Through Tool Coolant Mod

[number40Fan]

I hadn't seen this anywhere on here, so I figured I would toss up a picture.

I hadn't yet sealed all of the threads on this picture so there is leakage in a few spots, but it works very well now.



Also...notice the leak from the turret?

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[jeffrey001]

Nice setup, I wanted to do the same thing for quite some time.

I would try to add a pneumatic cylinder near the turret coolant hose, and use the cylinder to send coolant on the back of the drill holder (using the USB board), that way, it could be a permanent set up.

Could you post a couple more pictures.

Thanks for sharing, Jeff

[deadlykitten]

I would try to add a pneumatic cylinder near the turret coolant hose, and use the cylinder to send coolant on the back of the drill holder (using the USB board), that way, it could be a permanent set up.

hy jeffrey, please, i don't get it : thus there is coolant inside the turret, but there is no coolant for the drill ?! and if one would use a pneumatic cilinder, then won't it achieve discontinuous cooloant flow ? however, there should also be a pressure relief valve, etc, to avoid pressure build up

---

hi 40, please, i don't get it, what's the idea behind your post ? did you modified something ?

I hadn't yet sealed all of the threads on this picture so there is leakage

i would also recomand:
... using an o-ring on the sleeve neck
... if necesary, increase contact surface between the toolholder and the back cover, by decreasing surface roughness : i preffer to grind them

on my id holders, are 4-8 threaded holes, but in most cases i only use 1-2, so inside the ones that i don't frequently use, i have some bronze screws :
... length is in such a manner, that they get close to the inner bore, like <1mm radial clearance, in order to avoid the case when chips get inside the empty toolholder, thus they may get inside the bore, and from there to the threaded hole; how the bronze screw end is almost near the bore, then is easy to inspect and see 'wild' chips inside, and also, is much harder for small chips to remain stuck inside the threaded hole; like this, can be avoided downtime with adjusting marks leaved on sleeves or inside the bore, because of small chips; such marks are nasty, especially when play is low, and materials are soft
... they have a groove for a normal screwdriver
... the diameter of the head of the screw is a bit bigger then the thread, and there is a cone between the thread and the head, thus the screw, when is rotated, will end with making contact on the cone : this is the trick to prevent coolant going in, or out, from the toolholder; well, there is still a lick, but small, thus coolant is not being splashed, but is leaking/sticking on the surface of the holder, because of fluid surface tension
... because they are other color then the normal screw, also because they require a normal screwdriver while the normal screw requires an allen key, and because they are shorter, then is possible to avoid the case when an operator is tightening a screw that should not be tightened; such cases lead to marks, lead to deformation on sleeves with thin walls, and sometimes to having a hard time when pulling the damaged sleeve out from the holder

you may see such screws in this thread : https://www.cnczone.com/forums/okuma/362350-cnc.html

maybe seems to be a lot of 'text' for some screws, but prevention is better then adjusting sleeves, or damaging id bores, or putting a hammer on an aligned turret / kindly

[number40Fan]

First off, nothing other than the holder was modified.

1/2-14 pipe plug in the back. No drilling, just tapped it. Had to mill some of the plug off to clearance the plug from the turret housing.



Drilled from the top side down through the coolant port, coming into the holder from the turret, and down to the center bore of the holder. I think it was a 11/64" bit for the through hole. Then enlarged the opening with a 7mm bit and tapped for a 8mm-1.25 set screw.



Holes in the front with original nozzles. Removed nozzles, no drilling, tapped for 8mm-1.25 set screws.



Plugged the remaining holes with set screws.

[maker of things]

#40. Does there seem to be a way to address the leaking between the turret carousel and body? Or are we just going to go with "it helps keep the chips out" to feel better. My machine hasn't shipped yet but I plan to do this type of thing too.

[deadlykitten]

oh, i got it, i believe there was no coolant towards the back of the toolholder ...

if you consider, do a inner counter bore, thus inside, near the toolholder bore, so to avoid heaving the thread end near the bore, that may lead to demaging the sleeve / bore, if the thread end pitch will get "loose"; is dificult to adjust that area

each toolholder has it's own debit randament, and in most cases, the debit that comes out from the turret, is higher then the debit that comes out from the toolholder; randament may be 45-88%eq, thus depends on machine; if you wish to achieve higher debit, avoid turns, use bigger holes, and increase the number of holes; if you wish to check if it's worthy to do it, or not, then find these values :
... debit from turret
... debit from normal toolholder, without nozzles ( only front )
... debit from modified toolholder, without nozzles ( only back )
* compare those numbers ...

increasing the debit will increase tool life especially in deeper drilling, and when it comes to normal turning, also a lot of impact is made by the nozzles; for od tools, i use 2 coolant nozzles, one washing the top of the insert, and another being perpendicular to 1st flow, washing the bottom ... most machines are set-up to wash the top of the insert, but an important fraction of the coolant is not cooling the insert, but the chip ... this is very common, and few look into it, since toollife seems to be ok

all these are details, that make a difference

so far, between others, i have crafted & modified static and live toolholders, i have modified existing ones to increase their debit, or rigidity, or inner seal life spam, i have been replacing standard nozzles, i have looked into quick adjusting noozle types, etc ... hmm, just saying

Does there seem to be a way to address the leaking between the turret carousel and body?

hi, i don't know that machine, but there has to be a leak, somewhere, to avoid pressure build up

index the turret to a station that allows no coolant to go through ... the leaking that appears, is it normal? are the o-rings too old ? do you stop the coolant pump when indexing ? kindly

[number40Fan]

#40. Does there seem to be a way to address the leaking between the turret carousel and body? Or are we just going to go with "it helps keep the chips out" to feel better. My machine hasn't shipped yet but I plan to do this type of thing too.

There isn't any leaking between the holder and turret. The picture in the first post doesn't have any Teflon tape on any of the set screws so it was leaking from everywhere. Probably why it looks like it is leaking between the holder and turret. I even put some tape on the tool itself to help seal the bore.

My last statement in my first post was to point out the oil leak on the turret housing. Maybe I should edit that to make it more clear.

Edit: Can't edit the first post any more.

[maker of things]

Also...notice the leak from the turret?

This part

[number40Fan]

I was referencing the oil leak. I was probably editing my last post and adding that snippit after you already replied.

[deadlykitten]

hy, i was recently at someone who did a modification similar to what was discused here, and i remebered this thread

please find attached his approach

i hope it helps / kindly

[number40Fan]

New coolant through boring bar. 3/8" carbide CCMT.

Made the same mods as the first one except for the original coolant nozzles on the front had 10mm coolant bores behind them. I didn't have anything to plug them so I left the plastic bushings in and screwed in 1/8" NPT plugs (no taping required).



Next on the list is to replace that aluminum bushing with a steel version. Even though it is split to clamp on the tool, I have a hole drilled in the side of it so the holding set screw bears directly onto the tool. Still get more chatter than I would like.

[number40Fan]

I do wish this pump was higher pressure. Even though it isn't enough to push chips effectively, the coolant through tooling does get the coolant where it needs to be. Which is a lot more effective than the nozzles.

When using the indexable drill pictured in the OP, I do have to pause after drilling to manually blow out any remaining chips when using it with SS.

[deadlykitten]

Since these tools generally have some pretty small passages

hy, the size of the inner bore is dependable on the material from which the tool is crafted, and, generally speaking, there is low quality steel 3d, high quality 5d, vhm 7d, and some vendors may have a tool with bigger inner dia

another method is to craft your own tools, also to start with a bigger bore near the far-end, and size it down near the top/cutting edge; i recently messed up with an inner roughing tool, chaning the way it clamps the insert, as shown in attached image ( from external clamp w/o ik , to inner lever + ik )

I'm doing this primarily for deep hole work such as boring & drilling

higher pressure, for drilling, is ok, but for boring, it may be a problem, because you may still end up with all your chips inside the bore(when drilling, chips are forced towards the entrance, but when boring, chips are forced forward), especially for deep bores, so, my advice, if you have through holes, is to drill on 1st chuck, and bore on 2nd chuck + tsc; thus, if you wish, consider coolant through spindle, so to always wash the chips away

For drilling I found this guideline

yup, very good, definetly state-of-the-art

So I was planning on adding a high pressure pump

when it comes to small tools, if you will use a pump with more debit, like 2 times more flow, you may not get 2 times more flow also through the tool

my advice is to maximize the flow of your current setup, because there may be a huge debit loss, only because of the way the coolant goes through the toolholder; on one machine, i can tell for sure, that the loss is 10-56%, depending on toolholder; to maximize the flow, consider bores with bigger diameter, and less joints/less direction changes; you may also consider a method that delivers the coolant from the turret, directly to the back(or the nose) of the tool, without passing through the toolholder, so to avoid entirely the loss caused by the toolholder

if you would have all these, then is possible with your current pump, to achieve a coolant flow that is higher then when adding a 2nd pump

if you wish to improve the flow, then is good to know the randament of your current system, and also where the randament drops, and why

another advice, is to try to add another identical pump(or 2 more) inside your coolant tank, near the one that you allready have; you should also check how your actual pump works, because, on some machines, they are not submerged properly, and also, the coolant tank is not that deep in the area where the pump is; actually, this is the idea behind high-coolant-pressure-pumps : a normal pump is filling a tank that has a higher level of coolant inside it, because the high-pressure-pump has more elements on it, and it requires all of them to be submerged; extra coolant ( like coolant that can not pass through a small tool ) is not recycled to the main coolant tank, but to the 2nd one, and when the 2nd one gets filled, it recycles to the 1st/main tank

all these are details, but is the way it works; if there is too much pressure, you may end up blowing the joints inside the turret, etc

but, before considering all these, i would definetly disconect the hose from the main pump, and connect it to the harser, only to see what happens / kindly

[number40Fan]

Next on the list is to replace that aluminum bushing with a steel version. Even though it is split to clamp on the tool, I have a hole drilled in the side of it so the holding set screw bears directly onto the tool. Still get more chatter than I would like.

I made a bushing from some SS and that took care of all chatter I was getting!

New problem. Through tool now means through spindle! Most of the pieces I am making lately have a bore through them and coolant is now being pushed through the spindle bore and out the back. I rigged up a temporary plug for it and will make a proper o-ring sealed version tomorrow.

I remembered having a 1/2 HP sump pump that I hooked up to it temporarily as a test. Quite a bit more pressure and definitely more flow. When I get back to making the parts that aren't through drilled, I'll give it another try and see if that helps with chip removal.

[deadlykitten]

Through tool now means through spindle! Most of the pieces I am making lately have a bore through them and coolant is now being pushed through the spindle bore and out the back.

hi 40, i don't know your machine, but on many cnc lathes there are all these :
... a hose on the back of the spindle, so to allow the coolant that is reaching the back of the spindle, to go back into the main tank
... just before the hose, there should be a sieve that collects the chips that are coming from the back of the spindle, so to prevent them for reaching the coolant tank
... on the back, there should be 2 covers :
...... one on the back of the spindle, that is rotating with the spindle arbor
...... one on the back of the hidraulic cilinder, that is stationary, thus it is not rotating with the arbor
* if you remove the 1st cover, then coolant may hit the 2nd cover, from where it is redirected to the sieve + back hose
* 1st cover does not have an o-ring
* 2nd cover may have an o-ring

if you wish, share a photo, from the back of your spindle; you may no longer have those covers, but is possible that you have the tapped holes

I rigged up a temporary plug for it and will make a proper o-ring sealed version tomorrow.

plugs with o-rings are generally inside the chuck, not on the back of spindle

main idea is to prevent coolant from getting inside, but, if the coolant is inside, then it must have a place to go, and if you use a plug with o-ring in the back, then it will prevent coolant from draining, and, if you are machining, then voila, you will always have coolant inside ... some cnc producers don't recomand this method of machining, thus they don't recomand having coolant inside, because, in time, it may find a way through, and it may damage the hidraulic cilinder; the effects of such a setup do not manifest imediatly, but they are rushed when there is used a spindle liner that is not designed properly

in short, if someone is running a long term setup, with a weird spindle liner, he may get into trouble so far i managed to craft several types of liners, allowing to machine materials that are longer than the spindle, without vibrations, etc

Next on the list is to replace that aluminum bushing with a steel version. Even though it is split to clamp on the tool, I have a hole drilled in the side of it so the holding set screw bears directly onto the tool. Still get more chatter than I would like.

it may be possible to avoid chatter, with an aluminiun sleeve, by avoiding to split it, but still having the window that allows the screws to clamp the tool directly

if you are using split sleeves, on the long term, you may damage the bore of the id holder, but, however, you may use a split sleeve, inside a bigger one, that is not splitted, especially to clamp tools with small shanks; to protect your holder and tools, on the long run, avoid split sleeves

i don't recomand clamping the od of the sleeve, because this may damage the sleeve, induce ovality etc, thus whenever possible, clamp through the window ( those drilled holes ); however, is safe to clamp on the sleeve, only when there is a flat, and a small shank is clamped, thus only when the sleeve wall is thick

i don't recomand clamping the tools directly, on their shank, because this may damage the tool shank, making it hard to remove from ( put back inside ) the sleeve; this is not a must for vhm shanks, because is harder to create a mark on them, but it helps with soft shanks, that are easy to scratch : i use an intermediate part, thus the screw is pushing this part against the tool, and like this, i always protect the tool

after years of service, the sleeves still enter smooth inside the bore, and tools are entering smooth inside the sleeve; sleeves are from steel, 28-32hrc; at lower hrc they are too soft, at higher hrc they loose the capability to damp vibrations; you may put an o-ring between the sleeve and the toolholder, so to prevent coolant leakage

i hope it was useful / kindly

[maker of things]

Based on your mod, but am trying a few variations. I hand drilled from one coolant in port to the unused side set screw hole and I am trying a press fit plug in the 3/4 bore. This will be for a micro 100 quick change tool holder.

[number40Fan]

That's a good idea. A 3/4" freeze plug would have been an easy route to go.

[number40Fan]

Had another idea. Not really coolant through, but more direct coolant.

Instead of using the nozzle for the boring bars, drill bits, threading tools, drill out the bushing used to hold the tool in the tool holder.

2, 3, 4+ coolant channels from the back side of the bushing towards the front. Taper the front 10°-15° (whatever needed to hit towards the end of the tool) to help give a flat spot to drill the angled section of the channel. Drill the exit holes, flip it around and come in from the back side with through holes.

Patent pending..

[number40Fan]

Just thought of something that would be even easier.

Put the channels along the outside so you won't be needing to drill deep with a small hole. Can just mill them in.




BTW, if you haven't drilled a 4" hole on the right side face of the door (just above the H), installed a rubber flap on the inside, you don't know how much easier it is to clear chips while the lathe is running!!

[deadlykitten]

Instead of using the nozzle for the boring bars, drill bits, threading tools

me again

boring bars have a flat : once you put them inside the sleeve, coolant will come between the flat and the sleeve

drill bits, taps, etc, may be used inside an er chuck + unsealed collet, or collet with peripheral cooling ... also, for such tools, the collet acts like a dumpner

thus no nozzles, no modifications, only standard sleeves used ... the single expensive thing is the er collet with peripheral cooling, and you may get a normal metallic sealed one ( that is much cheaper ) and modify it on a edm machine

Taper the front 10°-15° (whatever needed to hit towards the end of the tool)

this will work only for a specific tool overhang, and coolant flow won't be focused and powerfull, but only present

also, if you start to drill / mill ( in order to modify your sleeve ), you may reduce the coolant flow, unless the hole size is close to the size of the hole that is inside the turret

yes, many people think about it, and they conclude that this is not true, a smaller hole means that they will achieve more pressure no, actually the pump will start to send coolant back in the tank, through the safety pipes, that do not allow pressure build-up

Taper the front 10°-15°

adjusting nozzles may be time consuming ... if you wish to modify something, i would advice you to use adjustable coolant nozzles, that do no require to untight a screw, adjust, then tight the screw back, but are using a friction play, in order to stay in place ( pls check attached )

some capto toolholders are using a very minimalistic approach, having an andjustable noozle that is burried inside the holder, thus is harder for chips to hit it ( no need to buy the holder, but only the spare parts ) / kindly