Oil coolant pumps – which type of pump

[Martin NewboldParticipant @martinnewbold]

Hi everyone which type of pump is best suited to pump oil coolant on to machined item . Are there specifics about the type of pump that is most effective to pump this and material around. Can a motor drive a pump pulley as well as the lathe head?

[Martin NewboldParticipant @martinnewbold]

[David George 1Participant @davidgeorge1]

Hi this is the type of coolant pump which I would recommend but you would need to have a tank with lid to support said pump. They are available in various sizes depending on tank depth and volume you need to pump and they come in single and three phase electricity supply. they work regardless for many years with little attention. I personally wouldn't run a pump from a spindle motor as it is not good to run coolant at the same time if anything goes wrong i.e. forgot to turn the coolant tap off it would take your concentration off the spindle work which could be dangerous and you could get wet with coolant. You would also need a control circuit with a no volt safety built it to the circuit.

David

 

Edited By David George 1 on 21/01/2017 18:08:45

Edited By David George 1 on 21/01/2017 19:14:19

[Nick HulmeParticipant @nickhulme30114]

Most commercial coolant pumps work on the same principle as pond pumps, I suspect that pond pumps may not be compatible with all types of coolant though.

[Brian HParticipant @brianh50089]

I have a Vertex pump in a self contained unit similar to this from Rotagrip:

01a) Coolant Pump Kit 1/8 HP

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Price per Unit (Each): £192.30
£153.84 (including 20 % tax)
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Vertex 1/8HP Coolant Pump Kit

Fully combined unit consisting of a single phase 1/8 hp pump , flexible feed pipe, bracket to secure to your machine and magnetic base with coolant hose. This unit is ideal for the small to medium size lathe or milling machine

Specifications

Tank : 14 x 10 x 7.5"
1/8 hp motor
240 volt or 110 Volt

Capacity : 27-28 l/min @ 1m / 25-26 l/min @ 2m
Height excluding stem : 160mm
P.C.D. of mounting holes : 128mm
Diameter of impellor body : 92mm
Diameter of flange : 155mm
Outlet : 3/8NPT

Part Number 1026-030

Click here for data sheet

Brian

[Mark EisenParticipant @markeisen61287]

I am going to a washing machine pump, seen some good set ups on an Aussie forum.

[davebParticipant @daveb17630]

I bought a used surface grinder a while ago, the PO had cobbled together a coolant system with a washing machine pump, the oil had caused all of the rubber parts to disintegrate.

Dave

[ScrumpyParticipant @scrumpy]

My Mitchell lathe 8 1/2 swing X 10 ft bed has a built in pump being run from the main motor it also has a pressure valve to bypass the system some years ago it failed so we fitted a washing machine pump after adjusting the bypass it works perfect

[Martin NewboldParticipant @martinnewbold]

Hi everyone and thank you for the posts am looking for a small pump for a self build on a small lathe. My post was in relation to the types of pumps as there is a lots of types usually gears are used for oil pumps and not an impellar or propellor. I am wondering if there are any small pump motors that use gears to pump. This is a water pump but i wonder if they make metal pumps at this site . Does anyone know the viscosity of the cutting liquid please?

 

I was thinking of something like this 

Edited By Martin Newbold on 29/01/2017 11:57:15

[David JuppParticipant @davidjupp51506]

Big advantage of centrifugal pumps is they are contamination tolerant, and will tolerate being 'shut in' on delivery side (for a while anyway). Depending on precise detail, delivery head may be a bit low (e.g. aquarium style).

Gear pump is possible, but prone to wear – quite expensive because much more difficult to manufacture. Won't be at all happy if shut in on delivery side, they are a positive displacement type and can generate high pressures.

Old fashioned fuel lift pump is another possibility. Contamination may give issues with the check valves, won't mind being shut in, as diaphragm is actually pushed back by a spring not the cam.

I bought a cheap mains solenoid pump to try – rather noisy, and again valves potentially prone to contamination problems.

Gravity feed is effective for some people – very simple.

Good luck!

[Martin NewboldParticipant @martinnewbold]

Whats sort of pressure does the cooling pump ideally need to deliver?

[David George 1Participant @davidgeorge1]

If you were to get a pump with 25 litre a minute at 2 meter head you would have a reasonable pressure to flush down a drilled hole with a small bore nozzle and if you turn off the tap without turning off the pump you would be better with a centrifugal type as there will be no increase in pressure with that type of pump.

David

[RJWParticipant @rjw]

Martin, it may be worth you looking at something similar to the parts cleaner shown in the link, you could use it as either a parts cleaner or a coolant tank and pump combined, they're designed to pump solvent as well as crap that escapes a filter, all the data you need is probably on the listing,
I've no connection to the seller, it's just to illustrate an alternative solution which would work for you,

I've saved a 'Safety Clean' parts washer pump myself for just such a job and which came as a spare with my parts cleaning tank, the intention being to make a coolant tank for the lathe, but the mill I bought last year came with a portable unit and has saved me the trouble,

I'll post a photo up of the pump unit later, it came with a flexible metal hose and appears to be a dead ringer for that shown in the listing.

John

**LINK**.

[Mark P.Participant @markp]

A few years ago I picked up a 240 volt”vibrating” type of pump off ebay. It came with a strainer, I mounted it in a plastic 5 liter paint kettle from Wlikos. Good rate of flow and had no problems with it, works for me.
Mark P.

[David JuppParticipant @davidjupp51506]

Posted by Martin Newbold on 29/01/2017 11:59:32:

Whats sort of pressure does the cooling pump ideally need to deliver?

At least enough to lift the chosen fluid from bottom of your reservoir to the highest point in the pipework – plus a bit more if you want it to do more than crawl out of the end.

Assume a soluble oil (so treat is as water for calculation), say 1.5m lift height (lets say 2m for luck) – that's about 0.2 bar or 3 psi. If piping is very small or fluid particularly viscous, add some more to cope with pressure drop.

[John ReeseParticipant @johnreese12848]

I have used submersible pond pumps successfully for many years in water based coolants. Not sure if they are compatible with straight oil.

A lot of old machines used gear pumps. As already said, they don't tolerate particulates very well. If worn they don't prime well. If you want to go the gear pump route chjeck out carbonator pumps.

[Martin NewboldParticipant @martinnewbold]

Hi RJW yep still to big though any idea what pump motor the parts washer uses please?

David by centrifugal i presume you mean like a slurry pump that will cope with particles I.e a rotating disc witch is like a slinger.

John are carbonator pumps this centrifugal design is there a particle size limit

Thanks for all your help

M

[MuzzerParticipant @muzzer]

Central heating pumps are pretty rugged and silent, and can develop a fine pressure head (~5m) and a decent flow rate. They are also very simple centrifugal pumps and don't cost a lot, particularly if you find a used one. The main problem is that they don't self prime, so you need to mount them below the fluid level.

This is a typical (Grundfos) performance characteristic:

[RJWParticipant @rjw]

Posted by Martin Newbold on 01/02/2017 21:25:13:

Hi RJW yep still to big though any idea what pump motor the parts washer uses please?

Thanks for all your help

M

Hi Martin, sorry I'm still looking for the spare pump for my machine, it's buried somewhere under all the clutter I've been moving into the building, I'll pull the tank off my machine and take a shot of that next time I'm in there,
It's a different pump I think to what the tank uses shown in the link I gave,
From memory it's about 100mm diameter and deep, 240V, plenty of pressure too, you can get a fair old fan of spray by covering part of the knozzle, but the motor doesn't stall if you shut off the end, so the delivery could be regulated with a tap, it does need to be submerged, but you could shove it in a 5 litre container if size of the tank is an issue,

Something like this might do the job:

**LINK**

John.

[RJWParticipant @rjw]

Martin, done a bit of digging around on the web, the pump in the link is the same as mine, there's a data spec' on the listing that should help.

What about a fuel transfer pump?

John.

**LINK**

Edited By RJW on 01/02/2017 23:07:37

[Ex contributorParticipant @mgnbuk]

Central heating pumps are pretty rugged and silent

But CH pump motors have sleeve bearings that are lubricated by the pumped liquid, so would require pretty good inlet filtration to give reasonable bearing life.

Nigel B

[Anthony KnightsParticipant @anthonyknights16741]

Not sure what size machine you want the pump for. I have small C3 lathe and have used a car windscreen washer pump for the oil coolant. Running from a 12 volt supply, I've had to fit a series resistor to slow the flow down.

[MuzzerParticipant @muzzer]

Posted by Nigel B on 02/02/2017 07:40:23:

Central heating pumps are pretty rugged and silent

But CH pump motors have sleeve bearings that are lubricated by the pumped liquid, so would require pretty good inlet filtration to give reasonable bearing life.

Nigel B

You'd have to define "reasonable" for a pump that typically pumps rust and hot gritty sludge around a heating system on a near continual basis for years on end vs a hobby application that may only see a couple of hours a year. Most of the swarf and particles drop out into the tank quite rapidly. Other suggestions appear to have gears and seals that may not stand up very well. Gears in particular would seize up with little provocation.

Unless you want to buy the proper coolant pump, there are downsides to most of the alternatives. In the case of washing machine motors, they aren't generally enclosed mechanically or electrically.

Murray

[Michael Cox 1Participant @michaelcox1]

I too use a windscreen washer pump to pump coolant. Most windscreen washer pumps are gear pumps. They are not designed for continuous use but if run on 6 volts or less rather than 12 volts they seem to run well without getting noticeably hot for extended periods.

There is a write up on my website, see:

http://mikesworkshop.weebly.com/coolant-pump-system.html

Mike

[Gordon WParticipant @gordonw]

Petrol pump from old car- diaphragm type can be driven off eccentric or cam, suggest old fiat or skoda. We used one to pump a mix of hydraulic oil and white spirit for many years. Output easily adjustable with a tap.

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