Through Coolant project

[northwest]

Finding myself with a good few through coolant bits I thought it would be a good idea for me to actually use them for the purpose designed. I forget who but there is a very good youtube video out there about making a through coolant retaining bolt for the Mill. Most of my deep hole drilling and trials and tribulations happen on the lathe so I thought I would stick with that.

First up was the purchase of a suitable ER32 3MT arbour. Then a tang insert from ARC Eurotrade: https://www.arceurotrade.co.uk/Catalogue/Chucks/Drill-Chuck-Arbors/Screw-In-Tangs so then to modify it to take a spigot I had turned up earlier:



After I had fitted the spigot I found it intruded a little into the back of the Collett housing so I cleaned it out with the die grinder, turned out fine:



But then I needed a resevoir a return tank and associated pipework. The simple answer is a 20 L drum a hole cut in the side and a small (cheap) pond pump:



Feed and return in silicone tube. This is how it looks all fitted up:



All ready to go. The Colletts of course are Coolant rated so they don't squirt coolant everywhere and it goes down the tooling. I have made a small catch tank to return the coolant to the "reservoir". I am very hopeful this enables me to cut stainless and titanium with less hassle, we will see.

 

[northwest]

Found it. This is the drawbolt through coolant mod which I think is very cleverly done:

 

[Agroshield]

Is there a through hole in the collet chuck? If so, perhaps wind some PTFE around the threads of the screw-in tang or it might leak.

You might need a flow regulator in the line. Right now you have two settings: on or off.

 

[northwest]

The colletts are marked ERS XX so ER SEALED colletts so if you are looking for through coolant collets be sure they are the right thing or you will have coolant everywhere except down the tooling.

 

[northwest]

Is there a through hole in the collet chuck? If so, perhaps wind some PTFE around the threads of the screw-in tang or it might leak.

There is indeed and an O ring and locktite has dealt with that. As for your other comment of a flow regulator or control valve, this is a good idea but I want to get it working first then work on the finer points :-)

 

[Erie Fred]

Not so much a regulator I would say, rather a relief valve at the pump plumbed back to the tank.

FWIW one of the first hi-pressure systems (one was made nearby called chip blaster) used a simple triplex
plunger pump for a car wash, CAT brand.

However having 1000 psi might be a bit much in your application......

 

[Agroshield]

Not so much a regulator I would say, rather a relief valve at the pump plumbed back to the tank.

Most OEM coolant systems on a manual lathe use a simple centrifugal pump and a tap to regulate the flow (rather than a positive displacement type). I do not think the pond pump he is using would suffer if the tap is switched off, so the relief valve is maybe unnecessary in this set-up.

It would be good to invent something automatic that does not allow the coolant to flow until the tip of the drill is 1mm inside the workpiece and switches it off at the same point when withdrawing.

Perhaps give the system a dead head test (like a solid drill in a collet) before starting something too serious - you want to confirm the hose will not blow off the fitting in the tailstock when maximum back pressure builds up.

 

[dieselsamurai]

this guy did an interesting one for a milling machine

 

[Erie Fred]

Most OEM coolant systems on a manual lathe use a simple centrifugal pump and a tap to regulate the flow (rather than a positive displacement type). I do not think the pond pump he is using would suffer if the tap is switched off, so the relief valve is maybe unnecessary in this set-up.

It would be good to invent something automatic that does not allow the coolant to flow until the tip of the drill is 1mm inside the workpiece and switches it off at the same point when withdrawing.

Perhaps give the system a dead head test (like a solid drill in a collet) before starting something too serious - you want to confirm the hose will not blow off the fitting in the tailstock when maximum back pressure builds up.

So has pretty much every manual lathe I have used.

Coolant thru the tool needs higher pressure, or the chips will plug the holes.

automatic valve ? How automated is this going to get ?


Just make a simple DIY chuck splash guard, as the chips & coolant is going to fly even when the tool is in the piece.