Inaccurate cuts by 1/4 inch

[msantos]

recently, when i am performing cuts on my prs standard with a router, my cuts are off about 1/4 inch on both the x and y axis.

how do i correct this error?

thanks

[Gary Campbell]

Martin...
What type of cuts were you doing when you encountered the error? What software did you use to toolpath? Were you machining inside, outside or on vector?

If using the ShopBot [C] [?] commands has your cutter value ([V] [C] been set to the proper value?
Gary

[ken_rychlik]

Are you cutting on the inside or the outside of your part? It the cuts are off by the diameter of your bit, that me be the problem.
Kenneth

[Mike Windsor]

did you generate the toolpath for a 1/2" router bit , but cut it with a 1/4" bit ?

[msantos]

sorry for the delay in my response. i live on the other side of the world where your morning is my night.

anyway, let me explain me problem better. i set a mark on my work piece at 5,5 and tell the shopbot to jog to 5,5 the bot goes to 5 1/4, 5 1/4.

i use vcarve pro to create all toolpaths and cutters have proper values,

[Gary Campbell]

Martin...
It seems that what you perceive as your zero points in X & Y may be off. If you move 90 inches are you still off by 1/4"?

Can you install a V bit and make a cross at 0,0 then another at 5,5, then check the measurements? The diagonal should be a litttle over 7 1/16". (7.0711) IF this is correct then make a mark at 90" and check this for accuracy.

If the measurements are accurate, then the position that you assume to be zero may be off. If the measurements are off then your unit values may need adjusting.
Gary

[msantos]

gary,

r my unit values correct
x & y 1833.465
z 2291.831

what are the a 2291.831 & b 34.72225 values

[Gary Campbell]

Martin...
I wouldnt know if your values are correct. Did you test the moves for accuracy?
Gary

[gundog]

When I first got my machine something was off and it did not move the right distance I called SB and they walked me through changing some settings and it fixed the scaling issue.

Mike