Hydraulic Holder Failure

[MotorCityMinion]

Recently I have had 2 holders where the tools are pulling out. A.25 and 6MM dia. holder, while doing finish operations, HSM, .005 max stock, not heavy machining. We use e-mills with an H6 class fit. These tools have not been crashed nor do there appear to be any leaks. Tools were fresh, holders looked clean. Lock screw bottoms out, but I've read that this is normal. Any clues or tips?

 

BTW, these are fixed dia. holders.

[Watcher]

http://productnews.sandvik.coromant.com/us/#corochuck-930

[Newbeeee™]

MCM,

This is mad - especially a 6mm pulling out!

We use Schunk holders with collets and have never had a problem - the 14mm dia will be HS routing at F7500 with no issues (talking ally of coarse )

As for why with your prob - I would contact the rep or manufacturer to discuss.

 

Silly question thou and don't shoot me......is there any big cusps that you didn't realise were there so the tool over engaged??

Even so, I'd expect a 6mm to snap looooooooooooooooong before pulling out.

[MotorCityMinion]

Newbee, clever to think of that. Rgh at +.005 with a .156 ball in a collet on a Haas, no problem. Off to the Makino for finish work. 2.0mm is the smallest internal rad on the part so the rougher had the cusp scenario covered. 3.5mm ball, 6mm shank at +.002 in the hydraulic holder, 3.0mm ball finish in a heat shrink holder.

 

We use OSG tooling for finish work and the gussets are very small with these tools, there is very little clearance. Stock awareness is a priority. I thought there may have been a burp in the code but backplot, verify, and Cimco backplot with solid simulation, NC code, show no erratic moves. This also occurred while milling a horizontal feature with only .005 stock on it. Copy , paste the op from from semi finish to finish and change a few parameters done. The finish path was pristine.

 

By all rights, this tool should have snapped but it still looked good enough to rgh with. Funny how you can accidentally plow through a part and not have a tool snap. ( Is this how adaptive clearing got stated? ) LOL, who hasn't fat fingered a feed rate and knurled a flat face at some time in there career?

 

Laser weld , rgh again, then finish. No biggy on the rework but this happen on two different parts, different terrain. Now I'm spooked.

[Pilot Plant Supervisor]

I have had problems with cusps when using Surface High Speed toolpaths to rough with a ball endmill. If I use a bullnose, everything is fine.

[Mick]

http://productnews.s.../#corochuck-930

 

We just ordered a bunch of those chucks, and they arrived yesterday. I'm looking forward to using them

[Watcher]

We just ordered a bunch of those chucks, and they arrived yesterday. I'm looking forward to using them

 

We also ordered a few last week. It seems very promissing...

[mkd]

how small would you experts go on these fancy toolholders?

noticeable benefits compared to ER16/ER32 on tools as small as:

1/4"?

3/8"?

[MotorCityMinion]

3/16 all day long. My best reasons for using these: Run out then rigidity. I have not used anything smaller.

 

I've seen too many guys over torque the ER's and either spring the collet or ruin the nut. I resorted to stashing the new collets just to keep run out sane.

[mkd]

i find myself fighting chatter on 1/4" endmills using ER collets. just don't want to pony-up the dough if it would not help much.

 

vvvv edit; long length to diameter ratio vvvvvv

[Newbeeee™]

_{One big thing you would notice with hydraulics is tool life when drilling. Whenever we have steel jobs running we always use hydraulics and tool life is waaaay better.}

_{Also, we use schunk hydraulics - they are 'reasonably' priced and work very well.}

_{For out an out roughing, I'm leaning back towards showa micron chucks. They work really well with naff all run-out, but we went towards the schunk because they are shorter. But now we're hitting things a bit (lot) harder pull-out is a worry, and the showa chucks have way more holding than the schunk.}

_{mkd - chatter on a 1/4 endmill???? Are you sure you're running M03}