quick help

[JFettig]

I got a pully set made up for my mini mill and the pully for the motor is .007" too big and rotates on it, He told me he was making it so that it would slide on really tightly and not come off, well its reather loose.

Does anyone have any ideas how I can get it tight on there? My cnc conversion is looking sweet so far, Ill have some sweet pictures to post soon!


Jon

[wms]

Personally I would take it back and make them stand behind their work. And remake a new one that is right.

JMO

[HuFlungDung]

Take it back and either:

a: give him the stoney stare of death,

or

b: ask him nicely if he could rebore it and put a sleeve inside of it.

[JFettig]

Well, the guy that made it for me no longer responds to e-mails or snailmails, nooones, so that is basicly out of the question, I bored it out and put asleeve in it and it still spins on the shaft. Got any ideas how I can make it not spin?
I was really hoping to see this thing run! 9000rpm at the spindle!


Thanx
Jon

[Stevie]

well once you change what they did; you screwed yourself; if yu already sleevd it; re-sleave it again; but smaller this tme; in fact make it tight by 0.002; heat it with a propane set-up and put it on hot

[HuFlungDung]

Stevie is right.

Typically, a drive component also uses a keyway and/or a setscrew engaging a keyway/flat spot on the shaft.

If you have the fit quite close, within a thousandth or two, you can also do a bandaid repair with Loctite 262 permanent lock compound. This makes your easy fit very difficult to remove, after the Loctite has set up for a few hours. The best removal method then is to heat the pulley to about 350 or 400 degrees F to melt the Loctite.

[JFettig]

Well, yes I did sleeve it and I screwed it up really good. Do you know if I can use those pullies that people use for steppers to run a 1:1 ratio on the spindle? I would need a 1:5/6 ratio to get 9000rpm but I probably wont find that kind of combination, 6k will be good.

Btw, I put it on the 2500rpm pullies and I can turn it all the way up, and overload it by grabbing the spindle, on the 9000rpm pullies I cant even hit a few thousand rpm. I think my bearings in the head might be pressed a little tightly.

but waht I want to know is if those pullies that people use to gear down steppers would work for my spindle.

[Hobbiest]

Just use some JB weld! Seriously though, I say to bore and sleeve again, then bore to .001 or .002 like suggested above for a proper friction fit. If you can get the spindle out, even better! Put the spindle in the freezer, and the pulley under the torch. It should slip right together and never come apart (at least not without the REALLY big hammer!)!

[JFettig]

I wish I would have done something like that but its already screwed up.

-edit- it just might be fixable, what I want to know is if those steel timing pullies and belts can handle the rpm(6000-9000) and the tork? can anyone here help me on that one?

Jon

[NeoMoses]

Torque - Definately. RPM - Maybe. It all depends on how well balanced they are. My gut instinct says that the ones I got from McMaster for my mill conversion should be good to 5000 RPM without much problem, possibly higher.

How many HP is your motor?

[HuFlungDung]

If we are talking about timing belt pulleys, they do get annoyingly noisy running at high rpms. Kinda like undoing your zipper at 60 miles per hour The larger the pulley, the more teeth per revolution = more noise

[JFettig]

The ones I am looking at are the bushing steel ones, ones where you make the bushing for. Theres the urithane belts that mcmaster says they are quiet, I wonder if they are different from the rubber belts?
The motor is 4/5hp
-edit- now that I think about it, my lathe uses this same thing to power it, I beleve the motor is the same and the rpm is probably the same, if its not horribly noisy I might do it, I beleve its the gears that are noisy in it, thats the way it was on my mill, I was amased at how quiet the mill motor is.

Jon