Dampened holder for endmills

[Leon82]

Any recommendations for a dampened milling chuck for endmills? 

 

Do they perform better than a shrink fit?

[crazy^millman]

Many things to consider before saying one over the other. Size of tool, Gauge Length, Spindle Taper, RPM and other things before saying I will go to the Dampened holder. Yes they do what they advertise, but yes not cheap.

[Colin Gilchrist]

https://www.sandvik.coromant.com/en-us/products/silent_tools/silent-tools/pages/milling.aspx

Look about 1/2 way down that page for a dampened versus regular tool chart...

[Leon82]

.25 to .75.

Sticking out about 4".

3" approximate gauge length. 

Finishing. Deep pockets. My boss was having me look at the Nikken dream holder

[nickbe10]

Dapra make carbide cored insert holders.

True 90 degree cut

[robk]

We use a ton of dampened holders here. Most are super long dampened bars from Sandvik. It's their silent tool line. In our case they accomplished what non dampened holders couldn't do.

[crazy^millman]

16 hours ago, Leon82 said:

.25 to .75.

Sticking out about 4".

3" approximate gauge length. 

Finishing. Deep pockets. My boss was having me look at the Nikken dream holder

What is the spindle taper and if a CAT spindle is it a dual contact? If not there is half of your issues before even looking at using a tool like this.

[Leon82]

5 hours ago, crazy^millman said:

What is the spindle taper and if a CAT spindle is it a dual contact? If not there is half of your issues before even looking at using a tool like this.

It's a bt40 big kaiser spindle on an mx850

[jslaero99]

Not sure to understand the 3'' gauge length with 4'' stickout but over 4XD stick out, problems start to occur. You'll see that they're not really expensive if you really need them, otherwise, you'll have to slow down you parameters a lot... Used Sandvik a lot with good results.

[crazy^millman]

Okay that is not a long stick out then. I thought were talking about some of the 15" long tools with holders I have run on HSK-63A at 15k rpms and 200 ipm. I am running some 8mm tools right now with a total gauge length of 206.5mm(8.13")  and some barrel tools at 232.19mm(9.14") and part is turning out like a new penny. Speeds and feeds are 12k rpms with 2880mm/min(113.39"/min) on the ball endmill and 8000 rpm and 1440mm/min(56.7"/min) on the barrel from tool taking 1mm steps. I have some tools with gauges lengths of 283mm for some drilling my longest endmill gauge length on this current project is 265mm(10.43") with a 12mm x 2mmR bull endmill sticking out of a shrink extension 65mm that is sticking out of a Hydraulic chuck 120mm.

 

(Off Topic) I didn't double shrink this one because Kennametal refused to warranty the double shrink on the KM4X63 holders they make. The specifically state must shrink carbide into them etched on the side of the shrink fit holders. I called and they said it should work, but if it didn't the end customer would be out a holder if we couldn't shrink the shrink extension into their holder even thought it was their shrink extension and holder.

 

(On Topic) Point is adjust speeds and feeds until you find the sweet spot sometimes slower is not better. I will keep kicking up the feedrate to see what happens. If I am already maxed out on RPMS then I start slowing down and see where the residence and harmonics are the best. That just takes good old fashion observation. 

[Leon82]

2 hours ago, jslaero99 said:

Not sure to understand the 3'' gauge length with 4'' stickout but over 4XD stick out, problems start to occur. You'll see that they're not really expensive if you really need them, otherwise, you'll have to slow down you parameters a lot... Used Sandvik a lot with good results.

To me gauge length is a holder dimension from the spindle gauge line to the end of the holder. 

[Newbeeee™]

Depending on application....I've mentioned before that in a couple of times the only thing that worked for me was an ER25 holder. Schunk hydraulic, Showa micron chuck, shrink, all rang like a church bell. ER25 was quiet as a mouse.

Just checking and these parts were ally, and the tools were:-

6mm Dia 2Flute x 7mm LOC x 88mm relief x 130.0mm O/A  - 90mm out 
10mm Dia 2Flute 40Deg x 10mm LOC x 90mm Relief x 130mm O/A - 90mm out

Harmonics are a funny thing....
 

[jslaero99]

On 2/18/2022 at 11:36 AM, Leon82 said:

To me gauge length is a holder dimension from the spindle gauge line to the end of the holder. 

Ok, now I get it, f or me, gauge length is from spindle to tool tip (as in image) that's why I was confused.

[crazy^millman]

17 minutes ago, jslaero99 said:

Ok, now I get it, f or me, gauge length is from spindle to tool tip (as in image) that's why I was confused.

What it has been for me going back to the V9 days when we didn't have G43.4 and G68.2 we always had to know the gauge length and change the posted code anytime that changed. Why is surprises me that Mastercam machine sim still cannot support Gauge Length for holders and we have to chop off the taper when building holders to use it. Still cannot support holders correctly for MT either have to chop off the tapers there also.