Crown Test partial failure

Mostly Printed CNC - MPCNC Troubleshooting
1

Hey All!
I have recently completed my build and decided to run a Crown Test. I brought the pen a hair higher than the worksurface and hit go. It did a pretty good job except for the right side. So, I decided to grab a new piece of paper and try and again after putting the paper in generally the same place, I lowered the pen just a little bit more. This resulted in all of the lines being quite a bit thicker. However, there were still issues on the upper right side. I have included pictures of my crown test as well as general build pictures. I can provide more pictures as well as a video if needed. CAM work was done in EstlCAM. What do you think I need to do?

20240119_154410
20240119_1544101920×2560 357 KB

20240119_154414
20240119_1544141920×2560 329 KB

20240119_154424
20240119_1544241920×2560 307 KB

20240119_154446
20240119_1544461920×2560 417 KB

20240119_154453
20240119_1544531920×2560 334 KB

Crown Test
Crown Test1920×2560 233 KB

2 Likes
2

That looks like your machine isnt quite level to the surface. Happens all the time. Best thing you can do is tram your router in really well and then surface the top. Take real like passes. A bit like this is what Ryan always suggests and uses…

https://www.amazon.com/Freud-Dia-Dovetail-Shank-22-104/dp/B00002241Z/ref=sxin_14_pa_sp_search_thematic_sspa?content-id=amzn1.sym.3f105dd1-731e-46ec-8a78-5849a8226882%3Aamzn1.sym.3f105dd1-731e-46ec-8a78-5849a8226882&crid=BL9N7WAVJ4N0&cv_ct_cx=1%2F2%2Binch%2Bdovetail%2Bbit&dib=eyJ2IjoiMSJ9.50uVHDsvdsta4wM0sj-GMXwvlAWCyS5Lvp3fzG4pJnzKaCdhp4cGs9y_D2ZnvF8U72DsXthG8VnH_7dTTdFeQw.hVr4c52AX8JHaQvQzaUtApIAnV07YifzguXsnUTD0KM&dib_tag=se&keywords=1%2F2%2Binch%2Bdovetail%2Bbit&pd_rd_i=B00002241Z&pd_rd_r=f0553133-6107-4ca3-a3a6-f62def020434&pd_rd_w=FWHa8&pd_rd_wg=ZAz9o&pf_rd_p=3f105dd1-731e-46ec-8a78-5849a8226882&pf_rd_r=FFDN2F471PCY5QTAJKVX&qid=1705704855&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=1%2F2%2Binch%2Bdov%2Caps%2C132&sr=1-4-364cf978-ce2a-480a-9bb0-bdb96faa0f61-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&th=1

There is also a code generator that Jamie made linked in the docs for making surfacing gcode and all kinds of other useful things… G-Code Test Pattern Generator

Ask any questions you may have. Forum is full of really helpful people!

And congrats on your new build!!!

1 Like
3

Gotcha! I will look up how to Tram it. Is there a benefit to using the dovetail bit over a typical surfacing bit? I’m very new to CNC’s, and while I’ve done a lot of research, I hadn’t heard of this one yet?

4

Its a lot less stress on the machine. Those larger surfacing bits take a big bite and on an untested brand new machine that’s a lot. I know because I use them lol. I see your username is CNCnewbie so I assume this is your first machine. Nothing at all wrong with that, every one of us here started from that same spot lol. Just always best advice to take it slow in the beginning. Also that smaller bit will be a lot more forgiving if your tram isn’t perfect.

What spindle/router are you using?

1 Like
5

Ah, good to know! Yeah, this is my first CNC Machine. I am using the recommended Makita Router.

2 Likes
6

This will help with tramming

https://www.printables.com/model/191192-makita-700-cnc-tramming-tool

1 Like
7

@vicious1 Is there yet a remix of this for Kobalt router? If not I could try to remix for it.

8

He doesn’t have one on printables. At least I didn’t see it when I went to find the one I posted.

9

I am pretty sure that fits, I just used it.

2 Likes
10

Cool! Good to know.