Strange CNC router noise

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canman
Posts: 11
Joined: Wed Jun 29, 2016 1:15 am

Strange CNC router noise

Post by canman » Tue Oct 18, 2016 5:06 pm

Hi everyone,

I hope you don't mind me posting here...I don't have a Shapeoko machine, but I've found quite a bit of helpful information here when I was upgrading my machine. And other forums seem like the members try to make you feel stupid when you ask questions. Anyways, the machine is a Chinese 3040 machine that I've mounted a Makita RT0701 router to, and I've upgraded the driver boards so the machine reliably runs. I've got fairly decent accuracy, within .002" in the x-axis and within .008" in the y-axis. Need to work on the y-axis a little bit.

Anyways, I've been doing a lot of wood work with the router lately, inlay work in particular. I've begun to notice a noise I'm certain isn't good coming from the machine. See the video...it makes the noise right at the beginning, and again here and there in the rest of the video (only 16 seconds long).

https://www.youtube.com/watch?v=95VRTZj ... load_owner

Specs of the job:

1500mm/min feed rate
2mm depth of cut
6.35 downcut spiral bit
Uncertain about the width of cut...it varies. Programmed in Fusion 360, I think the maximum stepover was set to roughly 4mm.
Spindle speed: in this video, I don't remember. But I typically set it between 3-5 on the Makita, depending on chatter.
Stock: soft maple. Makes the same noise in poplar, walnut, and beech (only other woods I've been cutting)

The problem is, I get this weird noise at all router speeds. I ran the code without cutting anything, and it doesn't really make this noise. There are parts where it sounds like it's grinding a little bit, but certainly not like in the video. But as you can hear in the video, I don't get that noise all the time. Just in spots.

So my questions are...where do you think this noise is coming from? Am I cutting too deep? Am I cutting too fast? Can the machine just not handle this kind of work? I've read about depth of cut being related to the horsepower of the router/spindle. I'm working with 1.25hp...maybe that's not enough to cut 2mm into wood?

I hope you all don't mind me joining your discussions. As mentioned, I've found this forum to be friendlier and thought I'd find better help here. Many thanks!

GoSpeedRacer
Posts: 61
Joined: Mon Apr 20, 2015 12:22 am

Re: Strange CNC router noise

Post by GoSpeedRacer » Tue Oct 18, 2016 8:11 pm

On my 3040 I never had that noise but I was using the stock spindle. I actually broke the shaft on the spindle once and had to replace it. Your noise doesn't sound like anything with the machine imo, simply the router itself. Likely bearings. Was it a new router? If you have some scrap around, maybe fire up the router and cram some material into it and see if the noise is there.

I like what you did with the spindle. I LOVE my cheap China machine. It was so much less work than this belt nonsense. I might have to upgrade the spindle like you did.

canman
Posts: 11
Joined: Wed Jun 29, 2016 1:15 am

Re: Strange CNC router noise

Post by canman » Tue Oct 18, 2016 8:52 pm

It's a relatively new router...within the last few months. Maybe sawdust got up in the bearing and is jamming it up sometimes? I do have a bunch of scrap around, that's a good idea. I'll cram it in and see if the noise presents itself.

If you want, I can send you the Fusion 360 file for the clamps, or the gcode itself even. It cuts three parts out of 3/4" wood (I used plywood) with a space for a vacuum attachment. Very similar to other mounts designed here. I then glued the three pieces together to make as rigid a clamp as I could, without dealing with aluminum. Works well so far! Not quite perfectly square so I need to make some small adjustments. But let me know if you'd like the file/gcode and I'll send it along!

I'll update later today when I get a chance to test the router on some scrap.

canman
Posts: 11
Joined: Wed Jun 29, 2016 1:15 am

Re: Strange CNC router noise

Post by canman » Wed Oct 19, 2016 12:49 am

OK, I set the router to various levels and physically pushed scrap wood through it. At nearly any depth other deeper than 1mm, I got that crazy noise. So, good to know it isn't the motors! Unfortunately...I'm wondering if this means this router just can't handle the stuff I'm trying to throw at it.

GoSpeedRacer
Posts: 61
Joined: Mon Apr 20, 2015 12:22 am

Re: Strange CNC router noise

Post by GoSpeedRacer » Wed Oct 19, 2016 2:52 am

Without digging thru user reviews it seems like a good router. Could just be a bad bearing or something in the bearings. Might be worth tearing it apart and replacing the bearings- although it's most likely just the bottom bearing. Maybe see if there is a rubber seal version that fits. If you decide to replace it, the Dewalt that we use is a great router. I use the porter cable version of it.

I'll keep that file in mind- I would have to do it in aluminum tho. With the material I cut I would want to be extra sturdy

canman
Posts: 11
Joined: Wed Jun 29, 2016 1:15 am

Re: Strange CNC router noise

Post by canman » Wed Oct 19, 2016 2:59 am

GoSpeedRacer wrote:Without digging thru user reviews it seems like a good router. Could just be a bad bearing or something in the bearings. Might be worth tearing it apart and replacing the bearings- although it's most likely just the bottom bearing. Maybe see if there is a rubber seal version that fits. If you decide to replace it, the Dewalt that we use is a great router. I use the porter cable version of it.

I'll keep that file in mind- I would have to do it in aluminum tho. With the material I cut I would want to be extra sturdy
How deep and how fast can you cut through something like maple or beech with the Dewalt router? The Makita is fantastic, I'll open it up tomorrow and see if something is in the bearing. I'm inclined to think it isn't though...wouldn't it make that noise all the time if that was the case?

Do you cut aluminum with your China machine?

GoSpeedRacer
Posts: 61
Joined: Mon Apr 20, 2015 12:22 am

Re: Strange CNC router noise

Post by GoSpeedRacer » Wed Oct 19, 2016 3:52 am

Depending on the failure of the bearing it could only make the sound under a side load

I cut G10 material so I can't really speak for wood cuts. My cuts are around 50ipm at .075" but it will go .125" at 35ipm just fine. I just like using the second cut to clean up the edges anyway

canman
Posts: 11
Joined: Wed Jun 29, 2016 1:15 am

Re: Strange CNC router noise

Post by canman » Wed Oct 19, 2016 4:03 am

G10 is also way harder than wood, so I'd expect the Makita router (similar specs) to be just fine at the speeds I'm trying to cut at. I'll check out the bearing tomorrow morning and post an update. Thanks!

canman
Posts: 11
Joined: Wed Jun 29, 2016 1:15 am

Re: Strange CNC router noise

Post by canman » Wed Oct 19, 2016 8:47 pm

OK. Took router apart. Somewhat dusty inside, but actually fairly clean down by the lower bearing and spindle. I didn't take pictures, but I should have. Anyways, the bearing doesn't look like it can easily come out (nowhere to tap the inner race, the inside diameter of the casing and the bearing are flush). I didn't seem to have any problems spinning the bearing though. It wasn't loose/spinning fast when I spun it by hand, but it felt smooth and I didn't really feel any resistance.

I dropped some oil around the bearing's edges in hopes that it would seep down into the guts. Reassembled and ran more wood cramming tests. At first it complained again, even on really light passes. But when I cranked up to full speed, I was cramming wood through at probably 4-6mm depth and it wasn't really complaining. It's tough to tell what feed rate I was pushing the wood through, and unfortunately this just confuses me even more!

Could it be the tool jumping around that would make this noise? Maybe the cutter is too long...or maybe the router is just defective. I'll have to try cutting another piece of wood and see what happens.

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