20-inch bandsaw diagnosis

[Susumu Mori]

Hi all,

I have a 20-inch BS (Felder FB510) and I want opinions from anybody who have Euro BSs about some symptoms I have.
First of all, it is a beast and really changed the way I do woodworking. It is fitted with a 1-inch Resaw King and Felder ceramic guides. I use it for veneer, resaw, dimensioning, curves, rip, etc. It does everything I want.
I know I should not complain anything about it but what I want to ask is the noise and vibration levels. You can say, why bother as long as it cuts well, but because I don't have experience with any other large BSs, I can't tell what is normal. Maybe I'm missing something and I can tune it for even better performance. So, I want your opinions.

I have my 10-year old 14-inch Griz, which still see some use with a 1/2 blade for small jobs and tight curves. It is spooky quiet and I think many say BS is one of the quietest machines.

Quite contrary, my BS is the noisiest at around 91-93 db. Even my 2HP Oneida emits only 90 db. A331 and the table saws are around 84-88 db and the shaper is almost nothing (is it running?).

Anyway, here they are;

> The motor makes loud (>100 db) noise for few seconds in the beginning. A Felder tech says it's normal and it happens when the motor switches the modes (whatever they are).
> Depending on the tension of the belt, another noise kicks in after 4-5 seconds that lasts the entire session. Somehow, I can adjust the tension such that this noise doesn't kick in (I discovered it accidentally). This is regardless of the existence of a saw blade. So purely motor and motor loads. Or it is possible that the poly V-belt is resonating.
> The blade guides contribute to the sounds. The sounds go down to 88-90 without the guides.
> The vibration level is not too bad, because a nickel can stand up during the steady state, but the guide post has visible shake.
> The existence of the blade does affect the vibration. Without it, the guide post shake is mostly high frequency invisible vibration but with a blade, the shake starts. So I assume most of it is caused by the irregularity of the blade,,,, or the upper wheel. If this level of vibration is what expected, I wouldn't bother.

Maybe these are the way 20-inch BSs are (the huge mass is moving while the saw itself is not as heavy as 30-inch BSs) and I should not measure anything based on my experience with the 1/2 HP BS....

Anyway, any opinions would be highly appreciated.

Thanks!

[Erik Loza]

All hollow-frame bandsaws have their own harmonics. In my experience, the bigger the saw, sometimes the more noticeable. Have you tried a different blade?

Erik

[Susumu Mori]

Thank Erik to help out a Felder user :)
OK, to some degree what I'm experiencing is expected for the hollow-frame design. I see.

I have two blades but they are both the same 1-inch RK. I have love-hate relationship with it. When it cut smooth, it is very smooth. I love the narrow kerf. Everything is so satisfying until... Well, all these good things seem to influence adversely once the kerf gets clogged; thin kerf, minimum sets, shallow rake,,,,, The burn saw dusts and tar build start to kick in once I start many resaw of 10-inch boards; once they reach a point, the performance precipitates quickly. Of course, it is possible that I'm doing something wrong. I am an armature.

OK, answering your question, no, I haven't tried except for the one came with the saw.

[Erik Loza]

Very first thing I would do is try a new blade, then perhaps a new drive belt. Eliminate the obvious stuff first. Also, make sure the machine is absolutely level and stable on the floor.

Erik

[Susumu Mori]

Thanks Erik.

I guess link belts are not really to replace a poly v. Am I correct?
My poly v actually looks a bit tired.....

[Erik Loza]

I don't believe link belts can replace poly-V's. Entirely different design and profile. Just look on your belt for the length and number fo cogs, then google that. There should be a lot of options from many vendors.

Erik

[John TenEyck]

91 db from a BS when it's not cutting wood sounds like something is very wrong.

John

[Andrew Hughes]

My 20 inch B20/20 is very quite and smooth.The thrust bearing on the upper guide starts screeching when my blade get dull, because I start to push harder on the wood.I did find the break was rubbing last year,so I did something to fix that.Cant remember what.
Thats all I got to help.Hope you get it Figuerd out.

[David Eisenhauer]

My MM 16 just quietly hums along when not cutting, noise level increases some when cutting. I don't own a decibel meter, but it is way-way-way quieter than my Oneida DC and other equipment. I am in agreement with Eric (as I should be), try a new belt and a new blade. Almost all problem fixes on a BS start with "try a new blade" and that quite frequently actually holds true.

[Susumu Mori]

Thank you all.

I'm not sure if there is anything wrong to fix with my bandsaw. It certainly seems a noisy side, though.
With just a lower wheel turning, it hums around 84 db. Compared to other induction motors I have, this 4 HP motor buzzes a bit more than others, but I guess this is a reasonable level.

[Susumu Mori]

OK, things gets VERY interesting here.

After Erik's suggestion, I recalled that I had a blade that came with the saw.
It is also a 1-inch blade, but, of course, not a carbide blade. I don't know the actual manufacturer.

Next to the Resaw King, they are like, a scalpel and an ax. The Resaw King is impressive; it's shiny, very thin and flexible, and the carbides are so sharp. Very sophisticated. A master piece. The other blade is stiff, thick, almost be able to stand by itself (OK, I'm exaggerating). The blade tips are, I guess they are sharp enough to cut woods.

Anyway, I tried the no-name blade. With only the lower wheel turning, it was 83-84 db. Could be lower, but not bad. I believe most of the noise is from the belt slap. I should buy a better belt.
Then I put the blade and tensioned. It was 84 db,,,, I said "WHAT?". I put the blade guides. 85 db.

I was confused. Now it became one of the quietest in my shop. Even my small 14-inch BS goes around 80-82 db.

Then I put the RK back. What I immediately noticed while I'm installing it is, the RK is like a violin string. High-tension without tension and keep giving nice sounds every time it hits something.
After I put it on the wheels and tension it, I basically created a violin. Turning it gives 90 db. Putting the blade guides, the guides start to play the violin with the hollow BS chassis possibly act as a resonator giving solid 93 db!

OK, I can see Erik smiling. It was the blade. My FB510 somehow has love affair with the RK. I can't believe it.

[Alan Hick]

Susumu,

I have a FB510, manufactured 2014, with the Felder ceramic guides. I use a 1/2 inch Lenox Trimaster, and a 3/4 inch Resaw King. I get the same initial loud noise upon startup, which goes away after 3-4 seconds. Using the decibel meter app on my phone, I get an average of 86 db with the RK, and an average of 83-84 db with the Trimaster. Of note, if I tighten the RK beyond a certain point it creates a harmonic wave in the blade in the rear of the saw and the blade starts hitting the channel wall, which makes a horrific noise. Problem is solved by letting off some tension. The Trimaster doesn't do that.

I also have an 18 inch Jet BS with a 1.5hp motor and use a 1/4 inch Wolf blade on it. Average db from this saw is 73.

[Susumu Mori]

Thanks Alan, that's exactly what I wanted to know.
OK, with a regular blade we are both hitting around 84-85 db. For some reason, my RKs are doing something wrong. I'll try to de-tension it.

[Jim German]

Could you post a video of the noise?

If you're hitting a resonance on the saw due to the tension from the blade, you should be able to easily solve that by adding a mass to the saw where it is vibrating.

Just as a point of reference by 20" northfield runs at 75db... even 84 sounds way way to high.

[Susumu Mori]

Well, Jim,

Even though we are talking about the same 20-inch bandsaws, the Northfield is 1,200lb with solid chunk of metals, while the Felder is at 600 lb with hollow chassis. I'm not sure if we can put them in the same league. If I can hit the chassis of FB510, I can hear hollow sounds. Also, the whole thing is on wheels for one side of the base. So, I can easily shake it. Sound-wise, it is not quite a good design, but most modern euro-type BSs have the same design, I believe.

[Erik Loza]

Susumu, I'd be willing to be that if you were able to find a way to plant your machine more firmly to the ground, it would get quieter but maybe that's not a priority. Glad you got it figured out.

Erik

[Susumu Mori]

Thanks Erik,

I wonder MM16/20 and Italian Laguna users can chime in with noise levels.
I use an app for a smartphone, although not sure how accurate they are.

[Erik Loza]

Thanks Erik,

I wonder MM16/20 and Italian Laguna users can chime in with noise levels.
I use an app for a smartphone, although not sure how accurate they are.

Never had a reason to actually measure that but I know that an FS30 is about 78db at idle and the bandsaw does not seem much louder to me, so maybe 80db? The dust collector is normally the loudest thing in the shop.

Erik

[Frederick Skelly]

Susumu, I'd be willing to be that if you were able to find a way to plant your machine more firmly to the ground, it would get quieter but maybe that's not a priority. Glad you got it figured out.

Erik

I wonder if you could insert some thin wedges between the floor and the bottom of the saw in a couple places. I use mobile bases, and every once in a while an uneven spot on my floor keeps a machine from sitting flush. Than I get vibration. A wedge, just slightly tapped in usually stops it.

I don't know these big machines you guys are discussing, so forgive me if I'm off base. But Erik's comment made me think of it as a possible troubleshooting step.

Fred

[Mike Hollingsworth]

Hey Guys

Where do you measure these decibels?

[Susumu Mori]

I measure where I usually stand to use the saw. Right in front of it, above the table.

[Alan Hick]

Replied to your PM Susumu.

I hadn't really thought about the noise level of the bandsaw. It never bothered me. But that big trapezoidal rear column probably does act like a resonating chamber. I haven't looked to see if it's possible, but it makes me wonder whether filling that column with something like very dry, very fine sand wouldn't "deaden" the sound a good bit?
Just as an aside, a previous poster mentioned how quiet his Northfield 20 is compared to the FB510 being discussed. Well, this isn't apples to apples but I've watched videos on 3 different Northfield 36's and those DO NOT sound like quiet machines.
When I think about other band saws I've used over the years, I don't recall ever using a "bigger" machine--meaning both size and HP--that I found to be particularly quiet. But I've never used a Northfield 20, and I've never used an Agazzani. I think that as long as there aren't any sources of unwarranted vibration, there's going to be some noise in a bigger machine, no matter what. I wish my bandsaw only had the gentle hum that my J/P has, but it is what it is, as they say.

[Susumu Mori]

Hi all,

I want to follow up my investigation of the source of the noise. I found a significant amount of the noise was from my particular blade, but I though 84 db without a blade installed was a high side for a machine with an induction motor. So I suspected my drive belt is doing something wrong. Then I noticed an interesting thing and I wonder somebody sheds some light on it.

What I noticed was, the noise goes away at the second I turn off the motor. Almost dead silence. This means, the majority of the source of the noise is not mechanical like the drive belt slapping the pulley. It sounds like the motor itself electrically (not mechanically) emits the noise. This may be related to the terrible noise Alan and I are experiencing for few seconds in the beginning.

I posted the picture of the motor. This is not a typical motor with one or two humps of capacitors. It has a small box on its back and connected to another huge box-full of circuits to the right of the motor.

It is made by "CE".

I don't think it's is defective and this observation would help anybody in the forum, but I want to share my experience and some educational information would be highly appreciated. I mean, I was a bit surprised that a motor can electrically emit this much sound....



https://lh3.googleusercontent.com/FEmR4ixZytHdSxz2ZHcTMc6y5DtuiO7S1M-WA8M_TOU1sD17t2yiauDB9neKAyBTEooQVc0QnoJo1-t37NzWTq6IVqrWQ8hj-rIeB9gnKX7bS91b49bnjXXuR4Bph3ENrG3ND4n1RFULbVx5JPc 8OyBUz9zUWsENxybYJ0sIlJJL0Q6yZtJ9JXnh6jp74__kPPBMH zUb5qoRr8l3AIVYwgsglgBoxdwXXaZJV05sMaajhDb2AZgydvc p4WGGi59_Hpd9VHA0SbjwxeUguJrtNCSmTpjlW5Bj33EOWkwxe cR3Gce8CwJYz-370XNiFJIJ_g6r1qIh3OGYmfhlvsHVHzsXY-j-MUorOHcqmxBhTl7gFgwH5k5zWh6zWAgJdzmrnhJuhFTOL_tnYU AMQ99o-NzVxBdXkiGMaPtYgDitRUl2Dt0ebhJAhVLcFYywJK00Y9Bt4Fw XQDVbJlhC5K8IJIlpgZNO1DbOP1So-osKzb3A88xKCuP_cJ5IZevbd7hOXPZJG3JJzOiDjBElK5J_DLe M-zZ5j-vkguPSkxCWnJ0=w715-h1271-no

[Scott DelPorte]

Hi Susumu
I used one of the phone apps and measured my MM24 and at idle at about 80dB.
Scott

[Erik Loza]

Susumu, "CE" refers to "Certification, European", which is a manufacturing compliance norms standard they use over there. You'll actually see "CE" on all sorts of different electrical appliances. Akin to their version of "UL" approval.

I have a local customer with some single-phase machines from your mfr. and they have German ATB motors. But maybe an owner can verify.

Erik

[Alan Hick]

Susumu,
When you say the noise goes away when you turn the motor off, is this WITHOUT a blade on the machine, or WITH a blade on the machine?

I just tried mine, and with the Lenox blade on I get 83 db with the machine running. When I turn it off, the db level SLOWLY decreases as the blade speed winds down to zero.

As an aside, I'm using an app called "db meter pro" on an iPhone 6. And, with EVERYTHING turned off in the shop, and seeming to have "dead silence" the db level is 39. So I wonder what a real decibel meter would show. I've looked at a variety of charts showing approximate decibel levels. A refrigerator's hum is 40, a pin falling is 15, a whisper in a library at 6 feet is 30, a vacuum cleaner is 80, a lawnmower is 90, etc.

[Allan Speers]

Is this a 1phase or 3 phase machine?

That motor appears to be 3-phase, with a slightly larger-than-normal connector box. Maybe the saw has its own built-in VFD?

As far as motor noise, It could be bearings, (unlikely) or the fan could be rubbing against the back cover. There isn't much else insdie a 3-ph motor to go bad. However, I'd recommend pulling the lower wheel and pulley, then turning it by hand to see if you can feel any mechanical problems. Then put the pulley back & run it, then put the wheel & bel back & run it, etc.


BTW - You ARE going to fix those expose wires, going into the plug, yes? :eek:

============

Also a thought on resonant columns. If a hollow steel column really can resonate, as some have reported here, it might be worth filling the column with expanding foam. Even better, seal the bottom, then fill it with SAND. That would kill all vibration, and add some nice vibration-absorbing mass to boot.

[ian maybury]

I'd say that while it's very possible the problem isn't necessarily a specific motor or other component failure or problem - even though the sound may go away when you switch it off. Taking power off the motor will instantly reduce the tension in one side of the blade for example - and may be enough to stop it or some part of the chassis/frame from resonating. Changing the blade tension even fairly moderately should have this effect too - if the problem is down to the blade vibrating this should stop it dead.

If resonance is involved it's a particular sort of deal. It starts with something creating and feeding vibration (the driver) into something else (the driven) - which happens to naturally vibrate around the same frequency. At which point the amplitude of vibration of the driven item and hence the noise level goes way up. They can then act to cause other stuff to vibrate, and not always at the same frequency, but at harmonics. The trick to stopping it is to separate the driving and driven (natural) frequencies.

Steel can be notoriously problematical as a machine frame for this reason (think of a steel guitar), but it's cost and ease of fabrication means it's taken over from the cast iron of days of old and is pretty much universal. CI is a very good damper of vibration.

It just means in practice that designs have to take care to prevent the modes of vibration likely to arise that could cause problems - using braces, webs, struts, more or less thickness etc. Stray sources of vibration can arise too - stuff like say a rough bearing.

Foam, sand or concrete in the frame (presuming it's part of the problem) would likely be effective, but could have unintended side effects. (corrosion, preventon of access to wring etc)

It'd be worthwhile to just try adjusting whatever is easily got at first, as it sounds like these saws can be AOK. Which might suggest that there's something about your machine or more likely it's set up that's causing the problem. Try adjusting blade tension, guide positions/pressure, popping clamps on the frame box sections in a few places (so it can't resonate in and out), supporting it properly on blocks etc.

With a bit of luck you may figure out what's 'buzzing', and find an easy way to stop it/dial it out. Or you may find a defective or wrongly set up part - bad bearing, out of balance wheel or motor, overly tight guides etc..

[Allan Speers]

Here's a thought:

Buy an inexpensive stethoscope (used on Ebay?) then run the machine, and listen with the scope to all areas. Maybe you can narrow down exactly when the loudest part is. Of course, that may not be the actual SOURCE of the noise, but it should help you deal with it.

[Susumu Mori]

Thank you all! You are all great!!

> Erik, you are right, it says ATB.
> I'm not sure if it is 1 or 3 Phase. The plate doesn't say it. Inside the box is filled with circuits and components. I don't know what they are doing...
> Alan and Ian, you were absolutely right. It was not the blade, but the buzzing noise seemed from the drive belt because I can visually see the belt is vibrating (or resonating) at a certain frequency. As soon as I turn off the motor, the belt vibration stopped and so as the sound. I could remove the sound by decreasing the tension but the belt started to slip. If I tightened it, the vibration got a higher frequency with less amplitude. I don't know how high I should go and I am afraid of over tightened it, but now there is no noticeable buzzing sound. Not sure if it a normal behavior or the belt is simply resonating to something, but at least now I know how to control it.

So, I identified two sources of the sound so far;

> The RK is definitely noisier. Solid 5 db or even more.
> The buzzing sound that stops with the motor switch was caused by a loose belt resonating to something.

I'll keep the hunting for the sound source. There seems still something around the lower motor/wheel assembly. Maybe I'll try one of those "quiet belts".

Thank you anyway and I'll keep you posted if I get another important finding.

[ian maybury]

Wondering if it's a well used bandsaw or a new one Susumi? Did it run OK before?

This is entirely speculative, and just adds to the list of stuff to check - but if the belt is vibrating it could be just that you have a bad belt (they can have dimensional inaccuracies and the like on occasion), or a pulley that's worn or not accurately machined/centred. Belts are cheap, it might be worth just trying a replacement belt to the stock spec. (which seems to work on other machines)

Just bring the belt to a power transmission place, plonk it on the counter and say you would like the same in a top quality item like a Gates or similar.

If the belt doesn't make a difference turn the machine manually with the power off and watch each pulley carefully in turn - the belt shouldn't be riding up and down between the sides. Just sitting at a consistent height in the 'V'. Trying heaving on the pulleys to check for a bad bearing too.

It might be worth checking the wheels out carefully too in case there's anything odd about the tyres or the machining. Maybe give the top one a spin, or at least try pulling sideways to see if you maybe have a bearing problem or something too?

If everything that moves checks out as running true/smoothly then maybe it's a resonance issue of the sort described...

[Susumu Mori]

Thanks Ian.

This has been like this from Day 1.
If I just turns the motor, it is mighty quiet and smooth. Almost no sound.
The belt is definitely doing something. Could be pulley - wheel alignment but I'll follow your suggestion and test a better poly v belts. It has 6 ribs and the length is quite long, giving enough room to vibrate.

[ian maybury]

Guess if it's within warranty (and even if not) it's probably something to take up with Felder. They might have something to offer at least by way of information. Depending on who pays you might or might not decide to go with a service visit - depends on how confident you feel about running the issue to ground.

Sorry, i presumed it was a stock V belt - cheap Eastern ones are fitted on some machines and may not be very good. Yours could be better/more expensive. Even so check it and the pulleys out. A belt problem will normally show as some sort of dimensional variation in the belt or the pulleys that will cause it to bounce or not ride smoothy on the pulleys, or maybe a stiff section or a sideways bend.

Is there any way you could conveniently get to hear another example of the machine run? Or might there be somebody local that's good on bandsaws? My saw is a 24in Agazzani, but apart from a bit of a bang as the rotary converter kicks in (which is normal) and a slowish spool up caused by the heavy wheels it's quiet. More of a heavy hum than anything more once up to speed...

[Alan Hick]

Ian,
Not to be contrary, but what does "quiet" mean? "My saw is a 24in Agazzani, but apart from a bit of a bang as the rotary converter kicks in (which is normal) and a slowish spool up caused by the heavy wheels it's quiet. More of a heavy hum than anything more once up to speed..."

Could you put that adjective into a decibel value, and list what it is that you're using to measure the db level? Within the confines of this thread "quiet" means different things to different people, and it seems that units of measure, and the measuring stick, are really helpful in this regard.

[Erik Loza]

Obviously, I can't comment on a different manufacturer but when it comes to SCM, I have seen all different brands of belts on their machines. Goodyear, Megadyne, etc. Same machine, different belts at times. I've always assumed it was just a case of whatever the factory got a good deal on at the time. Personally, I've never found poly-V's to be unusually noisy. Minimax uses them on the shapers and I just ran one in Vegas. It was quite quiet, in fact. Just the normal hum. You should be able to source out a replacement belt from Grainger or any other industrial supplier and it's never a bad idea to have an extra one around. Get a fresh belt and see what happens?

Erik

[Susumu Mori]

Thank you all again.

I, for the first time, took off the bottom wheel. Man, isn't a 20-inch wheel heavy!
I took out the belt and inspected. It is a long 120mm, v belt. Without the belt, the motor is quiet (66 db).
So it is either the motor changes its nature under the load or the bottom wheel assembly that makes the solid 84 db.

I'm ordering a replacement a belt or two. I'll follow up the results.

By the way, mine has 6 grooves and 7 ridges. Is it 6- or 7-rib belt??

Thanks!

[Erik Loza]

Susumu, that's a 7-rib belt. Look for the stamping on the belt. All the info is always there. Might be something like "7PK120". I made up the PK-part (usually the mfr's internal designation) but almost without exception, the belt will be stamped with the length (120mm in your case) and the number of ribs (7). Hope this helps,

Erik

321800

[Susumu Mori]

Oh, I see. It says PJ1154. So, it's not PK type. Not even 1200mm.
You saved my life.

[Erik Loza]

...It says PJ1154...

LOL, they put a washing machine belt on there....

http://www.solocorreas.com/PJ-1154/en

Seriously, though, you should be able to find a cross reference for it. Very rare that that is not the case.

Erik

[ian maybury]

Hi Alan. You got me there, in that i don't have the means to measure noise level. My phone is an ancient Samsung. While the saw spools up it creates the impression of power (almost the classic movie big machine/space ship start up noise), the bandsaw is fairly obviously the quietest power machine in my shop. The sound it produces is a relatively low frequency hum as i said. Not a low light hum as might be produced by a small and very smooth running device, more of a heavier almost low rumble. No sign of any rattles, vibrations, squeals or higher pitched noises though - other than perhaps a bit of a ssshhhhhh (blade and guides?) buried in what is probably mostly motor and a low level of generalised mechanical noise. It's no louder than it's 14in predecessor - but probably a bit lower in frequency.

It's not impossible that it's noisier than it sounds in dB terms as differing frequencies can be deceptive, but for example it wouldn't cross my mind to use ear defenders with it.

Go carefully Susumi so you don't lose your wheel alignments, especially the lower one. Its going quiet when the belt or something else is removed might just mean that its preventing it from feeding vibration into something else, it may not be the cause of the noise per se. Look carefully at the pulleys as well as the belts.

:) You are officially on a trial and error wild goose chase now - hoping that you'll run to earth where the noise is coming from...

Do you know Erik if wheel balance is ever an issue on these machines?

It's a lot of weight, if one was off a bit?? It should show up as a tendency for a wheel to always stop with a given point low when the blade and belt is removed, and presuming they spin freely at that stage i.e. are not prevented from doing so by bearing seals etc...

[Geoff Crimmins]

Have you checked to ensure the motor pulley fits the shaft and that the set screw is tight? If the pulley was able to wobble on the shaft, that could fairly noisy, and would probably cause the belt to vibrate. Or could the lower wheel be rubbing on the wheel cover or part of the brake assembly?

--Geoff

[Susumu Mori]

Hi all,

I feel I owe you, especially Erik, a follow up report.
Today, I got a new belt, called Optibelt. I had a hard time to find this belt. Most multi v belts are PK class, which are abundant because they are used for cars. Mine is PJ class, which seems to be used for home appliances.
Anyway, I found a Optibelt dealer and bought one at $21. Upon arrival, I noticed it is almost half the thickness and more flexible. The one in FB510 is much more heavy duty. So, I don't know how long this belt will last.

With the original belt, just with lower wheel without a blade gives 82-84 db. With the new one, 70 db. Huge difference. Gone is a high frequency buzzing noise and vibration, caused by visible flapping of the belt.
So I successfully removed one big source of the noise/vibration.

I appreciate all your help.

Having said that, the RK is still a source of a large noise. I also have a little doubt with my upper wheel because a good amount of noise comes from the upper housing, although, it can be simply a wind noise from the large 20-inch wheel. The wheel-turn test doesn't show any issue of the wheel balance.
Anyway, if there are FB510 users who have the same symptom, I hope my experience would be informative.

Thanks guys!