Your brain works like no other person I have met. I consider myself very clever and capable of fixing most things I attempt, but compared to you I am so humbled. I think you deserve all the accolades you receive. I really enjoy your videos.
I find a bit of Blue Tack (putty) under my coin stops it falling over on my table saw :) , this wont solve the water ripples but a good amount of gelatine may help.
Practical, modest, and just good. I love your format and methods. These videos should be supplemental material to every engineering course. Thanks for your work.
I am always in awe at your inventiveness and execution. Your videos are what encouraged me to actually use the (cheap and nasty) tools I have and of course to upgrade/replace/fix/make them and other stuff. The 'workshop end of my two-car+ garage is now starting to look like a proper working space instead of a mess. The saw and router tables are on wheels so I can take up as much space as I want, after I get rid of those annoying cars.
You are in the wrong line of business, you shoul work as an inventor or problem solver of tool and machines out on the market. Good job, you are my hero
Added link belt to my old craftsman saw and got small improvement. Huge improvement by adding isolation mounts to motor. They wear out after a while, but are easy and effective.
I recently bought an older table saw that works beautifully except for exactly this. I've fiddled around with the mount a ton and found as happy a medium as I could between belt tension, mount tightness, and ease of raising and lowering the saw. I'm embarrassed to admit that I never even thought of changing the belt. Thanks.
Thank you for addressing a very real problem for many woodworkers( unless you are fortunate enough to own an expensive cabinet saw). I would be interested in seeing your take on dust collection for the same saw.
I think you've experimented with link-belts in one of your previous videos haven't you? Also, do you think it would make any difference if the saw cabinet itself were stiffer or heavier? Of course you already have a box built into the bottom so it probably is pretty stiff. Could drop a cinder block inside the base. Hmm, now I want to test my saw! Interesting to see you work through the experimental process!
My mind was not in the gutter until you put it there and then the very next cut - to the mallet made me flinch. I thought this was the safe end of youtube! actually great work Matthias - as usual a pleasure
I had terrible problems with vibration on the 30 year old Craftsman contractor saw that I bought half a year ago when I first got it. Even after I changed the banana-shaped pulleys, at certain belt-tension levels the saw would really vibrate like crazy, to the point where work pieces would dance around a bit on the table top -- it was actually a fair bit dangerous. The only thing I've really found that really helped was a link belt, which I know you aren't a big fan of for your hybrid saw, but on these smaller, less massive contractor saws, they really seem to make a huge difference.
I have a vintage Craftsman with a similar setup, but I never paid much attention to the vibration levels. Interesting fix, good troubleshooting process.
Additional deadweight makes sense to make contractor saws they use light thin metal or plastic so a lot of the damping you get from the mass of metal is lost. I like that spring strut, did you try using two bungee cords on the motor frame hooked to the saw base?
Thanks for the great work, Matthias. When lifting the motor by hand, the damping from your body may have helped more than the reduced belt tension. Which might explain why the spring didn’t have a similar effect.
Very good process of elimination. Very creative (as usual) dampener device. ** Check the arbor bearings for wackiness. I use a mechanic's stethoscope. Most older saws I work on have going or gone bearings. ** The original pulleys on the arbor shaft and motor may also be a source of vibration. I sand the inside faces of old pulleys or I replace them. as needed ** I will also replace regular v-belts with cogged v-belts since they are more flexible and can pull a tighter curve around small pulleys.
I know you are not super keen on the link belts but I use them on my lathe and the difference they made to noise and vibration were astounding, vibration being a problem for good finish on a metal working lathe
I love these videos with your ol' beaver. I have the exact same saw. Took a lot of fiddling to get John Heisz's wooden fence on it. Now my only complaint is motor hop.
Very informative, thanks Matthias. I recently bought an older contractor saw (the same Beaver model your brother has, shown in previous videos) and have been trying to sort out the vibration issues.
Shocks basically do two functions, keeping motion of the spring linear, and keeping a wheel on the ground. Hydraulic fluid is forced through small holes to keep the suspension stiff enough; which is why you have a harder suspension when you have a sudden dip as compared to softer suspension through a consistent force applied to a vehicle. Because of how light bikes are, and how heavy people are, they don't need the hydraulic part of the shock, as you only need a spring for dampening.
So the solution was the inferior(?) belt plus the friction shock absorber. But the overall lesson is that vibrations are tricky to dampen because of so many variables.
You're correct. Vibration is a tricky problem. Generally speaking, you can stiffen the structure to push resonant frequencies out of your rotational speed range. Changing the mass of the system can also affect the resonant frequency, but from my experience it takes a lot of change to get meaningful results. Belts themselves add another level of damping/vibration and it is all very speed dependent. Lots of variables can effect the outcome.
No springs in the bicycle shock absorbers? I didn't know that. Was there perhaps a gas inside to act as an absorber? I do know that Menards (and I'm sure other hardware stores) stock expansion springs. You'd probably have to cut them to fit. Neat idea, I'll have to check my saw.
I was fortunate enough a few years ago to get a used Rigid TS2424, one of the last of the Emerson, Built In USA, contractor-style table saws. When I saw a Matthias video on vibrations of his hybrid saw many months ago he then also suggested that pulley belts were an issue due to them taking a set when the saw is not in use (this is my recollection of a long-ago video and I could have the details wrong). To my surprise, his hybrid saw had v belts and v-belt pulleys; my older, cheaper saw has machined pulleys that use flat ribbed belts, thin flat belts. And I have no vibration problems. Possibly such pulleys could be retrofit on the saw of this video.
I added a second belt by changing both pulleys on my old saw and it got rid of all vibrations. I was able to buy the pulleys at a local bearing store (I think Canadian Bearings).
Matt, the Power Twist link drive V belts really cut down on vibration of belt-driven tools. You should give that a try. You buy a length of the stuff and make your own custom belt sizes.
Haven't read all the comments - somebody may have already pointed out that the assembly is the actual shock absorber. The assembly consists of a spring (for restoring force) and a DAMPER - for damping spring oscillations. You'll be wanting DAMP the motor oscillations.
I changed my pulley's to Serpentine set up . Made world's of difference.The main problem is where v groove belts are joined they leave a slight buldge in belt
I bought a serpentine belt + pulley set like this years ago for my Craftsman cast iron contractor saw -- www.ebay.com/itm/Ridgid-Craftsman-Table-Saw-Serpentine-Belt-and-Black-Steel-Pulley-Kit-420J6-/191479013478?hash=item2c9509e066:g:QfQAAOSw1ZBUspTl
That's really the best solution to start. I'd like to see how low the vibration could get with Matthias tweaks _and_ a good serpentine belt. I wasted money on a link belt (Matthias experimented with them too and found they weren't so amazing) when I should have just went for the serpentine conversion, which is actually cheaper.
2 things come to mind: First - why did you not try to dampen the motor directly? I mean right where it was connected to the saw, that is where you need the dampening. And of course the wood wouldn't help much as the vibrations are only very minor in relative distance. Second - what about going the opposite way? absorb the shocks before they reach the large board - so mount it with a sheet of rubber or some cloth.
Because you found the vibration changed a lot with the belt swap, I'd investigate additional belts and hot vs cold belts. Rubber takes a 'set' when cold. Sometimes car tires induce a vibration from sitting over a cold night to driving until they warm up.
I do not apologize for the long reply. I apologize to anyone with the cast iron stomach to read it all the way through. My Dad & I did a lot of analysis and testing on this very vibration issue back in the 80s. (1980s not the 1880s as my children like to say.) It was a lot of fun as I was in vibrations classes in college at the time. There is a long story but let’s cut to the end. Equipment: Power King 14” bandsaw, Delta 6” jointer, Boice-Crane table saw, and my Surtevant #2 forge blower. Dad bought all the equipment (except my forge blower), motors and motor mounts separately in the mid-40s. As was common at the time, except the table saw, all the equipment used hanging motor mounts. Observations: 1.) Belts take a set from the weight of the motor. This set bumps over the motor and driven pulleys adding vibration. (Thus, when Matthias changed the belts the vibration decreased.) The belts will coast back to the stretched location after the motor is turned off, thus perpetuating and increasing the set., 2.) The less rigid the motor mount hinge the more vibration can occur. Tests with adjustable friction split wood bearings on the mounts helped but did not significantly eliminate the vibration. The intent is to increase the dynamic mass of the motor so the kink in the belt will pass over the pulley without significantly moving the motor. 3.) Belt dressing had a slight improvement but was undesirable to keep applying for the small benefit., 4.) Increased motor mass (adding weights) had a noticeable improvement as dynamic mass increased, but the time to stretch a belt and for it to take a set was significantly decreased., 5.) Worn or frayed belts showed no significant effect on vibrations, but they took a set faster than new belts., 6.) The forge blower was using a thick belt since the motor end is a stepped vee pulley and the driven blower end is designed for flat belt drive. Changing to a thinner belt reduced vibration without slipping. Conclusions: 1.) Wherever possible change to a rigid motor mount with an adjustable tensioning slide. The slide should be able to be locked into position before starting the machine. This is not possible for Matthias’ contractor saw as there are too many degrees of freedom needed., 2.) Always remove tension from the belt at the end of the day., 3.) If possible, remove the belt and store flat, not on a hook., 4.) Only use clean, pliable belts., 5.) Use the smallest belt for power transfer and balance against life expectation. Implementation: 1.) All equipment except the jointer was converted to rigid motor mounts with tension locks. 2.) Because the jointer is 26” center to center, temperature and humidity have a significant effect during operation. So, the hanging motor mount is a special split friction block on the hinge posts and spring swings over the motor base to provide tension to the belt and increase the dynamic motor mass., 3.) All belts are removed at the end the of the day and stored flat on the machines, even if returning in less than 8 hours. Results: There is significantly less to no noticeable vibration compared to prior to the changes. I have been using the same belts for 30+ years of average operation 1 time/month. Vibration is less than first implementation probably due to the belts wearing in. Recommendations for contractor saw: 1.) Pop the belt off the pulley at the end of the day. If possible fish it out and set flat on a horizontal piece of wood. Condensation is probable in Canada, so better on wood than a metal table top., 2.) Add some friction to the motor mount posts so the motor is harder to move but does not cause wear or binding when it needs to move., 3.) Experiment with the extra mass. You might try a long rod vs a concentrated mass as the intent is to increase moment of inertia. 4.) Do use the Rube Goldberg shock absorber but find a way to get the motor to be more rigid, which means both ends need to be firm and the friction needs to be increased. (Wow! Ave would have a great time with the massive double entendre in this last sentence.) Sincerely, ElWet (Remnants of Harvey rain is starting, thus I am All Wet.)
Try a good quality cog-type V belt. It's notched to prevent vibration from belt set, and since they've had material removed they aren't likely to have a stiff point where they're joined. They also last longer because they don't get as hot from the repeated bending around the pulleys.
With the vibrations coming from the belt taking the tension off helps decouple it from the pulleys, reducing the vibrations transferred to the table. While I applaud your attempt to engineer a fix, I think the simplest fix would be to replace the belt. With the size of the pulleys and the only tension coming from the weight of the motor I would say a cogged V-belt (I'm guessing AX?) would be a better fit for the application than a standard V-belt. The reduced weight and better flexibility should inherently reduce vibrations, they also transfer power better, and generally wear better then standard belts, balancing their slightly higher price.
I have found that link belts often reduce vibration on equipment but on occasion with make it slightly worse. It seams that it is a little hit and miss.
Have you tried a grooved V-belt? Switching to one from a solid V-belt made a world of difference on my lathe; its motor is similarly suspended by the belt tension, as well.
there are true shock absorbers for "downhill" mountain bikes, they work with air and adjustable valves. you can easily spot them, they look different without a spring. Cost can be saved if you buy the used on ebay or diy.
Hi Matthias, would you consider designing and making a drum sander? I know you won't make stuff you personally need but if you make it, they will come. cheers.
The vibration comes from the belt taking a set around the small pulley. Just add a small low rpm motor to continuously turn the belt when not in use so it can't take a set.
I've heard that link belts tend to make a huge improvement in vibration and noise level reduction. I guess the reason is that v-belts tend to get lopsided from either the way they are made and when they sit for any given period of time.
Although I have watched your previous video on link belts, I personally found that using one on my contractors saw reduced the vibration significantly, probably due to fact it doesn't have the issue of memory.
The bike shock has a plunger that moves back and forth in a sealed cylinder... are you supposed to add your own oil (so you can pick viscosity and therefore level of damping)? Certainly my cheap old mountain bike had a shock absorber that stopped absorbing shocks once enough grit got in to break the seal and let the oil out.
What would happen if you hung a bag of sand from the motor, would that act as a place for the vibrations to be absorbed due to the movement of the sand?
yes, it makes an impact. Just engaging the wheels on the mobile base makes an impact. But - surprisingly, lifting it onto it's wheels, which makes it less rigid, often cuts down on vibration. It's all about harmonics and such. Vibrations are complicated.
Watching the video, I just wanted to hang a weight off the motor or somehow add mass, bags of sand inside the base? The vibrations don't affect how it cuts, right? We used a blade stabilizer with good results on an old 5hp Jet tablesaw. I know this isn't the problem you're addressing in this video, maybe an upcoming one?
I had a chance to try the same water test on my saw. With my hand I could feel some vibrations on the saw top but to my surprise the water stayed completely flat as I raised and lowered the blade. I also tried the nickle test on my saw and although I could see it wiggle a little during start up and shutdown it never fell over. However, I was using an American nickel so I'm not sure if that makes a difference :)
How about a shock absorber from an old washing machine, or a steering damper from a motorcycle or even a vibration damper from the belt tentioner which you can find at some car/truck engines? must be plenty of those on a well sized scrapyard. I like it very much how you try to give all kinds of materials a second life. Greetings from The Netherlands. Peter
You can find a real shock absorber in an old washing machine, front loading, not sure about the US type. The new ones have cheap plastic friction dampeners only. I made a dampener for the horizontal bandsaw from a pneumatic cylinder and a needle valve between the two ports, filled with oil of course instead of air.
I noticed that when you held the motor that reduced the vibrations. Maybe having the motor being held by something detached from the table and standing on the floor would do the same?
I imagined that your hand would transfer the vibrations to your water filled body damping them and then disperse the widen frequencies onto the floor through your feet.
Switch the old belt back on and see if the vibrations return. I'm wondering if it was changing the belt the ceased the vibration not the belt itself. As you say - you couldn't see anything wrong with belt #1
Your brain works like no other person I have met. I consider myself very clever and capable of fixing most things I attempt, but compared to you I am so humbled. I think you deserve all the accolades you receive. I really enjoy your videos.
I find a bit of Blue Tack (putty) under my coin stops it falling over on my table saw :) , this wont solve the water ripples but a good amount of gelatine may help.
Stuff I Made going to check out your channel you are making sense
Stuff I Made you got a new subscribers when I spotted knows made from epoxy
Frozen water will take care of those ripples :)
two new subscribers
breakinn403 I thought the ripples mean a trex,is approaching.
Practical, modest, and just good. I love your format and methods. These videos should be supplemental material to every engineering course. Thanks for your work.
I appreciate how you show the entire process and not just the final fix that works!
I am always in awe at your inventiveness and execution. Your videos are what encouraged me to actually use the (cheap and nasty) tools I have and of course to upgrade/replace/fix/make them and other stuff. The 'workshop end of my two-car+ garage is now starting to look like a proper working space instead of a mess. The saw and router tables are on wheels so I can take up as much space as I want, after I get rid of those annoying cars.
You are in the wrong line of business, you shoul work as an inventor or problem solver of tool and machines out on the market.
Good job, you are my hero
Added link belt to my old craftsman saw and got small improvement. Huge improvement by adding isolation mounts to motor. They wear out after a while, but are easy and effective.
Matthias, you blow my mind sometimes with the stuff you make. Keep up the amazing content.
I recently bought an older table saw that works beautifully except for exactly this. I've fiddled around with the mount a ton and found as happy a medium as I could between belt tension, mount tightness, and ease of raising and lowering the saw. I'm embarrassed to admit that I never even thought of changing the belt. Thanks.
Thank you for addressing a very real problem for many woodworkers( unless you are fortunate enough to own an expensive cabinet saw). I would be interested in seeing your take on dust collection for the same saw.
I already did it on this saw, more about it on my website
I think you've experimented with link-belts in one of your previous videos haven't you?
Also, do you think it would make any difference if the saw cabinet itself were stiffer or heavier? Of course you already have a box built into the bottom so it probably is pretty stiff. Could drop a cinder block inside the base. Hmm, now I want to test my saw!
Interesting to see you work through the experimental process!
The belt links video came up for me at the end of the video. ruclips.net/video/Nc4Mt-O5tcQ/видео.html
2:11 i was actually not thinking that till the text came up lol
So innocent!
Ball joint! Ha! Ha!
BALL!
Just the tip.
Came here to say exactly that.
My mind is always in the gutter, ALWAYS, but I also thought no such thing until the text.
That was kind of a tortuous process, but in the end you found a winning technique. Persistence wins the day. I enjoyed this video a lot. Thanks!
Love these testing and experiment videos. It just shows that assumption and common sense are no substitute for testing and pragmatism.
Reminds me of a sign in a testing department where they made and tested naval weapons systems: "One test is worth a thousand expert opinions."
yeah, they should make a youtube video of their tests. Then they could get ten thousand expert opinions!
My mind was not in the gutter until you put it there and then the very next cut - to the mallet made me flinch.
I thought this was the safe end of youtube!
actually great work Matthias - as usual a pleasure
Was the saw at full height at the end Matthias? Appeared to be down to half depth.
I'm so stupid. Me at the end of the video: "But who was the contractor who saw the dampener?"
That's why I'm glad to speak German with its beautifully long compounds which circumvent this issue.
If English had compounds, it would be titled "Contractorsaw vibrationdampener"?
CONTRACTORS REACT TO VIBRATION DAMPENERS
kraklakvakve, you joke, but yes, that's what I clicked for...
I love seeing the different vibration modes in your water cup.
Extremely clever plan. You have a knack for working with problem to solution. Keep it up I enjoy watching it.
I had terrible problems with vibration on the 30 year old Craftsman contractor saw that I bought half a year ago when I first got it. Even after I changed the banana-shaped pulleys, at certain belt-tension levels the saw would really vibrate like crazy, to the point where work pieces would dance around a bit on the table top -- it was actually a fair bit dangerous. The only thing I've really found that really helped was a link belt, which I know you aren't a big fan of for your hybrid saw, but on these smaller, less massive contractor saws, they really seem to make a huge difference.
You are inspiring me to try this on my own contractor saw. Off to watch your video on the link belts first.
I have a vintage Craftsman with a similar setup, but I never paid much attention to the vibration levels. Interesting fix, good troubleshooting process.
I'm always amazed at how your mind works. You are incredibly innovative.
Well done. I'm glad you worked out what the problem was, and how to fix it. Even if the band looked fine.
Glad you found a use for the dumbbell.
Additional deadweight makes sense to make contractor saws they use light thin metal or plastic so a lot of the damping you get from the mass of metal is lost. I like that spring strut, did you try using two bungee cords on the motor frame hooked to the saw base?
Would the drum steadying arms from a front loading washing machine do something similar?
don't know. never took one of those apart.
Allofus Moreofus they're actual grease filled shocks! That would work for this application
Your solutions are absolutely remarkable. Genius!
Wel. Of all your top videos, this is a gold one! Rob
Thanks for the great work, Matthias. When lifting the motor by hand, the damping from your body may have helped more than the reduced belt tension. Which might explain why the spring didn’t have a similar effect.
As always: some very interestings findings and well presented. Well done.
That's a pretty ingenious set up! Quite impressive!
Very good process of elimination. Very creative (as usual) dampener device. ** Check the arbor bearings for wackiness. I use a mechanic's stethoscope. Most older saws I work on have going or gone bearings. ** The original pulleys on the arbor shaft and motor may also be a source of vibration. I sand the inside faces of old pulleys or I replace them. as needed ** I will also replace regular v-belts with cogged v-belts since they are more flexible and can pull a tighter curve around small pulleys.
More expensive bike shocks have shock absorbers. Thats probably only like 10 dollars.
Buy one in a place other than k-mart right!? :)
Yes. Exactly
You could try this one: gzmyu4ma9b-flywheel.netdna-ssl.com/wp-content/uploads/2016/04/2017-fox-Float-X2-and-DHX-rear-mountain-bike-shocks.jpg :D
i know. it was a joke. :D
Didn't want to spend a lot of money just to try it (I still don't know if a proper shock at that spot would have worked)
Who would have of thought bike shocks don't contain shock absorbers? Shocking! That made my day
I know you are not super keen on the link belts but I use them on my lathe and the difference they made to noise and vibration were astounding, vibration being a problem for good finish on a metal working lathe
I love these videos with your ol' beaver. I have the exact same saw. Took a lot of fiddling to get John Heisz's wooden fence on it. Now my only complaint is motor hop.
very cool fix man that ball and socket is awesome
I wouldn't be too bothered about that much vibration .... every time I turn mine on it bounces out the shop
Very informative, thanks Matthias. I recently bought an older contractor saw (the same Beaver model your brother has, shown in previous videos) and have been trying to sort out the vibration issues.
I love the Rube Goldberg jury-rigged aspect of this one... didn't seem to do much, but it looked like a lot of fun to do!
Shocks basically do two functions, keeping motion of the spring linear, and keeping a wheel on the ground. Hydraulic fluid is forced through small holes to keep the suspension stiff enough; which is why you have a harder suspension when you have a sudden dip as compared to softer suspension through a consistent force applied to a vehicle. Because of how light bikes are, and how heavy people are, they don't need the hydraulic part of the shock, as you only need a spring for dampening.
So the solution was the inferior(?) belt plus the friction shock absorber. But the overall lesson is that vibrations are tricky to dampen because of so many variables.
You're correct. Vibration is a tricky problem. Generally speaking, you can stiffen the structure to push resonant frequencies out of your rotational speed range. Changing the mass of the system can also affect the resonant frequency, but from my experience it takes a lot of change to get meaningful results. Belts themselves add another level of damping/vibration and it is all very speed dependent. Lots of variables can effect the outcome.
He came, he saw, he conquered the problem . Nice job.
No springs in the bicycle shock absorbers? I didn't know that. Was there perhaps a gas inside to act as an absorber? I do know that Menards (and I'm sure other hardware stores) stock expansion springs. You'd probably have to cut them to fit. Neat idea, I'll have to check my saw.
were you able to return the bike shocks? or have you got some kind mind blowing gadget planned with them?
Oh Matthias, you've already built the perfect lathe to machine a new shock absorber :P
Thanks for also stating the problem you were trying to solve - I was wondering the whole time untile you mentioned the wandering scrap wood.
I was fortunate enough a few years ago to get a used Rigid TS2424, one of the last of the Emerson, Built In USA, contractor-style table saws. When I saw a Matthias video on vibrations of his hybrid saw many months ago he then also suggested that pulley belts were an issue due to them taking a set when the saw is not in use (this is my recollection of a long-ago video and I could have the details wrong). To my surprise, his hybrid saw had v belts and v-belt pulleys; my older, cheaper saw has machined pulleys that use flat ribbed belts, thin flat belts. And I have no vibration problems. Possibly such pulleys could be retrofit on the saw of this video.
I added a second belt by changing both pulleys on my old saw and it got rid of all vibrations. I was able to buy the pulleys at a local bearing store (I think Canadian Bearings).
Matt, the Power Twist link drive V belts really cut down on vibration of belt-driven tools. You should give that a try. You buy a length of the stuff and make your own custom belt sizes.
see video description
Matthias you are extremely clever and I love your scientific way to look at thinks. Bra-vo!
Haven't read all the comments - somebody may have already pointed out that the assembly is the actual shock absorber. The assembly consists of a spring (for restoring force) and a DAMPER - for damping spring oscillations. You'll be wanting DAMP the motor oscillations.
I changed my pulley's to Serpentine set up . Made world's of difference.The main problem is where v groove belts are joined they leave a slight buldge in belt
I bought a serpentine belt + pulley set like this years ago for my Craftsman cast iron contractor saw --
www.ebay.com/itm/Ridgid-Craftsman-Table-Saw-Serpentine-Belt-and-Black-Steel-Pulley-Kit-420J6-/191479013478?hash=item2c9509e066:g:QfQAAOSw1ZBUspTl
That's really the best solution to start. I'd like to see how low the vibration could get with Matthias tweaks _and_ a good serpentine belt. I wasted money on a link belt (Matthias experimented with them too and found they weren't so amazing) when I should have just went for the serpentine conversion, which is actually cheaper.
You're a genius, you make a solution for almost everything!
2 things come to mind:
First - why did you not try to dampen the motor directly? I mean right where it was connected to the saw, that is where you need the dampening. And of course the wood wouldn't help much as the vibrations are only very minor in relative distance.
Second - what about going the opposite way? absorb the shocks before they reach the large board - so mount it with a sheet of rubber or some cloth.
My mind wasn't in the gutter until I saw your note.
Awsome! Now you have me thinking that I need to check my saw.
Wow, that friction dampener arm thing is bad ass.
Did you consider filling the empty shock absorbers with some sort of viscous oil? Similar to a dash pot on a door.
Shock absorbers aren't just a bolt sticking into a cavity. There's much more to it than that
Because you found the vibration changed a lot with the belt swap, I'd investigate additional belts and hot vs cold belts. Rubber takes a 'set' when cold. Sometimes car tires induce a vibration from sitting over a cold night to driving until they warm up.
I do not apologize for the long reply. I apologize to anyone with the cast iron stomach to read it all the way through.
My Dad & I did a lot of analysis and testing on this very vibration issue back in the 80s. (1980s not the 1880s as my children like to say.) It was a lot of fun as I was in vibrations classes in college at the time. There is a long story but let’s cut to the end.
Equipment: Power King 14” bandsaw, Delta 6” jointer, Boice-Crane table saw, and my Surtevant #2 forge blower. Dad bought all the equipment (except my forge blower), motors and motor mounts separately in the mid-40s. As was common at the time, except the table saw, all the equipment used hanging motor mounts.
Observations: 1.) Belts take a set from the weight of the motor. This set bumps over the motor and driven pulleys adding vibration. (Thus, when Matthias changed the belts the vibration decreased.) The belts will coast back to the stretched location after the motor is turned off, thus perpetuating and increasing the set., 2.) The less rigid the motor mount hinge the more vibration can occur. Tests with adjustable friction split wood bearings on the mounts helped but did not significantly eliminate the vibration. The intent is to increase the dynamic mass of the motor so the kink in the belt will pass over the pulley without significantly moving the motor. 3.) Belt dressing had a slight improvement but was undesirable to keep applying for the small benefit., 4.) Increased motor mass (adding weights) had a noticeable improvement as dynamic mass increased, but the time to stretch a belt and for it to take a set was significantly decreased., 5.) Worn or frayed belts showed no significant effect on vibrations, but they took a set faster than new belts., 6.) The forge blower was using a thick belt since the motor end is a stepped vee pulley and the driven blower end is designed for flat belt drive. Changing to a thinner belt reduced vibration without slipping.
Conclusions: 1.) Wherever possible change to a rigid motor mount with an adjustable tensioning slide. The slide should be able to be locked into position before starting the machine. This is not possible for Matthias’ contractor saw as there are too many degrees of freedom needed., 2.) Always remove tension from the belt at the end of the day., 3.) If possible, remove the belt and store flat, not on a hook., 4.) Only use clean, pliable belts., 5.) Use the smallest belt for power transfer and balance against life expectation.
Implementation: 1.) All equipment except the jointer was converted to rigid motor mounts with tension locks. 2.) Because the jointer is 26” center to center, temperature and humidity have a significant effect during operation. So, the hanging motor mount is a special split friction block on the hinge posts and spring swings over the motor base to provide tension to the belt and increase the dynamic motor mass., 3.) All belts are removed at the end the of the day and stored flat on the machines, even if returning in less than 8 hours.
Results: There is significantly less to no noticeable vibration compared to prior to the changes. I have been using the same belts for 30+ years of average operation 1 time/month. Vibration is less than first implementation probably due to the belts wearing in.
Recommendations for contractor saw: 1.) Pop the belt off the pulley at the end of the day. If possible fish it out and set flat on a horizontal piece of wood. Condensation is probable in Canada, so better on wood than a metal table top., 2.) Add some friction to the motor mount posts so the motor is harder to move but does not cause wear or binding when it needs to move., 3.) Experiment with the extra mass. You might try a long rod vs a concentrated mass as the intent is to increase moment of inertia. 4.) Do use the Rube Goldberg shock absorber but find a way to get the motor to be more rigid, which means both ends need to be firm and the friction needs to be increased. (Wow! Ave would have a great time with the massive double entendre in this last sentence.)
Sincerely,
ElWet (Remnants of Harvey rain is starting, thus I am All Wet.)
Try a good quality cog-type V belt. It's notched to prevent vibration from belt set, and since they've had material removed they aren't likely to have a stiff point where they're joined. They also last longer because they don't get as hot from the repeated bending around the pulleys.
maybe I missed something, but what was the final combo that worked properly for you, just using a piece of wood with a friction joint in the middle ?
yes, like I showed
Wow Matthias has done it again!
Good idea.
With the vibrations coming from the belt taking the tension off helps decouple it from the pulleys, reducing the vibrations transferred to the table. While I applaud your attempt to engineer a fix, I think the simplest fix would be to replace the belt.
With the size of the pulleys and the only tension coming from the weight of the motor I would say a cogged V-belt (I'm guessing AX?) would be a better fit for the application than a standard V-belt. The reduced weight and better flexibility should inherently reduce vibrations, they also transfer power better, and generally wear better then standard belts, balancing their slightly higher price.
I'm probably asking a stupid question: why is the lack of vibration useful?
I have found that link belts often reduce vibration on equipment but on occasion with make it slightly worse. It seams that it is a little hit and miss.
Have you tried a grooved V-belt? Switching to one from a solid V-belt made a world of difference on my lathe; its motor is similarly suspended by the belt tension, as well.
yes, that would help. Just haven't take the time to source the pulleys so far.
I guess the proper term for them are 'cogged v-belts'; they use regular pulleys. goo.gl/images/vPQzNh
Cool, it was fun watching you tinker my friend. Try a link belt as well
there are true shock absorbers for "downhill" mountain bikes, they work with air and adjustable valves. you can easily spot them, they look different without a spring. Cost can be saved if you buy the used on ebay or diy.
You really know how to fine tune your machines. Would be great to see you build a decent piece of house furniture with them.
we already have too much furniture in the house
Hi Matthias, would you consider designing and making a drum sander? I know you won't make stuff you personally need but if you make it, they will come. cheers.
The vibration comes from the belt taking a set around the small pulley. Just add a small low rpm motor to continuously turn the belt when not in use so it can't take a set.
I like seeing the iterative process!
"Some kind of thing sticking out should work" Love it!!
I've heard that link belts tend to make a huge improvement in vibration and noise level reduction. I guess the reason is that v-belts tend to get lopsided from either the way they are made and when they sit for any given period of time.
My experience is they are much louder than V-belts. I used to have on on my other table saw but got rid of it.
Matthias Wandel I'll have to keep that in mind, I was about to switch over mine to link belts.
Although I have watched your previous video on link belts, I personally found that using one on my contractors saw reduced the vibration significantly, probably due to fact it doesn't have the issue of memory.
RUN, Matthias! You have a whole herd of T-Rexes stampeding toward you house!
The bike shock has a plunger that moves back and forth in a sealed cylinder... are you supposed to add your own oil (so you can pick viscosity and therefore level of damping)? Certainly my cheap old mountain bike had a shock absorber that stopped absorbing shocks once enough grit got in to break the seal and let the oil out.
What would happen if you hung a bag of sand from the motor, would that act as a place for the vibrations to be absorbed due to the movement of the sand?
Wondering if wheels vs. bolted in place had an impact on things.
yes, it makes an impact. Just engaging the wheels on the mobile base makes an impact. But - surprisingly, lifting it onto it's wheels, which makes it less rigid, often cuts down on vibration. It's all about harmonics and such. Vibrations are complicated.
Watching the video, I just wanted to hang a weight off the motor or somehow add mass, bags of sand inside the base? The vibrations don't affect how it cuts, right? We used a blade stabilizer with good results on an old 5hp Jet tablesaw. I know this isn't the problem you're addressing in this video, maybe an upcoming one?
the remaining water vibrations might just be the sound waves of the blade bouncing off the water surface?
I had a chance to try the same water test on my saw. With my hand I could feel some vibrations on the saw top but to my surprise the water stayed completely flat as I raised and lowered the blade. I also tried the nickle test on my saw and although I could see it wiggle a little during start up and shutdown it never fell over. However, I was using an American nickel so I'm not sure if that makes a difference :)
I look very much like watching every one of your videos. I am also good enough.
Brilliant you are. It's a real pleasure to inform our selves with your work. Merci. 👍🏻💡👍🏻
I love watching the articulation of the wooden shock absorber at 6:40.
How about a shock absorber from an old washing machine, or a steering damper from a motorcycle or even a vibration damper from the belt tentioner which you can find at some car/truck engines? must be plenty of those on a well sized scrapyard.
I like it very much how you try to give all kinds of materials a second life.
Greetings from The Netherlands.
Peter
You can find a real shock absorber in an old washing machine, front loading, not sure about the US type.
The new ones have cheap plastic friction dampeners only.
I made a dampener for the horizontal bandsaw from a pneumatic cylinder and a needle valve between the two ports, filled with oil of course instead of air.
Increíble solución a las bibraciónes. Eres un maestro
Some belts are welded badly. As a result they are stiffer at certain points. That caused alot of vibration on my drill press.
My drill press belt or pulley system tries to push upwards when under heavy load. It's annoying as now it stops the drill bit moving!
Get a name brand belt. It's not a very common expense.
So those bike shock absorbers are just to hold the spring and to trick your friends?
You can find some suitable size friction shock absorbers from washing machine. They are cheap and can be found on ebay.
I noticed that when you held the motor that reduced the vibrations. Maybe having the motor being held by something detached from the table and standing on the floor would do the same?
that would make it much worse, actually
I imagined that your hand would transfer the vibrations to your water filled body damping them and then disperse the widen frequencies onto the floor through your feet.
Did you get rid of your other table saw when you moved?
Switch the old belt back on and see if the vibrations return. I'm wondering if it was changing the belt the ceased the vibration not the belt itself. As you say - you couldn't see anything wrong with belt #1
except that it was causing the motor to go up and down a lot (watch the video)
Aún sin entenderle nada
Me gusta ver sus videos
Exelente gracias por subirlos
Why haven't you set up your main table saw yet?
cause I wanted to experiment with this
Matthias Wandel this is the best reason. I like this reason. SCIENCE!
What brand-name is his drill cause I've have never seen those things before.