Inlay Issue

This topic contains 35 replies, has 7 voices, and was last updated by Profile photo of Neil Neil 3 months ago.

Viewing 30 posts - 1 through 30 (of 36 total)
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  • #31885
    Profile photo of Kris
    Kris
    Participant

    Tried doing a test inlay tonight with a 1/16″ bit … set up the pocket as a hole (pocket) and the inlay as a part in Estlcam… ran at a pretty slow speed…. pocket is too small…. used the same bit for both… not sure what I am doing wrong.

    #31892

    My best guess would be that your bit isn’t exactly 1/16th. You may want to measure it precisely to make sure.

    Could also be deflexion of the Z axis.

    Could also be because your CNC is not perfectly squared and you made your parts at different places of the bed.

    Also, you didn’t precise what tolerance you accounted for. You need to make the inlay a bit smaller than the pocket in any case,

    How much of a difference did you get exactly?

    #31893
    Profile photo of Kris
    Kris
    Participant

    I will need to check the bit. I am just trying to learn – trial and error….

    I didn’t realize I needed a tolerance or to make the inlay smaller.

    What is the best method for doing something like this?

    #31894

    I would just scale down the inlay or scale up the pocket by a few percent, should do the trick

    #31904
    Profile photo of Kris
    Kris
    Participant

    I checked the bit I used and it measures 1.65mm which I don’t think matches what I had in Estlcam. I’m not sure where I should start to toubleshoot .. scaling or modifying the tool measurement in Estlcam or both. I just ran a 1.5″ square pocket and that is with me adjusting the bit to 1.65mm as measured with my digital calipers. The pocket only measures 1.489 so I am not exactly sure what I am doing wrong.. should I be adding some finishing parameters?

    Could an improper step over cause this issue ?

    I don’t have all of the functions of Estlcam down …. looking at it the tool is set up as in the screen print.

    #31907
    Profile photo of Jim Hildebrandt
    Jim Hildebrandt
    Participant

    Maybe check your spindle to make sure it’s square to the table. http://www.thingiverse.com/thing:1525661
    I set my endmill shape to 180 degrees for regular end mills.

    #31909
    Profile photo of Kris
    Kris
    Participant

    So I made a change to the end mill to be 180 degrees and the square is still measuring 1.48….

    I will try the other test you suggest but not sure how I will adjust if its not square with the table. I have the 500w Amazon spindle that I am using. So I’ll have to make a remix of that thing for it to fit.

    Are my expectations wrong… if I pocket a 2″ hole it should be 2″ right?

    #31910
    Profile photo of Kris
    Kris
    Participant

    On that thingiverse thing.. how do you use it? You certainly do not turn on the spindle do you?

    #31912
    Profile photo of Ryan
    Ryan
    Keymaster

    If you are going for super accurate, are you doing a roughing and finishing pass? With just a roughing pass you get the bit moving around from all the torque if you leave a little material and come back with a finishing pass you should get tighter tolerances.

    You do need to leave some sort of gap though. How big depends on you end use and your adhesive.

    #31913
    Profile photo of Kris
    Kris
    Participant

    I am merely trying to learn how to do a simple inlay. I have not set anything for a finishing path. Should I be?

    Sorry but this stuff is so greek to me I am having a hard time “getting it”.

    #31914
    Profile photo of Jim Hildebrandt
    Jim Hildebrandt
    Participant

    Correct, do not power the trammel bar up. Manually turn it, if it touches the table and you turn it 180 degrees and does not touch the spindle is crooked. Some paper shims is all it should take. Check it along the X and Y. A finish pass would probably help as well.

    #31915
    Profile photo of Ryan
    Ryan
    Keymaster

    I completely understand, I’m here to help. Adjust your bit diameter, use .5-.75mm finishing pass and see if anything is better.

    You should be using a finishing pass, almost always, unless dimensions do not matter very much.

    In my 2.5D tutorial you will see I use finishing passes there (they are easier to do now than the 2 path method I used in there).

    #31916
    Profile photo of Kris
    Kris
    Participant

    So something like this?

    So I assume it will do the rough cut and then go back and do this .75 finishing work correct?

    Does it pause for any user input, etc?

    #31921
    Profile photo of Ryan
    Ryan
    Keymaster

    If you are using a 1/16 you need to half that finishing pass.

    It is just another tool pas, no pause.

    I have a video of it. You might really want to work though my 2.5D and see how I cut things. It really might clarify things for you. It has everything except tool changes.

    #31922
    Profile photo of Kris
    Kris
    Participant

    I’ll check out the 2.5 —

    When you say have that finishing path.. meaning half of .75 ?

    One last question… in Estlcam when the gcode is generated it looks like this at the top…

    ;Project 1.5 inch square
    ;Created by Estlcam version 10 build 10.017
    ;Machining time about 00:28:20 hours

    G90
    M03 S24000
    G00 X0.0000 Y0.0000 Z0.0000 F2100
    G00 Z2.0000 F480

    I always have to edit the 3rd line changing G00 to G92…. is there anyway in Estlcam to just have it generate G92 all of the time. will save me several steps in prepping the file for the SD card.

    #31923
    Profile photo of Kris
    Kris
    Participant

    Well, just finished this past round with the finishing path at .75 and I am now even more confused…

    the x dimension is 1.47 and the y dimension is 1.45. where as before I added the finishing path it was square at 1.48

    #31924
    Profile photo of Ryan
    Ryan
    Keymaster

    Why would you edit that. g0=go to these coordinates, meaning if you are not there go there. G92 is reset coordinates. If you want that you should reset the arduino.

    Your cut is now undersized pretty equally, maybe you should put the bit back to 1/16″. By making it larger in the CAM you are making a smaller cut, to truly test that you would do an inside and outside cut, one will get too big, one will get to small.

    Good luck, I will be back this evening.

    #31928
    Profile photo of Curt
    Curt
    Participant

    Depending on what you are doing you will need to use the overcut feature on the corners or manually trim them with a chisel or something.

    #31929
    Profile photo of Kris
    Kris
    Participant

    The measurements are off all the way around… not 2″ so it’s not a corner issue.

    #31931
    Profile photo of Bradley F
    Bradley F
    Participant

    It looks like it could be as simple as a path location issue (outside, on, or inside contour cut on the inlay part).

    Are you selecting outside border of the inlay piece? and the inside of the line for the pocket?

    For the piece that gets placed inside, since it is too large, you could tell it to cut on the line (or even inside) to bring that cut in closer to the dimensions of the pocket.

    #31932
    Profile photo of Neil
    Neil
    Participant

    I have been wanting to try an inlay myself. I will have to give it a go. I honestly do not think you have anything wrong you just need to remove a bit more material with your pocket. I see you are concerned with your dimensions being slightly less than expected. I had a similar issue and resolved it by modifying the steps per mm on your x+y travel. You can do this through the LCD screen. Just press button on ‘configuration’ and then select ‘motion’ you will see a screen like this.

    https://ohai.lulzbot.com/media/uploads/DSC_0463.JPG.600x0_q85.jpg

    You would want to concern yourself with XSteps and YSteps. Based on the stepper angle and GT2 teeth and such you should be at 200. Things and tolerances are not dead on so you may need to swing this a bit. In your scenario if you are putting in 1.5 and getting 1.48 then you would want to start with your math like this.

    (expected) / (actual) x (curent value default: 200)
    so your math would be

    1.5/1.48 = 1.013513513513514

    then take

    1.013513513513514 x 200 = 202.702702

    So you could then input this number in both your x and y estep values (simply highlight each value click and spin).

    Hopefully this makes sense. I think you are darn close. I have wanted to try an inlay for awhile now. If I get time this weekend I may give it a go and let you know my findings.

    Neil

    #31933
    Profile photo of Ryan
    Ryan
    Keymaster

    Do not adjust the steps unless you test an inside and outside cut. The steps should be very accurate. If you get a small inside cut and a big inside cut the tool diameter is wrong.

    #31934
    Profile photo of Kris
    Kris
    Participant

    Here is exactly what I am doing… I am now using a 1/8″ bit which I think the size is dimensionally correct where as the 1/16″ bit was some cheap crap off Amazon.

    Even with the 1/8″ bit re-running I ended up with a 1.48″ square pocket.

    #31936
    Profile photo of Ryan
    Ryan
    Keymaster

    Still no finishing pass?

    #31937
    Profile photo of Kris
    Kris
    Participant

    Perhaps I am confused on the finishing path… the last attempt netted a smaller pocket that was not square.

    #31939
    Profile photo of Ryan
    Ryan
    Keymaster

    You are within .02″ in wood, you realize that is pretty good right?

    .5mm is pretty small the average layer I use on a 3D printed is half that thickness. In these sizes it could be anything, the wood could be compressing, or expanding from the heat. I have put some tolerance examples in the FAQ’s.

    #31941
    Profile photo of Kris
    Kris
    Participant

    so i just cut the part and it’s 1.48″

    I guess I should not be complaining… I sort of look at things black and white.. I’m a bit OCD too.

    Though the pocket is too 1.48″ the inlay will not fit inside without some sanding. Is this normal ?

    Is there anything else I can do to the tool or software? Will adding the finishing path to both the pocket and inlay make a difference and if so what sort of settings should I use for this simple square test?

    #31942
    Profile photo of Ryan
    Ryan
    Keymaster

    Have a look at the faq’s about tolerances, .02″ in wood is is beyond excellent. That is less than 1/32″, it can’t be measured with a measuring tape.

    You cannot cut anything as an exact fit, ever, you always need extra room, even more if you are using glue or epoxy.

    Look at my 2.5D tutorial if you don’t understand the finishing pass concept. Yes they will make a difference, it is a standard machining process if you are dimension critical.

    To do a test, as I said befor do an inside and outside cut. Same square on cut inside the line, one cut outside the line.

    But really, you are within.02″ if you want to try and get accurate measurements you can not do that with wood to this degree.

    #31943
    Profile photo of Kris
    Kris
    Participant

    So here is my next stupid question… “To do a test, as I said before do an inside and outside cut. Same square on cut inside the line, one cut outside the line.”

    How do you cut inside and outside of a line? I thought I had to use part for the inlay and a hole for the pocket.

    #31944
    Profile photo of Ryan
    Ryan
    Keymaster

    You would be making a test part, not your part.

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