Machine Chatter and Pocket Finish

Hey Guys,

At my ends whit with this machine, have been troubleshooting it for nearly a month now (with the only outcome being tons of wasted wood.)

So ill start with some background, have the 1000mm model with the dewalt 611 and NEMA 23’s. Also just performed the stiffening mod on the X-Axis (the 30 min one with M5 screws).

Have done everything, adjusted VWheels, locktight on all the set screws, even replaced the ACME lead screw and Delrin nut, but still cant get my cuts to come out properly

For one, I continue to see “gouges” in my pocket finish (Z-Axis) when cutting MDF. Interestingly, these appear to be more prominent when the router is beginning a cut into a new portion of the wood, and are extremely repeatable (whether I scale or move design relative to waste board). Have included a sample image below

Z-Axis Finish

Additionally, Im now noticing chatter while cutting. I have included a video below of the behavior, but its especially pronounced in the top left and bottom right portions of circle. Its odd because I dont recall this behavior earlier, almost seems like my calibration work is causing a deterioration in cut quality. Including a link with an example below. Using a 1/8 bit with feed of 100 and Depth of .125 (however, I have reduced feed to 40 and Depth to 0.0625 with similar results).

Video of Chatter

At the point of exasperation with this machine, I have no idea what more I can do. Any help would be greatly appreciated!!

I reduced a lot of chatter by doing a stiffening mod to the y axis. you can test this by attaching a few blocks of wood to the y xis and the wasteboard. I had found out how much flex there was when doing a 7 hour time lapse of a 3d wood carving in the video flex could be seen and it was a fair amount. this was before any mods and there was more movement in the y axis than the x axis.

This video looks like loose v–wheels, or an exceptionally poor bit. Did you also do the y-axis mod? Also, can you “twang” your belts like a guitar string? Your v-wheels should be very difficult to turn with your finger, but you should still be able to turn them. Your work should be held down securely - screwed in.

If none of that works, then you’ll have to slow down or take shallower cuts.

I still don’t get the point of the 30 minute mod. You can put a STEEL plate between your makerslides in less than 30 minutes and it adds actual rigidity, but this is exceptional chatter without any mods.

@ShaneBell, thanks for the feedback, ill deff take a look at the Y-Axis stiffening mod and experiment with it. Only weird thing is that most of the vibration seems to occur when its traveling on the X-axis. Also, more generally, it just seems so strange that these machines require custom modification just to enable machining of MDF.

@Earwigger, many thanks as well, it does seem like excessive chatter, especially considering the fact that its just MDF, and I stiffened the X-Axis. Ill deff double check the VWheels again, but i had re tightened all of them earlier this morning. The bit was also brand new, bought from Inventables and just began using it earlier today, but ill switch it out as well. Belts were also just tightened, but Ima try to tension it some more. Hoping the combination of a bit from all 3 areas helps.

I actually tried the same cut at a feed of 40 and .0625 depth, still had chatter. As to the steel mod, would have preferred to, but dont have a drill press handy to help drill the holes through the maker slide, plus im a bit apprehensive about messing it up in the process :).

Many thanks for the feedback so far, really appreciate it

Dude, those figures are for aluminum. He’s talking about MDF. I cut .25" deep at 40 ipm in MDF with NO chatter. He’ll find the source eventually.

Sorry, I cross posted in the wrong thread :blush: .

Hey Everyone,

An update as to what Ive done and the progress i’ve made.

Firstly, I spent a good several hours tightening up all the bolts on the machine, messing with belt tension, adjusting all VWHeel, changing the bit/collet on the router, improving my X-Axis Stiffness, adjusting spindle RPM, etc.

Oddly enough, the thing suddenly improved (i think it sensed it was about to go up on criagslist), in terms of both chatter and pocketing. In fact I just finished a cut at feed of 100 and depth of .125 with no chatter at all and only very minor pocket gauges on the Z-Axis (when entering a new portion of uncut wood). Honestly, its a huge improvement, wish I could put my finger on what exactly was going on, but Im glad to finally see improvement. It did highlight a new issue that I was unaware of earlier, but ill save that for a different forum post.

Either way, thanks everyone for the awesome feedback, glad to finally see the light at the end of the X-Carve tunnel.

1 Like