Gears! - But Were Afraid To Ask (MiniLathe)

Hey, these

gears

really work well. I will be welcome back to Greek. One more stinky thing on the channel today. I thought we could talk about

gears

and more gears, courtesy of the plastic gears that came with my recent mini wave purchase. This is a I enter the topic with some trepidation for two reasons: first, there are already many better videos on the topic and second, I'm not exactly Cosmo Spacely. I don't do this every day, but if you pay attention, you'll find It's Not That Hard Now, if you had the rewind to hear that last sentence again, you'd stop this video right now, specifically the two big drive gears.

I would like to make them out of plastic, not plastic, I mean steel, aluminum or brass. Whatever I might have in my pile back there, I haven't dug out yet, but I'd like to make them as big as I can and still fit in the gear train of the mini blades to slow the feed rate. of the machine, you may or may not remember my complaint in the infamous mini lathe video that, out of the box, this gear train seems too fast for my taste and that slower might be better for putting all those pieces together for you , although I run the risk of insulting your intelligence starting from the beginning, be patient.

I'll try to make this as painless as possible for both of us. A gear is a simple machine. I think the weight is a component of the machine. Maybe not, that's not right. The definition seems strange, sir, look, we all know what gears are right, these round things, full of bumps and bumps and are used in pairs to transmit torque and quite efficiently. You could add spur gears like this that are pretty close to 100 percent efficient, ninety-eight percent maybe. What that means is that if I put 100 twerks in this, say one car engine, the other will generate 98 pairs again, maybe two tires, only two of those pairs are lost to friction, heat, cosmic rays or whatever , Let's say.

We reduced the gears to just these two wheels to round out things that don't slide where they touch and can therefore transmit torque from one to the other, since we lost this anti-slip smooth wheel technology when the Aztecs chased away the aliens using On Egyptian pyramid lasers, we have had to come up with another way to prevent two wheels from skidding. I've pulled out some prehistoric Flintstones style gears. You'll notice that the teeth are square and, with any luck, you've never seen a gear like it. this in real life outside of maybe some bad clip art, also note that they are the same size, so our gear ratio is one to one, no torque or speed change, just a change of direction, a fun fact, made up, this was probably our first collective attempt at this. two wheels to engage without slipping.

I mean, at first maybe they weren't square lugs, maybe they were wooden pegs or like dinosaur ribs, but you get the idea that we have some kind of tooth for lack of a better word on both that mesh into each other. . another with teeth hooked between the two, now there is a place where one wheel can push the other and transmit torque. Taxa set up this way probably worked very well for a long time until our ancestors tried building things like wristwatches and helicopters, but they worked. funny and eventually they broke apart general rule if you build something it tears alone it's a good sign you're probably not there yet let's take a closer look at what the teeth on our gear are doing note where the contact point is between the teeth.

You will slowly move a gear and try to trace that point of contact. You see it move up the tooth flank from the bottom of a tooth to the top and, more importantly, the direction of the contact force between the teeth also changed. What that means in practice is that the speed of our output gear is not constant. If you drive the input gear at, say, a hundred rpm, it will oscillate around that 100, perhaps going from 95 to 110 and back again as the teeth mesh in and out. I'm just doing those numbers, but I hope you see that here we do not have a constant speed.

This has been what one might consider a gross oversimplification just to get the point across. I ask geologists to take a deep breath and unzip your panties, the shape of the teeth is important and for many more reasons than just speed or constant torque, I mean notice these gears are exactly the same size unlike most of the other things on this channel that weren't an accident on this In case you can't make a different size square tooth gear with the same profile and get the gear to work, they jam the binder, they probably won't even mesh if you don't You noticed my use of the words jam and bind well, there is a problem and Of course, you don't want to customize each and every gear when you need a gear train.

Well, let's get to the point mainly because I don't understand this topic myself, but instead of admitting that, let's say that gear profile development is out. the scope of this video is involutional gears, there you have it, hopefully the tooth shape looks familiar to you. These are just three teeth per gear, of course, through these, cut them out and plan to demonstrate what this shape of the tooth does now that I'm sitting here holding these. The fact that they look like cow udders is scaring me or that Howie Mandel glove, I'm not sure which is worse.

Instead I'll borrow this cute animated gift from the internet from 2019 anyway, the involute is the most popular team for Launch Fails, in fact it's been in the top two for probably a hundred years now. It's not the only one that works, but it has many things going for it that make it very popular with children. First, the speed is constant like teeth. It rolls in and out of the mesh, it doesn't fluctuate like it did with the square peg gears in particular, keep an eye on that blue arrow showing the direction of the force, notice how constant that direction is where it's pointing from the beginning of the mesh. mesh to the end of the mesh, second, this is a big problem, it can be hard to understand, but we'll get to that in a second, the tooth profile only changes based on how many teeth the gear itself has, not based on the number of teeth the gear has. other gears that it needs to mesh with has a small gear that will mesh with a large gear just as well as it will mesh with this medium gear, it makes each gear somewhat independent of the rest of the things you're trying to design it for.

Involute third gears have the added advantage that the distance between centers at which you ride them is not very sensitive. You can install them closer or further apart and the speed and torque they transmit will remain the same. I mean, if you separate them that much. that they don't fit, that's a problem as it jams them all in each other's personal space, but at a reasonable distance that tolerance is not as strict as it could be with other tooth profiles, in fact, you remember the machine Alex pasta. In fact, they used the gear mesh to accommodate the thickness of the noodles because of that involutional gear profile, it didn't really matter if the roller gears were closer together or farther apart, they still ran at the same speed because the gears were of the same size but the same speed but in opposite directions.

Can you imagine what that would look like if one of those two rollers moved at a different speed? This isn't really important, but I thought I'd take the opportunity to demonstrate it. How involute is, it may sound like an intimidating mathematical term, but it doesn't have much to do with it and since this demo has always been a hit for me at parties, I thought I'd make it for you too. What we have here is a square now, if I take a rope, I wrap it around this square, keep it taut and I trace the curve that that taut rope generates those curves are the involute of a square, it is the involute of this shape if you did this with, say, a mini lathe you would end up with the involute of a mini lathe in the case of gears, when they say involute they mean the involute of a circle, so if the shape of your base is round and you trace the curve using a rope like this, this is the gear.

The tooth shape we've been talking about or will talk about a larger base circle will give you a slightly different curvature than the volute, as will a smaller diameter you start with, but mathematically the shape you get is the same where On earth, even to begin with, ears are measured by their pitch and number of teeth, not by their diameter, not directly anyway, but of course those things are related, you can't say a gear one inch or a 30 millimeter gear. how many teeth they have and how big those teeth are. Kind of like with sharks, we have two popular systems, one for imperial gear called diametral pitch and one for metric gear called module and just like inch and metric screw threads, the diametral pitch in module are essentially what same except they don't work with each other for clarity we're going to stick with the module system in this video simply because the gears I want to make are metric my mini onda uses module one metric gears if I have imperial tendencies just think about the step diametrical every time I say module.

I know the mini permit uses module one metric gears because it is molded directly into the gear m 180 teeth z is the number of teeth just like with threads the skiers must all have the same pitch if they are going to mesh you can't gear a modulus one gear with a modulus two gear, just as you can't mesh 1/8 DP with a 60p gear, just as you can't put a coarse thread nut on a fine thread. bolt I mean, I'm sure there are some people determined to do it, but it won't be pretty. I mentioned that the shape of the teeth changes depending on the number of teeth a particular gear has, it is still the involute shape, but it changes slightly the fewer teeth you put on a gear, the more accentuated the shape of the tooth considers these two extremes this it's a small module, a crash and this is a one gear module out of the mini leaves this smallest one that I could find in the mix It would have been better to show you this with a larger gear pitch, but this is the only combination of things that I have around here, they both have the same pitch, so they fit together very well and if we zoom in on the gear tooth, hopefully we can see that involute profile that we've been talking about, but if you look closely at the tooth on the rack, you'll notice that The sides of the teeth are straight, they are not involute, they are what makes this rack think of as a round gear with infinity.

The diameter like this dirty rusty gear here is gigantic and from our puny human perspective this section here looks flat, it looks straight, if you unwind a rope from a circle of infinite diameter you will get a straight line, so for the rack the gears are straight, the flanks of each tooth is still technically the involute of a circle, it's just that that circle is so big that the curve it traces is effectively a straight line, okay, I think we're starting to get onto something, we're looking at the extremes here more or less. At least, the smallest gear you can usually get is around I don't know 12 to 15 teeth and the largest gear you can get is a wreck with theoretically an infinite number of teeth and since the shape of the teeth changes slightly for each number of teeth between minimum and infinity well, in theory each gear would need its own special cutter on paper 22 than a number of twenty one two three holes between minimum and infinity you don't need an advanced degree in physical therapy to see that well , that's a lot of cutters by a lot I mean infinity and infinity in general tends to be impractical so here's the deal: we divide infinity into eight parts this is a set of cutters for module 1 gears and there are eight cutters eight cutters will do everything The range each set of Imperial or Metro gear pitch are cutters, each fits a certain range of gear teeth.

I just bought this game for this project. I had a couple of m1 cutters but not the one I needed. I thought about importing the full set, I had about 55. It ships for $60 I think, and while I got eight cutters for the m1 set, I'll give them that amount, they didn't exactly order it right. I didn't get a number one cutter. I got a number two, number three, no number. four were kind enough to give me two number fives, six sevens and two eights, fortunately I got the number seven cutter that I need for this project, the change in the shape of the involute in a certain range of number of gear teeth is Solon ufff that can be grouped on the same cutter reading from left to right is for module one the pressure angle is20 degrees that's something we're not going to get into is cutter number two and a note on that in a minute, but you can see it's The tooth is 14 to 16.

Now the numbering here is a little bit backwards from my point of view. A 14 to 16 should be a number 7. These imported cutters tend to reverse what I believe is the standard numerical range if we go by number. 7, the range of teeth it makes is 55 to 134 and since I am cutting a 100 tooth gear this is the one I will use so be careful if you want to cut say a 100 tooth gear. I think you technically want number 2 and not number 7, but my suggestion is to ignore the cutter number and just follow the tooth range that is stamped on it because we are involutely cramming a lot of gears into a single cutter.

Here each cutter is only technically correct for its first number of teeth. so this cutter would be the exact involute for a 55 tooth year and it works well up to about one hundred and thirty four once you get to 135 the error in that tooth shape is large enough to justify the next cutter of this number eight, which I think should have been number one, it's good for anything from 135 teeth to infinity, meaning if you wanted to cut a spur gear this is the cutter you would use as we are all very up close and personal , let's compare the two extremes in The least I have here is that if you need high precision gears and each tooth shape has to be perfect, you can't do it with this system is good, unless I make a custom cutter just for that number of teeth gear, I would resort to gear hobbing instead.

Gear hobbing generates the involute curve naturally by the way the cuts are made, as if the cutters were straight, there is no involute shape and the gear. blank movements with respect to the cutter, resulting in the perfect omluke for any number of gear teeth, but gear hobbing is outside the scope of this video which was quite long, my apologies, this was all to say that we need the right cutter for the equipment we would like to make, we will shoot, that's what I said from the beginning, it could have saved me ten minutes, this is the cutter I need and it will mount on a milling spindle that will fit my milling machine and allow Now the next key to this puzzle is indexing and slicing which I thought this video would mainly be about before I get into the whole thing, if this ends up getting the short end of the stick maybe I'll make a follow up video to have my shape cutter , it will be the right shape and I have a blank gear, maybe I can get out of this.

I'm not sure yet, but I think I can fit in. a hundred tooth gear in this diameter my next problem is holding the blank and more importantly moving it so that each cutter lands in the right place to make a functional gear my problem now is dividing it's no use having the right cutter if not I have a way to move my work exactly one hundredth of a division at a time and I mean exactly ninety-nine and a half gear teeth may seem close enough to 100, but it won't work, believe me. I tried to rephrase the problem.

Starting with a blank with no teeth, if I had a hundred blank teeth, I wouldn't be making this video in the first place. Making the first cut is easy. I just go in on the centerline and finish with my first gear tooth. but how can I reposition the work to get to the second tooth of the gear so that it is where it is supposed to be so that when I finish rotating all this work I end up exactly where I started and have a hundred teeth in my case? hundred teeth, but you know you might want 99, 101 or fifty-two Wood, some splitter heads, this is a BS size zero guesser head, it's a semi-universal head and I apologize for not cleaning it before showing it on camera here.

As the name implies, it's really good at splitting heads to give you a better idea of ​​what it's for. Let's step back and look at simpler division methods. These are called blocks, they come in square and X and contain 5c Kaulitz and the 5c Kaulitz holds your work. I also have a 5c 2 ER 32 adapter. This one has a 5c tail that fits the block and an ER 32 taper in the front for ER 32 Kaulitz. Anyway, I have more ER 32 Kaulitz than 5 seats. You've probably seen this come up a lot on this channel. The square block can divide the work into 2 or 4 parts. 2 or 4 sections held in a vise.

I can cut the top of something, turn the whole block 180 degrees and cut the other one. side that results in two divisions. I can also move it or index it as we like to say the business four times as it has four sides so it's clamped in the vise. I take a cut, turn 90 degrees, cut, turn 90, cut, turn and cut which would convert, say, round material into square material, the hexagonal block does exactly the same thing, except it was born with six sides, six is ​​a bit more interesting than four, this can also do two divisions and three divisions by turning it every two faces that I can do. 120 degrees at a time and end up with something triangular and of course six indexed divisions on each face and the vice, and I can use this to put a hex on things.

Next is perhaps a link between a turntable and a turntable, sir. These are technically for two different things. So far there is a bit of overlap with a caliper block. We have been able to do two, three, four and six divisions. If you need five, seven or a hundred, they won't help you much. rotary table, well, it rotates, this one has a 42 gear reduction and graduated scales on both the handle and the table itself. If I wanted to make a hexagon out of this I would have to move it in 60 degree increments 60 then 120 then 180 and so on, if I wanted to make a hundred tooth gear I would have to move it in 3.6 degree increments which is not easy to make neither very precise nor very nice, they are mainly used for rotating work. so you can cut round features or round slots for example, you can of course do some non-critical splits, let's say you need 10 hole bolts, that's probably fine, but if you do a more precise split you'll struggle with one of these.

You can buy a dividing plate kit for most rotary tables, so if you already have one of these you can convert it into a dividing head, but we'll come back to that in a minute. The slewing platform, sir, or the slewing indexer, like the clamp blocks that this requires. five C clamps or year 32 in my case and although you can use it to simply turn things, its main purpose in life is to provide quick and easy indexing, easy division, it does this through a series of precisely spaced holes, in fact, 36 holes around this large diameter. 360 divided by 36 is 10 degrees, so if I line up that 0 I put the pin at the zero mark, I can accurately do 10 divisions at a time 10 20 30 etcetera, so if I need to make a hexagon with this, I start at 0, I make a cut, then go to 6, make a cut, go to 12, make a cut, go to 18, etc.

Also this has another 9 holes that allow you to break down those main 10 degree increments into individual degrees, it's a vernier scale so if I go to 0 release the pin at the zero mark which is locked then you could make a cut If I move the pin it will come to 1, I let it drop, that's 1 degree, 2 degrees, 3 degrees, etc., until it reaches 10 degrees, I go to the last pin. matches the zero degree hole at the 10 degree mark so it offers a 360 degree division in 1 degree increments, meaning we can use this to divide a circle into 360 hole number divisions ​​again with the clamp blocks with which we had two, three, four and six. the twist exercise now we have 2 3 4 5 6 8 9 10 12 15 18 points for 30 36 44 562 90 120 and since that was totally improvised, I hope I didn't miss any, but if you were paying attention, I didn't say a hundred, this doesn't can do 100 equal divisions.

I can't make the rig with this yet, hence the splitter head. Dividing heads can be considered the love child between a rotary table and an asp indexer, although technically that would be like its grandfather, there are some sordid things going on with this, just like the turntable, sir, offers a plate quick divider, this one has 24 holes instead of the 36 for the turning platform sir, so if we and all these other rubbish for now with 24 holes you can do 2 3 4 6 8 12 and 24 divisions you can't do 5 no they can make 7 they can't make a hundred which brings us to the dividing plates wait let me go get the other one that came and here they are you can remove the plate that is installed on the dividing head and put one of these on whichever one has the pattern complete that you may need for the job in question.

Remember that the rotary indexer had 36 holes and this one has 24. and 36 and 24 gave us an integer number of divisions we could do with both tools. Let's think of this as adding to that and expanding the ones we can put on the plate, resulting in the entire division we need, although the dividing head has one more trick up its sleeve, the connection between the dividing plate and the business end runs at a 40 to one ratio on that reduction, plus these full plates allow a splitter head like this to work. I'm not even sure it's really 2 to just over 360, it's probably almost 400 divisions, moral of the story, this will have no problem making the hundred divisions we need to make the hunter tooth gear for the mini lady, give me just a moment to prepare the gear blanks, install this. in my grinder and we'll talk about how they work, how you would use one.

I won't go into it too much, but it really comes down to being careful and patient, it's easy to make mistakes with one of these, remember it's a big one. The aluminum round I showed you a few moments ago I took to a local deli and asked them to take a couple of pieces out of their slicer. There are two blank spaces there. They are mounted on a bolt. You can see the nut on that side. There is a spacer so I put these clamps together which is probably almost sacrilege, you probably want to do this on some type of spindle like a machined spindle but for the mini lathe and demonstration purposes I hope this is good enough because that bracket is very thin and I want to stay far enough away from the chuck to clean it with the cutter I brought on the tailstock, the end bracket.

I drilled a small center on the lathe on that bolt and I think it's supported pretty well. General image of what is about to happen. I'll make a cut, I'll go back, I'll turn this whole thing a hundredth of a turn, I'll make another cut, do it a hundred times until it's all the way around, but first, a crash course on how to split with one of these and this isn't hard, it's just tedious. , I mean, at least for the type of splitting we're doing, if you start making helical conical flutes or something like that, it gets crazy.

I mentioned that this head has a 40 to 1 crank to spindle ratio, 40 turns of the handle. make one turn of the chuck see if you can keep up with what I'm about to leave, dad, we want to divide the end of the chuck into 100 equal spaces to make a gear of one hundred teeth, that means we need to divide the crank of 40 turns. for the same 100 that's it so how the hell do we make 41 hundredths of a turn on that crank? Think about it this way, if we had a board with a hundred holes, after all, we could simply move 40 holes at a time.

That's what 41 hundredths means, from a hundred you can make a cut, move 40 holes, make another cut, move another 40 holes and keep doing that until you finish dividing, but I don't have a plate with a hundred holes. in it, so let's change that fraction a little bit 41 hundredths is the same as four tenths, that's for more than ten, keep in mind not 0.4 don't convert to a decimal, you want to stay in fractions with these things. They're like fourth graders, they only understand fractions. Unfortunately, four-tenths means moving four holes on a ten-hole plate and you probably guessed it.

I don't have a 10th hole plate so this is what I did. I looked through my plates and found this one that has a pattern of holes that is a multiple of ten. this board has a full series of twenty, so I installed it on the dividing head now that four tenths that we were trying to do before in the context of this board becomes eight twentieths, eight over twenty, it's still the same fraction, it's still being the same division, let's say I start. on that hole where I make my first cut where the twenty is stamped for the second cut, I would move one, two, three, four points in eight holes, technically that's eight spaces, but the same thing is done mechanically, the crank on these heads has a Spring Pin I already set it up for this 20 hole pattern and if I start in that hole I can make a cut, retract the pin, move eight holes and drop it inthe last hole.

My camera lens keeps fogging up. It's raining and today. I apologize if this is starting to get confusing. I'm getting tired of taking it apart and cleaning up one last thing while we're here. You see, these two arms, they're not just for tracking in the moment. They are called sector arms that encompass this. sector of a circle are there to help you avoid counting the machinists realized a long time ago that counting was for fools, so if we started here on this hole we made a cut, we moved eight holes we took a cut instead of counting another eight .

You could simply move the sector arms having set them to eight spaces or eight holes ahead of time, perform a cutting motion again, advance the sector arms and continue until you are done with the project. I haven't actually measured them, but at the risk of speaking too soon I think they might have turned out okay I don't think there's anything more anxiety-inducing than cutting gears You've prepared the blanks Set up your machine Done all the calculations but I'll tell you I mean when you clicked that last index mark for your final cut, let's just say if you weren't a God-fearing person until then, I beveled them a little bit and filed them into a keyway shape and cleaned them up a little bit, as you can see, I pushed the smaller.

I mesh these meshes this way, but let's mount them on the lathe and see how they work. I have good news and bad news. The good news is the gears work great, the reduction to the lead screw now seems much better before we had a 20 - theta dental plate gear 22 8 that's 1 2 4 and the same here 1 2 4 4 by 4 is 16 we had a 16 to 1 gear reduction on the main screw now we have 20 to 120 to 100 which reduces to 5 times 5 is a 25 to 1 gear reduction, they are also not as loud as I expected. I don't know, the comments section of the mini lathe video made me think that the metal gears would be absolute noise, it sounds almost the same as with the plastic gears the bad news is that 102 years doesn't actually fit this mini lathe.

I had to remove the engine cover which would need some sort of notch cut to clear this larger gear and the side cover is just missing because this thing would have to be an extra, I don't know, inch wider, probably about 25 millimeters, If that wasn't bad enough I had to modify the banjo hardware, the banjo is that black metal plate that supports these two gears that this bolt used. to clean the 80 tooth level, but now it runs into the back of the 100 tooth gear, so for now I modified it with an m8 screw with a reduced head on a stack of washers, although it is working well enough to a demonstration he would probably make. a new banjo bolt and not just to make it nice and solid but it's really no big deal in my case.

I realized this might sound a little bitter. I don't even plan to have these years on the back of the gearbox. is to go see and see with this thing and then all this is not even necessary, that's why I made them out of aluminum and not steel. One of the reasons I realize that these videos are already too long anyway and what I would like to do if you are still with me is to make two more videos in a short time. In a particular order, I would have liked to start making your own tooth cutters for gears, not like this one of course, but close enough to make working gears and then, armed with what we learned in this video, how to make your own gears at home using just the mini.

Granted lathe, there are one or two more accessories you need for the mini lathe, but the mini lathe would be the main machine, no mill, no dividing head, that sort of thing is basic as I could sum it up to, frankly, be fine, I've finished now. For now, this is usually the point where I thank you for watching, but unfortunately that's outside the scope of this video.