Marking bottom of pocket

I’m trying to “plane” a piece of wood with a pocket operation but it’s getting all marked and burned. The burning I understand could be from my feeds and speeds, but it started when I tightened a z carriage nut that was loose.

And what about the marking?

Any thoughts? I’ve read it could be an alignment issue but how could I fix that on the shapeoko?

Thanks in advance,

Jesus

The machine lines are not going away unless you get your router perfectly trammed to the machine, and even then won’t like completely go away. They, largely, are the result of the bit not being perfectly perpendicular to the workpiece/bed.

There are other things you can, other than tramming, do to make them less aesthetically displeasing such as choosing toolpath strategies that only have the bit move over the wood in an horizontal fashion and using bigger surfacing bits that will increase the distance between the lines.

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As for the burning that looks like to shallow of a depth of cut and the bit just rubbing the surface instead of cutting much of anything away.

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I guess it would also help to show you what bit I’m using

Any resources for tramming?

Thanks!

The top two are good.

https://www.youtube.com/results?search_query=tuning+shapeoko

So yeah. That bit is the right tool for the job. Tramming is your next step and smart toolpaths after that. I am not sure how to do the the kind of tool path that has the bit move only horizontally (for example) across the workpiece in Carbide Create but I am sure it can be done with some trickery or effort. Others might be able to advise on that.

If you’ve not read it yet

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I’m using carbide create and motion for now, I’m just getting started with fusion. I tried using the surfacing tool path in carbide create, but it wanted to take 3x the time.

Thanks for the tips.

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You may need to re-tram your spindle. At least to me this is what I see without feeling the cut itself.

Thanks, it does seem that way, the ridges are really subtle, I’m measuring 0.09ml average. They are just more pronounced because of the burn.

The burn is likely from moving the spindle too slowly over the workpiece.

When you can take a shallow final cut with the machine moving faster for a finish pass, I normally leave 0.5 to 1mm in wood and take a finish pass at 1500+ mm / min surface speed to avoid burning. After that some light sanding should take out the ridges.

Some woods also tend to show the cutter direction just as burnishing in the top surface, even when you have the tram close to perfect, you have to sand that out.

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You can make adjustments in Carbide Create to cut as fast as you want. Faster than the machine can handle.

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I see the marks and the burns. I had an issue with marks and did not see how they were caused originally. I had not taken sufficient care to square everything properly. Undoing the machine and rebuilding it from scratch with proper regard for squareness (and a lot more insight into tramming errors) left me with a machine that cut perpendicular to the workpiece. Belt tension is crucial too. Both Y rail belts should be equal in tension or they can cause uneveness. If you can match the tension in the X rail, it helps to prolong their life.

The burning of wood is something that you learn as you cut more wood and different types of wood to see how it reacts to being machined. When you are running a job, do not forgot that in Carbide Motion there is a page which will allow you to up increase or reduce the feed speeds while the job is running.

The pocket toolpath is good for surfacing and I ensure that my workpiece size is increased by the amount of stepover required to ensure that the cutter extends over the edge by at least 50% of its diameter so it does not leave a curved corner to remove. I take small cuts (0.2) and do not worry about the time it takes. Cutting easily and without stressing the machine is helpful. The way to preserve the sharpness of tools is to treat them well.

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