Need help with DXF gear files???

[JCAD]

Hi there, I am currently modelling a product for a university project, and need to model different size spur gears,one with 50 teeth (approx 51mm OD), and one with 10 teeth(aprrox 11mm OD).I need to build a working prototype so I need to model the gears then create DXF files to laser cut these from 6mm sheet acrylic. Does anyone have any files of gears? or know of a site where i candownloadsome? ( the ones in the files section dont' help) I find the whole business of modelling gears very complex. I know how to pattern them easy enough,I'm just findingit difficult to get the larger cog to mesh with the smaller one.Ifanyone can explain how to model the teeth correctly that might help.


Thanks in advance


JCAD

 

[puppet]

if u upload the specs to ur gears i will be happy to help u when i find the time.

 

[JCAD]

Puppet,


I have attached a picture of the gears that I am trying to model, I need to change the axles on these gears, that is why they are not suitable. The large cog has an outside diameter of approx 51mm to the end of the tooth, the diameter of the cog at the base of the tooth is approx 47mm, this makes each tooth approx 2mm long. the cog has exactly 50 teeth.


View attachment 794


The outside diameter of the smaller cog to the end of the tooth is approx 11mm, and to the base of the tooth is 7mm, again this makes the length of each tooth to approx 2mm. This tooth has exactly 10 teeth.


The width of each tooth is also around 2mm at the base, going down to about 1mm at the tip,I have noticedlooking at the other cogs that i have,the two in the middle shown here, that for each one the tooth shape changes slightly. There is obviously some mathematical formula that is relative to this shape, one that i am not familiar with.


The gears are not being used on a precision mechanism, so the size of the backlash is not too important. If you need any more information just let me know.


Thanks mate, really appreciate it if you can help me,


JCAD

 

[JCAD]

Puppet,


Though I had better mention that I am using the student version 2001


JCAD

 

[puppet]

aa no point. sorry. u can not open my files.

 

[JCAD]

Can anyone else help me with this?


JCAD

 

[puppet]

actually if ur only after a dxf then anyone can open it. but if u
want a prt file thats when u start facing trouble..

 

[Zaki]

Hi Jcad
I have a solution for u. Its a module based gear. Just what u do ?? copy this file at your pc and when u need a gear just save a copy as ur desired name, then open that file and go to perameters and change the number of teeth and module size. Then pick the tooth 2 in model tree>>RMB>>pattern and give the number of items as one minus total number of teeth (one teeth already made) for example if u need 40 teeth then u type 39 in the pattern and its done..
thickness could be change any time

Zaki2005-04-04_051453_gear20.zip

 

[JCAD]

Thank Zaki for the zip file but unfortunately the part file will not open up on my version of pro E. If anyone can help by sending a DXF file that would be great, as i will be able to create a part from this information.


Thanks


JCAD