I actually just wanted to do the drawing, but once the drawing was done I figured since I had come that far, I might as well explain the darn thing too. =)
I am not generally highly impressionable. But in your case, I am making a large exception. This presentation removed the confusion that I have had with worm gears. I am coming back for more of your information and enlightenment. Thank you. You should market the “cad system” that drew your opening graphics. Again, thank you.
Outstanding drafting skills! And a good explanation too. As a side note you could definitely do a series of these in real time with the sound on and call them ASMR.
Another excellent explanation. Little side note: A worm gear assembly is basically self-locking. The worm wheel cannot (back-)drive the worm. Only the worm can drive the wheel due to inherent friction and direction of forces. Can be desired or not. But if you want to use it, you should be aware of this.
I was going to make this important point as well - but checked and see you have it covered. This locking feature is what makes it a perfect design for a tuning gear on a guitar for example- not only the gear reduction.
man this is probably one of the more difficult things to model in CAD, is there some video in detail about dimensioning the gears and teeth, of both parts? meshing and stuff
I would like to ask you about, what are the differences between putting the warm speed reducer on the input (filling material) and on the output (where the material is being discharged “
I didn’t realize how much torque was multiplied through the worm gear assembly! You didnt mention that a worm gear may turn a worm wheel, but a worm wheel may not turn a worm gear.
Very good explanation. And yea draft skills are like other said outstanding. Could You please only check direction of moving wheel (3:08) I believe it is oposite direction. It would be very good if You can clear it out please. Thank You in advance.
If you could design your own tools (especially disregarding costs) would you prefer power tools to have worm gears, wholistically than a hyper specific tool? Say if you wanted to design a circular saw and choose if its direct drive or not (for I assume worm gears would overall provide, on average, less RPM while giving you higher torque and maybe more suited through going into hardwoods) (also direct drive might be more cost effective and probably ideal for small drill bits that you need wicked fast RPMs to have the correct cutting speeds but this being a niche case?). Thanks!
I like the idea but at first glance there may be a problem. The issue being that the worm wheel can not (typically) drive the worm. So if you are using something like a circular saw, the moment you let up off the trigger, the motor stops, but the blade would not... and the inertia of the blade would tear the gears apart.
Hai, wonderful vedio. I have 2 questions for you. Does the worm and roller require grease or steering oil of ranges 140 or 300 or 450 or 600. By second question is does the worm and roller make driving more effortless than circulating ball bearing also called as ball and nut or is the recirculating ball mechanism more effortless than the worn and roller. As I had a fiat 118 NE which was the 124 fitted with the Nissan A12 engine which had the recirculating ball mechanism which was smooth like butter , I still regret for having sold it. It was so smooth even though it didn't have power assistance
Could varying the thread distance (pitch) allow you to change the gear ratio along one shaft? For instance, if it was used in a vehicle moving the gear further forward would change the gear ratio and increase speed.
@@INTEGRALPHYSICS I don't quite know how to describe this, but if a normal rotation of the worm would move one tooth of the wheel, couldn't it be adjusted so half a rotation would move one tooth?
There is definitely energy loss, whether or not you need to worry about it depends on the application. One thing to keep in mind though, is that energy loss will NOT affect the gear ratio, only the actual mechanical advantage.
Great video, can you help me with some worm ratios. I’m making an ebike and using a worm gear with motor to power it, I have a motor that spins at 3500 rpm and would like an output of 350 rpm. I’m looking at a NMRV030 gearbox. What ratio would I need for an input of 3500rpm to get an out put rpm of 350? 10:1? Many thanks
Im not sure of the application, but all other conditions being the same, changing gear ratio like that is likely to overload the motor. Additionally a 10t worm wheel is going to be VERY difficult to design to run smoothly.
I suggest you determine the desired gear ratio. Then, provided you know the desired output torque, find the gear tooth size that will support the needed torque (theoretically this is based on the shear strength of the material as well as tooth profile, gear lash, tolerances and width). In reality, find an existing worm gear design that is rated to a certain load for a given material, use that design.
I have a silly question actually!! If we directly rotate wormwheel and not using the worm what will be the difference!? Should we have to gather more torque or power to work!?
The point of the worm gear is to provide an increase in torque. Using a worm gear, a low torque motor can be used to produce high torque on an output shaft.
Recommend that you take a look at a modern spinning reel schematic.. this is the exact case use in real life.. the worm wheel (handle) is used to turn a pinion gear (which is what drives the rotor) which lays the line The point of using this great mechanical advantage is that it can still drive the rotor even under heavy load (the fish pulling) which is torque I believe Google spinning reel schematic (stella, saltiga, exist, Certate) all model names 👍🏻
I am surprised that leads on the worm wasn't mention, that is extremely important on knowing the ratio, the example assumes the worm gear will always be a single lead, but there are worms with more then one lead, that is how a worm gearbox achieves various ratios, such as four leads on a worm would have changed this example to a 6:1 ratio, when you have a gearbox with a missing nameplate where the reducer is so worn out you cannot turn it by hand to get the ratio you must know this because the speed reducer once broken down almost always has enough tooth left on the wheel gear to count as well as counting the leads on the worm to know the ratio.
Is there a way to switch the input and output shafts on a worm gear? As in could I hookup a gear reducer to the worm wheel to produce an output force to cause translational movement on the worm shaft?
Under normal circumstances if you drive the wheel it will not turn the worm. However if you allow the worm to move translationally, what you essentially have is a rack and pinon.
hi all. i have a question. is it possible for a worm wheel to rotate a worm gear . im trying to design a pedal sysyem for my boat . im after max revolutions on the prop shaft to one turn of the pedal. cheers. plus a worm gear would eliminate the need for a 90 degree gear box
Yes but... When you factor friction into things, I suggest you consider a bevel gear. You can produce the low gear ratio you desire and easily build in the perpendicular relationship between the crank spindle and the prop shaft. Hope my suggestion helps, let me know how it goes and good luck!
i want to make my electric train (DC) free rolling. I.e., u can push it back n forth w ur hand when the elec. pwr is not applied. I call it a free rotating gear box. All the electric model locomotives i have can't be pushed to rotate the driver wheels freely. The drivers r stationary. The only way to rotate the drive whls is to rotate the worm shaft either by the motor or by my fingers... Do u get the picture? How do u design that? I've heard u need a helix worm w a matching wheel gear. But i think it's much more complicated than just the two gears (a worm and a wheel gear plus perhaps a spur gear?). Yes, to produce torque to pull more cars, the gear box also need the gear ratio reduction as u've explained in ur video. I've searched here in the utube and guogle et al, for: 'Free turning worm gear' or 'Free turning gear box' but no luck. Pls advice, u or any audience?
@@INTEGRALPHYSICS Thx 4 ur immediate reply. There was a man from Japan who was able to do that on his 0-scale - 2 rail locos. But lost touch w him. I don't think he used a clutch (to disengage the spur gear from the worm). But perhaps, i may need to look into this clutch deal.
Short Answer: Gear lash = wiggle room between gears Longer Answer: In reality the line of action between gears is not tangent to the base circle of a gear. As a result the gears are not moving PRECISELY at angular velocities given by GR=Win/Wout. To put it another way... If the input shaft turns at constant velocity, the output shaft is going to speed up and slow down just a little bit with every tooth. Gear lash can affect how rapidly that speeding up and slowing down occurs.
Short answer: its 40x the input torque. Longer answer: you are going to need to know the frictional losses along with the worm pitch and tooth profile to factor in losses and inefficiencies.
@@INTEGRALPHYSICS Worm gears aren't anything close to 100% efficiency. Spur gears in the limit of perfection can be 100% efficient, and in practice tend to be 98% efficient. Worm gears are inherently inefficient and are limited by the kinetic friction coefficients of the materials we can use. For a worm gear, 50% efficiency is optimistic, and is typical of what you can expect from the best worm gears available. A worm gear not built specifically for efficiency, will likely have an efficiency around 25%.
Most worm gear systems are specifically designed so you can't drive it in reverse. An application of the worm gear, is the tuning knobs on a musical instrument, which allow you to tighten the string, but don't allow the string to unwind the tuning knob. It is possible with an extremely steep helix of the worm threads, to make a worm gear that can be driven by the worm wheel, but it is rare that we desire such an application. It is much more likely that we would use other gear arrangements if we wanted bidirectional power transmission.
Where is the actual math? I need to figure out the dimensions and angles etc. to make a worm gear for an extruder... I don't know a whole lot about this but i need to make the worm gear to at least... work
you want to machine one? as far as I know it's one of the hardest to machine gears so good luck :D what you should do is just check classified ads, or scrap yards in your area, some snowblowers use worm gears in the differential. some cars do too. save yourself the headaches.
I try to keep these sorts of videos very general because, as you are seeing, things become very specific very quick. My suggestion is start at your desired gear ratio and work backwards from there. The distance between the shafts is the effective sum of the worm and worm wheel radii (to the line of action). Tooth profile and pitch are dictated by load, shaft speed, shaft stiffness, motor torque, gear hardness, surface finish, service life etc. I assume you are trying to 3d print these parts. Worm gears are based on slippage, they are effectively inclined planes, so think about your print orientation. I suggest you print the worm gear on its end so that the layers are mostly in the direction of slip. The wheel can be printed laying on its face. Its not perfect but at least that way the edges of the layers will be perpendicular to each other along the line of action which should smooth the action of the gear set. If 3d printing, I suggest you coat the parts or sand them smooth between the teeth. If you are going to turn or cnc these parts I suggest you pull gears from something like Autodesk Inventor which already has gears designed in the catalog.
@@INTEGRALPHYSICS Thankyou, we have a 4th axis in class in one of our Haas machines, and im thinking about making the gear in there, I'm trying to use everything from a Bondtech Bmg extruder, except I designed a new case, heatsink and now working on the worm gear problem. It's going to be really small so printing won't work great
![[TH] 2024 PMGC League | Survival Stage วันที่ 1 | PUBG MOBILE Global Championship](http://i.ytimg.com/vi/FVFT-PFwU80/mqdefault.jpg)
only 40 seconds in, and oh my god the effort you put into that drawing is crazy. respect
I actually just wanted to do the drawing, but once the drawing was done I figured since I had come that far, I might as well explain the darn thing too. =)
I am not generally highly impressionable. But in your case, I am making a large exception. This presentation removed the confusion that I have had with worm gears. I am coming back for more of your information and enlightenment. Thank you. You should market the “cad system” that drew your opening graphics. Again, thank you.
Thanks!
Great video, was looking how to determine a worm gear dimension size for replacing a lost one..Thanks !
Outstanding drafting skills! And a good explanation too.
As a side note you could definitely do a series of these in real time with the sound on and call them ASMR.
I published my bevel gear sketch once with an explanation, and once just as the drawing. Thats something I can think about in the future.
youtube.com/@thaaiveeduchannel
@@INTEGRALPHYSICS Could you please share the tool you use for strength calculation, particularly for globoidal gears
It's a super clean draft
Another excellent explanation.
Little side note: A worm gear assembly is basically self-locking.
The worm wheel cannot (back-)drive the worm. Only the worm can drive the wheel due to inherent friction and direction of forces.
Can be desired or not. But if you want to use it, you should be aware of this.
Whether the worm assembly is self-locking depends of the pressure angle between the worm and wheel, or if the worm has a double start thread...
I was going to make this important point as well - but checked and see you have it covered. This locking feature is what makes it a perfect design for a tuning gear on a guitar for example- not only the gear reduction.
I didn't expect to have an advantage in slowing down the rotations in the bigger gear by put the worm, but then you reminded me of tork.
Torque is the goal with a worm gear.
This was super helpful! Could you do one about rack and pinion?? Is it a similar concept?
This drawing should be Appreciated
Thanks! It was fun to do.
best drawing ive seen
Phenomenal video! Great explanation and presentation
man this is probably one of the more difficult things to model in CAD, is there some video in detail about dimensioning the gears and teeth, of both parts? meshing and stuff
My god the drawing is so satisfying to watch
Thanks.
Brilliant drawing skills, and great explanation, thanks.
I think it's a visual illusion. The teeth of the worm aren't really moving. It's the edges that are inclined.
You are absolutely correct. No part of the worm ever moves axially.
youtube.com/@thaaiveeduchannel
What a nice explanation and hand writting. Thanks for introducing worm gear advantages.
Glad it was helpful!
I love that stop motion drawing!
HAWK TUAH AT 1:03
please dont spit on the worm gears...
I would like to ask you about, what are the differences between putting the warm speed reducer on the input (filling material) and on the output (where the material is being discharged “
I didn’t realize how much torque was multiplied through the worm gear assembly!
You didnt mention that a worm gear may turn a worm wheel, but a worm wheel may not turn a worm gear.
Big wheel + Small Pitch = Big Torque
If the pitch of the worm is large enough the wheel can in fact turn the worm.
Very good explanation. And yea draft skills are like other said outstanding.
Could You please only check direction of moving wheel (3:08) I believe it is oposite direction.
It would be very good if You can clear it out please.
Thank You in advance.
You are absolutely correct. Good eye. Thanks!
Fantastic explanation. 😊
Thanks!
I really enjoy the art and content of this channel 👍❤️
Thanks! Glad you enjoy it.
nice drawings bro... you take your time
thanks
Cool video! Have you ever tested the Apiro wormgears from Igus? They seem pretty clean and practical to use.
No, I have not.
Wow amazing schematic talent!
Thanks!
Very good information sir thank you
Welcome
If you could design your own tools (especially disregarding costs) would you prefer power tools to have worm gears, wholistically than a hyper specific tool? Say if you wanted to design a circular saw and choose if its direct drive or not (for I assume worm gears would overall provide, on average, less RPM while giving you higher torque and maybe more suited through going into hardwoods) (also direct drive might be more cost effective and probably ideal for small drill bits that you need wicked fast RPMs to have the correct cutting speeds but this being a niche case?).
Thanks!
I like the idea but at first glance there may be a problem.
The issue being that the worm wheel can not (typically) drive the worm. So if you are using something like a circular saw, the moment you let up off the trigger, the motor stops, but the blade would not... and the inertia of the blade would tear the gears apart.
i get it, i get it thanks to your amazing explanation skillls. thank you
should go over number of starts because it does change the ratio
You are absolutely correct. I thought I would save that for another video. This one was just meant to be a very basic intro.
Other benefit is force redirection
Hai, wonderful vedio. I have 2 questions for you. Does the worm and roller require grease or steering oil of ranges 140 or 300 or 450 or 600. By second question is does the worm and roller make driving more effortless than circulating ball bearing also called as ball and nut or is the recirculating ball mechanism more effortless than the worn and roller. As I had a fiat 118 NE which was the 124 fitted with the Nissan A12 engine which had the recirculating ball mechanism which was smooth like butter , I still regret for having sold it. It was so smooth even though it didn't have power assistance
Thanks bro
Finally I got understand this relation.
Glad it helped
@@INTEGRALPHYSICS Yes it is bro. Here i did it.
th-cam.com/video/X6_9PTJOmk0/w-d-xo.html
Dude you're awesome
So far we agree 100% =)
Could varying the thread distance (pitch) allow you to change the gear ratio along one shaft?
For instance, if it was used in a vehicle moving the gear further forward would change the gear ratio and increase speed.
Its a good idea, but unless you change the actual tooth count on the wormwheel, the GR will not change.
@@INTEGRALPHYSICS I don't quite know how to describe this, but if a normal rotation of the worm would move one tooth of the wheel, couldn't it be adjusted so half a rotation would move one tooth?
Yes, you could have two threads on the worm rather than a single thread.
Is energy loss from the friction between the worm and the worm wheel neglible?
If not, how does one go about its mitigation?
There is definitely energy loss, whether or not you need to worry about it depends on the application. One thing to keep in mind though, is that energy loss will NOT affect the gear ratio, only the actual mechanical advantage.
Thank you, wonderful explanation
Glad you liked it!
Great video, can you help me with some worm ratios. I’m making an ebike and using a worm gear with motor to power it, I have a motor that spins at 3500 rpm and would like an output of 350 rpm.
I’m looking at a NMRV030 gearbox.
What ratio would I need for an input of 3500rpm to get an out put rpm of 350?
10:1?
Many thanks
Worm bike. I like that. Is it going to be a shaft drive?
I wonder if you could use a worm gear to create a reciprocating mechanism using a rack gear
If you prevent the worm gear from rotating and then drive the wheel as the input you effectively have a rack and pinion.
very clear and useful explanation !
Glad it was helpful!
Super
Thanks
What will i do to change the gear box ratio 15:1 to 10 : 1 for same motor.
Im not sure of the application, but all other conditions being the same, changing gear ratio like that is likely to overload the motor. Additionally a 10t worm wheel is going to be VERY difficult to design to run smoothly.
Can you do the reverse? Cna the worm gear ever be the output and the input be driving it so that we get a good ratio for speed?
Typically no. Once friction is factored in, it is extremely inefficient (or even impossible) for the wheel to drive the worm.
Awesome video!
Thanks!
How u calculate the pitch of the worm an the gear to cut on the lathe
I suggest you determine the desired gear ratio. Then, provided you know the desired output torque, find the gear tooth size that will support the needed torque (theoretically this is based on the shear strength of the material as well as tooth profile, gear lash, tolerances and width). In reality, find an existing worm gear design that is rated to a certain load for a given material, use that design.
What are the names of the templates you're using to make that awesome drawing?
is there any way in which the screw drives the gear along the screw, whilst also rotating the gear?
Do mean like if we let the worm travel axially along the input shaft?
I have a silly question actually!!
If we directly rotate wormwheel and not using the worm what will be the difference!?
Should we have to gather more torque or power to work!?
The point of the worm gear is to provide an increase in torque. Using a worm gear, a low torque motor can be used to produce high torque on an output shaft.
okay.. like how & what is this thing which make this transition happened!?
Recommend that you take a look at a modern spinning reel schematic.. this is the exact case use in real life.. the worm wheel (handle) is used to turn a pinion gear (which is what drives the rotor) which lays the line
The point of using this great mechanical advantage is that it can still drive the rotor even under heavy load (the fish pulling) which is torque I believe
Google spinning reel schematic (stella, saltiga, exist, Certate) all model names 👍🏻
I am surprised that leads on the worm wasn't mention, that is extremely important on knowing the ratio, the example assumes the worm gear will always be a single lead, but there are worms with more then one lead, that is how a worm gearbox achieves various ratios, such as four leads on a worm would have changed this example to a 6:1 ratio, when you have a gearbox with a missing nameplate where the reducer is so worn out you cannot turn it by hand to get the ratio you must know this because the speed reducer once broken down almost always has enough tooth left on the wheel gear to count as well as counting the leads on the worm to know the ratio.
thank you ❤
Welcome!
I wish there were 1 tooth gears so it’s 1:1 ratio
That would defeat the purpose of a worm gear. (a high GR)
@@INTEGRALPHYSICS oh i thought the worm gears were made to make a rotation different other than something like a bevel gear
Is there a way to switch the input and output shafts on a worm gear? As in could I hookup a gear reducer to the worm wheel to produce an output force to cause translational movement on the worm shaft?
Under normal circumstances if you drive the wheel it will not turn the worm. However if you allow the worm to move translationally, what you essentially have is a rack and pinon.
@@INTEGRALPHYSICS thank you very much
I should say that I meant rotational movement, and not translational
Rotational Movement: not going to happen unless the pitch of the worm is INCREDIBLY LARGE.... But it is possible.
Woo hooo woo hoooo 🎉🎉🎉🎉🎉
there's a song 2 reference here...
2:52, explanation of worm gear ratio
That 1 depends on how many spirals does worm have
Indeed. I thought that may be to complicated for a worm intro, but you are absolutely correct.
hi all. i have a question. is it possible for a worm wheel to rotate a worm gear . im trying to design a pedal sysyem for my boat . im after max revolutions on the prop shaft to one turn of the pedal. cheers. plus a worm gear would eliminate the need for a 90 degree gear box
Yes but... When you factor friction into things, I suggest you consider a bevel gear. You can produce the low gear ratio you desire and easily build in the perpendicular relationship between the crank spindle and the prop shaft. Hope my suggestion helps, let me know how it goes and good luck!
Show 👏👏
i want to make my electric train (DC) free rolling. I.e., u can push it
back n forth w ur hand when the elec. pwr is not applied. I call it a
free rotating gear box. All the electric model locomotives i have
can't be pushed to rotate the driver wheels freely. The drivers r
stationary. The only way to rotate the drive whls is to rotate the
worm shaft either by the motor or by my fingers... Do u get the
picture?
How do u design that? I've heard u need a helix worm w a matching
wheel gear. But i think it's much more complicated than just the two
gears (a worm and a wheel gear plus perhaps a spur gear?). Yes, to
produce torque to pull more cars, the gear box also need the gear
ratio reduction as u've explained in ur video.
I've searched here in the utube and guogle et al, for:
'Free turning worm gear' or 'Free turning gear box'
but no luck.
Pls advice, u or any audience?
The drawback of a worm gear is that the wheel can not drive the worm. It sounds like you probably need a clutch between the gearbox and the wheels.
@@INTEGRALPHYSICS Thx 4 ur immediate reply. There was a man from
Japan who was able to do that on his 0-scale - 2 rail locos. But lost touch
w him. I don't think he used a clutch (to disengage the spur gear from the
worm). But perhaps, i may need to look into this clutch deal.
can you explain the backlash of gears and why do we need or not need them
Short Answer: Gear lash = wiggle room between gears
Longer Answer: In reality the line of action between gears is not tangent to the base circle of a gear. As a result the gears are not moving PRECISELY at angular velocities given by GR=Win/Wout. To put it another way... If the input shaft turns at constant velocity, the output shaft is going to speed up and slow down just a little bit with every tooth. Gear lash can affect how rapidly that speeding up and slowing down occurs.
change the center distance for difference backlash, Am i right?
@@何良-x7r Yes.
How can I calculate the torque on the output of a 40-1ratio worm gear box
Short answer: its 40x the input torque. Longer answer: you are going to need to know the frictional losses along with the worm pitch and tooth profile to factor in losses and inefficiencies.
@@INTEGRALPHYSICS Worm gears aren't anything close to 100% efficiency. Spur gears in the limit of perfection can be 100% efficient, and in practice tend to be 98% efficient.
Worm gears are inherently inefficient and are limited by the kinetic friction coefficients of the materials we can use. For a worm gear, 50% efficiency is optimistic, and is typical of what you can expect from the best worm gears available. A worm gear not built specifically for efficiency, will likely have an efficiency around 25%.
TIENES UN TUTORIAL DE COMO DIBUJAR EL ENGRANAJE?
no, pero volveré a dibujar el engranaje pronto para un video sobre engranajes hipoides.
@@INTEGRALPHYSICS ojalá pronto
hi
if i try to spin the wheal will the screw rotate or is it locked ?
Most worm gear systems are specifically designed so you can't drive it in reverse. An application of the worm gear, is the tuning knobs on a musical instrument, which allow you to tighten the string, but don't allow the string to unwind the tuning knob.
It is possible with an extremely steep helix of the worm threads, to make a worm gear that can be driven by the worm wheel, but it is rare that we desire such an application. It is much more likely that we would use other gear arrangements if we wanted bidirectional power transmission.
برافوووو
Technical hari sir
Thank you.
فديو رائع ممكن اخباري من. اين احد الشفت
Where is the actual math? I need to figure out the dimensions and angles etc. to make a worm gear for an extruder... I don't know a whole lot about this but i need to make the worm gear to at least... work
you want to machine one? as far as I know it's one of the hardest to machine gears so good luck :D what you should do is just check classified ads, or scrap yards in your area, some snowblowers use worm gears in the differential. some cars do too. save yourself the headaches.
@@chrishayes5755 yeah but the thing is tiny, and my class ha s although axis, we have plenty of tools and I only need to design it
It's supposed to be 8mm Dia and 24 mm long those are the maximum dimensions...
I try to keep these sorts of videos very general because, as you are seeing, things become very specific very quick. My suggestion is start at your desired gear ratio and work backwards from there. The distance between the shafts is the effective sum of the worm and worm wheel radii (to the line of action). Tooth profile and pitch are dictated by load, shaft speed, shaft stiffness, motor torque, gear hardness, surface finish, service life etc.
I assume you are trying to 3d print these parts. Worm gears are based on slippage, they are effectively inclined planes, so think about your print orientation. I suggest you print the worm gear on its end so that the layers are mostly in the direction of slip. The wheel can be printed laying on its face. Its not perfect but at least that way the edges of the layers will be perpendicular to each other along the line of action which should smooth the action of the gear set. If 3d printing, I suggest you coat the parts or sand them smooth between the teeth.
If you are going to turn or cnc these parts I suggest you pull gears from something like Autodesk Inventor which already has gears designed in the catalog.
@@INTEGRALPHYSICS Thankyou, we have a 4th axis in class in one of our Haas machines, and im thinking about making the gear in there, I'm trying to use everything from a Bondtech Bmg extruder, except I designed a new case, heatsink and now working on the worm gear problem. It's going to be really small so printing won't work great
Good 3-minute video. Poor 7 1/2 minute video!