TL-1, Noisy spindle drive belt

[DEAN]

Hey there Guys...
My spindle drive belt has been making noise for a while, probably has been doing this from the beginning but it is just starting to be irritating. I dont believe there is anything wrong with the belt. I think it is just that it is tight running on the pulley making a pulsing squishy sound at low rpms.
Is there some sort of belt dressing to elminate this?
Thanks

[Geof]

I guess 'pulsing squishy sound' is one of these arcane technical only used by people in the know . I had the local Haas tech in looking at my TL1 to find out if it made a 'funny sound' (another technical term used by one of his customers). He went through the full spindle speed range and there is a rythmic sound that seems to be more pronounced at 300 rpm then at 600 rpm but it gets lost in the general noise at 900 and 1200. He figured it was just some sort of resonant vibration related to the motor drive frequency and when he visited the other customer I think it sounded much the same so he told them not to worry.

I don't think anything is supposed to be put on the toothed belts that are on the TL1 and I do know some coolants will cause them to swell if they are exposed for a while.

[DEAN]

I knew someone would like that highly technical term.
It definetly is the belt. I pulled the cover and if I press firmly on the belt I can get it to make this noise from the pulley-belt interface. I suppose I would call it more of a rubber to metal squeak. Not a show stopper.
I suppose there is a tight and loose side to a belt, just like there is in a chain. This must be causing the pulsing effect.

[Geof]

Can you adjust the belt tension? I haven't taken the back cover off to see.

Also I thought came to me while I was typing this; Baby Powder or talcum powder, try dusting it with a bit of this or use powdered French Chalk which you might know as soapstone. Powdered French chalk is used when you repair the tube in a tire as it stops adhesion between the rubber surfaces. I know it is not harmful to rubber.

[xiondavis]

Just to add to the thread...

My MiniMill was squealing from the day it was delivered - training guys said it sounded fine, but at 6000 rpm, you didn't want to be in the shop with it for more than 10 min or so.

I thought it sounded like VFD noise, but after talking with the haas factory guys, they determined it was belt noise.

The haas tech came out and determined the belt was too loose - was riding against the pulley lip (all the way to the bottom) causing the noise. He put a new belt on and got it to ride in the middle - now is quiet as can be! Can actually hear the spindle fan now!

-J

[philld]

Before I Started My Job The Boss Had The Haas Guy In To Look At The Same Noise, Happens At Low Speeds, He Said Ther Was Nothing To Worry About It Was Belt Noise.

[rkonnen]

I have a friend who bought a TM2, it had a belt noise, the installer said it was normal, my buddy disagreed. My friend already had a TM1 in his shop, it didn't make a belt noise. A salesman stop to checkup on his new machine and said the belt didn't sound right! Turns out the belt was to tight. I think when it comes down to it if you are feeling something is not right, better check it out real good, before you know it the warranty is up and your shelling out a bunch of bucks because the machine finished in the factory late on a Friday( old car manufacturing joke) and something was over looked.

[Wiseco]

My TL-2 does the same sound. I tryed to resolve this with baby powder as Geof said. It does the job a bit for a while but came back again later. Now I think I will try to adjust the spindle motor because the belt run beside a pulley lip so it looks like a missalignment problem.

Maybe crowning the surface of pulleys could help to centered the belt? What do you all think of this?

[Geof]

Originally Posted by Wiseco ...Maybe crowning the surface of pulleys could help to centered the belt? What do you all think of this?

They are toothed belts? Yes,no? I am too lazy to run out and look. I would expect crowning would not be an option if they are toothed.

Why don't you look at your motor alignment and see if it is adjustable.

[Wiseco]

Yeah they're toothed but maybe just a little crowning would help to centered them no?

Yeah I just tryed to ajust the drive plate. It help a bit with the noise but not to keep the drive belt in the center of pulleys.

I can ajust the parallele missalignement with the drive pulley but if it have a little angular missalignment cause by the drive motor plate, I will not be able to centered it at all.

Anyway, It's 5hpm, friday... I need beer now! I'll check it on monday and I'll keep you all inform if I find a miracle to that noisy problem.

[Wiseco]

Ok so I've solve my problem. The belt was too tight. I think guyz at Haas tighten the belt using the weight of the spindle motor, which is alot for my opinion. So I've just tighten a bit one of the 3 motor plate bolts, push the motor plate up using a pry bar so the belt loosen a bit and tighten all the bolts. The belt is still tight but it doesn't cry out loud when the spindle turn at full speed, it just make noise when the spindle rev up, rev down and when the machine is making big chip, but nothing to get tirred of.

To be sure that the belt would not slip, I've put a 4" dia bar in the chuck and start the machine at 25% spindle for the first cut, 50% at the second and increase feed rate throught 100% of the spindle load during the cut and watching the belt. It was still tight enought to not make a slack in the belt pass the spindle motor, so everything is ok then!

I will surely appreciate more my little toy now! So Dean, try it out!

And my alignment is centered also.

[axis]

i would also suggest you shim the motor front or back the belt should run in the middle of the front sprocket and about 1000rpm this stops almost all of the noise the techs can tell you that the noise is ok but it is not. it will cause a vibration that will kill the bottom bearing in the motor and it will need to be replaced. the belt is designed to run at a certan noise level but that level its not very loud. you should just be able to hear it at 4000 rpm or 6000.you should not need wd40 or baby powder (or ear plugs) to make it quiet doing this can also void warrenty even if the tech told you it was ok it was designed as a dry run belt and should be run so. haas sold you a machine and you paid good money for it hold them to acount if somthing dosnt feel right say somthing get a tech in and get them to fix it.

this is just my view from my own experiance take it as that and do with it what you will.