Brand new KMG is LOUD

Edbriver

Edbriver

Joined
Jan 12, 2020
Messages
51
I splurged bought a new KMG from Beaumont. I've never had a 2x72 belt grinder, I just barely started making knives and started out on 1x30 and 4x36.

It showed up today and I set it up and threw a belt on it and it is LOUD. Like I can't even stand next to it without hearing protection loud.

Without a belt, just spinning the drive wheel it's super quiet, runs silky smooth. I got excited and put a belt to do some grinding and it shocked the heck out of me, I thought that the belt was grinding on something metal, but it's fine. Full clearance all around, belt is not too tight or too loose, bearings seem good, all the bolts are tight, set screws tight, no visible vibration, and I left a gap between the platen and belt just in case.

Is it supposed to be this loud with a belt on it?

I'm freaking out because I live in an apartment with close neighbors that don't mind me using power tools outside, like my 4x36, 1x30, or the occasional angle grinder, but if I used this thing for more than a few minutes I'd feel bad/they would kill me.

I've seen lots of videos of people using their grinders in their backyards. Are they just jerks and don't care about the noise or am I missing something?

I'll call Beaumont tomorrow, but in the meantime I thought I'd ask here in the hopes that I might be being a dumb newbie and can get some grinding done tonight.
 
Last edited:
Try it with the contact wheel if you have one, or try a j weight belt to see how much difference it makes.

A heavy grinding belt over small wheels will be loud.

Hoss
 
It does not seem like it should be that loud if you are worried about the neighbors.

You might put a decibel meter app on your phone and check the level from 2-feet directly in front of the grinder. Also, move it around near all the wheels and parts to see if any place is making more noise.

Questions/comments:
What belt is on the grinder? - An X-weight 36 grit belt will make a lot more noise than a j-weight 400 grit belt.
Is it variable speed and what speed is it running at? - A full speed only grinder or one running at max speed on the VFD makes more noise.
Does the sound appear to be coming from any particular place? - Check the two idler wheels on the platen while running to see if one is making the noise.
Is the platen adjusted properly so the bely is ever-so-slightly not touching? - If the belt is dragging on the platen it will make noise.
 
I gonna put this out there that you should be wearing hearing protection as part of your PPE kit around many power tools. When you get older you'll be happy you did. Too late for me though, the Who and Rolling Stones were pretty loud. I'm not too bad but many of my friends have issues.
 
Stacy E. Apelt - Bladesmith said:
It does not seem like it should be that loud if you are worried about the neighbors.

You might put a decibel meter app on your phone and check the level from 2-feet directly in front of the grinder. Also, move it around near all the wheels and parts to see if any place is making more noise.

Questions/comments:
What belt is on the grinder? - An X-weight 36 grit belt will make a lot more noise than a j-weight 400 grit belt.
Is it variable speed and what speed is it running at? - A full speed only grinder or one running at max speed on the VFD makes more noise.
Does the sound appear to be coming from any particular place? - Check the two idler wheels on the platen while running to see if one is making the noise.
Is the platen adjusted properly so the bely is ever-so-slightly not touching? - If the belt is dragging on the platen it will make noise.
Click to expand...
I threw an 80-grit ceramic and an 800 J-weight AO belt on real quick this morning before work and it made a difference, the noise level with the 800 J-weight was only slightly louder than what it is with no belt on it. The crazy loud belt is a 36-grit Combat Shredder belt. 80-grit X-weight is loud-ish, but not unbearbly loud.

I bought the KMG Classic 3-speed pulley driven, and it was running full-speed (3600 f/min). I'm going to try running it slower when I get home.

I couldn't pinpoint a specific location where the sound might be coming from, mainly because I didn't run it that long because I was afraid of bothering the neighbors.

The platen was the first thing I adjusted, it has about 1/16" gap.
 
y weight belts create a lot of noise it's just how it is. I never use heavy belts at high speed without hearing protection
 
Thanks for all the replies. It's possible that it's just running too fast for the belt grit. I won't know until I get home a mess around with it some more. I'm averse to getting a contact wheel because I don't like hollow grinds.

Called Beaumont and explained my concerns, she said it's "probably normal?", I got the impression she wasn't really listening to what I was telling her, kind of gave me canned responses like she didn't want to help me, told me a story about her last job, then she just sort of ended with "so just keep experimenting with it and if it seems bad or gets worse call us back and we can troubleshoot it, but thanks for calling."

Perhaps it's just this person, but when I called Beaumont a couple times during the ordering process and talked to a guy named Andrew he was super helpful, made me think really highly of Beaumont, he's one of the main reasons I bought the KMG and not a different grinder I was looking at. Maybe I'll just call back later.

Anyway, so the sound issue could possibly be normal? It could just be that I'll have to run sub-100 grits as slow as it takes to get the decibels down. Hopefully not too slow.

I'll have more time to experiment this afternoon.
 
Last edited:
Would probably be a good idea to download a decibel level app and then give us the info ( belt used, sfpm, and distance and location of phone when taking the measurement) then we can mimic what you did and post our results on different grinders here 🤷🏻‍♂️
 
Downloaded a db meter app. Here's the data, I'll try to upload the audio files somewhere. I held my phone (iphone 15) around where my head would be while grinding and rotated it to get an average db.

Grinder is Beaumont KMG Classic with 3-speed pulley drive and flat platen attachment. All bolts tight, bearings seem good and smooth, no vibration, tension not loose but not tight.

Belt ------------------------- Speed ---------------------- db level

Combat Shredder 36 ------- High (3600 f/min) ------------108
Combat Shredder 36 ------- Medium (1800 f/min) -------- 99
Combat Shredder 36 ------- Low (900 f/min) -------------- 80

Combat Shredder 80 ------- High (3600 f/min) ------------ 94
Combat Shredder 36 ------- Medium (1800 f/min) -------- 88
Combat Shredder 36 ------- Low (900 f/min) -------------- 75

Combat AO 800 ------------ High (3600 f/min) ------------ 93
Combat AO 800 ------------ Medium (1800 f/min) -------- 85
Combat AO 800 ------------ Low (900 f/min) -------------- 73

It's weird to see these numbers because with the 800-grit at full speed (93db) I can stand there and be perfectly comfortable, but with the 36-grit at full speed (108db) I can't even be within a few feet without wincing from ear pain, and even the 80-grit at full speed seems louder than the 800-grit (93db vs 94db), so maybe it has to do with the frequency as well.
 
Prior to retirement I was a practicing Hearing Aid Dispenser and strongly recommend the Sound Level Meter app from NIOSH .... it is very good ..... it is not in the test instrument area.... those cost hundreds of dollars. My HF Bauer portable bandsaw runs at 105 dB BEFORE it cuts metal and now wears 2" wide yellow tape labeled " WEAR MUFFS" on three sides ! And the app is free!
 
jorasco312 said:
Prior to retirement I was a practicing Hearing Aid Dispenser and strongly recommend the Sound Level Meter app from NIOSH .... it is very good ..... it is not in the test instrument area.... those cost hundreds of dollars. My HF Bauer portable bandsaw runs at 105 dB BEFORE it cuts metal and now wears 2" wide yellow tape labeled " WEAR MUFFS" on three sides ! And the app is free!
Click to expand...
That’s the app that I got, it seemed like a good one.
 
You must log in or register to reply here.
Back
Top