irregular circles help

[ted mcwilliams]

new joes 4x4 using vcarve pro and mach 3 cutting 7 in circles out of .75 pine drew and created toolpath using vcarve saved as txt file and ran with mach 3 circle cut very irregular with some wavy areas and x and y measurements varied .375 very consistantly started with .375 upcut spiral bit have changed bit to .25, varied cut direction , changed feed speeds and plunge rates end result the same ran pocket circle wizard 8 in diameter ( which i think would eliminate mechanical problems and mach 3 ) had a friend create drawing using auto cad he sent to me i created toolpath from his drawing save as txt file ran thru mach 3 and circle cuts were perfect. appreciate any advice and help ted

[Jerome Stanek]

Is this vcarve from vectric if so send Tony or Brian an email. Also post on the vectric forum. Can you send me the vcare file and I will see if my Shopbot will cut it correct.

[Dave Spitzer]

Ted,
Also send me a Vcarve file so I can check on my machine. I haven't had any problems with vcarve, but what post-processor are you using?

Dave

[Gerry Grzadzinski]

post the code for the irregular circle.

[james mcgrew]

gerry how do you guys check resolution in mach for distance traveled, square, circle etc?

[Michael Simpson Virgina]

When you say you are getting wavy cuts, ist hat on straight lines? IE what happens when you cut a square of say 6" x 6"

[Gerry Grzadzinski]

gerry how do you guys check resolution in mach for distance traveled, square, circle etc?

Do you mean how do we check if it's cutting the right size?

I just cut something and measure it.

There's a calibration function in Mach3, but I've never had the need to use it.

Once you do the math and enter your steps/inch, you should be very close. Then cut and measure, and you can fine tune the numbers to get it as close as you want.

[james mcgrew]

josh created a resolution calculator sometime ago i am not even sure i still have it. i believe mach has it on board the software. if i had distance problems and after checking for loose axis etc. resolution would be my next look.

i have yet to see vectric produce a bad circle, and you are right this is why we need to see the .crv or the code

[ted mcwilliams]

michael the wavy cuts are part of the irregular circle cut 7 in diameter circle wavy portion on the cut at about 5o and continues approx 3 in ted

[ted mcwilliams]

james im assuming your using mach3 go to settings screen just above the reset button see set steps per unit. i used a 5 ft ruller from home depot and a 4 ft for x the software will compute steps per unit ted

[Mike Package]

In Mach, on the general config screen, is your Distance Mode set to absolute or inc? If inc, try absolute...

[Michael Simpson Virgina]

What I found that helps with a new DIY build is to create a pen attachment. This eliminates things all the router and cutting aspects so that you can concentrate on tuning the machine. Also remember a picture is worth a thousand words.

If you are getting wavy lines while cutting a circle with a router from the 6oclock to the 3oclock that definitely sounds like your bit is wandering during the cut. There are a number of things that can cause this.

Play in the axis, cutting too fast and too deep, Play in your router mount. If it’s not your router, look at your stock holding system.

Just remember you should not cut more than the width of the bit you are using. The thinner the bit the more it will flex and cause chattering.

[ted mcwilliams]

many thanks to all who tried to help turns out primary problem was slipping gear on the "x " truck contacted ahren who apologized for the troublems he suggested " loc tite " did and solved the bulk of the problem. along with a littli tweaking on mach settings and now producing perfect circles will soon treat y and a motors to their loc tite again thanks to all ted

[Mike Package]

many thanks to all who tried to help turns out primary problem was slipping gear on the "x " truck contacted ahren who apologized for the troublems he suggested " loc tite " did and solved the bulk of the problem. along with a littli tweaking on mach settings and now producing perfect circles will soon treat y and a motors to their loc tite again thanks to all ted

Ted, can you elaborate - what is the X truck? And what mach settings did you have to tweak? Thanks!