Hi all,
I have just setup my new 1000, but I’m not happy with the accuracy.
I have squared the whole setup, tensioned the belts, etc…
But when I carve a circle with diameter 50mm, I get a cirle with diameter 49.90 at the widest point and 49.07 at the most narrow point.
When I careve a square of 40mm, it is in the X direction 39.14mm and in the Y direction 39.68.
What can I do to correct this? Tension the belts even more?
These are the grbl settings
$100=80.040
$101=80.040
$102=188.976
Thx!
Keep in mind this:
First of all, once all is mechanically sound you need for maximum accuracy fine-tune the $100-102 parameters.
This is done by using a ruler long enough to cover the maximum travel for each axis and measure over the longest possible travel (or close to)
Here is a video made by @CharleyThomas which explain the procedure.
Note that any machine will have some level of accuracy discrepancy, components of backlash, belt tension, wheel tension, tool depflection / wear etc. Getting it tuned to suit your needs is the key, some won’t ever notice +/-0.5mm while others chase the last thou. Take note of the first link I posted 
Happy calibrating
That’s double the ideal. What’s your microstepping set to be? It should be set at 8X.
Thx both!!
I have corrected the microstepping and testen using the video above.
These are the new grbl settings
$101=39,9429386590585
$101=39,9429386590585
But still, I carved a 50mm square and the X 49.06 and the Y is 49.45. so still not within the accuracy it should be, and it is also not square.
Any more ideas please?
Have you squared the machine? Here is a easy way to do it. https://youtu.be/cr68yJruDHI
Maybe get a precision collet to reduce runout from your router or spindle. Be aware that machines that cost 1000 dollars shouldn’t be expected to perform like a machine that costs 10x as much. Non flexible structural components, linear guides, and precision lead screws are what really can create more accuracy. You can upgrade parts here and there and that will help some.
What speed is the Dewalt on?
Are you compensating for your actual bit cutting diameter? Some bits that are advertised as like 1/8” only cut 0.123” which would need to be measured and toolpaths adjusted.
Most parts hav let tolerances specifies for a reason.
Sorry to hear that. I’m pretty happy with mine!
I’m extremely happy with my 1000mm unit. I’m currently not looking for extreme precision, but what I am getting I couldn’t be happier with. I did go ahead and upgrade my x- and y-axis belts and pulleys, as well as my front and rear y-axis mounting plates and stiffners to go along the y-axis, all from tbdcnc.com. Great company to work with and top-notch products as well.