Thank you so much for this great tutorial. I'm really glad to learn the equation driven function for drawing the involute, instead of drawing numerous tangent lines and confusing myself. You've helped me out so much!
Thank you so much for this. Absolutely spectacular. I'm using this to make a clock, and I found that by simply inputting "N" for the number of instances in the circular pattern you can have it auto update. Also, I made the diametral pitch dependent on the pitch diameter via adding another variable. Just a couple things to make changing gear sizes easier.
Matthew Miller I'm using SDW 2014, not sure if it will work on older versions. I simply put "N" (without quotes) into the field "Number of Instances" when I did the circular pattern. This way I can make a bunch of different size gears without having to update the number of teeth in the equations AND the circular pattern. As for the pitch diameter, I just made another variable (named pitchdia I think) and changed the value for "P" to an equation based on "pitchdia." This really doesn't solve anything for most practical uses, but when you're making a bunch of different sized gears, it shaves a minute or two off each one.
Thank you so much! I am helping a client design a machine utilizing a few existing parts and needed to create gears with a dimetral pitch of 4.62. I couldn't make it work, but with this, it was a breeze!
This is fantastic! I was able to follow along using OpenSCAD instead of Solidworks because of how detailed your explaination was. It also cleared up a bunch of questions I had regarding gears in general. Thanks for sharing!
Hello, thanks very much, you saved my life :D Just a suggestion, to automatic define the root fillet, i used 0.8*c, so we got 80% of clearance (a safe value).
Great tutorial, sir! Just one note: when creating the circular pattern, one might need to be sure to have the "Geometry pattern" checkbox checked in the circular pattern dialog box, otherwise it might not let one propagate the fillet as well
Damn it. I just lost an hour erasing and redoing everything step by step. I was going crazy until I figured it out on my own.... I was going nuts! Now that I'm reading your comment I feel trolled xD BTW great tutorial Yang Cao, but you should have used an equation in the circular pattern, that's pretty obvious. So you don't have to manually adjust it every time. Number of patterns must be equal to "N". Same thing for the fillets, you could have used an equation like "fillet radius equals 0.5*clearance" or sth like that.
Super helpful video. Some advice would be set the number of instances of your circular pattern to "n" and the fillet to a fraction of "c" (for example he used R.10 with a .125 clearance, so you could set your fillet to 4/5*"c") to ensure it will never be larger.
Hello, I very much enjoyed your presentation and demo, excellent, you kindly explained all the steps and it was relatively easy to follow, much appreciated. Thanks.
Thank you for sharing! Note: to write equation you may need to write with " " the variables. Improvements: - Number of tooth can be linked to the circular pattern instances - Fillet radius can be setted as Diameral Pitch / 10, this prevent manual adjust - Alpha calculation is not required, simply link the line to the intersection with Diametral pitch, than simpler equation as 360/4/N. - Not necessary to write two equation, can be used one than mirror it
If you're referring to the *180/pi, this is the conversion from radians to degrees. This is here because the equation calls for radians, (notice "phi rad"), however our pressure angle is in degrees
he chose 0.68 so he can put bounds on the curve of that first involute line, otherwise it would keep plotting for all infinite points of t (reference for anyone else wondering)
this determines the length of the curve from the start . it is the end point of the curve. it just needs to be long enough to go past the outer edge of the gear body so you can trim it later. type 2.00 in that field and you will see what happens.
I just wanna thank you for this, this is an incredibly helpful tutorial and your other videos are very helpful as well. You're a fantastic professor. I wish SolidWorks had a gearing tool though. Also, it would be helpful if you could speak up a little bit in your videos.
Hello Mr. Cao. I am trying to create my initial equations just like you do on the video. However, I am not able to do so. After I enter the Global Variable name I press enter and continue to the Value/Equation area. Once there, I enter the value I want and press enter, but it does not accept the value. I cannot continue beyond that point. Hope you can make a suggestion to my problem. Thank you in advance.
In SW 2013 if you double click the pattern and edit the dimension in the view window, you can enter the global variable there. This also works for helix.
why does this don't work when I go to more teeth? it collapses in 42 teeth. the dedendum circle becomes bigger than the base circle and it doesn't work. it is a great tutorial but I've been struggling with this all day long...
it probably has to do with the pressure angle you're working with. remember that if we want to constrain the dedendum and base circles, we can express their relationship as: (pitch diam) - 2(dedendum) < (base diam) with pitch diameter equal to (module)*(num of teeth), or (num teeth)/(diametral pitch) and base diameter equal to (pitch diameter)*cos(pressure angle), just like the textbooks give us. you can solve for your max number of teeth by moving all other variables to the opposite side, but you should see that the num of teeth at 20 degrees pressure angle is mathematically limited to like 41 or something.
Dr. Cao, thanks for posting this! Now to find out why Solidworks fails at 39 teeth (when the dedendum circle diameter is greater than the base circle diameter).
+tobyteddy222, nope, I have not figured out why. I have contacted my reseller and they said that they are looking into it, I sent them my part file. I think that it has something to do with base circle being a smaller diameter than the dedendum circle. If you look at the results of 39 teeth, you'll see that the tooth base produces "notches" with the involutes. Trimming the dedendum circle and each involute turns one of the involutes red and the "The sketch has not been undated..." message is displayed. I will post any resolution when I get it.
+tobyteddy222, I still haven't received a reason why this fails but have developed a work around: 1. Open an new sketch on the same plane as that which holds the equation driven involutes. 2. Select the involutes and the base (dedendum) circle. 3. Click Convert Entities. Those features are now copied onto the new sketch with no equation driven relations between them. They can now be trimmed as required so that you can use the new sketch to Extrude Cut the disc. After you extrude cut, simply create a Circular Pattern using that Cut-Extrude feature and you're done! You can now create spur gears of any number of teeth up to 105. There is a problem with this method because 360/(4*N)-alpha equals zero when N = 105.3916. So, gears with 106 and more teeth will fail.
Awesome tutorial! I think you can also drive the fillet and circular pattern using equations. That would make it a little more time saving. Thanks again for this tutorial! =)
Dr Yang, really helpful video. Question from my side (couple of years after your video and the majority of the responses) But, can you please describe / explain why are you using "t2=0.68" which such value? I've reviewed your material, and I don't see, yet, the correlation Could you please help me to understand? Thanks
I played with it. I could be totally wrong but I think t2=.68 just guarantees the involute curve will extend past the addendum circle diameter. Like if you made both t2s=.75, the gear would still be exactly the same.
when dedendum lies above base circle, i found an interesting thing. involute profile generated from base circle cuts pitch circle somewhere between addendum circle. Would you please help me through this problem?
I have the same problem. But I guess you will have to change the sketch for these cases. My solution was to make the base at dedendum, in which case the fillet would be between dedendum circle and the involute curve.
This was an excellent lesson. I managed to create this in AutoCAD INVENTOR. If anyone needs the Equation Formula for INVENTOR, I've listed them below. INVENTOR is very particular about the syntax and unit parameters: BaseCircleDiameter / 2 ul * ( cos(1 rad * t) + t * sin(1 rad * t) ) BaseCircleDiameter / 2 ul * ( sin(1 rad * t) - t * cos(1 rad * t) ) BaseCircleDiameter / 2 ul * ( cos(1 rad * -t -2 * BaseCircleDiameter / 1 in * 3.14159265359/180) - t * sin(1 rad * -t-2 * BaseCircleDiameter / 1 in * 3.14159265359/180) ) BaseCircleDiameter / 2 ul * ( sin(1 rad * -t -2 * BaseCirceDiameter/ 1 in * 3.14159265359/180) + t * cos(1 rad * -t-2 * BaseCirceDiameter/ 1 in * 3.14159265359/180) ) tmin = 0.00001 tmax = 0.68
Is it possible not to use alpha? Let's say the straight line attached to involute curve is line "A". What if I draw a line "B" from center to where involute curve meets pitch circle where D=9. Then draw another line "C" from center at 360/4N degrees from line "B". Then mirror involute curve and the straight line "A" attached to it accross line "C". I tried this which should make sense, but then angle between line "B" and "C" is 4.2 degrees instead 4.15 shown in your video. Which part did I do wrong?
Hi, I would really like to know what needs to be changed if the base circle diameter is smaller than the diameter of the dedendum circle? None of the videos on youtube has a solution for my question.
Hi Dr Yang Cao, i did succesfully created a pinion with N= 36 Teeth , Moudle= 1.25, with P=0.8 . However when creating the Gear of N=108 Teeth (3:1) ratio, i had a problem with beta angle as it turn to be negative and this cannot be accepted in solidworks , so resulted in a different involute profile for the gear ?. How to solve this problem? and what angle beta should be used for the gear. i would really appreciate your help. Cheers
hI, on the begining when I write "p" then I write Value =2 and try to confirm this value by enter, nothing's happened. In your case you have the possibility to fill the comment. I have not. What i am doing wrong?
Hi Dr Yang Cao, Thanks for the video! it help a lot, but I noticed the link for the tutorial file isn't working any more, I wonder where I can download it again, it's very good information.
Thanks a lot for this awesome tutorial. Till now, it is the best one with scientific basis. The voice is clear, the accent is very good, and referring to lecture is very nice. Can you please tell me why the "base circle diameter=Pitch circle diameter*cos(Phi)"?
khkgears.net/new/images/basic_gear_terminology_and_calculation/Fig.-2.6-Working-Gear-Nomenclature.jpg This is the link to a picture, on which you'll see that it's a simple right-angled triangle
Thank you for this video. Is there a way where I can dictate the addendum circle diameter? I am trying to remake a gear I currently have that has a addendum circle diameter of .94454 with a diametral pitch of 24, 42 teeth, and pressure angle of 20deg. Thank you
This video worked out great for my except for one thing. When I finished my gear even though I had an N of 21 I ended up having 24 gear teeth. I noticed that on yours too you ended up having 20 gear teeth when you finished your circular pattern. Is there anyway to fix that?
i have a problem in equation driven curve . . it says wrong equation i just copy paste it? X(t) = "D2@Sketch2"*0.5*(cos(t)+t*sin(t)) Y(t) = "D2@Sketch2"*0.5*(sin(t)-t*cos(t))
+John Medina If youre still having this problem, all you have to do is copy and paste the formula into the x_t and y_t boxes, and you'll notice that the formula turn red in colour which signifies that it has an error. For some reason solidworks doesnt like having things copy and pasted. After this, just click the 'explicit' check box, and then click the 'parametric' checkbox again. It somehow makes solidworks forget that it was copy and pasted and the formula will turn black and it should work. If that doesnt fix your problem, you may need to change D2@Sketch2 to D2@Sketch3 if youve accidentally done it on a new sketch. That worked for me
+Sam Isaac I think if the formula turns red you have a problem with the formula. My issue was having multiple sketches/dimensions not lining up with equations, such as - Equation for Xt in the 2nd involute"D2@sketch2"*0.5*(cos(-t-2*"D4@Sketch2"*pi/180)-t*sin(-t-2*"D4@Sketch2"*pi/180)). Problem I found was that I had D4@Sketch2 on a separate sketch! D1@Sketch3!To maintain consistency/efficiency I kept the formula and changed the sketch to match.
Could be you have a different language version in SW? I.e. in german "Sketch" is called "Skizze", therefore straight copy/paste wouldn't work for involute equations.
Hello! Excellent tutorial! I am running into one issue though with the Phi value. I can change N and P to all the combinations I need without issue, but when I change Phi to 30 degrees I get a Dedendum circle that is larger than the base circle and the pattern won't cut. Any advice on how to fix this? I am trying to draw a 5/10 36T 30deg involute gear.
Hi and thanks for sharing this great tutorial! It has been very helpful. Can I ask, is this gear design based on a "zero backlash" basis? And if so, how would you recommend building in backlash? Is there way to do it using global variables such as modifying the pitch circle diameter or module etc? Many thanks again!
Why t1 is 0 and t2 is 0.68 in equation driven cure "D2@Sketch2"*0.5*(cos(t)+t*sin(t)) and "D2@Sketch2"*0.5*(sin(t)-t*cos(t))? Any clear description please ?
It's the beginning and end of the curve. You can use other values for t_2 as well, as long as the curve ends outside the material (and can finish the cut).
How can I adjust the equations to make gear with different diameters? If I adjust the "P", the size of the teeth changes also such that the new gear cannot fit into the original gear. How can I change the equation so that I can make different size gears that can still work with the original gear?
great job displaying the exact equations necessary to produce a gear that can be changed with only a couple variables. Could you produce a video teaching us how to build equation driven helical bevel / miter gears?
Very nice tutorial Mr Cao, I have a question, do you know, how to design a rack and pinion (obviously I learned how to do a pinion), but I cannot to draw a rack to matching pinion with, I will be very happy, If you could do that. Thank you very much.
Thanks for the demo. I noticed on SW14, that for the circular pattern, I was able to set the number of instances to be the global variable N so it auto updates. Also the fillet radius can be set to "c" / 3 or 4 or whatever.
I am running into a problem with the equations where my gears are large and my base circle ends up being smaller than my dedendum circle example 50 gears. Is this something that I am doing wrong? Maybe i copied and equation wrong or a problem with the format. Let me know plz
to clarify.. when you input your equation curve, the genereated curve goes from left to right...0 degrees, to the right, with the given equation... my line goes up... from 0 degrees, vertical...I have No idea why its doing this. I even went back and did it with all your numbers..
Does anyone know how to do this with SW2007? I can work out the equation feature differences, but this version does not have the Equation Driven Curve feature. Any ideas?
What should I do, when it is saying Unable to create instance for the pattern. Try again by decreasing the number of instance or the distance between instances
There seems to be a limit to the number of teeth you can have given a specific a and d because eventually the base circle, which is Dp * cos(phi) becomes larger than the d circle. Is this a real property of these gears, or a side effect of the way we drew it?
Yes. I mentioned the issue in the description of the video. It is possible for the base circle diameter to be "smaller" than the dedendum circle diameter. Gear profile will be all involute. No more straight line between the base and dedendum circle. I haven't been able to figure out a general method to accommodate both cases.
I really appreciate your effort. I am just beginner of solidworks and followed your lecture and got it. As you mentioned I encountered the base circle diameter is smaller than dedendum circle diameter. Do you have other lecture for this or should I draw from the beginning? Please let me have your tip for this. Thanks in advance
Thanks for uploading this, it really helped me understand the process a lot more. I have made my version of your model, are there any conditions that need to be modified to account for a much larger spur gear? I am trying to model the angle but my value comes back as a negative value and cannot define the angle. Diametral Pitch = 0.3333 No of teeth = 110 Pressure angle = 20° Addendum Diameter = 336mm Pitch Diameter = 330mm Base Circle = 322mm Dedendum Diameter = 322.8mm My tan and beta angle values in the involute curve come back with a value of -0.3° Has anyone used this to create a relatively large spur gear?
Very usefull material. Thanks a lot. When you say "a" need to hear "b" as well. Don't you have a tutorial for internal involute gear too? Hot to direct involute curve toward center now?
good morning, i have a problem. when i put the value of the number of teeth equal to a high number, like in my case 94, it creates between two teeth a strange thing, how can i do to remove it? thaks for your attention
Great video! Helped me a lot. Just one comment. When you named your global variables, you called "P" Diametral pitch but I think that should be the pitch diameter (in) and you called "dp" pitch diameter when that should be diametral pitch(teeth/in). The values are correct though. Thank you so much for your help.
John, could be you have a different language version in SW? I.e. in german "Sketch" is called "Skizze", therefore straight copy/paste wouldn't work for involute equations. Or you may have to use quotation marks as sb mentioned below.
the start and end bounds for the t parameter. 0 means start at the beginning (t = 0) and the 0.68 number is arbitrary, it just needs to be high enough to make the curve extend beyond the addendum diameter so that you can use it to cut the gear profile later. You can "guess and check" the 0.68 value until it extends past the biggest circle.
hello, nice video,first i modeling 2 gear but i have a probleme for collision when i want to assemblate them, why ? the second, i want to simulate stress gear, how can i do it ? thank you very much
Wow, wish I had Dr. Cao as my professor. What an excellent demonstration and accompanying material. Thank you for making this accessible to everyone!
Thank you so much for this great tutorial. I'm really glad to learn the equation driven function for drawing the involute, instead of drawing numerous tangent lines and confusing myself. You've helped me out so much!
Thank you so much for this. Absolutely spectacular. I'm using this to make a clock, and I found that by simply inputting "N" for the number of instances in the circular pattern you can have it auto update. Also, I made the diametral pitch dependent on the pitch diameter via adding another variable. Just a couple things to make changing gear sizes easier.
Can you explain why you made the diametrical pitch dependent on the pitch diameter? What does this solve?
Matthew Miller I'm using SDW 2014, not sure if it will work on older versions. I simply put "N" (without quotes) into the field "Number of Instances" when I did the circular pattern. This way I can make a bunch of different size gears without having to update the number of teeth in the equations AND the circular pattern. As for the pitch diameter, I just made another variable (named pitchdia I think) and changed the value for "P" to an equation based on "pitchdia." This really doesn't solve anything for most practical uses, but when you're making a bunch of different sized gears, it shaves a minute or two off each one.
I wish, I had lectures like these 10 years ago in university. Great tutorial! Thank You!
Thank you so much! I am helping a client design a machine utilizing a few existing parts and needed to create gears with a dimetral pitch of 4.62. I couldn't make it work, but with this, it was a breeze!
Great tutorial. This video captures the difference between hobbyist level CAD and actual mechanical engineering XD
Your video has certainly helped my team design our own gears for a design project. Your video is very clear and concise. Thank you Sir.
This is fantastic! I was able to follow along using OpenSCAD instead of Solidworks because of how detailed your explaination was. It also cleared up a bunch of questions I had regarding gears in general. Thanks for sharing!
Hello, thanks very much, you saved my life :D
Just a suggestion, to automatic define the root fillet, i used 0.8*c, so we got 80% of clearance (a safe value).
Great tutorial, sir!
Just one note: when creating the circular pattern, one might need to be sure to have the "Geometry pattern" checkbox checked in the circular pattern dialog box, otherwise it might not let one propagate the fillet as well
Damn it. I just lost an hour erasing and redoing everything step by step. I was going crazy until I figured it out on my own.... I was going nuts! Now that I'm reading your comment I feel trolled xD
BTW great tutorial Yang Cao, but you should have used an equation in the circular pattern, that's pretty obvious. So you don't have to manually adjust it every time. Number of patterns must be equal to "N". Same thing for the fillets, you could have used an equation like "fillet radius equals 0.5*clearance" or sth like that.
You are a gentleman and a scholar. Thank you so much for this comment.
I had an issue with that, but I changed my fillet so that it was included in the sketch, and then set it to an equation.
Thank you sir. True legend lol
thanks alot for this
Thanks Yang, the tutorial is detailed and easy to follow. Save me tons of time!.
Super helpful video. Some advice would be set the number of instances of your circular pattern to "n" and the fillet to a fraction of "c" (for example he used R.10 with a .125 clearance, so you could set your fillet to 4/5*"c") to ensure it will never be larger.
Hello, I very much enjoyed your presentation and demo, excellent, you kindly explained all the steps and it was relatively easy to follow, much appreciated. Thanks.
Thanks for putting together this video, really appreciate it. Comprehensive and easy to understand.
Well, that's about as good a demo as can be done. Nice job, sir. And thanks for a solid technique.
This is an amazing tutorial, thank you very much for taking the time to make it and sharing it with the world!
Thank you for sharing!
Note: to write equation you may need to write with " " the variables.
Improvements:
- Number of tooth can be linked to the circular pattern instances
- Fillet radius can be setted as Diameral Pitch / 10, this prevent manual adjust
- Alpha calculation is not required, simply link the line to the intersection with Diametral pitch, than simpler equation as 360/4/N.
- Not necessary to write two equation, can be used one than mirror it
Circular pattern when linked revert back to same value any idea
Why pattern 20 when he got 18 teeth? it happened to me when i designed my gear (different characteristics)
Very good work. I have now a complete parametric gear !
Thank you very much !
Hi there, on your notepad, the alpha equation is different than shown on the PDF. It is wrong?
If you're referring to the *180/pi, this is the conversion from radians to degrees.
This is here because the equation calls for radians, (notice "phi rad"), however our pressure angle is in degrees
It basically saved my life thanks sir
Excellent video - very helpful. One question though. At 9:45 you enter 0.68 into the T2 field. What does this value represent, and how is it derived?
That is just a value for "t" I randomly selected after a few trial.
he chose 0.68 so he can put bounds on the curve of that first involute line, otherwise it would keep plotting for all infinite points of t (reference for anyone else wondering)
this determines the length of the curve from the start . it is the end point of the curve. it just needs to be long enough to go past the outer edge of the gear body so you can trim it later. type 2.00 in that field and you will see what happens.
This is best video about gears in SW! Pro. Thank you!
I just wanna thank you for this, this is an incredibly helpful tutorial and your other videos are very helpful as well. You're a fantastic professor. I wish SolidWorks had a gearing tool though. Also, it would be helpful if you could speak up a little bit in your videos.
Thank you so much!! I needed to crank up a bit but it was totally worth it!
Im so happy I can make gears now!!!!
屏幕录像专家。。。记得当时看黑客视频就是用这个软件。
现在在油管上看到了，满满的回忆啊
Thank you for the post! Helped me immensely!
Hello Mr. Cao. I am trying to create my initial equations just like you do on the video. However, I am not able to do so. After I enter the Global Variable name I press enter and continue to the Value/Equation area. Once there, I enter the value I want and press enter, but it does not accept the value. I cannot continue beyond that point. Hope you can make a suggestion to my problem. Thank you in advance.
Unreal tutorial! Thank you so much!
Would it be possible to mirror the second involute istead of using another parametric curve?
In SW 2013 if you double click the pattern and edit the dimension in the view window, you can enter the global variable there. This also works for helix.
Excellent video
Thank you my Teacher
Nice info,thanks for sharing it with us, well done :)
finally sb who knows his shit. though those long ass equations in the notepad could be given in desription to copy
why does this don't work when I go to more teeth? it collapses in 42 teeth. the dedendum circle becomes bigger than the base circle and it doesn't work. it is a great tutorial but I've been struggling with this all day long...
thats bad
it probably has to do with the pressure angle you're working with. remember that if we want to constrain the dedendum and base circles, we can express their relationship as:
(pitch diam) - 2(dedendum) < (base diam)
with pitch diameter equal to (module)*(num of teeth), or (num teeth)/(diametral pitch) and base diameter equal to (pitch diameter)*cos(pressure angle), just like the textbooks give us.
you can solve for your max number of teeth by moving all other variables to the opposite side, but you should see that the num of teeth at 20 degrees pressure angle is mathematically limited to like 41 or something.
Dr. Cao, thanks for posting this! Now to find out why Solidworks fails at 39 teeth (when the dedendum circle diameter is greater than the base circle diameter).
+Jeff Biss
Have you, by any chance, figured out yet why it fails at 39 teeth? I'm experiencing the same problem.
+tobyteddy222, nope, I have not figured out why. I have contacted my reseller and they said that they are looking into it, I sent them my part file. I think that it has something to do with base circle being a smaller diameter than the dedendum circle. If you look at the results of 39 teeth, you'll see that the tooth base produces "notches" with the involutes. Trimming the dedendum circle and each involute turns one of the involutes red and the "The sketch has not been undated..." message is displayed. I will post any resolution when I get it.
+tobyteddy222, I still haven't received a reason why this fails but have developed a work around:
1. Open an new sketch on the same plane as that which holds the equation driven involutes.
2. Select the involutes and the base (dedendum) circle.
3. Click Convert Entities. Those features are now copied onto the new sketch with no equation driven relations between them. They can now be trimmed as required so that you can use the new sketch to Extrude Cut the disc. After you extrude cut, simply create a Circular Pattern using that Cut-Extrude feature and you're done!
You can now create spur gears of any number of teeth up to 105. There is a problem with this method because 360/(4*N)-alpha equals zero when N = 105.3916. So, gears with 106 and more teeth will fail.
Awesome tutorial! I think you can also drive the fillet and circular pattern using equations. That would make it a little more time saving. Thanks again for this tutorial! =)
Thank you so much for this sir !! this is Absolutely well done and very helpfull !!
thanks for the tutorial, very good! Can you give me a solution for a number of teeths >420 and metric module 4?
THANKS a bunch from australia :)
while draw the equation driven curve, how did you come up with t = 0.68
See Chad Wassink's comment below: Yang Cao replied "That is just a value for "t" I randomly selected after a few trial. "
@@harmonytan6746 Lmao. I was just wondering about that
Very good! Two question. The parametric part remains blue is it still undefined then?
Very helpful video. Thank you very much!
Dr Yang, really helpful video. Question from my side (couple of years after your video and the majority of the responses)
But, can you please describe / explain why are you using "t2=0.68" which such value?
I've reviewed your material, and I don't see, yet, the correlation
Could you please help me to understand?
Thanks
I played with it. I could be totally wrong but I think t2=.68 just guarantees the involute curve will extend past the addendum circle diameter. Like if you made both t2s=.75, the gear would still be exactly the same.
when dedendum lies above base circle, i found an interesting thing. involute profile generated from base circle cuts pitch circle somewhere between addendum circle. Would you please help me through this problem?
I have the same problem. But I guess you will have to change the sketch for these cases. My solution was to make the base at dedendum, in which case the fillet would be between dedendum circle and the involute curve.
Yucel Sert This isn't a good idea because having a base of the wrong size will lead to improper geometry.
This method looks pretty strong
Thank you so much sir!! I m really greatful!!
Do you have similar explaination for Internal Spur Gear Modeling?
Thanks a lot Mr. Yang Cao.
Awesome tutorial. Thanks!
For number inside of the circular pattern could you not just call the variable "number or teeth"?
This was an excellent lesson. I managed to create this in AutoCAD INVENTOR. If anyone needs the Equation Formula for INVENTOR, I've listed them below. INVENTOR is very particular about the syntax and unit parameters:
BaseCircleDiameter / 2 ul * ( cos(1 rad * t) + t * sin(1 rad * t) )
BaseCircleDiameter / 2 ul * ( sin(1 rad * t) - t * cos(1 rad * t) )
BaseCircleDiameter / 2 ul * ( cos(1 rad * -t -2 * BaseCircleDiameter / 1 in * 3.14159265359/180) - t * sin(1 rad * -t-2 * BaseCircleDiameter / 1 in * 3.14159265359/180) )
BaseCircleDiameter / 2 ul * ( sin(1 rad * -t -2 * BaseCirceDiameter/ 1 in * 3.14159265359/180) + t * cos(1 rad * -t-2 * BaseCirceDiameter/ 1 in * 3.14159265359/180) )
tmin = 0.00001
tmax = 0.68
Great video sir!
I really love it, job well done!!! You have won a new subscriber :)
Thank you soooo much.....it was very helpful....😃
Is it possible not to use alpha?
Let's say the straight line attached to involute curve is line "A". What if I draw a line "B" from center to where involute curve meets pitch circle where D=9. Then draw another line "C" from center at 360/4N degrees from line "B". Then mirror involute curve and the straight line "A" attached to it accross line "C".
I tried this which should make sense, but then angle between line "B" and "C" is 4.2 degrees instead 4.15 shown in your video. Which part did I do wrong?
I am unable to add new global variables, only one is being entered ... what to do ?
Great Work Many thanks
Do you have vedio on helical gear tooth cut ..like you showed on spur gear
Fantastic tutorial
Hi, I would really like to know what needs to be changed if the base circle diameter is smaller than the diameter of the dedendum circle? None of the videos on youtube has a solution for my question.
Hi Dr Yang Cao, i did succesfully created a pinion with N= 36 Teeth , Moudle= 1.25, with P=0.8 . However when creating the Gear of N=108 Teeth (3:1) ratio, i had a problem with beta angle as it turn to be negative and this cannot be accepted in solidworks , so resulted in a different involute profile for the gear ?. How to solve this problem? and what angle beta should be used for the gear. i would really appreciate your help.
Cheers
hI, on the begining when I write "p" then I write Value =2 and try to confirm this value by enter, nothing's happened. In your case you have the possibility to fill the comment. I have not. What i am doing wrong?
Same with me but no one answers
Hi Dr Yang Cao, Thanks for the video! it help a lot, but I noticed the link for the tutorial file isn't working any more, I wonder where I can download it again, it's very good information.
Thanks a lot for this awesome tutorial. Till now, it is the best one with scientific basis. The voice is clear, the accent is very good, and referring to lecture is very nice. Can you please tell me why the "base circle diameter=Pitch circle diameter*cos(Phi)"?
khkgears.net/new/images/basic_gear_terminology_and_calculation/Fig.-2.6-Working-Gear-Nomenclature.jpg
This is the link to a picture, on which you'll see that it's a simple right-angled triangle
Thank you for this video. Is there a way where I can dictate the addendum circle diameter? I am trying to remake a gear I currently have that has a addendum circle diameter of .94454 with a diametral pitch of 24, 42 teeth, and pressure angle of 20deg. Thank you
How can I alter this to make less than 13 teeth possible?
This video worked out great for my except for one thing. When I finished my gear even though I had an N of 21 I ended up having 24 gear teeth. I noticed that on yours too you ended up having 20 gear teeth when you finished your circular pattern. Is there anyway to fix that?
Can u make the same tutorial for Bevel Gears? Thanks.
i have a problem in equation driven curve . .
it says wrong equation i just copy paste it?
X(t) = "D2@Sketch2"*0.5*(cos(t)+t*sin(t))
Y(t) = "D2@Sketch2"*0.5*(sin(t)-t*cos(t))
+John Medina If youre still having this problem, all you have to do is copy and paste the formula into the x_t and y_t boxes, and you'll notice that the formula turn red in colour which signifies that it has an error. For some reason solidworks doesnt like having things copy and pasted. After this, just click the 'explicit' check box, and then click the 'parametric' checkbox again. It somehow makes solidworks forget that it was copy and pasted and the formula will turn black and it should work. If that doesnt fix your problem, you may need to change D2@Sketch2 to D2@Sketch3 if youve accidentally done it on a new sketch. That worked for me
+Sam Isaac I think if the formula turns red you have a problem with the formula. My issue was having multiple sketches/dimensions not lining up with equations, such as - Equation for Xt in the 2nd involute"D2@sketch2"*0.5*(cos(-t-2*"D4@Sketch2"*pi/180)-t*sin(-t-2*"D4@Sketch2"*pi/180)). Problem I found was that I had D4@Sketch2 on a separate sketch! D1@Sketch3!To maintain consistency/efficiency I kept the formula and changed the sketch to match.
+John Medina i am facing the same issue . .no mater what i type in it says invalid
nice thanks
Could be you have a different language version in SW? I.e. in
german "Sketch" is called "Skizze", therefore straight copy/paste
wouldn't work for involute equations.
Hello! Excellent tutorial! I am running into one issue though with the Phi value. I can change N and P to all the combinations I need without issue, but when I change Phi to 30 degrees I get a Dedendum circle that is larger than the base circle and the pattern won't cut. Any advice on how to fix this? I am trying to draw a 5/10 36T 30deg involute gear.
Hi and thanks for sharing this great tutorial! It has been very helpful.
Can I ask, is this gear design based on a "zero backlash" basis? And if so, how would you recommend building in backlash? Is there way to do it using global variables such as modifying the pitch circle diameter or module etc?
Many thanks again!
Why t1 is 0 and t2 is 0.68 in equation driven cure "D2@Sketch2"*0.5*(cos(t)+t*sin(t)) and "D2@Sketch2"*0.5*(sin(t)-t*cos(t))? Any clear description please ?
M A Motin Sobuj hello did you find this out? thanks
M A Motin Sobuj He (the teacher) said about this: "That is just a value for "t" I randomly selected after a few tria"l.
It's the beginning and end of the curve. You can use other values for t_2 as well, as long as the curve ends outside the material (and can finish the cut).
this is the best. It helps. Thanks
where does the 0.68 come from in the involute curve parametric equation
Excellent video
Great tutorial, but wouldn't be easier to make the second involute curve as a symmetry from the first one (via the constrution line)?
How can I adjust the equations to make gear with different diameters? If I adjust the "P", the size of the teeth changes also such that the new gear cannot fit into the original gear. How can I change the equation so that I can make different size gears that can still work with the original gear?
great job displaying the exact equations necessary to produce a gear that can be changed with only a couple variables.
Could you produce a video teaching us how to build equation driven helical bevel / miter gears?
Well this is way above my level, probably I will just guess the dimensions of my gears.
Very nice tutorial Mr Cao, I have a question, do you know, how to design a rack and pinion (obviously I learned how to do a pinion), but I cannot to draw a rack to matching pinion with, I will be very happy, If you could do that. Thank you very much.
Thanks for the demo. I noticed on SW14, that for the circular pattern, I was able to set the number of instances to be the global variable N so it auto updates. Also the fillet radius can be set to "c" / 3 or 4 or whatever.
Good to know. Thanks for the information.
I am running into a problem with the equations where my gears are large and my base circle ends up being smaller than my dedendum circle example 50 gears. Is this something that I am doing wrong? Maybe i copied and equation wrong or a problem with the format. Let me know plz
Is there any way to have the equation driven curve not show as under defined? I find that I can drag it with the mouse, and that makes me nervous.
Great job sir!
to clarify.. when you input your equation curve, the genereated curve goes from left to right...0 degrees, to the right, with the given equation... my line goes up... from 0 degrees, vertical...I have No idea why its doing this. I even went back and did it with all your numbers..
I made the same mistake. You probably wrote the Y(t) equation wrong. My error was putting a plus instead of a minus lol
Does anyone know how to do this with SW2007? I can work out the equation feature differences, but this version does not have the Equation Driven Curve feature. Any ideas?
What should I do, when it is saying
Unable to create instance for the pattern. Try again by decreasing the number of instance or the distance between instances
There seems to be a limit to the number of teeth you can have given a specific a and d because eventually the base circle, which is Dp * cos(phi) becomes larger than the d circle. Is this a real property of these gears, or a side effect of the way we drew it?
Yes. I mentioned the issue in the description of the video. It is possible for the base circle diameter to be "smaller" than the dedendum circle diameter. Gear profile will be all involute. No more straight line between the base and dedendum circle. I haven't been able to figure out a general method to accommodate both cases.
Yang Cao
Ah sorry, I should have noticed that in the description.
I really appreciate your effort. I am just beginner of solidworks and followed your lecture and got it. As you mentioned I encountered the base circle diameter is smaller than dedendum circle diameter. Do you have other lecture for this or should I draw from the beginning? Please let me have your tip for this. Thanks in advance
Thanks for uploading this, it really helped me understand the process a lot more.
I have made my version of your model, are there any conditions that need to be modified to account for a much larger spur gear? I am trying to model the angle but my value comes back as a negative value and cannot define the angle.
Diametral Pitch = 0.3333
No of teeth = 110
Pressure angle = 20°
Addendum Diameter = 336mm
Pitch Diameter = 330mm
Base Circle = 322mm
Dedendum Diameter = 322.8mm
My tan and beta angle values in the involute curve come back with a value of -0.3°
Has anyone used this to create a relatively large spur gear?
Very usefull material. Thanks a lot. When you say "a" need to hear "b" as well. Don't you have a tutorial for internal involute gear too? Hot to direct involute curve toward center now?
Thank you so much man
good morning, i have a problem. when i put the value of the number of teeth equal to a high number, like in my case 94, it creates between two teeth a strange thing, how can i do to remove it?
thaks for your attention
Great video! Helped me a lot. Just one comment. When you named your global variables, you called "P" Diametral pitch but I think that should be the pitch diameter (in) and you called "dp" pitch diameter when that should be diametral pitch(teeth/in). The values are correct though. Thank you so much for your help.
How would I modify the equations to suit a gear with a large number of teeth?
Is there any advice for how to enter the equations, mine keep showing up red
John, could be you have a different language version in SW? I.e. in german "Sketch" is called "Skizze", therefore straight copy/paste wouldn't work for involute equations.
Or you may have to use quotation marks as sb mentioned below.
How do you create a curve with profile shift?
how can you control face width in your method? does face width affect other parameters in gear design?
When defining the parametric curves, what are the values inputted into t1 and t2? 0-0.68. What are these representing?
the start and end bounds for the t parameter. 0 means start at the beginning (t = 0) and the 0.68 number is arbitrary, it just needs to be high enough to make the curve extend beyond the addendum diameter so that you can use it to cut the gear profile later. You can "guess and check" the 0.68 value until it extends past the biggest circle.
hello,
nice video,first i modeling 2 gear but i have a probleme for collision when i want to assemblate them, why ?
the second, i want to simulate stress gear, how can i do it ?
thank you very much
Hello Sir, Kindly provide me access to the drive file... Thank You !
how did we get that 0.68 value for t2, quite confused