Contractor Table Saw Vibration Noise

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Mike Camp

New User
Mike
Just got my contractor table saw started up. It doesn't pass the nickel test right now. I ran the saw without the link belt on and the motor runs smooth. With the link belt on it runs, but is not exactly quiet. I checked the link belt orientation and it is correct. The bearings on the arbor don't have any play when I jerk the blade and spin freely when I just spin the blade by hand. The one pulley on the motor is 3.5" in diameter while the one on the arbor is 2.5" in diameter which is overdriving it from 3450 to approx 4800. Any ideas of what this could be (arbor bearings, pulleys?)or is this amount of vibration sometimes par for the course. The saw was built in 1993 and probably had the original arbor bearings. Also the link belt felt warm not hot after about a minute of running not sure if that tells you anything.

Video of the Saw turning on.

Any comments would be appreciated.
 

Joe Scharle

Joe
Corporate Member
I think I heard on shutdown, what sounded like the motor vibrating on the motor plate. If true, the pulleys are no longer co-planner and adding to the ruckus. Then again, I might be lying :rolf:

Anyway, things like this are like getting a haircut over the phone. One really needs to be there, but it's possibe that someone has your saw AND has had the same problem....With any luck...
 

CDPeters

Master of None
Chris
What Joe said... plus sounds like the belt might be slipping too. Getting warm is a good indicator for that, though misaligned pulleys can also cause added friction.
 

Mike Camp

New User
Mike
Thanks Joe and Chris. I'll take a straightedge between the pulley's tonight and make sure they are aligned. If the belt is slipping after that I assume that means that the belt is undertensioned, correct?
 

CDPeters

Master of None
Chris
Correct Mike. When you look at the belt running, there should be little to no "slap" in the return side of the belt (top? depends on motor orientation). But you also don't want it over-tensioned either.

C.
 

Mark Gottesman

New User
Mark
I did the following when refurbing a contractors saw.

Replace bearings. Yours are 18 years old, might be time. Durex seems to be a canadian branded saw. Could not figure out who made them. Accurate bearing should have replacements.

Machined steel pulleys. The cast pot metal ones can have some concentricity issues.

Link belt: I use one, it seems to help, but I have a feeling they will slip under a heavy load.

Make sure everything is tight. Go over machine, clean all adjusting gears and make sure all bolts are tight. I replaced the trunnion bolts with grade 8s and new lock washers.

Lube and make sure everything is square and parallel.

I had to shim my motor out with washers on the pulley side to square things up. A pain to do on a contractors saw, but well worth it when you can cute square and safe.

Set aside a day one weekend to fluff and buff the tool. You'll feel like you have a new saw.
 

Mike Camp

New User
Mike
Thanks, Mark. This is actually already an almost finished restoration that is ongoing; however, I didn't replace the bearings figuring they were good for now. Now that I know how the table saw comes apart I think I may tear it down again in the spring and swap the bearings (scared to attempt but have read that it isn't too scary if you are careful, may just take it to a machine shop). During this I may upgrade the hardware as well to stronger grade 8 bolts, great advice.

I just readjusted the entire alignment of the pulleys and it dropped the vibration of the saw considerably to a usable levels. I think I still am going to replace the pulleys with machined ones. What source did you use for your pulleys by the way? I've found that highland woodworking and in-line industries.

Thanks again guys for your advice. The pulley alignment was definitely off and even though I still have some tuning to do this saw is usable now. :saw: After I get the new fence installed it will be time to make some sawdust!
 

junquecol

Bruce
User
Mike, congrats of restoration. I bought that Delta off CL last week. But I didn't pay anywhere near the asking price, as it was missing parts, and had been left outside way too long. As for arbor bearings, your saw most likely uses 6203's. I keep a bunch on hand, as this is the most common bearing in use on small motors, table saw arbors (both contractor's and Uni,) idler pulleys on cars, and alternators. Replacing arbor bearings is easy once you get arbor out. Pulley side bearing is removed when removing arbor. Blade side is removed with a gear puller. Replacement bearing is placed on top of a 60 - 75 watt light bulb (try that on a CFL:rotflm:) for about three minutes, and then literally dropped on arbor. Heating causes it to expand. What kind of fence are you going with? (Asheville Hwd still owes me some replacement parts for my Uni fence.) In-Line is the source I use for turned pulleys, but all cast iron pulleys are machined. Take the blade off and see if vibration still exists. If belt is warm, it is most likely too loose. Remove a couple links. My job site contractor's saw will literally walk across the floor when using a Goodyear Poly-Flex belt (top of the line), but behaves nicely with a link belt.
 

Mark Gottesman

New User
Mark
I also used in-line for pulleys.

Out of curiosity have you checked you blade for flutter. Also check the face of the blade arbor for burrs and if it has any runout in it.
 

Mike Camp

New User
Mike
Mark:

Thanks for the suggestions I actually cleaned the arbor face last night and it didn't have any burrs just one tiny spot of surface rust. The blade on there right now is not a great one when I start it and stare down the line of it does not look like it is fluttering, but my father is coming down this weekend with his dial indicator so I'll use it to check the arbor for runout and align the saw.

Bruce:

Thanks, I think "the project" has turned out better than I imagined. A buddy of mine powder coated the crank handles and the motor mount it all turned out nicely and I ace rattle canned the rest. Also great deal on that Delta. I figure you'll have it restored and ready for sale or as a second saw and save time on blade changes. For the fence I went with the Delta T2 (Bies Lite), I was thinking about waiting for your unifence, but there are two small home projects I need the saw for in the next month. So I went ahead and got the T2 at a good price online. Gives my Dad and I something to mount on the saw this weekend anyhow.

Questions:

1. Currently with a 3" drive pulley and 2.35" arbor pulley I'm getting approx 4400 rpm at the arbor. When I order from inline should I just get two 2.25" pulleys or maybe one 2.25" and one 2.5" to give me about 3800rpm (motor is 3450 @ 1.5hp). I guess the question is what is the ideal speed for the blade and what OD pulley's should I order?

2. For the bearing removal do I need to remove the casting piece that holds the arbor bearings to the trunions, it sounds like I can simply:

1) Remove the pulley from the arbor.
2) Remove the retaining nut from the pulley side of the pulley side arbor bearing.
3) Tap out the arbor with a mallet or dead blow hammer from the pulley side.
4) Remove the pulley side bearing via heating the casting and possibly tapping out with a socket on the outer race or maybe the retaining nut was doing all the work so it will just fall out, dunno.
5) Remove the blade side bearing with a gear/bearing puller.
6) This is wear I'm confused wouldn't I want to freeze rather than heat the bearing and the arbor so they contract making the bearing slip onto the arbor easier? Also possibly heat the casting to make them slide in easier?
7) Freeze the pulley side bearing then slide it onto the arbor.
8) Put nut and pulley back on
9) Buy you both a beer for your advice :gar-La;

3. When not in use should I leave the motor on the belt or should I remove it from the belt and let it hang down?
 

CDPeters

Master of None
Chris
Mike -

Most contractor style saws seem to run at about 3800 - 4000 RPM - I would shoot for that. The higher the arbor speed, the more you risk 2 problems: 1) overheating causing burning and 2) higher step-up ratios mean less arbor torque, which means it will be easier to stall the saw.

Always use heat (sparingly) to remove a pulley/bearing/bushings. Remember that heat causes metal to expand. Because the object being removed is "longer" around the circumference, it expands more than the shaft, loosening it relative to the shaft.

Back in the day (many many moons ago) we used to do an experiment in high school science class with a ball and ring. At room temperature, the ball would not fit through the ring - but heat them and the ball slips easiliy through the ring. Unfortunately - I don't think this simple experiment is done in HS anymore. I know neither of my kids were exposed to it - on the up side, they both thought I was a genius when I showed them this principle! :rotflm:
There is no harm in leaving the belt on when not in use, unless it will be un-used for a very long period of time (+1 year).

C.
 
Last edited:

Mark Gottesman

New User
Mark
Mark:

Thanks for the suggestions I actually cleaned the arbor face last night and it didn't have any burrs just one tiny spot of surface rust. The blade on there right now is not a great one when I start it and stare down the line of it does not look like it is fluttering, but my father is coming down this weekend with his dial indicator so I'll use it to check the arbor for runout and align the saw.

Dial Indicator will be very helpful. Check Arbor face and blade at 90 and 45. If things are not square this will help ferret it out.

Bruce:

Thanks, I think "the project" has turned out better than I imagined. A buddy of mine powder coated the crank handles and the motor mount it all turned out nicely and I ace rattle canned the rest. Also great deal on that Delta. I figure you'll have it restored and ready for sale or as a second saw and save time on blade changes. For the fence I went with the Delta T2 (Bies Lite), I was thinking about waiting for your unifence, but there are two small home projects I need the saw for in the next month. So I went ahead and got the T2 at a good price online. Gives my Dad and I something to mount on the saw this weekend anyhow.

RE: T2. It is a great Fence. I used exisiting holes in my Craftsman and it made the fence ride about 1/4" above the table. Made a wooden sleeve to fit over fence and that took care of that.


Questions:

1. Currently with a 3" drive pulley and 2.35" arbor pulley I'm getting approx 4400 rpm at the arbor. When I order from inline should I just get two 2.25" pulleys or maybe one 2.25" and one 2.5" to give me about 3800rpm (motor is 3450 @ 1.5hp). I guess the question is what is the ideal speed for the blade and what OD pulley's should I order?

I checked mine and I am using a 2.5" pulley on motor and 2.25" on blade to get 3800 rpm which is what Craftsman tool manual calls for.

2. For the bearing removal do I need to remove the casting piece that holds the arbor bearings to the trunions, it sounds like I can simply:

1) Remove the pulley from the arbor.
2) Remove the retaining nut from the pulley side of the pulley side arbor bearing.
3) Tap out the arbor with a mallet or dead blow hammer from the pulley side.
4) Remove the pulley side bearing via heating the casting and possibly tapping out with a socket on the outer race or maybe the retaining nut was doing all the work so it will just fall out, dunno.
5) Remove the blade side bearing with a gear/bearing puller.
6) This is wear I'm confused wouldn't I want to freeze rather than heat the bearing and the arbor so they contract making the bearing slip onto the arbor easier? Also possibly heat the casting to make them slide in easier?
7) Freeze the pulley side bearing then slide it onto the arbor.
8) Put nut and pulley back on
9) Buy you both a beer for your advice :gar-La;

Would need to see photos and parts breakdown, but I'm guessing you would be better off removing the unit from machine to work on it. Basically put shaft in freezer for a while. When ready, heat bearings on light bulb and place on shaft. I have sometimes lubed a shaft with gear oil. Have everything in place including various pipe/sockets to press on bearings. Move quickly.


3. When not in use should I leave the motor on the belt or should I remove it from the belt and let it hang down?
I keep a belt around and swap out when saw is going to be idle for a while.
 

Howard Acheson

New User
Howard
The design of link belts causes a "hum" when they are running. A new standard v-belt is actually quieter.

Also, Contractor type saws do not have a way of increasing the tension on the drive belt. It's the weight of the motor that creates the tension.
 

ehpoole

Administrator
Ethan
Also, Contractor type saws do not have a way of increasing the tension on the drive belt. It's the weight of the motor that creates the tension.

Just to expand on this point, but you can increase the tension on gravity tensioned equipment by bolting additional weight onto the motor (e.g. 1/4" or better steel plates secured by same bolts that secure the motor).
 

Mike Camp

New User
Mike
Mark and Chris,

Thank you for your detailed responses. I think once I get some time after the holidays I'm going to tear down the saw (again) and replace the bearings. I also ordered 2.5" and 2.25" pulleys from inline today which should dial me in around 3800 rpm. My current speed is 4400 which definitely cannot be helping the vibration. I'll let you all know how it goes once I get the saw on the stand, aligned, and a new blade and fence installed and check the arbor for runout. ncwoodworker has again proved invaluable.

Just to expand on this point, but you can increase the tension on gravity tensioned equipment by bolting additional weight onto the motor (e.g. 1/4" or better steel plates secured by same bolts that secure the motor).

Good idea Ethan. The motor weighs a lot so I don't think under tensioning is my problem now but I appreciate the idea if I go that route.
 

junquecol

Bruce
User
Knowing the weight of that motor, I can tell you that you don't need any more weight. Your motor weighs about twice what a Delta (Marathon) motor weighs. As for arbor removal, remove drive pulley and nut. Nut probably uses a spanner wrench, but a drift pin and a small hammer substitutes nicely. I use a gear puller to press arbor out. Blade side bearing will come out with arbor. Use gear puller to remove old bearing from arbor. Take new bearing and heat on light bulb, and it will almost drop on shaft. Be sure and wear leather gloves when you pick it up - it's HOT! Pulley side bearing is usually a "light press" into bracket. I use a short section of pipe, along with some washers and a bolt / nut assembly to press it out and back in. You are welcome to borrow one of my dial indicators and mounting base for alignment. If you really want to go fancy, you can use my A-Line It Jr, instead of my shop made one. A - Line It is only prettier, it doesn't work any better. I am also willing to lend you my jig for setting blade at 90. HF has both magnetic base and DI for about $20.
 

Mike Camp

New User
Mike
So a quick update I pulled the pulley and key to check the bearings and they seem a little loud. It doesn't seem to be picked up by the camera but there is a small click right before they stop. I think it may be time for new bearings before anything else.

http://youtu.be/tZ1Q6len7pM

Thanks Bruce, the nut is a 23mm nut which is slightly recessed I assume it is LH threaded to compensate for the LH nut on blade side. I'll go pick up a socket at Lowes for that today. If I can't dig one up could I possibly borrow your gear/pulley puller as well? Also I assume buying the fastenal $1.50 (Bearings Limited brand read import) is probably not a good plan. They have Koyo's on sale right now will just take a few days to get them once I get this arbor out.
 

Mike Camp

New User
Mike
A couple shots of the pulley side.

IMG_00461.JPG

View image in gallery

IMG_00493.JPG

View image in gallery

IMG_00471.JPG

View image in gallery
 

Howard Acheson

New User
Howard
Just to expand on this point, but you can increase the tension on gravity tensioned equipment by bolting additional weight onto the motor (e.g. 1/4" or better steel plates secured by same bolts that secure the motor).

That's risky. On contractor saws, the weight is transferred to the trunnion which is attached to the table top. This could cause warping of the tabletop and cause the trunnion to need frequent adjustment.

There should never be a need to add weight. If the belt is slipping, it's a problem with the pulley or the belt. The cheaper link belt frequently slip.
 

Howard Acheson

New User
Howard
Just to expand on this point, but you can increase the tension on gravity tensioned equipment by bolting additional weight onto the motor (e.g. 1/4" or better steel plates secured by same bolts that secure the motor).

That may not a good idea. The weight of the motor and any additional weight is transferred to the trunnion and to the saw tabletop. Added weight could cause warpage or sagging of the tabletop and/or the need for frequent adjustment.

The contractor saw manufacturers will not recommend adding weight.

If the belt is slipping, look to the pulleys and/or the belt. Some of the cheaper link belts will tend to slip.
 
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