[2Bits]

Hey all!

I been trying to figure out how to create some simple plastic gears using my 3 axis cnc, but unable to find anything that could create the drawing without alot of painstaking work. Then the other day as I was browsing the Partmaster Pro application directory (don't ask me why) I stumbled on a Gears.exe file so I ran it. Wala! Here's a program to enter some specs and options and it creates it for you, just add toolpaths and cut it. Well at least it seems that simple.

The problem is that there are some options and terminology used that I don't have a clue about and was wondering if anyone knows how to use it?

I can't seem to find the gears I want online or have to buy either tons of them or a bunch of assorted ones, or pay thru the nose for some custom stuff. This looks like I could create my own and why not, I got the hardware and plastic to do it. If you're not aware of the app, browse to that directory and give it a spin.

Mark

[benjamint76]

I can't find what you're talking about, have a link?

[2Bits]

No link, look in the DolphinCadCam directory under Program Files on your hard drive. In that directory is where I found gears.exe. Just double click on it and it will run. At least that's where I found it.

Another option is to do a search (Start - Search), look for gears.exe on your local hard drive.

[andre-dolphin]

I have produce a movie showing how to use the Involute software.

This is not intended to teach you about designing an involute form, you must know the form of the teeth before you can make sense of the software.

Look at Misc page on www.dolphin-online.net

The movie will run under XP and Vista.

Note that your software license must include the Involute module to run properly, contact your agent if in doubt.

ATB
Andre

[2Bits]

Outstanding! Thanks for the video!

Do you or anyone know where I can find more information about gear design to understand it better?

Thanks,
Mark

[John S.]

Do a search for a book called Gears and Gearcutting by Ivan Law.
Not expensive and it covers making gears in the home shop as opposed to one that covers complicated industrial methods.

http://www.abebooks.com/servlet/Sear...ears&x=54&y=14

John S.

[2Bits]

I found enough information to create and cut a gear successfully that had a circle diameter of .5

Tonight however, I tried to create one that was .6, but when I load the gcode into Mach3, I get those damm tiny extra circles (wild random toolpaths). I get tired of that! So using Mach3_Inc post processor, cuts everything else just fine. So why am I getting these with this part?

[benjamint76]

I have had that problem with BobCad from time to time and it sucks. Check out this free program:
http://www.cncedit.com/

It is simple and powerful. You can view the cutting path and the associated lines of code and the same time...so you can delete the lines that are causing the goofy circles.:banana:

[harley4ever]

I dont think he is looking at another program for answers. He has a question about dolphins gear generator. Hopefully someone can come forward and answer the question.

[2Bits]

No, don't really want to resort to another app. The gcode generated by the Dolphin Cam should work as expected and not generate these wild random circles. I did and should point out that this 'Gears' app is accessible via the CAD application via 'Involute' option on one of the menu dropdowns (can't remember exactly which one right now, I'm at work).

Another issue I ran into, in the video tutorial you can generate the gear into cad by saving the .vbs script and then open or activate the script in cad. But when I do, my .5" part is generated into cad as a 16" diameter part. If there's some way to scale it back, I don't know what it is, nor again, would I expect it to do this. I had to use the save as .dxf option and then create a new drawing/part using the dxf file to get the correct sized part, which I then had to manually create the contour/toolpath whereas the .vbs version already had it done, just 16" across.

[andre-dolphin]

Please send me the following files and I will see if I can find where the problem lies.

In the Involute module use Save As.. and send the .gear file

Also send the original .dxf .dra and the .cnc files.

[email protected]

Thanks
Andre

[2Bits]

Thanks Andre,
Will send it when I get home tonight.

** updated **
Files sent, zip file attached to email

[metalworkz]

It almost sounds like the IJ Mode is set wrong in Mach3 for the gear application. Do other toolpaths from the same CAM display correctly when loaded? Is it possible that the IJ mode in the gear application is set to Absolute and Mach3 is set to Inc? Or vice-versa?
Regards,

[2Bits]

No, IJ mode set correctly, really goes out of whack if I change it. Haven't had this problem pop up for a long time.

[metalworkz]

I had a problem with the units of measure more than once when I first started using Dolphin. Does the part look oversized as if the units of measure is not the same between dolphin and mach3? Like metric in the CAM and inches in Mach3?
regards,

[2Bits]

No, it seems to be in inches and only happens on running the vbs file.
It's possible I'm missing a step? or having something not set right?

But the tutorial seemed pretty straight forward and I don't think I did it any different. Either way, the CAM program seemed to generate the gcode just fine, but once Mach3 loaded it up, then the circles appeared. It being a bigger part than the previous, .5 to .6 you would expect it to have a easier time with the code etc.

[metalworkz]

Did you send the files to Andre? Did he find anything?

[2Bits]

Yes, I sent the files. It is a weekend, so I expect it will be next week before I hear anything, but you never know.

[metalworkz]

I have to make some cogged wheels for cog belts I will be using for the steppers on 2 axis of a CNC router build I am working on. I was just thinking I might be able to use the gear application in Dolphin for those cog wheels? I was just going to turn them manually and mill the cogs, but if I could do it with Dolphin that would probably be easier and less work intensive than the manual idea. Do you think the gear app. would generate toolpaths for a cog wheel?
Regards,

[cncjunky]

I have bobcad v22 and I beleive that dolphin cad/cam is made by the same makers. I know bobcad v22 has supposabley a gear cutting capability/ feature, but what the feature actually produces is a sprocket not a gear and most likely that's what you have too with dolphin.