember which side is which. So that's really important. Just pry this off and give it a gentle tap. So anyway, while I remove that, again, we'll have another jump cut and hopefully I'll be able to take off the next part, which is taper pinned in. This part has a taper pin. None of the rest of the parts do until we hit the very end where there is a taper pin on focus, where there is a taper pin over here holding the other side. I probably will not need to remove that, which is a good thing. The fewer taper pins I have to remove the better. There are pieces of styrofoam all throughout this thing. And I'm wondering if some styrofoam didn't get into these bearings over here. So, wow, this one just does not move. So it's a really, really crucial thing to get all of these parts out. So that's why I'm working so hard on removing this. Okay, so after the jump cut, hopefully that part will be off. So jump cut now, maybe. All right, so we're back after the break. And in fact, it's been about four months. Life got in the way. But anyway, I'm back. So when we last left, I was trying to get the taper pin out. You can see that I did indeed get the taper pin out. Not without some unfortunate consequences. So before we get into that, basically these are the two parts that form the digit wheel. There is basically just a numeric wheel on a gear. And then there's a thing that sticks out here and a thing that sticks out here. One of them is to trigger the carry up to the next position. And one of them is for the carry mechanism to flip it by one digit. The other part here is basically just a spring-loaded detente. And you can see that there are 10 little divots in here, so that when both parts fit on the shaft and the digit wheel rotates, basically the spring and little rod thing here act as a detente. So the wheel has 10 distinct positions. So that's nice. What isn't so nice is what happened when I tried to take the taper pin out. So I had my heat gun and I sprayed some lubricant on to this part. This is where the taper pin goes in. This is where that is secured to. And I sprayed some lubricant, I heated it up, let it cool down, sprayed some more lubricant, heated it up, let it cool down. All of a sudden this digit wheel that was actually next to it just sort of started smoking. And I was like, oh, God, what's going on? And it wouldn't stop smoking. I blew on it and the whole thing basically just disintegrated into a piece of ash. It was like spontaneous. There was no stopping it. I ran it under water. That didn't stop it. It just turned into this black ash. So what happened? Well, this is actually made out of cellulose, which is the thing that old movie films are made out of. That has kind of a low spontaneous ignition temperature. I think it's something like in the high 200s or low 300 Fahrenheit. So when the shaft got hot enough, the heat was transmitted to the wheel and the wheel just spontaneously turned into ash. So that's pretty bad. But all is not lost because what I then did was I made a model and I 3D printed it. This is the result that I got from Shapeways. You can see hopefully the indentations of the numbers. These are pretty much identical. I even put five holes in here where these five rivets go. And let's see. What I also have is just get a little piece of the rivet. Here's a piece of the rivet that I cut off that went into here. So this is the gear without the wheel or the rivets. There's actually a piece of a rivet over here. There are spacers on each rivet because you can see that the wheel is held off of the gear by spacers. And I measured these rivets. They're more like pins, but they basically act like rivets. You stick them in the hole. And what I did was when I got this from Shapeways, I stuck this through the hole and it actually fit perfectly. And I couldn't believe it when that happened because usually with 3D printing, none of the measurements come out so exact. And this seems to have been exact down to like one or two thou, which is very impressive. The material that this was made out of is fine detail material. I did make other prints using their regular cheap plastic and that turned out really bad. It didn't look very good at all. I painted this white. I'm going to give it another coating so that hopefully it'll end up looking about the same. And then I'm going to put some black acrylic paint inside. So that is basically the story of how I only ended up with one of these digits when I took off two. Let's see. So the other thing is that there is one special rivet, this one, which is this one over here. And that is, I think, the carry up to the next digit. So in order to make the rivets, what I did was I took various samples of wire. This is aluminum wire. And I just found different gauges of wire. And I got the gauge that was closest, which is 16 gauge aluminum wire. This is actually copper wire. Copper wire that has been tinned. It's 16 gauge and it fits exactly in these holes. So this is a really, really good substitute. Now to make a sort of pseudo rivet out of this, basically it's kind of a jewelry technique. All you basically do is take the wire, stick it in the vise, and then take a small hammer with either a flatter or round end. I don't think it really matters that much. And you just gently tap the top of it and that sort of makes the top a little flat. That means that you can put it in and that's it. That's the end of it. So that's nice. So I can make four of those. I can put them through here, put the spacer on, put it through here, cut off the excess, and then, you know, with a hammer, secure it in place. That will work for four of these rivets, but not this one. This one, it kind of looks like the rivet is sticking out, but it actually isn't. It's actually thicker. And if I look at this closely, I can see that this has been turned on a lathe because there is kind of a tiny little central thing sticking out here. And you typically get that when you turn things on the lathe. Actually, no, I take that back. I'm not even sure what that is because if that were from a lathe, they would have filed it down. I'm not entirely certain that this is a cap that sits on the rivet. So anyway, what I did was I just measured it and I got on the lathe and I made a substitute out of just... This was made out of a quarter inch drill rod. Basically all I did was I went to the end of the drill rod and moved the cutter in and then moved the cutter this way. So the cutter was actually flush with the end. So I moved the cutter this way and then I measured it and then I readjusted until I got exactly the measurement that I needed. And then I just sort of cut in and that made the first section. The second section was just a matter of pulling the cutter out for the necessary distance and then cutting it over again. And then finally, this pin at the end, I used a parting tool just to go in there and measure the distance. And then I moved back out and used the parting tool to just cut the rest off. So that is basically this pin right here. So that's kind of cool. So that's really about it. The next thing that we're going to talk about on the next video is why some of these are working pretty well and why some of these are not at all working well. This one, it just seems to be greasy. It turns. This one, this one doesn't turn at all and I have no idea why. I can look at the detente to see if that's maybe stuck. This one turns really well and this one, this one's a little sticky. It works well when you turn it one way but not so well. It's a little notchy when you turn it the other way. So each one of these wheels has something wrong with it basically. So I am going to take all the wheels off, clean them basically, lubricate them, and I will examine the detente to see if there's anything wrong with that. It should just be able to push in and it should come out just like that. This obviously needs cleaning because it does get stuck. So cleaning, oiling, and hopefully when that's done this will work. The big wheels, do they have the same problem? Yeah, I think they do. Some of them definitely do have the same problem. So once I take apart the small digit shaft, I will have to open this up and take out the large digit shaft, which is a little unfortunate because we've got more taper pins and you know how much I love taper pins. This is going to be a problem because the digit wheel is right over here and I would have to apply heat over there. So one thing that I've been considering is using that freezing spray stuff to maybe freeze it and then maybe heat it up slightly, you know, not very much, and then freeze it again. That might be an alternative. We'll see if that actually works. So anyway, I guess that's it for this 14th episode of taking apart the calculator. Hopefully I will see you back on episode 15. Just a little bit of comment. I have disabled comments on all of these videos on YouTube. The reason that I did that is that I used to have a channel with some videos and it was just such a pain trying to curate all the comments. Every so often you would get some jerk who would be a typical YouTube user and post stuff that basically comes out of the cesspool and then I'd have to go and delete it. And it got to the point where I had so many videos and so many comments that were like that that it just wasn't worth keeping up anymore. So this time around I decided to just disable comments altogether. That's a little bit of a shame because I can't get any feedback from you legitimate people who are looking at this. So I'm going to have to figure something out about that. In the meantime, if you really, really want to contact me about something, you can contact me at robert.c.baruch at google.com. And hey, Google's got spam protection. So, you know, if I get spam or crazy emails, I can just teach Gmail how to avoid those in the future. So again, if you have a comment, please email it to me. I will see if I can address it in the video afterwards, kind of like a viewer mail section. So again, that's robert.c.baruch at gmail.com. Did I say at google.com? I did. I work for Google, so I have a different address for Google. So that's at gmail.com. Sorry about that. So until next time, I'm Rob. See ya.