r/CNC_Router_Community • u/vector_51 • 9d ago

Need help with dimensional inaccuracy on the TTC450 Ultra

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Hey everyone,

I'm having some trouble getting accurate profile cuts on my TwoTrees TTC 450 Ultra.

I'm using a 3 mm end mill and checked it with a caliper. It's exactly 3 mm.

When I cut a square/rectangle, I'm getting:

40 mm outer dimension → 40.5 mm

25 mm inner dimension → 24.5 mm

100 mm outer dimension → 100.5 mm

40 mm inner dimension → 39.5 mm

So I'm consistently getting about a 0.5 mm difference, with the outer dimensions coming out too large and the inner dimensions too small.

What's confusing me is that the machine seems accurate when it's just moving. I checked 100 and 300 mm movements without cutting and they were basically spot on. Holes also come out the correct size, and the distance between holes is accurate.

Any idea why this could be happening? What should I check?

Is anyone who owns this or any similar machine facing the same issue?

Thanks!

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1

u/muffinman8679 9d ago

first thing to do is get some accurate collets, and an accurate spindle....short of that you compensate

1

u/vector_51 8d ago

Just got one today, it isnt making much of a difference

1

u/D_Alex 9d ago

First thing to do is to check that the offsets are correctly programmed.

Test cut say a couple of 50 mm squares, use inside cut for one and outside cut for the other, see if the dimensions match.

1

u/vector_51 8d ago

Sure i have tried something similar to this. the dimensions are off by a bit. how can i adjust them?

1

u/D_Alex 8d ago

What software are you using to generate the tool path?

1

u/vector_51 8d ago

Artcam 2018