how to control and understand feed rate

Post by **msantos** » Tue Jun 19, 2007 7:10 am

hi tony,

yes i am using vcarve more than part wizard.

i need to know how to control the feed rate. when i load files to cut in shopbot, my move speeds are 12 for x & y and 10 for z.

in my sample cuts, the job runs along fine. then 30% into the job the shopbot jerks then the whole tool path is out of wack.

i want to slow down the feed rate. i feel that 12 is to fast. i have set the feed rate to 10 but still get a move speed of 12 & 10. i have deleted all tool paths created new ones with the lower feed rate but still get 12 & 10 move speeds. what am i doing wrong!!!

it takes me long to replys to post as the time difference between guam and uk way different. while i am working you are sleeping

please help

martin

Post by **BradyWatson** » Tue Jun 19, 2007 8:05 am

Martin,
The cutting speeds in VCarve are set in the tool database screen, which shows when you select a tool. Make sure your speed units are reasonable for the parts you are cutting & that the Units value is set to inches/sec.

If want to verify your speeds before you cut, simply enter in the FE command in SB3 & look in the 1st few lines for the MS command. This is the Move Speed command. The following command sets a move speed of 2 inches per sec on the X&Y axes and 1 inch per second on the Z axis: MS,2,1 - You can easily change these speeds in the shop before you run the part file.

If you are unsure as to what speeds you should run a part, start out slow - in the 1.5 to 4 Inches/Sec range on the XY and .75 to 1 on the Z. You can also get a decent idea what range the speeds should be in by using the Chipload Calculator under the Tools menu in SB3.

Hope that helps!
-B

Post by **msantos** » Tue Jun 19, 2007 9:15 am

hi brian,

i was able to cut my sample job. and turn out pretty good . i reduced the feed rate on all tool paths to 3 and that seems to do the job.

this shopbot has a real large learning curve and i need all the advice to reduce the curve.

thanks, will use your input

martin

Post by **BradyWatson** » Tue Jun 19, 2007 9:38 am

No problem Martin. You'll get the hang of it pretty quick & be cutting all kinds of good stuff in no time.

-Brady