That's a fascinating insight into gear making. I'm an electronics bloke so looking into the world of making gears is like entering a dark cave.

Well, yeah, that kind of gear caculus was one hell of exam at machinist school, 33 years ago...

I had to take some machinist's lesson in university. I only remember this "If the teeth do not meet you can add half a tooth or skip a tooth, OR you can learn from me how to do it properly." I was hoping for some hands-on exercises with a lathe, but it was all just boring equations and tables, so I soon forgot it all.

In the other hand this sharp tooh profile would be ideal for 3d printer extruder. Like in the new extruder from prusa.

no flat bearing would be best. LAteral

@@jasonputtock4428 even better👍

You're going to want the blank disc tight to the surface in a small device like this. I doubt there is a ton of clamping force here. Open space just allows "chatter" to happen.

Bien vu, il faut retenir dans cette démonstration que c'est une véritable petite pépite en matière de bricolage, et effectivement j'aimerais voir ces personnes qui abordent les caractères plutôt techniques des pignons d'engrenages fabriquer cet appareil avec la même imagination et une telle minutie, non seulement c'est réalisation est pratique pour qui elle peut rendre des services mais de plus c'est un bel outil parfaitement réalisé.

if you kept winding it in, so the gear got smaller, wouldnt it eventually go back in sync?

Of course this would happen, because the size of the circle determines how many teeth it can fit. Or in other words, the total circumference of the circle needs to be multiplied by the size of the tooth being cut into it.

@@peoplez129 To an extent yes, but it wasn't quite that simple. I'm not sure if I can describe it clearly, but if you started with a blank that had the exact circumference you needed for it to theoretically finish on a whole tooth, it still wouldn't necessarily work. The problem was that (For example) if you wanted a 10tpi gear with 100 teeth, you'd "know" that you'll need a blank with a 10" circumference, so a diameter of 3.183". The thing is though, when you start cutting on the 3.183" circle with the tips of the cutters teeth you'll have that 10tpi, but when those teeth are fully formed they'll be somewhere around 0.1" deep, so the effective root diameter will end up 0.2" smaller, and this new diameter may NOT be devisable into a whole tooth count. As I said, I'm not sure I've got the words to fully explain what I'm trying to say (It's 06:30 here at the minute, and I still haven't managed to get to sleep, so that doesn't help. :D). I found that way I needed to do was very slightly oversize the blank and start with a deep enough cut for the cutter to have a path of least resistance to follow on it's second pass. This usually resulted in one tooth looking too wide until the gear was finished, but every time it went round it would be taking material off the leading face of the teeth before it, both sides of the fat tooth, and the trailing side of the ones following it. Once the teeth get part formed then the gear sort of guides itself and it'll be OK, but it seems that a difference of 0.01" on the diameter could be enough to prevent it starting to do this self guiding. I hope this makes enough sense for you to work out what I'm TRYING to say. I've got a horrible feeling that I'll re-read this later and even I won't be able to follow what my sleep deprived brain's been wittering on about.

I’m guessing he simply measured the distance required between the pulleys..

you would need something like a drill driver for this most motors aren't easily reversible ...as far as I am aware anyway

@@TalRohan Just mirror design and direction of tap will be flipped too.

It looks like an DC motor, all you have to do to reverse direction is swap the power wires.@@TalRohan

@@TalRohan No, it's a simple DC motor, all you need to do is reverse the polarity in order to reverse the motor direction.

​@@seanporter8821j'y pensais à la première remarque, c'est à peu près sûr qu'il utilise un moteur à courant continu donc très facile d'inverser le sens de marche puisque c'est juste un échange de polarité, et aucun doute que ce monsieur est assez imaginatif pour coupler un petit inverseur à son moteur, enfin ci s'il voulait travailler avec un moteur à courant alternatif il peut essayer de récupérer un moteur de volet roulant extrêmement puissant et fiable avec une inversion de rotation toute aussi facile à réaliser, vous montez ou descendez vos volets à l'aide d'un simple interrupteur inverseur je pense même que c'est l'idéal s'il veut travailler en courant alternatif.

Probably by using the thread pitch of the tap to determine how many teeth per mm then figure how many teeth you need in the gear and multiply by the distance between the teeth to get your final diameter

@@jacobkudrowich I like your way of thinking. But you forgot to add the length of the circle

Your speed and diameter is going to dictate the number of teeth. What it seems like he’s doing is simply letting the tap cut. I’ll bet he didn’t take the angle of the taps thread in to consideration,that would make better running gears. Former gear cutter, you have speed, feed, pitch and cutter angle to cut correct gears. Your just playing around with something that kinda works.

@@morris4069 I don't think the speed matters in the case because the teeth will line up inside the tap threads without depending. You just have to make sure the diameter of the circle will give even teeth spacing

I guess the circumference of the gear must be devisible by the tap's thread pitch.

Another comment suggested to mount the tap higher, and then shimming beneath the gear being cut to move it one shim thickness at a time. I think the real difficulty might be aligning things so that the teeth are lined up.

From easy equation for module that is M = reference diameter/number of teeth, or M=Total Diameter/(number of teeth - 2) or M=circumferential scale/pi (circumferential scale is from google translate, not sure if it's called like that in english, it's just the distance from one point on one theeth to the same point on another teeth) hope it helps,

That is a cutting tap, you can tell because it’s cutting.

And perhaps having the tap come from the other side so that the gear is supported by the fixture base instead of being jarred upwards?

Indeed (involute) but it's not for backlash, it's for "smoothness". Here it doesn't matter : it's not for heavy application / he will be fine

Involute tooth forms will in theory roll at the contact line on the tooth flanks rather than slide.

Après avoir regardé ce type de vidéo c'est vrai qu'on peut émettre toute sortes de critiques , pour ce qui est de votre idée d'utiliser une perceuse qui permettrait de changer de tarauds là encore suffisamment d'imagination chez notre concepteur pour intégrer un mandrin sur le roulement et je suis quasiment certain que c'est pour cette solution qu'il opterait.

I was wondering the same thing

@@nicholaswouters1203 me too, I just came here from hackaday to ask this question

I may be wrong, but this seems quite similar to knurling where you need a specific radius for the blank you're cutting - based on the Tooth Per Inch of the cutting tool you'll be using (there are calculators online for this). So these gear blanks are likely cut to a precalculated size before being machined into gears.

@@Syclone0044Me too :) I found the answer in the comments below - the radius has to be a multiple of 2mm (as the tap has a thread pitch of 2mm)

@@nicholaswouters1203 not the radius, the circumference

It would bind with downward pressure, upward pressure allows the gear to turn as it's being cut.

@@MIKE_FROM_DETROIT You could add a nylon washer beneath it to minimize friction. I did it that way on my lathe and it worked flawlessly.

Climb cutting is the best for chips and making the teeth on the cutter last longer as the chips start smaller and form larger vs start large and go smaller. This is just my assumption though as to why he did it that way. CNC milling cuts the same way.

Upon further inspection it's conventional milling because the setup isn't very rigid

C'est un peu vouloir couper un cheveu en 4 votre remarque .

Bearing was not greased but glued.

Ce n'est pas de la graisse