Losing steps in Y-axis

LowRider CNC Troubleshooting
1

Hi gang, as I get used to my LR2 I’m trying to optimize speeds and feeds etc.
My x-axis can plow through pine with 7mm DOC at 1500mm/min with a 6mm 4-flute upcut flat endmill, but my y-axis is losing steps (sometimes, but it only takes once to ruin a job) at even 900mm/min. My router is quite happy at these speeds. My chips are about 1mm wide.

  1. Is this simply because X has two motors and Y has one? I turned up the current on my Y a little which helped, but I guess not enough.

  2. What speeds/feeds do you typically use with softwood? Am I just pushing too hard?

  3. I notice that even though I chose “conventional” milling is ESTLcam, is seems to use the same stepover in both directions when it is doing back-and-forth cuts.

If this is just a case of less power in Y I might just write a post-processing script to reduce feeds in that axis only.

Thanks!

2

I usually cut at 800 to1000 mm/min and doc of 4 to to8 mm 1/4 in 2 flute

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Here are examples of my issues.

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15822534241351578571732.jpg2448×3264 2.29 MB

  1. At the top I was losing steps in Y all over the place. I was definitely pushing too hard ~1500mm/min
  2. Was still pushing too hard I guess ~ 1200mm/min but I was great until it hollowed out the “O” and then it lost Y steps. Full 7mm DOC
  3. Then I thought I’d focus on speeds and feeds. On the 9 3/4 circles right to left, when using a small step downs, say 2+2+2, on the second pass the Z would take a dive right through the material. Then I switched to a single 7mm DOC and the left two are perfect.
  4. Down to about 800 mm/min. All perfect until hollowing out the letters, lost Y again.
  5. Now I’m down to a crawl ~450mm/min. Lost X and Y.

For #1-3 my driver voltages were about 1.1, 0.85, 1.1
For #4 my driver voltages were about 1.1, 1.1, 1.1. 6mm DOC
For #5 I brought them all down to 0.9. 4mm DOC

This is all with a very sharp endmill and a 6.5A router.

Below 0.9 I find I can give them a little poke with my finger and they lose steps but keep in mind that my router is a little heavier than yours. So it seems like on the low side they just can’t push and on the high side I’m probably getting thermal shutdown !?

I was thinking tomorrow I’d try 1mm DOC just to rule out forces vs. stepper drivers.

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FYI I’M making this to cover the pocket door I’m “fixing” :grinning:

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158225463915716774200522448×3264 2.15 MB

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5

That is nuts. That is a large endmill, and 4 flutes. I have no idea how you are getting nice chips. Try to find a single or two flute at the most. With high RPM routers 4 flutes is a very very bad idea. Typically you should just be starting fires.

Seeing how many ruined signs you have I would say, you are not that close to stable settings. Slow everything down. When you have 99% success rates, go deeper, when you can’t go deeper, go slightly faster over 20mm/s (cutting) and I would think you are really asking for trouble. Milling basics has my recommendations and they are no where even close to what you are attempting. Best I am comfortable with is 9mm/s 6mmDOC single flute 1/8" upcut in MDF…that is about as hard as wood gets but you can see numbers that I consider reasonable there.

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6

Thanks for the reminder to RTFM. I had everything tuned in nicely with Fusion but my starting points were way off for Estlcam.

7

Hi ryan I really dont know where im going wrong im losing steps at 15mms and doc just 1mm :frowning: im using 2209s with nema 17 2amp in uart mode current set at 1800 in marlin mode
Im running the lowrider 3 8 x4 build woth makita copy router 30000 rpm
Any ideas

8

Please open a new topic with all your own details.

From what you’ve posted so far, the current is way too high. Set it to 950mA.

But a new topic with only your details will give us all a better way to have a good back and forth about it.

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