Through Spindle Coolant Retrofit?

Has anyone though of trying to rig something up to get through spindle coolant on a tormach?

I drill lots of deep holes with tiny bits (1/16 - #60, 0.5-1.25" deep) in SS and nickel, and pecking is taking FOREVER.

My thought was to drill out a hole in the draw bar (send it out to get gun-drilled), tap the top for a deublin rotary union (this would require some bushings to keep the draw bar runout low inside the spindle cartridge), and tap the bottom for an extension.

The extension would would be inside the R8 collet, so a TTS ER tool could get inserted like normal, but the extension would end up inside the cutout on the back of the toolholder shank. I figure if I designed the extension right (plastic tip or something to that effect), i could get it to expand under pressure and catch the lip on the toolholders, creating a seal. If my math serves me right, if i keep the connection between the extension and tool holder to 1/4" diameter, i would only apply 74 lbf of pullout force to the tool at 1500psi max pressure which should be manageable. I have an SC hydraulics air-driven liquid pump lying around that can get me a few coolant at >1000psi using shop air-.

I'm I crazy for thinking this is feasible?

If anyone thinks I'm not a lunatic and it might be plausible, I could draw up my concept to get some feedback. I just keep seeing videos of TSC drilling- full speed feeding, finishing drilling cycles in 20 seconds that are taking me 20 minutes... And breaking a #60 drill off in the last .010 of the last operation of my part got old real fast...

-Michael.

Can you get through-coolant drills that small?

What about a gun drill with fluid coupler outside of the spindle?
Drilling Systems from Sterling Gun Drills

There are coolant inducers for larger sizes. It should be possible to reverse engineer one.

Coolant Inducers - BIG Kaiser

bob

The biggest hurdle would be FULLY enclosing your machine.
Unless, of course, you like coolant dripping down on you from the ceiling all day. :)

Quote:

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Originally Posted by RussMachine

The biggest hurdle would be FULLY enclosing your machine.
Unless, of course, you like coolant dripping down on you from the ceiling all day. :)

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Not to mention the safety issues that go along with anything at 1500 PSI... At that pressure, a pinhole leak can create a stream that will slice right through you like a scalpel.

Regards,
Ray L.

Mitsubishi makes TSC tools well under 1/16" (micro-MWS, as small as 0.020" or 0.5mm).

I looked into coolant inducers (buying and building). The biggest problem with buying is the custom nature of R8 or 3/4" shank (TTS type) results in the part being $2.5+k each from Big Kaiser. They also do not support anything over 300 psi. Inducers use O-Rings, and i could not find any companies willing to sell me a custom o-ring that can handle the P*V that I want (checked with AHP seals, Bal Seal, Kalsi, Trelleborg- basically every high end rotary seal company and they all returned No-Quote, or said i might be able to get a few minutes to an hour of use per seal (at $75-$150 each, and 2 seals per unit)).

Rotary couplers (like one one on full VMC's TSC systems) use mating carbide plates, so they can handle the high P*V required for tiny drills (1500psi at 4-5k rpm, or more). These can be purchased, the retrofit is what I am looking at (UNION POPOFF 5/8-18UNF RH .655 | Deublin Company this would allow dry running if you want to use flood coolant instead of TSC).

Tormach is releasing a full enclosure in the coming weeks- not sure if it will be sufficient, but it might be a start.

And as for the dangers of high pressure, I work with analytical instrumentation (this is my companies mill) and we routinely pressure check our welds / brazed joints to 5-6k psi, so while it is a serious concern, we have the skills required to deal with it.

I'll whip up a drawing with some more details of what i was thinking.

Thanks for the feed-back,
Michael.

Hi all,

I have done some design work on this, and have come up with some ideas to use the TTS system and keep the possibility of maintaining ATC functionality, but they are a bit complex (using the coolant pressure to pressurize the seal, moving parts, etc). I though a good intermediate step would be to use a stock R8 ER collet and rig up the TSC with that.

I would bore/gundrill the draw bar, and tap the top for a deublin rotary coupler. The draw bar already threads directly into the R8 collet, so i should be able to get coolant directly to the R8/ER16 collet.

My problem is that while i can find TSC drills down to 0.020", I cannot find a ER16 nut/sealing disk that will work under 1/8" (you can get 1/8" and above anywhere, maritool, kennametal, rego-fix, etc, but no-one seems to stock anything smaller).

Short of trying to make a sealing disk (my lathe is garbage: over 0.002" TIR) does anyone know where to source these nuts and the associated sealing disk in smaller sizes? I would need at least 1/16" sizes to even spend the money to try this, but need to be able to accommodate 0.040" sizes to really make it cost effective.

Thank you in advance,
Michael.

Never mind, reviewing the micro-MWS drills showed that they are all 1/8" shanks, so a standard sealing disk and/or sealed collet will be fine.

That said, they do recommend "thrust bearing" type collets (page #33 of: https://www.mitsubishicarbide.com/mm...df/b/b095a.pdf ), looks like some sort of dead stop. I have yet to find one- I'll keep this thread updated as i search in case anyone else is interested in a similar modification.

-Michael.

Please keep us updated. This would be an incredible upgrade.

Quote:

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Originally Posted by MLaVigne

...they do recommend "thrust bearing" type collets.

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Aren't they referring to the collet chucks?
"Thrust bearing type collet chuck holds the mill securely"
I know nothing at all about through spindle coolant so I could be wildly wrong, but aren't they referring to simple bearing collet nuts like these:
ER20 BEARING COLLET NUT MariTool
Step

Could be, so it just eliminates the rotational force when you tighten the nut? I guess that would only leave thrust force... thus the name...that would make sense...

That would mean i could use a Maritool ER16 bearing nut for $43, and a Rapidkut (never heard of them, but that's not surprising) sealed 1/8" ER16 collet (good to 2000psi) from MTS for $39, and a T&O (also never heard of them) R8 ER16 toolholder for $135, also from MTS.

So each tool that you want to keep set up will cost $217 (and drills cost ~$140 in the crazy small sizes i need so $357 each). Given that my current peck cycles can take 5 - 20 minutes and the cycle time would decrease to <20 seconds, at a shop rate of $80 an hour I need to drill at most 54 holes to make each toolholder worth it.

This has good economics for me- does this still look like a feasible upgrade for you GJeff? Thats not even including the new draw bar ($???) coolant inducer ($200-600 depending on the if you want auto shutoff, air and liquid selection, etc) and pump (i have one already but i think air driven piston pumps would be the most cost effective solution and they run $1-2k if i remember correctly).

-Michael.

Perhaps I should have said, "This would be an incredible upgrade for me to see someone do."

Drilling holes much faster is not something I'm willing to shell out much money for, but I love to see people push their Tormachs to new heights. I'm more interested in the potential to use it for longer, straighter holes with gun drill type bits.