Crown test is close

This topic contains 5 replies, has 4 voices, and was last updated by  Ryan 1 month, 2 weeks ago.

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  • #116173

    Vince
    Participant

    1″ OD Steel tubing, printed in PLA and PETg. Hardware purchased here; waiting to tackle dual end stops later. Haven’t gotten around to beautifying the wires yet, though cable chains are printed. ๐Ÿ™‚

    Crown test prints, with a sharpie on a PETg holder, are all identical — almost there, but the center circle at the top, and the circle on the left, don’t quite match up. I’ve tried with different starting points. I’ve tried printing twice from the same starting point, and it’s identical every time. I’ve tried using Repetier Host on Windows, and Pronterface on Mac. Same results. What’s up?

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    #116178

    Jeffeb3
    Participant

    I would guess it’s pressing the marker down too hard and the error is in the pen holder. Nice build though. Is that the same cabinet as Ryan?

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    #116179

    Vince
    Participant

    Thanks, the stand is slightly different (a Husky — and, since it was on sale, several hundred dollars (!) cheaper. Not sure how I’m going to cover it to cut down on dust & noise once I get to routing, though…)

    I’ve actually wondered if it’s the pressure, and might try a ballpoint for comparison. Also just found someone else just had similar issues, so I’ll check my pulleys and stepper motors next.

    #116186

    Bill
    Participant

    Yeah, set your Z0 to the work surface and have it only move down 0.5mm (depth of cut) when drawing. It’ll still move up enough for the clearance plane, but won’t try and push the pen down so hard.

    #116277

    Vince
    Participant

    Replaced the Sharpie with a pen, and got very similar results.

    I noticed the zip tie holding the end of the cable on the right had its bulky end facing inwards, so it was pushing the cable out away from the leg — slightly, but it meant the cable wasn’t straight. Also loosened all the bolts for the bushings on the X and Y axes.

    The latest try is definitely *much* better, though I’m still not happy with the (not-quite-a) circle at the top center. Am I just looking for too much perfection from the pen? I’ll be using this with a drag knife next, and have plans for a laser after that, so I want to make sure this is actually working properly. If not, what else do I check?

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    #116283

    Ryan
    Keymaster

    That is not a perfect circle in the file. It should be a close shape but it is not a circle. Slap a router on it and go have some fun.

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