Horizontal finish pass issues

(Josh) #1

Wondering if anyone has had issues in the past with horizontal passes in the past?
Running a simple box and I seem to get peaks and valleys a bit. Thinking the machine is fine as I’ve run flat ops before (from Carbide Create) and they seemed to have worked fine. Bit looked good. No wobble on the part.

These were run with standard 3mm stepover:

Then I did another pass with a smaller (1mm) max stepover. Still had some issues:

(Phil Gorsuch) #2

Hmmmm - looks like the links you posted are broken - probably have a bunch of carriage returns inserted into them at some point in the posting process. If they are photos can you add them into the post?

(mikep) #3

Tram issue?

(Josh) #4

Fixed pics (hopefully).
Not thinking its a tram issue. Again I’ve run smooth flat surface finishes in the past with carbide create. I’ll finish up this job (and hand sand [eugh]) this piece to get the surfaces flat and then run a face job on something else as a test.

(Dan Nelson) #5

What kind of wood is that? What bit are you using? Speed, feed, plunge?

I ask what wood first for a reason. I’ve had some woods that just don’t cut well no matter what I’ve tried. Some tend to spit splinters and the varying densities and sap woods make the cuts smooth, then sticky, then pull out along the grain, then cut just fine again. The other stuff I mentioned will all feed into cuts that look like that too.

Edit:Sorry, just realized this was on a Nomad, so I removed a couple lines above that are SO3 related.


(Josh) #6

Bit was a 1/8th inch flat end mill. I swapped to a fresh one for the last pass, and inspected the previous one. I don’t think the bit would account for the climbing feature. Wood is cherry. 7000rpm. 700mm/min. Plunge has been variable. I think for this last pass it was .5 mm. For roughing I’m using 2mm, which has been mostly good. I think I’ve had this issue a bit in a few woods, so I don’t think its the material.

Here’s a picture from the roughing. Used a long reach ball endmill there. I’m getting no real obvious issues other than in the bottom left, which I attribute to just being a slight missed segment.

I ran out of time tonight and I’m going to cut the piece out in the morning and run a flat pass to verify it isn’t the machine.

Toolpaths/model were generated in Fusion 360. I realize I didn’t post that previously.

(Dan Nelson) #7

Cherry is hard, really hard. That long reach end mill might be deflecting, looks like a lot of stick out. Do you have a shorter end mill that will reach all of the features? What happens if you slow it down and use a shorter end mill?


(William Adams) #8

As @DanoInTx noted, your endmill seems to be sticking out quite a bit — is enough of it securely in the collet?

What feeds and speeds are you using?

Please try the mahogany feeds and speeds from: https://docs.carbide3d.com/support/#tooling-support and test them per: https://www.precisebits.com/tutorials/calibrating_feeds_n_speeds.htm

(Josh) #9

As noted previously, the long endmill was used as a roughing pass. The 1/8th inch endmill (#102) from carbide was used for finish passes.

(mikep) #10

That’s also where the wood grain goes almost vertical - unless your endmill is extremely sharp and your stepover small, some grain following, all sorts of goofy.

(Josh) #11

Makes sense. I’ll try slowing it down and go with a fresh endmill next time I’m doing a box. Thanks for the input!

(mikep) #12

Be aware that although carbide is awesome, and lasts nearly forever in softer materials like wood and plastic, it is -not- as sharp as HSS. Sometimes, that’s the ticket (I prefer it for aluminum, for example).

(system) closed #13

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.