Hammer A3 noise...

[Steve Wurster]

I wonder if the cooling fan has slipped off its arbor a little bit and it hitting the inside of the fan shroud? That was not-uncommon occurrence with bandsaws back in my Minimax days. Doesn't really hurt anything but makes an annoying racket.

Erik

Is there anything I can do to verify that? Getting to the motor on these is not an ideal scenario, unfortunately.

[Erik Loza]

Is there anything I can do to verify that? Getting to the motor on these is not an ideal scenario, unfortunately.

"If" it's the cooling fan, you can tell pretty quickly by listening with a mechanic's stethoscope (or even a long screwdriver) on the fan shroud while the motor is running. But I would wait for tech support to call you back before you start pulling anything apart.

Erik

[Steve Wurster]

"If" it's the cooling fan, you can tell pretty quickly by listening with a mechanic's stethoscope (or even a long screwdriver) on the fan shroud while the motor is running. But I would wait for tech support to call you back before you start pulling anything apart.

Erik

I do have a medical stethoscope on hand, but didn't get it too up close to the motor; I just held it under the cabinet to see if I could hear anything specific. I can try that later today - I still have the belt off the unit at the moment. Can you be specific however on which part of the motor you mean by the fan shroud? I'm guessing you just mean the end furthest away from the pulley; these are TEFC motors, right?

And I would think the rat-a-tat-tat noise present at the end of the video would also be there when I run the motor without the belt attached, but perhaps it's there and just quiet(er) due to lower vibration overall in that situation.

[Brian Holcombe]

It's unfortunate at times but running machines always seems to make one into part diagnostic and part mechanic in addition to woodworker. I've had most of my machines down to nuts and bolts and some motors out/etc.

I would turn the motor over by hand with the room very quiet and just listen for repeating noises. I would do the same with the cutter head, both with the feed engaged and without.

Could be a simple thing, as noted, or could be a bearing or other wear part.

[Steve Wurster]

There's a curious lack of "strange" noise coming from the motor itself, when run either standalone or with the belt attached.

The cutterhead makes minimal noises when spun freely (without the belt attached). There is a small amount of noise coming from the belt-side, either at the pulley or the bearing, but unfortunately I can't pinpoint anything. I even removed the pieces that cover the rollers just to eliminate any turbulence-related sources, but the behavior is still the same.

At this point I'm wondering if it's something related to the belt, because I can only get this noise when running with everything attached. Of course I can't generate by hand anywhere near the speed the motor generates, so if anything is speed-driven then that's hard for me to recreate without the belt. Either way, I ordered a new belt off Amazon and we'll see how that behaves when it gets here on Thursday.

[Steve Wurster]

Update: I put a new belt on yesterday and still got the same noise when running. However I noticed that the belt was "flopping" a bit so I increased the tension (which is a pain to do on this machine, especially with the tension screw having some wiggle in it). With a good bit more tension the "flopping" went away and the noise lessened somewhat. It still makes that obvious rat-a-tat-tat sound when stopping, but even that sounds a little better to my ear. (And stupid me didn't compare the new belt with the old to see if maybe the old belt had gotten stretched a little).

I did record a video of the cutterhead spinning freely (with no belt attached), and there is some clicking noise coming from the bearing. The Felder tech said it could be going bad, and that we could either replace the bearings now as a preemptive measure, or wait until things start to get louder and maybe we'll be able to better identify the source. I have an email back to them just wondering about the odds that the cutterhead will break if we don't take that preemptive measure. In the meantime however I still need to use the machine, and will continue to do so in the short term to keep my current project moving along. They also asked whether I would want to replace the bearings myself or have them do it. Um, yeah, I don't think I want to mess with that on this machine!

[Erik Loza]

I've had bearings that were a little sticky or scratchy run for years without any other deterioration in machine performance. A "per-revolution" sound wouldn't worry me if the machine otherwise behaves normally. It's "constant" sounds like groaning/screeching/whining or any sudden new heat buildup in an area that would make me dig deeper. Just my 2-cents.

Erik

[Steve Wurster]

Yes, the machine appears to behave normally otherwise. So for now I'm just letting it go and will keep an eye on it.