Adding coolant wash down gun and pump

[Kapster]

I'd like to add a wash down gun to our new DMG Mori NLX lathe, I got a $4000 quote for the factory setup so think I can figure out something diy.

I'm thinking adding a pump will be the best thing but open to ideas. I've read of many guys adding a three way valve, been awhile since I tried but I believe it won't let you run the coolant with the door open without holding the idiot button on the side of the control. Bypassing the door overrides is not going to happen at our company either.

I've also seen guys put a switch to the pump contactor to turn the pump on without going through the control. This would be another option but not sure we're comfortable messing around with a brand new machine.

So if we add a pump, how big is big enough? I don't have much to compare to, our Haas mills have 3/4 hp pumps. The one has a 3/8 wash down hose and the other a 1/2", the extra flow is noticeable with the 1/2" but really the 3/8 is plenty. So I'm thinking either one is probably restricting some flow.

Would a 1/2 hp pump be enough? Not much more to get a 3/4 but don't want to go overboard.

Any suggestions on brand/type? The grundfos pumps I'm looking have a bronze or composite impeller, my hunch is to stay away from the bronze as our coolant turns smirf blue when exposed to brass/copper/bronze.

Thanks!

 

[13engines]

I have a Mori with a pallet station that has a separate wash down pump. It's operated by a small microswitch that is opened and closed by removing and replacing the hose end affixed garden nozzle in and out of it's holster. This is a very simple device on each side of the pallet station. This switch of course operates the coil of a contactor and overload device that the pump is connected to. My only recommendation for this setup is to use a small turbine kind of pump and not one of the basic coolant pumps that has the coolant channels running up from the impeller base along the sides. Can never seem to get any pressure out of those I've tried. Here is a picture I took of that setup while tearing my machine apart. Although what follows is the better setup.



My favorite setup is simply adding in at an opportune place, a quick release pneumatic disconnect of the 3/8 pipe size to your existing coolant line. (On my mill it's mounted right up at the head where all the other coolant nozzles are.) Then get a length of hose that seems long enough to cover your bases. Put the male fitting on one end and a multi spray pattern garden hose nozzle on the other. I finally found one where Jet and Fan settings are one click away form each other. Very convenient when those are the only two I ever uses. This setup has been working brilliantly for around two decades. Oh... this operates form the control panel coolant pump push button. I have a picture of this connection, but am not at the shop where it is.

Dave

 

[Kapster]

I have a Mori with a pallet station that has a separate wash down pump. It's operated by a small microswitch that is opened and closed by removing and replacing the hose end affixed garden nozzle in and out of it's holster. This is a very simple device on each side of the pallet station. This switch of course operates the coil of a contactor and overload device that the pump is connected to. My only recommendation for this setup is to use a small turbine kind of pump and not one of the basic coolant pumps that has the coolant channels running up from the impeller base along the sides. Can never seem to get any pressure out of those I've tried. Here is a picture I took of that setup while tearing my machine apart. Although what follows is the better setup.


Dave

Thats pretty cool, thanks for the picture. What do you mean by a turbine style pump, do they make them for coolant or just a water pump? Is it important to have pressure for wash down?

 

[13engines]

Thats pretty cool, thanks for the picture. What do you mean by a turbine style pump, do they make them for coolant or just a water pump? Is it important to have pressure for wash down?

This kind gives great pressure. A very small one should do fine.



Unless the coolant tank is super full and this thing is up to its neck in it, I cant seem to get this kind to work for squat.



There may be other types that work as well. Thing is if you use the second setup I mentioned, and have a valve that can keep coolant from flowing through the normal coolant outlets, you don't need to install another pump because you use the main coolant pump that's already there.

Seriously, the whole setup might be two ball valves, a 3/8 pneumatic quick disconnect pair, some hose, a garden sprayer and a couple hose clamps. No wiring or motors to buy.

 

[Kapster]

This kind gives great pressure. A very small one should do fine.


Unless the coolant tank is super full and this thing is up to its neck in it, I cant seem to get this kind to work for squat.


There may be other types that work as well. Thing is if you use the second setup I mentioned, and have a valve that can keep coolant from flowing through the normal coolant outlets, you don't need to install another pump because you use the main coolant pump that's already there.

Seriously, the whole setup might be two ball valves, a 3/8 pneumatic quick disconnect pair, some hose, a garden sprayer and a couple hose clamps. No wiring or motors to buy.

Good to know, thank you! The main pump on the Mori is a 1100w like the first style you pictured, seems to work very well. I had wondered about those when looking through the catalog for the wash down, I will look into these.

If I'd go with the other size, probably just have to get a larger one? Our Haas has that style and its 3/4hp, seems to do well. Like you said, that style seems to be limited on psi.

I see grundfos smallest pump in that style is 340w, rated at 13gpm and 30 ft of head or 13 psi with a max pressure of 145. Pump literature is one of the most confusing things I've ever seen!

 

[D.D.Machine]

I have been using the 1/2 HP sump pumps from Home Dump ... just hook a garden hose to them and use a foot switch ,,,there is some big foot switches on ebay for like $60 that are like 20 lbs so they stay were you want them ... its more of a volume that you need than PSI...

 

[gkoenig]

Just curious, but is it really $4k just for the washdown gun? Or are you getting a whole cabinet washdown system and the gun is just one bit of the kit that isn't available on its own?

 

[13engines]

Good to know, thank you! The main pump on the Mori is a 1100w like the first style you pictured, seems to work very well. I had wondered about those when looking through the catalog for the wash down, I will look into these.

If I'd go with the other size, probably just have to get a larger one? Our Haas has that style and its 3/4hp, seems to do well. Like you said, that style seems to be limited on psi.

I see grundfos smallest pump in that style is 340w, rated at 13gpm and 30 ft of head or 13 psi with a max pressure of 145. Pump literature is one of the most confusing things I've ever seen!

I don't know what it was, but I tried 3 different pumps of the type mentioned and couldn't get squat out of any of them. Two that came with the Mori VMC and 1 small one I bought new off ebay. Even when I disconnected everything from the pallet station but the main hose and nozzle... weak.

Below is the setup inside my Mori machine. Here I added a separate vane valve as the pump is of the good type and way too powerful for wash down.



Here's my YCM machine. Doesn't need it's own valve as a overall system control valve is towards the rear, and the pump is not too powerful at full go. (It's the other so-so type.) This pic has the hose and nozzle too.



Dave

 

[Kapster]

Just curious, but is it really $4k just for the washdown gun? Or are you getting a whole cabinet washdown system and the gun is just one bit of the kit that isn't available on its own?

Good question, I'm not really sure what all it includes. I'm pretty sure it includes a separate pump and a button is placed on the touchscreen to turn it on. There is already a wash down between the sub spindle and turret so wouldn't think it would be anything else. I believe they just call it a wash down gun.

 

[Kapster]

I don't know what it was, but I tried 3 different pumps of the type mentioned and couldn't get squat out of any of them. Two that came with the Mori VMC and 1 small one I bought new off ebay. Even when I disconnected everything from the pallet station but the main hose and nozzle... weak.

Below is the setup inside my Mori machine. Here I added a separate vane valve as the pump is of the good type and way too powerful for wash down.


Here's my YCM machine. Doesn't need it's own valve as a overall system control valve is towards the rear, and the pump is not too powerful at full go. (It's the other so-so type.) This pic has the hose and nozzle too.


Dave

Thats a pretty cool setup, I'll see if I can make something work with the door interlock arangement.

 

[footpetaljones]

Thats a pretty cool setup, I'll see if I can make something work with the door interlock arangement.

I would tee the three phase from the line side into a separate contactor for your washdown pump. Tie the coil into 24VDC that is interrupted by a momentary push button. Hold the button to turn the pump on. Saves having to do anything with the door circuit.

1/2 HP will work fine. We put a circulation pump from McMaster on a lathe, with I think a 1/2" pipe feeding it with no problems. Part number of the pump was 99875K94. Between the pump, plumbing, motor starter, and electrical bits you're looking at around $1000. I'm cheap, so I'd get everything electrical from Automation Direct and might be able to get out for $800.

 

[Kapster]

Is this overkill, 3/4hp Grundfos pump rated 13.2gpm and 86.2 ft of head(37psi). This is the smallest motor they sell on this style pump, this is three impellers but also comes in 1 or 2. This is about twice the price of the 1/2hp regular pump, $800 vs $400. These seem to be rated less flow but more psi. The regular pumps seem to be rated crazy gpm but low psi so they probably don't make that much flow unless there is very little restriction.

MTC2-6/3 A-WB-A-AQQV - 98992928 | Grundfos product center

 

[bosmos_j]

Not sure what your setup looks like. My machine has a immersion pump like so: mcmaster. There's a flood coolant enable button on the control screen (Speedio). When it is on, the pump is running (no coolant going through lines at this point). Then, there is a valve that turns on with M08 for flood coolant. I have a garden hose teed into the line before the valve, so whenever the pump is running the garden hose has pressure. Cost about $50. I've also teed into this another line for DIY enclosure side wash downs. I get sufficient pressure running 2 of the 3 at the same time.

 

[M.B. Naegle]

We have 2 mills set-up with the 3-way valve method as they didn't care about the door being open, but an extra pump has a lot of merit.

IMO which pump is going to depend on how you are using the coolant. If you're just rinsing some tray chips down at the end of the day, a little generic sump pump works fine. You don't even need to wire it into the machine. We have one floating around the shop that can just be dropped in a tank and plugged into the wall. But if you're fighting with chips getting packed into T-slots or dried onto the sides, you'll need more pressure, probably something similar to the main pump on the machine.

(as an aside, rinsing the machine out at the end of every day rather than when it's convenient and keeping covers over open T-slots really speeds things up)

 

[andrewmawson]

I added wash down to my CNC Lathe by adding two solenoid valves and a manifold. Original coolant pump feeds the centre, and the solenoid valves divert flow to wash down or the tool turret.

I've added rungs to the PLC ladder logic so only one can be on at a time, wash down can only happen when spindle stopped and door open.

I deployed some un-programmed buttons on the control panel (Siemens 820T) to control the wash down feature

Works a treat

 

[Kapster]

This is a turning center with Y axis milling so don't take to deal with tslots. The lathe chips seem to take care of themselves pretty much but the milling chips seem to cling to surfaces. The main pump is a fairly good size pump(1100 watt). I'm curious if it has a solenoid valve like described on the speedio that kills the coolant on turret indexes instead of turning the pump on and off, interesting. I probably don't need a serious pump but want to make sure it has enough to work well.

Lots of good ideas, thanks!