What do you use for vibration damping?

[So not a Guru]

We have a job with a bunch of pockets, that have 1/8" walls between them. The operation after we've completed the pockets will vibrate these wall & cause an unacceptable finish.

In the past, on other jobs, in other places, I've used different filler materials to dampen vibrations or to provide support.

I'm wondering what others use when you have an application that requires a filler to provide support. Fusible alloys, dental plaster, modeling clay or ??? And what kinds of success & difficulties you've encountered.

[balnh]

I've had success with plumbers putty. Only problem I had with it is that it left an oily residue.

[crazy^millman]

Have you tired waterfall finishing the walls? I have some I just did that were well over 2" tall and they came out great finishing them this way. 24000 rpms and 360 imp with a .1 step done per pass. Stub flute ball endmill with reduced shank. I would semi finish within .05 on all walls and then waterfall all the packets each step at a time and see how it turns out. Yes it seems weird not finishing each pocket to depth, but use the strength of the materiel to help finish as you go down. By using a stub flute endmill you limit how much contact the tool has with the part. Time you add up putting something to the part and then removing it you will see it is faster just going this route to get unattended run time. 

 

There is a product call toolstone, but it is not cheap.

[Watcher]

Sandvik Silent Tools if tool holders are a variable.

[Matthew Hajicek - Singularity]

Ron did you mean "bull", or did you actually use a ball for that?

[AMCNitro]

Waterfall?  IS this where you do a finish pass at every depth cut?

[TheePres]

Babbit putty (bear shyt) unfortunately not available any longer due to it contained asbestos. Deacon mold pac?? Is a good replacement for it.

[crazy^millman]

Ron did you mean "bull", or did you actually use a ball for that?

 

Yes Ball endmill. The part had a 3/16 R in the corner. Pretty amazing to watch 5 Axis toolpaths running at those speeds and feeds.

 

 

Waterfall?  IS this where you do a finish pass at every depth cut?

 

Yes.

[crazy^millman]

Sandvik Silent Tools if tool holders are a variable.

 

Yes, but on deep pockets you are still fighting material and where the approach of the toolpaths help negate the effects of harmonics by using strength of material in the upper areas to finish. Last case you use something to help stabilize the part.

[jeff]

Have you tired waterfall finishing the walls? 

I do that whenever I have steep, thin walls and it works out great.

[crazy^millman]

I do that whenever I have steep, thin walls and it works out great.

 

A little trick is to put a .05 draft on the walls so the step down is really moving away from the wall. Might change .001 to .002 by the time you get to the bottom, but if you have a .01 or .04 profile tolerance no one will ever be the wiser. I always tell inspection if they question it the tool was pushing away as it got to the bottom because it was removing more material. :geek:

[So not a Guru]

Have you tired waterfall finishing the walls? I have some I just did that were well over 2" tall and they came out great finishing them this way. 24000 rpms and 360 imp with a .1 step done per pass. Stub flute ball endmill with reduced shank. I would semi finish within .05 on all walls and then waterfall all the packets each step at a time and see how it turns out. Yes it seems weird not finishing each pocket to depth, but use the strength of the materiel to help finish as you go down. By using a stub flute endmill you limit how much contact the tool has with the part. Time you add up putting something to the part and then removing it you will see it is faster just going this route to get unattended run time. 

 

There is a product call toolstone, but it is not cheap.

I'm actually doing something very similar on this (titanium), but I have extra material on the bottomside of the pockets, that becomes the topside of the final operation. That final operation, a contoured surface across the entire part, will remove that material I used to help support my thin wall waterline operation. That is where I'm going to have to control the vibration.

[crazy^millman]

I'm actually doing something very similar on this (titanium), but I have extra material on the bottomside of the pockets, that becomes the topside of the final operation. That final operation, a contoured surface across the entire part, will remove that material I used to help support my thin wall waterline operation. That is where I'm going to have to control the vibration.

 

Okay well that is different and in that case where previous machining operations are coming into play you have to either design a fixture to support your part if doing production or put stuff in it to damper like you have asked originally. That is where not seeing it can lead to different directions, but hopefully this topic gives some food for thought to others.

[Pilot Plant Supervisor]

Everything from rubber rope and duct tape, to Nerf footballs here.

[So not a Guru]

Babbit putty (bear shyt) unfortunately not available any longer due to it contained asbestos. Deacon mold pac?? Is a good replacement for it.

Right now, I'm intending to try fusible alloy, using Mold-Pac to dam the area I'm pouring in.

[Matthew Hajicek - Singularity]

Just hold your finger on it while it runs.

[jeff]

 to Nerf footballs here.

Do you use the kind that whistle when you throw them? 

[absolute technologies]

Tool stone is not expensive as Ron said. It's similar to plaster of paris, pink in color not white, it doesn't nut up as quick so it gives you more time to work with it. You can clamp on it with good medium force and it doesn't grow or shrink much and doesn't absorb much coolant.

 

and yes we used to use babbit putty (de-orderized bear shyt) until we found out it had asbestos as its' main ingredient so we now use Deacon Mold-Pac to built damns and moats to contain the tool stone. If you're filling pockets up for support I would start with the putty because tool stone will be much harder to take out when you're done but would provide much better support however with a slight draft as suggested that would help release the tool stone otherwise we just break it apart to get it out. The putty doesn't hold up as well with oil/coolant but in your case it would be underneath so it might not get wet at all.

 

Cheers!

Len

[Matthew Hajicek - Singularity]

I've been using a Nerf dart to hold the spare SSD in my laptop.

[crazy^millman]

Tool stone is not expensive as Ron said. It's similar to plaster of paris, pink in color not white, it doesn't nut up as quick so it gives you more time to work with it. You can clamp on it with good medium force and it doesn't grow or shrink much and doesn't absorb much coolant.

 

and yes we used to use babbit putty (de-orderized bear shyt) until we found out it had asbestos as its' main ingredient so we now use Deacon Mold-Pac to built damns and moats to contain the tool stone. If you're filling pockets up for support I would start with the putty because tool stone will be much harder to take out when you're done but would provide much better support however with a slight draft as suggested that would help release the tool stone otherwise we just break it apart to get it out. The putty doesn't hold up as well with oil/coolant but in your case it would be underneath so it might not get wet at all.

 

Cheers!

Len

 

I can only go by what my customer who uses it tells me. You are telling me something different so thanks. Good suggestions also.

[So not a Guru]

Just hold your finger on it while it runs.

You ain't right son.

[crazy^millman]

I remember over 20 years ago using a stick to dampen parts on a lathe. We would start the threading passes and then push the stick against our hips and rid the part till the end of the cut and repeat for the 30 passes it took to cut the part.

[Newbeeee™]

We do a lot of thin wall parts and when it's a problem we use a seco (jabro)hemi cutter. They are 2x flute and slow helix, but with a great hook.

They look like the old style router tools and because they are slow helix, they don't pull the base of a part up, or pull the sidewall in.

[taperlength]

I remember over 20 years ago using a stick to dampen parts on a lathe. We would start the threading passes and then push the stick against our hips and rid the part till the end of the cut and repeat for the 30 passes it took to cut the part.

Used to use a big lead hammer for that. Just rest it on top the part.

[Mick]

I remember over 20 years ago using a stick to dampen parts on a lathe. We would start the threading passes and then push the stick against our hips and rid the part till the end of the cut and repeat for the 30 passes it took to cut the part.

 

 

Used to use a big lead hammer for that. Just rest it on top the part.

 

Haha, I've used both those methods back in the day. Times sure have changed