I think you nailed it near the end, apparently your motor speed is just very close to a harmonic in your saw..maybe changing the speed through a different drive sheave could help. Great video, it's inspiring that you continue to troubleshoot and show your logic for us all to follow, part of what makes your videos so enjoyable and great for other's to learn from!
A possible remedy is to place fiber washers between the casters and the saw. (Have seen them used under clothes dryers before.)My reasoning is if the casters dampen the vibration the saw resonates, a little bit more cushioning might dampen it more. Here in Greenville, SC, a 100 year old supply company survived selling 3M fiberglass reinforced rubber pads to go under heavy textile machinery. Machines which vibrated like pea thrashers.(They repackaged the product and obliterated all 3M trademarks. That way, their competitors were unable to source it, and undercut their 300% markups.) Internal machine vibrations which reverberated through the bases of machines got dampened. Machines ran more smoothly. If finding such washers is a problem, buy some HomeDepot felt furniture pads Drill/punch a hole and place a pad just above each caster. 1/4" might make a big difference. No down side. GOOD LUCK!
My favorite video, not because the content was any better than your usual very good stuff, but how patient you were with your young assistant. She is your best "project " so far. Can we assume that someone who thinks two bandsaws are better than one , feels that same about assistants?
Mathias, I love your use of good measuring devices and your accumulated knowledge. I never case to be fascinated and learn. Can't say enough thanks for your excellent work.
a suggestion, when balancing using bearings, pull the seals of the bearings and clean all the grease out of them. greased bearings add a lot of friction and make it really hard to figure out where the heavy spot is.
This may sound odd, but it's a technique I've used many many times to chase down vibrations (used to be a ski lift mechanic and millwright). Take a long screwdriver with a hard handle and while holding the handle to your temple, press the blade of the screwdriver to the problem unit, checking in various areas. You'll quickly close in on the problem by feeling the intensity of the vibrations, hotter colder style. We called it a mechanics stethoscope and used it to check bearings on lifts, cats, pumps, you name it. Hope I explained this well enough.
you could check the roundness by sticking the dial indicator on the blade where it goes around the wheel. I guess how square the wheel is to axle could also cause vibrations but that would probably be in a different direction
Thank you for sharing your shake problem and very systematic problem solving in attempt to get to the root cause of the problem. I would suggest at this point to consider using a stethoscope to probe the machine to see if a sound can be heard that corresponds with the deflection. Still,,, a thou of deflection is phenomenal when you consider the weight of the machine and materials used - you are inspiration to us all.
Excellent work Wendel, I've already built several machines and I know that Alignment and balancing is critical to good performance. Congratulations, your project was very good.
It is odd that the vibration has a non-normal amplitude. That tells me that it is not the spinning elements (wheels/axles) and is probably the blade. Probably a thick spot on the blade that is catching on your blade guides (since you like keeping them so close).
Chevee Dodd the vibrations from the same source, but out of phase can form interference patterns than can give the impression of a second, much slower wave. I initially also thought of the bandsaw blade weld, but period of the blade is way shorter than the period of the amplitude change
Matthias, I noticed you only checked your wheel for static balance. It can still lack dynamic balance, so may cause vibrations when spun up. See e.g. here www.bksv.com/media/doc/bo0276.pdf
your bandsaw is incredible! but What i really liked in this Video, was your daughter hanging around in your Shop. I always love it when my Kids give me a visit in my shop. my son got some little "sidekicks " in my Videos too 😆 best regards from germany Frank
To improve your use of your test bearings as a rotational pivot...find a couple bearings you are willing to sacrifice. Remove the seals and thoroughly clean out the current lubricant. Of course leave the ball retainers in place. To re-lube, use an extremely light oil. To store between use ,wrap in an oiled ,lint free cloth then place in a sealed container. ( Do not use an airogenated lube such as wd40)
Thank you for doing this video! You were so methodic about how to test and fix and had so many good ideas on how to cut down vibration. I think many of the things you did could translate pretty well into a lot of different machines. Great work I love your bandsaws!
I have had turned wooden pulleys run out of round due to uneven wear. Also V-belts can develop worn spots you can't even see that will induce vibration.
Such convenient timing! I am yet to solve the vibration issues with my own homemade bandsaw and there was a lot of useful information here for me to do some more trouble shooting :)
Love seeing that having your daughter in your shop with you as being no problem. My son is 6 now and hes my right hand man, weather im metal working, forging, work8ng on cars and now learning wood working hes always right there with me, always doing what dads doing..... but man does he love electrical tape, i always have to have seceret stashes of it incase i ever need any..... but i love every minute in my shop with him... this has been a great set of vids. Keep up the great work.... i always learn somthing watching your uploads.... cheers from Australia
How about some dampening feet? Does the RPM decrease at all when cutting? Does that increase vibration amplitude? All the test were done with no load, so maybe there are no vibrations when you're cutting(or they're worse!).
routari is correct and the sound supports it. There was a varying resonance like a beating sound of a half Herts. what happened to your marble balancing technique. that is much more accurate. shielded bearings won't roll when you get below a certain weight difference.
I don't have any marbles that big, and rolling bearings inside is better if I can. The marble technique was for a rotor that mounts to a shaft, so I couldn't use this technique.
I saw the "beating" (slow oscillation in amplitude) in your measurement and thought of the pattern created by the interference of two similar frequencies. So the beat frequency equals the difference between the two driving frequencies coming from the bottom and top wheels.
Maybe it was harder to hear when you recorded the video, but I heard a very clear change in pitch when you were plucking the saw blade after adding the paper shims to the wheel. Almost a semi-tone difference. I didn't really hear any change when you were plucking it before (indicating your wheels are quite circular).
If the cause of the vibration was the motor, wouldn't have been better to place under it some foam or rubber like material? a rigid mount just transfer more vibration right? anyway you got it just perfect at the end, I bet most Store band saw vibrates much more :')
a soft mount causes the motor to move, and that means the saw itself moves in the opposite way. If it's mounted rigidly, that doesn't happen. Yes, it coud transfer a 60 hz hum to the saw that way, but the vibrations I'm looking at are much lower frequency.
well, i don't think you should say you will never use the feature. i'm pretty sure if this bandsaw will last you 25 years, there will be a point in time where you will use it... even if it's only once, you will be glad you have it :)
A while back I had a blower fan blade I needed to balance and came across an article describing using parallel and leveled straight edges to support the fan shaft. This offered much less friction than using bearings and the set up was very sensitive to the blade balance. I didn't have any metal straight edges at the time so I used a couple of new 6 inch blades from my floor scraper. Scary sharp but just about 0 friction.
Check run out both on the face and the running surface of wheels with dial indicator, being timber there might be a little anyway, but you could identify a wobble or flat/high spot.
Matthias, I agree with you in your article that it is probably the V-belt that is the issue. Observing the resonance effect, I believe that your V belt is the transmission source of the vibration (dial indicator varying up and down while running, and going through an obvious resonance peak while slowing down). You obviously believe it is resonance as you instinctively added weight to the frame to alter the damping factor like any good U of W engineering grad would do. Part 2? Thanks for all of your videos, I enjoy them all. D
Wood has coefficients of thermal expansion and moisture expansion/shrinkage at different rates, with/against the grain of wood. So if your grains all point in the same direction on your wheel build, the amount of wobble will vary with humidity and temperature changes. And, your balancing would be calibrated on these two variables as well. One option is to custom vacuum press your own plywood made from thin laminate sheets, hand picked with uniform grain and oriented in pairs at 0, 45, 90 degree orientations to help with expansion uniformity. Another method is, carefully selecting and glue pressing quarter sawn pieces with grain oriented in the direction of the shaft (like you may do when making a cutting board). And finally one more idea would be to play with resin infusion methods, using alumilite, epoxy or cactus juice to stabilize your wood. There may be some other ideas that may give you more precision and less reliance on attempts to balance your wheel but these methods were ones that came to mind as pretty good.
Yeah, I figured as much. However, you don't know how many knots are distributed in your layer or how well they glue pressed the laminates. There could be a lot of air pockets throughout the composite because they just stick the layers in a hot press and don't care about eliminating air bubbles from in-between. That's why I mentioned vacuum pressing, which is something plywood makers usually don't do.
Hello Matthias, I feel the indicator you are using does not have the necessary compliance to accurately measure at the frequency of the bandsaw vibration. As an experiment, set up a lathe with a reasonably round object in a 3-jaw chuck. Position your indicator on the object and set the speed of the spindle for 'as slow as she goes'. Turn ON the spindle and note the reading. Next, turn OFF the spindle and set the speed for 'as fast as she goes'. Be careful because if the first indication shows too much of an amount in TIR you may damage your indicator when you run the spindle at high speed. Anyway, it is certain that you will see a much smaller reading at high speed than at low. Think of it as the difference of high speed vs low speed when hitting a washed-out riffle board on a gravel road with your car or truck. There is a lot less jostling about when you are driving a little faster. If you have a smart phone you can download a couple of apps that can help you with your fine tuning efforts. I am not affiliated with this company at all, but i use their apps a lot in my job of machine tool rebuilding. Search for keuwlsoft at any app store and look for the Accelerometer and Frequency Counter apps. The frequency counter can show you what your ears can't hear regarding the pitch change of a cold bandsaw blade. Yes, when they warm up (and your rubber tire) they cause less vibration. But this can tell you something about runout of your wheels, too. That is, if the period of pitch does not remain constant as the wheels are rotated by hand then you might want to look at how much wheel hop you have. The accelerometer will tell you how much vibration is actually in the system with far greater accuracy than the indicator. You can tape it to the machine and in the case of the Keuwlsoft version, record a period of testing for review, later. Oh, and its free. I enjoy your videos and look forward to seeing more. I hope these suggest help. Doug
I tried to read the comments before asking, but gave up after 20 or 30 as I am on a smartphone. I was wondering how this level of vibration compared to a typical commercial unit? Also, I saw several mentions of the belt, and remembered that those link belts seem to quite down tablesaws a bunch (I have a very old Craftsman Flex Shaft, so I never got to try one), also, I also seem to remember that one of those wheels had the glue lock up before you finished straightening it (of course that could have been someone elses video building with your plans :-). I love seeing your family in the shop, it is more than delightful.
6:15 Hi Matthias! Just came past this old video. Actually the amplification due to its eigenfrequency helps to investigate. The periodicity is rather low - giving an impulse about every second which excites the saw to ring. Longer periods in the saw could be the blade weld.
If you put your mouse on the edge of the turning wheel, it shows it's slightly out of round @ 1:11. Another factor could be the varying thickness of the rubber around the edge of the wheel. This would also slightly make it oscillate in the plane of rotation.
You get a similar effect in your vehicle when you hit a certain speed and your missing a wheel weight... The whole car starts to shake... I think your right.. if you slow it down or speed it up.. You will probably break free from the shake and become stable. Curious if you put rubber feet or shocks on it.. if it takes out vibration. All and all... Great video bud.
Interesting... as a non-woodworker (but an aspiring one!) why does vibration matter so much? Other than making it uncomfortable for the user to cut pieces over an extended period of time, I can't see any major issues. Anyone care to enlighten me?
Jess Page if something is vibrating it means something is wrong. in this case the lower wheel was out of balance which wasn't a major problem but could lead to more serious problems later. And he's a perfectionist; -)
Jess Page Good question. Obviously one reason is OCD is kicking up. As fimbles mentioned, vibration makes it difficult to make precise cuts. And it creates stress, reducing the life of the machine. And I can't recall the other reason.
I love the fact every object has its own resonant frequency. Imagine building bridges or skyscrapers without this information. I wonder if it's possible to calculate the frequency before the build or just manipulate what you have created as Mathias did?
Hmm, It might be neat to see if taking an audible sound recording of the band saw, then change it into an inverted/opposite sound track and play it back though a small amp. and transducer mounted on the saw? I'm not sure if Mathias would use settle for this kind of a fix. I am curious to see if it "wood" work. ;)
You balanced the wheels using a static method, a dynamic method could give you much better results. I've been looking for some DIY dynamic balancer projects and haven't found one yet, was hoping to find an Arduino library if anyone knows I'd be happy to hear it. I've done balancing both static, using a similar fixture to what you used and dynamic using WWII era balancer machines that were converted to digital displays. I've found the easiest way to reduce vibration is to remove as much mass as possible, sometimes that alone eliminates the need for playing with weights. If you were to take a large hole saw, something like 6" dia. and remove as much weight from as close as you can get to the outside of the wheels it would make a larger difference than adding or removing a bit of weight. I would do this if it were the aluminum that I'm familiar with. Hey maybe you should contact a local aluminum foundry? With your woodworking skills you could easily make wooden matchplates and have your wheels cast! You might even get some work making and repairing wooden casting pieces. It's becoming a lost art and hard to find people who still work with wood.
I wonder if rather than leaving weights attached to your bandsaw, could you damp the vibration by attaching a cable with a tensioner mounted to the top section and the riser post in the middle? I think the spring in the cable would change the resonant frequency of the saw.
If the vibration is from the belt of the motor, maybe you want to consider magnetic coupling. This needs some room, but you can reuse the motor for other machines easily. I will try that.
i'm surprised you didn't add a dampener under the wheels such as a rubber pad. It's also fascinating that, for instance, if it gets warm in your office, the humidty will be in a higher level of your room, thus increasing the moisture content of certain parts of your equipment. ( since theyre wood )
A good demonstration of why you should always do the easiest first when troubling shooting. Just putting weights on it from the start would have saved a lot of effort.
Hey Matthias, mein erster Gedanke war die Nahtstelle im Sägeblatt. Falls es die nicht ist würde ich mal auf eine dynamische Unwucht bei einem der Räder tippen. Also so, dass die Hauptträgheitsachse der Räder nicht identisch mit der Drehachse ist, sondern im Winkel dazu. Mit dem Ausbalancieren wie im Video kannst du nur die Lage der Hauptträgheitsachse relativ zur Drehachse bestimmen, nicht aber den Winkel. Ich musste mal etwas testweise auswuchten, ein Rad auf einer Art Schrittmotor mit elastischer Montierung und Dehnungsmessstreifen links und rechts des Rades. Dadurch konnte man relativ einfach die Lage der Hauptträgheitsachse bestimmen, das benötigte Auswuchtgewicht konnte man auch irgendwie ausrechnen. Das ganze gibt es, wenn ich mich recht erinnere, auch als statische Prüfmaschine, vor allem zum Testen von PKW-Reifen, aber da weiß ich nicht wie genau das funktioniert. Vermutlich mit wesentlich feinerer Messelektronik.
Hi Matthias, maybe you could also check your wheels with the measuring tool on the surface without the rubber lining. It might verywell be your wheels have a slight oval shape which could explain the cyclic bouncing effect of your readings.
My thought is that it is the wheels, and that they are out of balance in the in-out direction - that the axis of balance is at an angle to the axel. You'd need a computerised balancer to sort that out. But... maybe if you support them on springs, spin them up, and touch a marker to the wheel, that would allow you to see how they are vibrating, and to correct it.
I have a similar problem with my 20 yr old scmi mini max s -45 18in BS the top cast iron wheel was out of round. by .025 My machinest friend said it was to difficult to true up the wheel. I/ll make a check list of all your suggestions .Thanks for posting . Very helpful
I think you nailed it near the end, apparently your motor speed is just very close to a harmonic in your saw..maybe changing the speed through a different drive sheave could help. Great video, it's inspiring that you continue to troubleshoot and show your logic for us all to follow, part of what makes your videos so enjoyable and great for other's to learn from!
Aww the little helper is so cute.
A possible remedy is to place fiber washers between the casters and the saw. (Have seen them used under clothes dryers before.)My reasoning is if the casters dampen the vibration the saw resonates, a little bit more cushioning might dampen it more. Here in Greenville, SC, a 100 year old supply company survived selling 3M fiberglass reinforced rubber pads to go under heavy textile machinery. Machines which vibrated like pea thrashers.(They repackaged the product and obliterated all 3M trademarks. That way, their competitors were unable to source it, and undercut their 300% markups.) Internal machine vibrations which reverberated through the bases of machines got dampened. Machines ran more smoothly.
If finding such washers is a problem, buy some HomeDepot felt furniture pads Drill/punch a hole and place a pad just above each caster. 1/4" might make a big difference. No down side. GOOD LUCK!
My favorite video, not because the content was any better than your usual very good stuff, but how patient you were with your young assistant. She is your best "project " so far. Can we assume that someone who thinks two bandsaws are better than one , feels that same about assistants?
Was hearing the "Mission Impossible" theme there at 1:30 :)
Not so loud, else the copyright strike takes this video down.
hi john u ever smoked weed? xd
John Heisz I was thinking more along the lines of "these boots are made for walkin'"
I heard "good vibrations"
Vexy 420 Yes, but I didn't inhale.
It's shaking too much. Clearly you need to make another bandsaw
And much bigger.
That was implied. I wouldn't object to a tiny bandsaw though, It would be something I'd buy the plans to.
ThePetahs I'd love to see a tiny bandsaw project. Something for model makers.
Ya, 0.001" to 0.002" of vibration. The thing is junk. I will volunteer to take it off his hands. ;)
+lumspond Are small ones really worth the time it takes to build it? You can get a new one for $130.
The level of cuteness is off the charts, especially for a Matthias Wandel video ^^
yep...that baby tho
Those weights on top of the saw make me nervous for the little tacker. =)
+mickenoss Agree, and it also looked a bit too temporary of a solution. Adding some mounts would fix it.
I think it is the green paint. Also, your little helper is adorable.
You are the da Vinci of woodworking, sir!
Ferrariman601 da Vinci was the da Vinci of woodworking
ecahseb best comment ever!!
No, da Vinci never made anything. All he did was sketches.
That's not correct. Google da Vinci sculptures and educate yourself.
Awesome to see you here Ferrariman601! Loving your Asetto Corsa vids!
Mathias, I love your use of good measuring devices and your accumulated knowledge. I never case to be fascinated and learn. Can't say enough thanks for your excellent work.
a suggestion, when balancing using bearings, pull the seals of the bearings and clean all the grease out of them. greased bearings add a lot of friction and make it really hard to figure out where the heavy spot is.
This may sound odd, but it's a technique I've used many many times to chase down vibrations (used to be a ski lift mechanic and millwright). Take a long screwdriver with a hard handle and while holding the handle to your temple, press the blade of the screwdriver to the problem unit, checking in various areas. You'll quickly close in on the problem by feeling the intensity of the vibrations, hotter colder style. We called it a mechanics stethoscope and used it to check bearings on lifts, cats, pumps, you name it. Hope I explained this well enough.
I think this is great advice. Any rigid and dense object will work, but an actual stethoscope would be the best, though.
they make stethoscopes for auto mechanics. Same idea.
I really like the way you approached and finally assessed the problem you were having.
you could check the roundness by sticking the dial indicator on the blade where it goes around the wheel. I guess how square the wheel is to axle could also cause vibrations but that would probably be in a different direction
Your Assistants were awesome!
The cutest apprentice I've ever seen! Great job mom & dad!
me encanto ver a tu señora y a tu hijo ayudandote Muy buen video
please make a shaking comparison with a factory band saw.
You are a genius sir. With love from India.
Thank you for sharing your shake problem and very systematic problem solving in attempt to get to the root cause of the problem. I would suggest at this point to consider using a stethoscope to probe the machine to see if a sound can be heard that corresponds with the deflection. Still,,, a thou of deflection is phenomenal when you consider the weight of the machine and materials used - you are inspiration to us all.
No matter what kind of video you make it's always fun and interesting to watch :)
I CAN'T EVEN RIGHT NOW. I'M LITERALLY SHAKING.
Mitch Robinson: wedge a shim under your motor.
Man I love it when he shows his process. Great vid!
Excellent work Wendel, I've already built several machines and I know that
Alignment and balancing is critical to good performance. Congratulations, your project was very good.
It is odd that the vibration has a non-normal amplitude. That tells me that it is not the spinning elements (wheels/axles) and is probably the blade. Probably a thick spot on the blade that is catching on your blade guides (since you like keeping them so close).
having something excited just off frequency can ause it to go up and down.
Chevee Dodd the vibrations from the same source, but out of phase can form interference patterns than can give the impression of a second, much slower wave. I initially also thought of the bandsaw blade weld, but period of the blade is way shorter than the period of the amplitude change
I agree there was a rhythm to the deflection.
Matthias, I noticed you only checked your wheel for static balance. It can still lack dynamic balance, so may cause vibrations when spun up. See e.g. here www.bksv.com/media/doc/bo0276.pdf
Luke Wren The wheels are very flat, plus the vibration is in the other direction, althought its prone to change direction
I wonder if it would be possible to create some sort of compact tuned-mass damper to defeat the vibration...
You didn't compare the vibrations to a store bought model, another great video.
Your helper is adorable.
omega(e)=sqrt(k(red)/m(red)) : increasing m --> deacreases the eigenfrequency - well done Matthias
More videos with cute kids! More Rachel!
Good to see Rachel and Harriette; thanks for sharing : )
I bet that Dewalt saw vibrates more lol. Interesting video. Your daughter will be making her own bandsaw in no time.
Your QA assistant is starting to look real cute. I hope we'll get a chance to see her from time to time.
the kid has a real interest in the process and the wonders of the tool drawer
Your little helper is growing sooooooo fast!
Your child is so beautiful - wide-eyed and taking everything in :-)
your bandsaw is incredible! but What i really liked in this Video, was your daughter hanging around in your Shop. I always love it when my Kids give me a visit in my shop. my son got some little "sidekicks " in my Videos too 😆
best regards from germany
Frank
My suggestion is, that it depends on how the two wheels are positioned to each other. In my mind that could influence the whobble frequenz of the saw.
Good job isolating that issue. it takes a lot of patience and trial and error to fix that
To improve your use of your test bearings as a rotational pivot...find a couple bearings you are willing to sacrifice. Remove the seals and thoroughly clean out the current lubricant. Of course leave the ball retainers in place. To re-lube, use an extremely light oil. To store between use ,wrap in an oiled ,lint free cloth then place in a sealed container. ( Do not use an airogenated lube such as wd40)
Thank you for doing this video! You were so methodic about how to test and fix and had so many good ideas on how to cut down vibration. I think many of the things you did could translate pretty well into a lot of different machines. Great work I love your bandsaws!
I have had turned wooden pulleys run out of round due to uneven wear. Also V-belts can develop worn spots you can't even see that will induce vibration.
Love your helper, she is so cute. Also your work is fantastic.
Such convenient timing! I am yet to solve the vibration issues with my own homemade bandsaw and there was a lot of useful information here for me to do some more trouble shooting :)
Love seeing that having your daughter in your shop with you as being no problem. My son is 6 now and hes my right hand man, weather im metal working, forging, work8ng on cars and now learning wood working hes always right there with me, always doing what dads doing..... but man does he love electrical tape, i always have to have seceret stashes of it incase i ever need any..... but i love every minute in my shop with him... this has been a great set of vids. Keep up the great work.... i always learn somthing watching your uploads.... cheers from Australia
How about some dampening feet? Does the RPM decrease at all when cutting? Does that increase vibration amplitude? All the test were done with no load, so maybe there are no vibrations when you're cutting(or they're worse!).
The way the vibration seems to come in and out of phase, it suggests two or more sources that cancel and amplify each other at regular intervals
routari is correct and the sound supports it. There was a varying resonance like a beating sound of a half Herts. what happened to your marble balancing technique. that is much more accurate. shielded bearings won't roll when you get below a certain weight difference.
I don't have any marbles that big, and rolling bearings inside is better if I can. The marble technique was for a rotor that mounts to a shaft, so I couldn't use this technique.
I saw the "beating" (slow oscillation in amplitude) in your measurement and thought of the pattern created by the interference of two similar frequencies. So the beat frequency equals the difference between the two driving frequencies coming from the bottom and top wheels.
Practical advice balanced with adorable cuteness !!!
I dunno, the change in pitch seems pretty obvious in the video. Sounds like 3-5 half-steps in pitch.
That's quite the little helper there Mathias!
Thanks for walking us through your troubleshooting process. Another excellent video.
1:30 Ladies and gentlemen, please welcome to the stage Matthias Wandel and His Bandsaw Band.
Beautiful baby, nice to see you getting him involved.
Maybe it was harder to hear when you recorded the video, but I heard a very clear change in pitch when you were plucking the saw blade after adding the paper shims to the wheel. Almost a semi-tone difference. I didn't really hear any change when you were plucking it before (indicating your wheels are quite circular).
This is perfect timing. have gotten my bandsaw up and running and been trying to figure out ways to cut down the vibration. Thanks Matthias :)
If the cause of the vibration was the motor, wouldn't have been better to place under it some foam or rubber like material? a rigid mount just transfer more vibration right? anyway you got it just perfect at the end, I bet most Store band saw vibrates much more :')
a soft mount causes the motor to move, and that means the saw itself moves in the opposite way. If it's mounted rigidly, that doesn't happen. Yes, it coud transfer a 60 hz hum to the saw that way, but the vibrations I'm looking at are much lower frequency.
+Matthias Wandel Would you be willing to do a short talk about how to install a non tilting bandsaw table for your 16" build? Thank you
just install the tilting table, but don't tilt it...
The point is to not make the trunions if I will never use the feature. But thanks for your insight
well, i don't think you should say you will never use the feature.
i'm pretty sure if this bandsaw will last you 25 years, there will be a point in time where you will use it...
even if it's only once, you will be glad you have it :)
A while back I had a blower fan blade I needed to balance and came across an article describing using parallel and leveled straight edges to support the fan shaft. This offered much less friction than using bearings and the set up was very sensitive to the blade balance. I didn't have any metal straight edges at the time so I used a couple of new 6 inch blades from my floor scraper. Scary sharp but just about 0 friction.
رائع واشكرك على ماتقدمة ولديك عائلة لطيفة
brave ........ Fantastic
The baby............so cute.
Check run out both on the face and the running surface of wheels with dial indicator, being timber there might be a little anyway, but you could identify a wobble or flat/high spot.
I feel like i heard a little variation on the pitch, but could be an audio issue from the video, check with a digital instrument.
1st Newon's Law showing up! Great Job Mr Matthias! Now it's Tuned!
I would love to see your take on a Hand Spinner. Very simple concept and it seems fun to build and use!
Matthias, I agree with you in your article that it is probably the V-belt that is the issue. Observing the resonance effect, I believe that your V belt is the transmission source of the vibration (dial indicator varying up and down while running, and going through an obvious resonance peak while slowing down). You obviously believe it is resonance as you instinctively added weight to the frame to alter the damping factor like any good U of W engineering grad would do. Part 2? Thanks for all of your videos, I enjoy them all. D
Wood has coefficients of thermal expansion and moisture expansion/shrinkage at different rates, with/against the grain of wood. So if your grains all point in the same direction on your wheel build, the amount of wobble will vary with humidity and temperature changes. And, your balancing would be calibrated on these two variables as well.
One option is to custom vacuum press your own plywood made from thin laminate sheets, hand picked with uniform grain and oriented in pairs at 0, 45, 90 degree orientations to help with expansion uniformity.
Another method is, carefully selecting and glue pressing quarter sawn pieces with grain oriented in the direction of the shaft (like you may do when making a cutting board).
And finally one more idea would be to play with resin infusion methods, using alumilite, epoxy or cactus juice to stabilize your wood.
There may be some other ideas that may give you more precision and less reliance on attempts to balance your wheel but these methods were ones that came to mind as pretty good.
that's why the wheels need to (and are) made of plywood.
Yeah, I figured as much. However, you don't know how many knots are distributed in your layer or how well they glue pressed the laminates. There could be a lot of air pockets throughout the composite because they just stick the layers in a hot press and don't care about eliminating air bubbles from in-between. That's why I mentioned vacuum pressing, which is something plywood makers usually don't do.
Hello Matthias, I feel the indicator you are using does not have the necessary compliance to accurately measure at the frequency of the bandsaw vibration. As an experiment, set up a lathe with a reasonably round object in a 3-jaw chuck. Position your indicator on the object and set the speed of the spindle for 'as slow as she goes'. Turn ON the spindle and note the reading. Next, turn OFF the spindle and set the speed for 'as fast as she goes'. Be careful because if the first indication shows too much of an amount in TIR you may damage your indicator when you run the spindle at high speed. Anyway, it is certain that you will see a much smaller reading at high speed than at low. Think of it as the difference of high speed vs low speed when hitting a washed-out riffle board on a gravel road with your car or truck. There is a lot less jostling about when you are driving a little faster.
If you have a smart phone you can download a couple of apps that can help you with your fine tuning efforts. I am not affiliated with this company at all, but i use their apps a lot in my job of machine tool rebuilding. Search for keuwlsoft at any app store and look for the Accelerometer and Frequency Counter apps. The frequency counter can show you what your ears can't hear regarding the pitch change of a cold bandsaw blade. Yes, when they warm up (and your rubber tire) they cause less vibration. But this can tell you something about runout of your wheels, too. That is, if the period of pitch does not remain constant as the wheels are rotated by hand then you might want to look at how much wheel hop you have. The accelerometer will tell you how much vibration is actually in the system with far greater accuracy than the indicator. You can tape it to the machine and in the case of the Keuwlsoft version, record a period of testing for review, later. Oh, and its free.
I enjoy your videos and look forward to seeing more. I hope these suggest help.
Doug
I leave the pedantic exercises to you. Please do make a video about it
Great tip for checking the roundness of a wheel by twanging the blade :) Great video as always. Thanks :)
I tried to read the comments before asking, but gave up after 20 or 30 as I am on a smartphone. I was wondering how this level of vibration compared to a typical commercial unit? Also, I saw several mentions of the belt, and remembered that those link belts seem to quite down tablesaws a bunch (I have a very old Craftsman Flex Shaft, so I never got to try one), also, I also seem to remember that one of those wheels had the glue lock up before you finished straightening it (of course that could have been someone elses video building with your plans :-). I love seeing your family in the shop, it is more than delightful.
6:15 Hi Matthias! Just came past this old video. Actually the amplification due to its eigenfrequency helps to investigate. The periodicity is rather low - giving an impulse about every second which excites the saw to ring. Longer periods in the saw could be the blade weld.
Never thought I'd see Matthais play the upright (bandsaw) bass. Nice vid, haha!
If you put your mouse on the edge of the turning wheel, it shows it's slightly out of round @ 1:11. Another factor could be the varying thickness of the rubber around the edge of the wheel. This would also slightly make it oscillate in the plane of rotation.
As usual, my trusted source. Great video.
The blade "plucking" worked for me. My lower pulley was out of round. Replacing it fixed the vibration. Thanks! PS: ignore the trolls.
I appreciate your willingness/dedication for solving troubles. great job.
v-belts tend to vary in thickness, and they are going at the right frequency to introduce that vibration.
You get a similar effect in your vehicle when you hit a certain speed and your missing a wheel weight... The whole car starts to shake... I think your right.. if you slow it down or speed it up.. You will probably break free from the shake and become stable. Curious if you put rubber feet or shocks on it.. if it takes out vibration. All and all... Great video bud.
so the dumbbells is going to be part of the build plans ?
Interesting... as a non-woodworker (but an aspiring one!) why does vibration matter so much? Other than making it uncomfortable for the user to cut pieces over an extended period of time, I can't see any major issues. Anyone care to enlighten me?
this much vibration has no impact on using it. I just find it a bit unsettling to feel the table shake a bit as I cut small pieces.
Jess Page if something is vibrating it means something is wrong. in this case the lower wheel was out of balance which wasn't a major problem but could lead to more serious problems later. And he's a perfectionist; -)
Hard on the old eyes to follow a vibrating line. Or at least it is for me. :)
Jess Page
Good question. Obviously one reason is OCD is kicking up. As fimbles mentioned, vibration makes it difficult to make precise cuts. And it creates stress, reducing the life of the machine. And I can't recall the other reason.
That kid is helping and really interested, in a few years you will have that all messed up with his inventions :D
I really enjoy your scientific method.
I love the fact every object has its own resonant frequency. Imagine building bridges or skyscrapers without this information. I wonder if it's possible to calculate the frequency before the build or just manipulate what you have created as Mathias did?
Look for videos on the issues they had with the millennium bridge in London.
Hmm, It might be neat to see if taking an audible sound recording of the band saw, then change it into an inverted/opposite sound track and play it back though a small amp. and transducer mounted on the saw? I'm not sure if Mathias would use settle for this kind of a fix. I am curious to see if it "wood" work. ;)
Grumpy Garry There is a legendary video of a bridge were they didn't know, google "Tacoma Narrows Bridge Collapse"
They can calculate the frequency. My father did this sort of stuff in the 60's or 70's (he is a retired structural engineer).
That's actually a misinterpretation of what happened on the bridge, That bridge failed due to aerolastic instability.
You balanced the wheels using a static method, a dynamic method could give you much better results. I've been looking for some DIY dynamic balancer projects and haven't found one yet, was hoping to find an Arduino library if anyone knows I'd be happy to hear it. I've done balancing both static, using a similar fixture to what you used and dynamic using WWII era balancer machines that were converted to digital displays. I've found the easiest way to reduce vibration is to remove as much mass as possible, sometimes that alone eliminates the need for playing with weights. If you were to take a large hole saw, something like 6" dia. and remove as much weight from as close as you can get to the outside of the wheels it would make a larger difference than adding or removing a bit of weight. I would do this if it were the aluminum that I'm familiar with. Hey maybe you should contact a local aluminum foundry? With your woodworking skills you could easily make wooden matchplates and have your wheels cast! You might even get some work making and repairing wooden casting pieces. It's becoming a lost art and hard to find people who still work with wood.
I wonder if rather than leaving weights attached to your bandsaw, could you damp the vibration by attaching a cable with a tensioner mounted to the top section and the riser post in the middle? I think the spring in the cable would change the resonant frequency of the saw.
If the vibration is from the belt of the motor, maybe you want to consider magnetic coupling. This needs some room, but you can reuse the motor for other machines easily. I will try that.
i'm surprised you didn't add a dampener under the wheels such as a rubber pad. It's also fascinating that, for instance, if it gets warm in your office, the humidty will be in a higher level of your room, thus increasing the moisture content of certain parts of your equipment. ( since theyre wood )
I really like all of your work.. and your special way to explain..
A good demonstration of why you should always do the easiest first when troubling shooting. Just putting weights on it from the start would have saved a lot of effort.
mathias que tal ¡¡¡ como estas me parece excelente la cierra cinta ,soy de la tierra donde nació el tequila me dedicó a la elaboración de muebles
Your a mad scientist and your videos are great!!!!
Must be a heavy frame and of course balancing means a lot. Good Luck To You!
Wow, your kid grows like fast, nice to see.
good day Matthias could the vibrations be caused by the blade not being joined correctly?
Hey Matthias, mein erster Gedanke war die Nahtstelle im Sägeblatt. Falls es die nicht ist würde ich mal auf eine dynamische Unwucht bei einem der Räder tippen. Also so, dass die Hauptträgheitsachse der Räder nicht identisch mit der Drehachse ist, sondern im Winkel dazu. Mit dem Ausbalancieren wie im Video kannst du nur die Lage der Hauptträgheitsachse relativ zur Drehachse bestimmen, nicht aber den Winkel.
Ich musste mal etwas testweise auswuchten, ein Rad auf einer Art Schrittmotor mit elastischer Montierung und Dehnungsmessstreifen links und rechts des Rades. Dadurch konnte man relativ einfach die Lage der Hauptträgheitsachse bestimmen, das benötigte Auswuchtgewicht konnte man auch irgendwie ausrechnen. Das ganze gibt es, wenn ich mich recht erinnere, auch als statische Prüfmaschine, vor allem zum Testen von PKW-Reifen, aber da weiß ich nicht wie genau das funktioniert. Vermutlich mit wesentlich feinerer Messelektronik.
Hi Matthias, maybe you could also check your wheels with the measuring tool on the surface without the rubber lining. It might verywell be your wheels have a slight oval shape which could explain the cyclic bouncing effect of your readings.
Very cool to see you go through your problem solving method. I enjoyed the video!
My thought is that it is the wheels, and that they are out of balance in the in-out direction - that the axis of balance is at an angle to the axel. You'd need a computerised balancer to sort that out. But... maybe if you support them on springs, spin them up, and touch a marker to the wheel, that would allow you to see how they are vibrating, and to correct it.
Interesting analysis. Could uneven gathering and stretching of the tires contribute to vibration
I have a similar problem with my 20 yr old scmi mini max s -45 18in BS the top cast iron wheel was out of round. by .025 My machinest friend said it was to difficult to true up the wheel. I/ll make a check list of all your suggestions .Thanks for posting . Very helpful
Was really expecting you to calculate a mass and spring system to sort it out :)))