Mill rattling

[Noitoen]

My Optimum F45 always had a "problem". The splined shaft on the spindle always had a little play and when I use the fly cutter which has 4 blades, the rattling sound gets terrible. Is there a way to silence this? I has thinking of lubricating it with some heavy sticky grease hoping this would help . Any other ideas?

 

[MuellerNick]

That rattling is very common, not just for the Pessimum mills.
Usual solution is a friction brake that slightly brakes the spindle and thus keeps the driving flanks in contact.

Don't forget to open the brake at high RPM.


Nick

 

[enfieldbullet]

do you mean play in the quill?

there's usually some set screw that you can tighten that will lock the quill and reduce rattling.

if you mean the shaft itself then Nick's suggestion seems reasonable. grease could help but i believe the rattling sound comes from the shaft going forward after the cutting pressure is released and then back against the driving shaft when the cutter engages again. grease wouldn't reduce the noise, perhaps the wear.

 

[Noitoen]

It's not quill locking problem, it's the splined shaft that allows for the "column drill" action. If I grab the collet holder and move back and forth, it moves a little without moving the gearbox. The "stiff" grease would dampen, I hope this movement. Since the female part of the spline is way down that hollow shaft, I also thought about filling the void between the splined shaft and the hollow one with silicone. When dry, it could help. Must try something.

 

[chrsbrbnk]

I work in a tool and die shop and over the years some people have run big dia. cutters on there mills and some don't. after a few years it really shows, those big cutters really beat the crap out of your mill, that rattling is pretty much the sound of destruction .

 

[enfieldbullet]

how about babbit metal?

 

[MachineTom]

The way to stop that is to use a smaller diameter cutter so that the cutter is not spinning in air as much. It is the loaded unloaded action that causes that rattle, smaller diameter or more cutters engaged. What width of cut are you making, vs cutter diameter.

 

[chrsbrbnk]

using a cutter dia that will allow the cutter to enter the work gradually on the tooth not so much a smack hit kinda thing, also the tooth leaving the work gradually so the cut pressure on the tooth builds and ebbs gradually.

 

[cfellows]

I saw an article some months ago, don't remember where, that was for a drill press. Might work on your mill. He drilled and tapped a hole in the top end of the splined shaft. Then turned a bushing that he attached to the top of the splined shaft with a bolt. The bushing was sized to be a close sliding fit inside tube that the splined shaft slides up and down in. You might consider making the bushing out of delrin.

Chuck

 

[Noitoen]

The "fly"cutter was the only tool that came with the machine. It's about 60mm in diameter and has 4 "lathe like" cutting tools with soldered inserts pointing downwards. I only use it to face off aluminium. That play in the shafts, if "controlled" will benefit the overall noise/wear of the machine. I will try the bushing solution.

 

[gadabout]

Have a look at this page for someones "solution"

http://www.practicalmachinist.com/vb/member-shop-photos/sloppy-splines-146333/
cheers
Mark