Now I’m sure I have angered the machining gods.

[Redneck_Sophistication]

I think all my rednecking “good enough” projects has angered the gods!

Saddle of the lathe back together. Used it for a minute and it was making an odd noise. Checked to make sure the oil pump was working, noticed the shop made coupler between the stock shaft and the shop fitted replacement pump slipped off.

Got it back on and was indexing the shaft to tighten up the set screw and found this

When who ever made/installed this it was slightly out of alinement maybe that stressed the shaft into breaking.

Id figured on supplementing the mechanical pump with an electrical one. I guess that’s a replacement instead now.

Anyone know of a small inline oil pump that can lift 18-24”

Id planned to hook it to the drain plug pump it externally into a manifold of some kind to distribute the oil better.
Most things I see are 12v transfer pumps, line voltage pumps seem to be huge. Many a 12v power supply and pump.

I’ll have a brand new lathe by the end of this lol

 

[Susquatch]

Anyone know of a small inline oil pump that can lift 18-24”

Wow......

Is that a centrifugal pump or a positive displacement? Positive displacement pumps can be small and will lift hundreds of feet. Think power steering pump on a small lawn tractor. It will need an adjustable pressure relief valve - either built in or add on.

Can the pump be rebuilt? Certainly no good as is. Might as well take it apart to see how the shaft works. Might be replaceable or repairable. How long did it last? Maybe that's long enough......

 

[historicalarms]

The first fluid spray mechanism I built for my lathe used a simple pond pump from a garden/landscape shop. I think it was under $30 and was a simple plug-n-play setup with some surgical tube from CT...easily lifted 48" in my case and many more times the volume & pressure I needed ( I installed a needle valve/return line for pressure & volume relief back to the sump)

 

[Redneck_Sophistication]

@Susquatch i had it apart when I removed my spindle out of the lathe. It wasn’t working well then

It’s a small one directional gear pump, the gear was held on with red loctite which broke loose, the seal on the main shaft Was gone. Was someone’s previous “good enough” this old girl had a hard life.
I re-locktighted (that’s totally a word) the gear back on, and found an O ring that pushed the seal back into place. I thought then to fine an electric pump I can see working. With lots of oil since I’d just replaced the spindle bearings and don’t want to do that again.

@historicalarms
I’d thought of a pond like submersible pump but my head stock has a lot going in it. Routing power and a hose though all those gears would be hazardous and VERY tight to get in.

There’s a 3/8” drain plug I figured I could replace with a long nipple and shut off. Then pipe in a pump.
That’s my theory anyways

 

[Redneck_Sophistication]

Was looking at brewing transfer pumps thinking they might work. One has this in the write up though.

I guess I should add looking for an 115v oil pump that isn’t hundreds of dollars.

I guess I could find some sort of hydraulic pump off something and couple it to a small 115v motor.

 

[Susquatch]

Was looking at brewing transfer pumps thinking they might work. One has this in the write up though.

That is a centrifugal pump. I'd think a positive displacement pump would be better.

0.5Mpa 1800r/min Gear Oil Pump, Insert Type Lubricating Cycloid Gear Pump Made of Iron(TOP-12A) https://a.co/d/cxPPwal

Not suggesting this particular pump, just the overall idea.

 

[Redneck_Sophistication]

Well this is something, and here I thought I’d memorized princess autos catalogue


Has NBR impeller think I might go put their No sale is final policy to the test

Edit. Oh Now I see @Susquatch’s post.

Nitrile (also known as NBR rubber and Buna-N) is the seal industry's most widely used and economical elastomer. This is partly because it displays excellent resistance to petroleum-based oils, fuels, water, alcohols, silicone greases, hydraulic fluids.

 

[Susquatch]

Has NBR impeller think I might go put their No sale is final policy to the test

So, the problem is the word "impeller". That makes it a centrifugal pump. Centrifugal pumps go to hell in a hand basket when flow is restricted - even to the point of dropping pressure to near zero. They need guaranteed flow to work.

As an insight, think about what happens to the blower speed and the vacuum suction when you block the flow to a vacuum hose.

You need a pump that increases pressure with restricted flow. You need a positive displacement or a gear pump. One that is designed for oil.

 

[Redneck_Sophistication]

@Susquatch what about these pumps that have a rubber impeller, but it’s squished to one side folding the vanes over pushing it through the other side. That would be positive displacement wouldn’t it?

I get that a typical impeller type wouldn’t work the best.

I’ll to find an example of one.

Oh. That was easier then I though



EDIT:
I guess if they use the word impeller instead of vane it’s not the right application.

 

[Susquatch]

@Susquatch what about these pumps that have a rubber impeller, but it’s squished to one side folding the vanes over pushing it through the other side. That would be positive displacement wouldn’t it?

I get that a typical impeller type wouldn’t work the best.

I’ll to find an example of one.

Oh. That was easier then I though

View attachment 27050

EDIT:
I guess if they use the word impeller instead of vane it’s not the right application.

Actually, the pump you show is not a centrifugal pump. It really is a displacement pump. Just not the best kind. The way to know the difference is in the name. A centrifugal pump relies on spinning the fluid to create an outward centrifugal force. The inputs are in the center and the output at the sides.

A positive displacement pump has a squishing area near its outlet (like the one in your drawing) and it squishes the fluid from a high volume area to a low volume area much as you described.

In the case of your example the pump has the volumetric difference between input and output but it's based on bending those vanes to follow the different space at the input vs the output.

However, a flexible vane pump will never be as effective as a gear pump would be. Also, those vanes are not wear proof and will not last as long as a gear pump would.

Small gear pumps do exist. That's what your lathe had originally and that's what I would get to replace it. Although it would be ok if it was electrically driven, that wastes the very reliable drive system you already have.

 

[140mower]

Have you taken this one apart yet? I suspect that a fella with a lathe could make a new shaft, and bore and key a gear for next to nothing but time.....

 

[Redneck_Sophistication]

I did have it apart before. It’s a pretty small, imo under flowing pump. Which I why I wanted to install a second one to increase flow of oil to the new bearings.

Obviously having a built in pump running off the gear would be simpler. The problem is access.

This small pump is attached to half of the housing of the original pump that was milled down as a supporting block. It’s also down pretty far in the head stock. Was a pain to reinstall when the spindle was out of the lathe. Fitting a new one and figuring attaching it let alone alinement as it looks like that caused my failure.

Wanting an external electrical pump is pure efficiency with a sprinkling of laziness.

Wondering If a PA hydraulic pump for 90$ And a old 1/2hp for 20$ on kijiji is the way to go now. I am
Running aw32 in the lathe .

 

[Susquatch]

Wondering If a PA hydraulic pump for 90$ And a old 1/2hp for 20$ on kijiji is the way to go now. I am
Running aw32 in the lathe .

As long as the PA hydraulic pump has the same flow rate as the old gear pump, it should work. The biggest problem with an actual hydraulic pump is the output pressure - typically 1500 to 3000 psi. You would want to have a pressure relief in that system to make sure it didn't blow up the plumbing and fittings.

The other problem is the longevity of a hydraulic pump. You would want to monitor pressure on an ongoing basis.

EDIT - Can you fire up the old pump enough to determine its output characteristics so you have something to shoot for. Maybe drill and tap the input shaft for a screw in extension? It wouldn't have to last very long. Just enough to take some pressure and flow rate measurements. You will need to get and mount a pressure gauge anyway to monitor the new pump's function.

 

[Chicken lights]

Was looking at brewing transfer pumps thinking they might work. One has this in the write up though.

View attachment 27034

I guess I should add looking for an 115v oil pump that isn’t hundreds of dollars.

I guess I could find some sort of hydraulic pump off something and couple it to a small 115v motor.

I needed a way to drain my engine oil drain pan. I scammed a Chevy small block oil pump (free) and run it using a cordless drill. I’m sure with some redneckery (totally a word) you could make something like that work for not much money

 

[140mower]

I needed a way to drain my engine oil drain pan. I scammed a Chevy small block oil pump (free) and run it using a cordless drill. I’m sure with some redneckery (totally a word) you could make something like that work for not much money

I like this idea of using an automotive oil pump, and since you would be making it remote, it's dead nuts easy to add a spin on filter. I would think that a 1/4 horse motor should be enough. Could even install a pressure gauge or light to confirm flow.

 

[Former Member]

If the pump is still good, why not fix the break. If its the shaft (sorry picture doesn't do it justice) you have three options.

Replace the shaft (drill rod right dia).
Solder it, low temp solution.
TIG it.

If you can't do it find someone that can.

 

[Redneck_Sophistication]

@Susquatch
I ran The old pump when I rebuild it, without the spindle in the lathe.
Not much flow really. 1/4” copper line and it wasn’t streaming out that fast. Honestly think anything i out here will be an improvement.

As far as pressure build up from running a hydraulic pump isn’t pressure a factor of flow? Hydraulic systems only make high pressure when flow is reduced. If I run my lines all open with out resistance pressure build up should be minimal.

@Chicken lights first of all redneckery is not a word…..it’s a way of life.
An automotive pump could be a way to go. Would definitely take some fiddling to work in-line.

I’ll power it with a small motor tied into the E-stop on the lathe. Thinking having it power on a work light too. Remind me to shut it down when not in use.
Or if I mount it in the base of the lathe I could steal drive from the motor. So it will work similar to the original set up off drive gears.

@Degen i could do those options but the pump wasn’t that great. And how it’s mounted it is not aligned properly which I think is what causes this break.


I need to find some generic pumps for lathes, searching with my phone sucks. Keeps pushing me to Amazon which has nothing.

 

[Susquatch]

As far as pressure build up from running a hydraulic pump isn’t pressure a factor of flow? Hydraulic systems only make high pressure when flow is reduced. If I run my lines all open with out resistance pressure build up should be minimal.

Absolutely correct. However, if you think about the implications of what you say, you will realize that lots of things from dirt, to metal flakes from gear wear, to sludge and varnish buildup could block the flow at some time in the future. When and if that happens, the pressure from a hydraulic pump could reach 2500 or even 3000 psi which could burst pipes, burst hoses, pop connections, or cause a leak before the locations where oil is needed.

That's why I advocate a pressure relief valve and a pressure gauge if you decide to go with a hydraulic pump.

 

[historicalarms]

@Susquatch
I ran The old pump when I rebuild it, without the spindle in the lathe.
Not much flow really. 1/4” copper line and it wasn’t streaming out that fast. Honestly think anything i out here will be an improvement.

As far as pressure build up from running a hydraulic pump isn’t pressure a factor of flow? Hydraulic systems only make high pressure when flow is reduced. If I run my lines all open with out resistance pressure build up should be minimal.

@Chicken lights first of all redneckery is not a word…..it’s a way of life.
An automotive pump could be a way to go. Would definitely take some fiddling to work in-line.

I’ll power it with a small motor tied into the E-stop on the lathe. Thinking having it power on a work light too. Remind me to shut it down when not in use.
Or if I mount it in the base of the lathe I could steal drive from the motor. So it will work similar to the original set up off drive gears.

@Degen i could do those options but the pump wasn’t that great. And how it’s mounted it is not aligned properly which I think is what causes this break.


I need to find some generic pumps for lathes, searching with my phone sucks. Keeps pushing me to Amazon which has nothing.

Personally, concerning the flow rate of your pump, I think you are worrying about something that is no worry.
On my lathe, and thousands of others from China/Taiwan, the head stock is 3 " above the oil level in the sump and the bearings are fed an oil supply from only the splash of the gears turning in the oil puddle and slashing up to the top lip of the housing, from there the oil fallows a trough to a small 1/8" hole that drip feeds the bearings...no pressure and just gravity feed down the hole. My bearings have run happily for 20 yrs or so this way and even after a long run of steady cutting there is no heat climb that can be felt at the bearing boss's much above room temp.
I think the volume of oil you describe is very sufficient for a small lathe.

 

[RobinHood]

Here is the low pressure lubrication system on my Colchester Master 2500. Might help you (re) design your system.

The oil drains from the HS into a holding tank. From there a pressure head of about a foot through a 1” hose feeds an impeller pump. The outlet is via a 1/2“ tube up to the top of the HS where the flow is divided into two main paths. Each of the distribution lines has small (3mm ?) holes which provide a steady, open port flow to the main bearings and the clutch. The rest of the gears/bearings are lubricated from the oil splashing around the HS. Then it drains back into the tank.

My lathe is at least 35 years old and has seen a pretty hard life before I got it. I believe the main bearings to be original. I doubt it had seen many oil changes during its life. So, as simple as the lubrication system is, it certainly seems plenty adequate to prevent damage / excess wear on a lathe with a 5hp motor that will take some serious cuts in all sorts of tough metal.

How about a small submersible pump? They are generally low pressure, high flow and are quiet. If the lines get restricted, the pump does not care much, it just heats up the oil a bit more.

A small circulating pump may also work (just check the pump curves and look for one that can handle viscous fluids).