Andymark gear CAD files

[bardd]

Does anyone know where to find CAD files for Andymark gears? Both firstcadlibrary.com and team 1323's library don't contain the gears I need. Also, I can't use Inventor's "generate gears" function, since I want to design around the gears, and not incorporate them in an existing design.
Also, if anyone has a tutorial on creating gears in Inventor, it would work just as well.

Thanks in advance.

[R.C.]

Originally Posted by bardd

Does anyone know where to find CAD files for Andymark gears? Both firstcadlibrary.com and team 1323's library don't contain the gears I need. Also, I can't use Inventor's "generate gears" function, since I want to design around the gears, and not incorporate them in an existing design.
Also, if anyone has a tutorial on creating gears in Inventor, it would work just as well.

Thanks in advance.

The 1323 library has been down for a decent amount of time. We haven't had time to make the new layout and get parts sorted, we have about 500-1000+ parts that need to be uploaded etc... If anyone has a decent amount of spare time and knows HTML/CSS/MYSQL etc.../ would like to work on it PM me. We'd highly appreciate it.

But to answer your question you can find CAD drawings of similar gears to Andymark here:

http://wcproducts.net/cad/ - Most are 1:1 to AM's but you'd have to check each page. We try to make 1:1 drop ins.

You can also use:

http://www.rushgears.com/Tech_Tools/...fromHomeP age

Just type in 20DP - 14.5 PA and the tooth size you'd like. Download the model and modify to make an AndyMark gear. Unsure if there is another online database of AM gear models. I'm sure you can email AndyMark and they would be more than happy to send you the models.

-RC

[tim-tim]

What exactly are you trying to do? You can simplify the gears by modeling the gears as cylinders, using the outside (or overall) diameter (OD). This will represent the amount of space required for the gear. Note that using this uption will show interferences between gears. I will typically place a sketch of the pitch diamter (D) to show the mesh location between gears.

The pitch diameter (D) can be found using: D=N/P where N is the number of teeth and P is diametrical pitch.

The outside diameter (OD) can be found using OD=(N+2)/P.

So for this gear the pitch diameter would be 12/32=.375" and the outside diameter would be (12+2)/32=.438"

Hope this helps. In large assemblies, especially on lower end computers, it is better to make simplified representations like this and allow for the resources to be used where needed.

[bardd]

Originally Posted by R.C.

You can also use:

http://www.rushgears.com/Tech_Tools/...fromHomeP age

Just type in 20DP - 14.5 PA and the tooth size you'd like. Download the model and modify to make an AndyMark gear. Unsure if there is another online database of AM gear models. I'm sure you can email AndyMark and they would be more than happy to send you the models.

-RC

Can you give an example for input? I may have misunderstood you because I got nothing after several attempts. Thanks!

Originally Posted by tim-tim

The pitch diameter (D) can be found using: D=N/P where N is the number of teeth and P is diametrical pitch.

The outside diameter (OD) can be found using OD=(N+2)/P.

So for this gear the pitch diameter would be 12/32=.375" and the outside diameter would be (12+2)/32=.438"

Hope this helps. In large assemblies, especially on lower end computers, it is better to make simplified representations like this and allow for the resources to be used where needed.

I will start with this. Thank you!

Maybe I should've mentioned this: I'm trying to design a gearbox with an random ratio and no purpose, to gain experience in gearbox design.

[tim-tim]

Originally Posted by bardd

Maybe I should've mentioned this: I'm trying to design a gearbox with an random ratio and no purpose, to gain experience in gearbox design.

If you are designing a "random" gearbox, I would avoid using actual gears in your design, until you have the ratio locked down. Why? If you are using simple cylinders you can update the diameter on the fly and restructure the gearbox quickly. Just be careful to choose gears that you can actually purchase. For example, I don't know that i have ever seen a 13 tooth pinion gear for a CIM. Not saying they don't exist or you can't make one, but it is something that is not commonly available.

Good luck!

[Akash Rastogi]

Originally Posted by bardd

Maybe I should've mentioned this: I'm trying to design a gearbox with an random ratio and no purpose, to gain experience in gearbox design.

I would suggest that you identify a gear ratio based around a realistic problem and then create your gearbox based around gears which are commercially available from WCP, VEX, or AM (or something like SDP/SI). Making a "random" gearbox is not clear to me what you are trying to do, but if you create a ratio and gearbox based around calculations for a problem such as the elevator problem in this or any other problem you create on your own, you'll have a much better understanding of the design you are creating.

The basic criteria you need for the elevator are: 1) load on the mechanism (in this case, the weight of the elevator), 2) The height the elevator has to reach 3) The diameter of the winch/pulley drum 4) In how many seconds do you want your elevator to reach your max height. Once you set those criteria, follow the equations in the link I gave.

Just my +0.02

[bardd]

Originally Posted by Akash Rastogi

I would suggest that you identify a gear ratio based around a realistic problem and then create your gearbox based around gears which are commercially available from WCP, VEX, or AM (or something like SDP/SI). Making a "random" gearbox is not clear to me what you are trying to do, but if you create a ratio and gearbox based around calculations for a problem such as the elevator problem in this or any other problem you create on your own, you'll have a much better understanding of the design you are creating.

The basic criteria you need for the elevator are: 1) load on the mechanism (in this case, the weight of the elevator), 2) The height the elevator has to reach 3) The diameter of the winch/pulley drum 4) In how many seconds do you want your elevator to reach your max height. Once you set those criteria, follow the equations in the link I gave.

Just my +0.02

I've been thinking of a human-carrying cart for quite some time. I didn't intend on using a custom gearbox, but I think I'll take the opportunity and design this gearbox for the cart. Thanks.

[bardd]

Final Product. Thanks for your help everyone!