146 letters for carnival

At my job (financial data analyst) me and my Maslow were a running gag. My colleagues belief/believed I am in a sort of a midlife-crisis since I started “making” things.
So, when my supervisor asked if my Maslow could “make” letters for their carnival carriage, I jumped in! (don’t know if this is a global known thing. During carnival every village has a parade, at least in the south of the Netherlands).
Next thing I know, I committed myself into cutting 146 letters out of 12mm plywood :flushed: :sweat_smile: .

Designed the letters in Fusion and used the CAM settings as noted in this post (smoothing / feed optimization / ramping) : Cutting Improvements: Ramp Down in Corners and Full Height Finish Passes - #27 by tinker
The results are pretty good, but I did notice some burn in sharp (outer) corners

I increased the “Reduced Feedrate” under Feed Optimization to 400mm/min, hoping the increased speed would decrease the burn. However, I did not notice any visual difference. Anyone has a clue?

This project will have me occupied for the coming evenings. Sure thing I’ll bite my tongue the next time someone has a “nice” project :grinning:


Did you check that there is no slop or sticking with the chain? This is usually indicative of slop. Is this the only letter that has it? Does this happen only on a particular part of the plywood? If yes, then try moving your maslow around that part (without the bit) and see for any signs of slop or sticking in that portion

1 Like

Btw, love your frame. What size is that?

1 Like

Thanks for the compliment. It’s a 350cm (12 feet) frame. Mostly made out of material the former owner of our house left in the garage, when we moved in. My brothers laser level made the frame as accurate as possible.

This evening I did some checks on the Maslow regarding the burn marks. The router (when idle) moves over the board without hiccups (left to right, up and down). All the letters have these burn marks on the sharp outer corners.

That leaves me to believe that my CAM-settings are the root cause. Tomorrow I will adjust the CAM-settings to see if that helps.
Thanks for your thoughts.

Yes that could be your CAM software. Additionally, you can check the depth of your cut and number of passes. If your bit is too deep it won’t have trouble on vertical or horizontal cuts, but on curve cuts that maybe causing the “slowdown” as your bit is having a hard time cutting through the material - thus the burn. Experiment with one letter and do more passes and shallower bites. If the burn mark is gone, then it should be your depth per pass that should be adjusted. What flute are you using?

I am using 6mm single flute

My depth per pass is half the bit diameter (3mm) at a speed of 750mm/min which worked fine in previous projects. In the corners the speed is 400mm/min

Today I checked the box “Inner corners only” in CAM and I have the feeling that the burn marks are less. But could also be me, wanting the burn to be less. Since I already delivered the first batch of letters I cannot compare to previous cuts :pensive:

Anyways, I’ll keep experimenting with different settings and ask my best friends (Youtube and Google) to consult me.

1 Like

Do you see burn marks even on the first cuts of a new bit? It could just be that the bit is getting dull. They will work for a long time after they get dull but with increasingly poor cut quality.

Haha. I get that feeling a lot. Looking at your settings it could probably be that your feed rate does not match your rpm, so please do try and adjust it. Second, 3mm per pass might be too deep, try shifting it down to 1.5mm to 2mm, i’ve cut numerous things and really there is no standard depth of cut, so you really have yo experiment here. Lastly, as bar said, your bit might be the culprit. Try another one and see. Do let me know if any of changes helped you😁

Sorry for the late response, life got in the way.

I cut a letter (left side on the picture) with the following settings : 2mm per pass, no ramping, no optimization. Unfortunately I do not see any visual difference (letter on the right is cut with the inital settings).

I do see a lot of gcode in GroundControl when the Maslow is passing the sharp corners. Is it possible that there are to many lines to handle in a short period of time, which results in the Maslow slowing down :thinking:?

Tonight I want to test it out with a new bit. I already changed to a new bit once during this project, but at that point I didn’t pay specific attention to the results with a new bit.

Can you say if it’s a continuous move or does the Maslow ‘stop’ for a short while after every line?
That could explain the burning. Depending on the software there could be a setting to reduce the amount of splines. Defaults are often set for far faster machines. A quarter (or any fraction) of a circle is 1 line of g-code and runs smooth without stops. Not sure if your letters allow to replace the curves with circle parts.

1 Like

Turning on “gcode buffering” in the advanced settings will help a bit with all the lines of code.

1 Like