GearHeads Corner

Help...

This morning I ran my first test cutting of a gear I made in Gearotic,
then sent it to Meshcam in .dxf format. MeshCam put out the Gcode, then to Carbide Motion to cut.

It ran perfectly until it got down to about 75% done,( I was so happy to watch it cut the gear)
then suddenly the feed rate sped up all by itself and the spindle started to go nuts....out of control.

The gear was partially destroyed by the last few seconds before I shut it down....

Any ideas on why this would happen???

RR

Hi RR:

  Ouch, I hate it when something liek that happens. Can you post
the Gcode the Carbide spit out. Ill let you know if it shows anything..

Art

Art,

I am new at this, how do I post the gcode on this forum?

RR

Art,

Do you have an email address that I can send you
a picture of the gear that got destroyed at end of run?

RR

RR:

  You can post photos here, but it wouldnt prove much, Ive seen thousands.. lol

The Gcode woudl be more usefull. To post any attachment, just click the +addition options
under your post as your enterin git. You can slect files there to attach.

    The Gcode will tell me if it was your machine or your file. As it cant be the DXF, Im suspcting the
feedrate was wrong on its final pass or something..

Art

Is this what you want?

No, I need the file you load into your machine, usually is a txt or tap file..

  The dxf is what you load into meshcam, that looks fine, what is the output of meshcam?

Art

Art,

The file is .nc and it won't load here as per file
types below.

just rename it from "whatever.nc"  to  "whatever.txt"  then it will  load for you

Or zip it..


Dont feel bad about the hassles, when you get into this it takes time to get used
to the definitions, how things work and what things are called. You got most of
a cut done, not a bad start.. :)

  Drop the file here, it will tell us if its the machine or the commands..

Art

Today I spent 5 hours just trying to make a simple gear
with 20 teeth in Gearotics.  I seem to go one step forward then two
backward sometimes.

Two major issues that I don't seem to grasp.

1. When I make a gear in Gearotic and my plan is to save it in .dxf,
then open it up in MeshCam.  Do I go through the steps in Gearotic
to pick the tools and make a toolpath or do I skip those things and let
Meshcam do all the adjustments and create the gcode.

It seems that what ever i choose I make some type of mistake along the way.

2.  All day today when I tried to run a job, they all started fine, but the end mill stayed about
1/4" above my material (which is great if you don't wish to have any dust).

Thanks......RR ( I feel like such a pain in the ass, I normally do all things myself and never need help...)

Hi:

>>1. When I make a gear in Gearotic and my plan is to save it in .dxf,
then open it up in MeshCam.  Do I go through the steps in Gearotic
to pick the tools and make a toolpath or do I skip those things and let
Meshcam do all the adjustmen ts and create the gcode.

  Either/or. There is no need to involve meshcam at all.Or to use a dxf. A dxf is just a drawing of a gear.
(in this case.). Meshcam is creating an output GCode file for you as whatever.nc , or *.tap, or *.txt,
doesnt matter the extension, they are all really text files.  Open one in a text editor and youll see the
GCode. GCode ios the language that drives your carbide. It follows the drawing (the dxf) and offsets to
one side or the other for the tool radius not to cut into your teeth.
  It also drops after each pass to make it incrementally deeper.

>>It seems that what ever i choose I make some type of mistake along the way.

  If your just beginning, exp[ect to make lots of those..

>>>2.  All day today when I tried to run a job, they all started fine, but the end mill stayed about
1/4" above my material (which is great if you don't wish to have any dust).

  Sounds like you didnt specify a depth..

  In Gearotic, you need to select the gear, send it to the 3axis workbench, and generate the toolpath by
telling it the parameters of your tool, how far down to go, and how far it may go each time. (Depth per pass)

  Watch the video on the 3axis workbench. Also, if you want to know why it screwed up, post the .nc file here,
just rename it to .txt an it should post. I can tell very fast by looking at that file
what your doing wrong..

Art

Art,

Watched the video twice.  Did everything (I think) as you explained.

Shapeoko3...ran job......started in lower left hand corner....spindle never moved for than 1/4 inch
in any direction.

File attached:

Am I nuts.............or what.

I installed a turbo charger to my Polaris Slingshot by myself.
I built a 5000 pound brick pizza oven on my patio with no plans.
I have build 10 computers in my life.

I cannot make a f************gear..........

Yikes...........

Richard

Richard:

  Well, the gear tap file looks fine. Its 10x10 and .25 deep gear. The question is 10 x 10 what? , If your trying to cut a 10" x 10" gear
1/4" deep, you did well, the file is fine, but your table is running metric mode I'll bet, and its seeing it as 10mm x 10mm, and .25mm deep.

  So you need to tell your carbide that your in standard mode. You should see some movement then..


  Am I rigth in assuming you added the  G43H5  to the file?  get rid of that as well. You need no G43's in
the files that Gearotic puts out. It would command an offset to the already offsetted drawing.But if you remove that
line and then tell the carbide its an inch file, you should be fine.. Adding a G20 to the top of the file may do it,
G20 tells a machine controller its in inch mode..

Art

Art,
I cannot thank you enough for all your help.

I did not put the G43H5 in the code.
I made about 5 different posts and each one comes up with that G43H5.

I removed that and added G20 as per your instructions and made
somewhat of a test gear.  Not perfect but an advancement as of now.

I also set Carbide Motions to inches, but it defaults back to metric each time it starts.

Is it better for all concerned to work in inches or metrics for the best product?
Or does that not matter?

I assume making a real perfect gear is the result of much tweaking of end mill sizes
and rates of speed and other settings.  Is that correct???

You have great patience, I wish I did also....

I will get this.............

Thanks....RR  That is a photo of my last table build, before getting interested in CNC...