Harrison L5 3HP Lathe

[Slooby]

Now, following on from my posts about the Bridgeport this is my other machine tool project and the one that I am currently focusing on to get running because I've owned it far too long without ever seeing it run...at least 15 years...

It came to me when ta friend of mine, an excellent machinist and trials motorbike whisperer, asked if I knew of anyone looking for a lathe...it was coming from the estate of motorbike engine builder who specialised in Pre-60's trials bikes who he used to do a lot of machining for. It wasn't a runner, but was being offered for its then value in scrap; £300. Naturally, being the type of project hoarder that I am, how could I refuse!

Anyway roll on a few years, marriage, a child, a divorce and the sell up of my martial home to settle the divorce, the Lathe has now found it's way back down with me to Kent and my childhood workshop to join my other metal working toys.

For years I had thought it was an L5A, but I'd never got round to measuring the swing clearance until this evening, it turns out that with the gap removed there's a throw of around 9 inches, so it must be an L5. The year is hard to pin down as it has features of both the Mk3 and Mk4. A bit like my Bridgeport it seems to have been quite a high spec machine coming with the stand, the two speed 3hp motor, 36 speed Norton gearbox, a suds system and a whole heap of additional chucks, collets, steadies etc. Anyway, pics time!

 

[Slooby]

The parts missing from the machine in my workshop are next door in my dad and brother-in-law's more woodwork orientated workshop from their now sadly defunct business (technically all mine as I bought everything from the reciever so it wouldn't be lost...):

Another curio, seen here with the gap, is a home brew toolpost grinder, comprising a small bench grinder mounted on a motorbike swingarm!

In amungst the now rather rusty tooling (a good soak in some De-ox-C required) there are the adjustable feet, I think 7 chucks, a magnetic face plate, I think a T slot face plate, collets, a drawbar, centring steadies, a tool post X-Y stage, Colchester type tool post and that cylinder was an arbour for cylinder liners.

 

[Slooby]

While I'm down in Kent this week ferrying my dad to hospital each day for a course of Chemo-Radiotherapy, I've been filling my evening giving it a good clean, and preparing to replace the motor.

Last night and this evening I set about the suds sump and removed the pump along with the main motor as it is suspect:

The old motor was an unknown quantity and it appears to be original:

The plan is to replace it with this new, old stock, ABB unit running delta from a Siemens VFD Inverter:

I'm wondering whether I can re-use the controls on the stand to run the VFD...

 

[Slooby]

Another part of the machine I need to take a look into modifying is the suds pump:

Replacing the motor with a single phase unit ideally with integral speed control...

 

[Sideways]

Do a search on here. There is a long thread on the refurb of my L5 1950 vintage, with valuable contributions by @Fergie 307 who has a nice L5A.

I've since traded up to a 20 year newer L5A myself.

You'll find a serial number stamped into the bed at the right hand end and this can be used to look up in a list of Harrison serial numbers by year to date yours to the year.

A couple of observations.
The inside of the belt cover is painted dark red. This was the practice in 1950 and had stopped by 1970.
The handwheels are solid centres. This was the practice in 1950 on an L5 but the L5A has 3 spoke handwheels.
Your motor mounts are L5 style, they were slightly improved on the L5A for greater adjustability.

I have upgraded both of my machines with the same square style ABB motors. Both 3 phase, 4 pole rather than 2 pole, 2.2kW versions. In doing this, you need to switch the motor pulley to a modern taperlock type.
A 2.2kW 4 pole motor has oodles of torque and will quite happily spin the lathe even dialled down to half speed on the VFD. There is some value in this as when facing the end of a bar, you can start the cut at half speed and twist the speed control as you cut towards the centre. This helps compensate for the reducing diameter and reduction in surface speed. The trick is a poor man's constant linear velocity function and gives a better finish on facing cuts.

Lastly, and to my shame, the L5A is the only machine I've ever dropped. They are heavy and tall with a pretty slim base. I vowed never to do that again and have copied the extended feet made of parallel flange channel you will see on Fergie's lathe for extra stability. I commend that idea to you.

 

[Fergie 307]

Nice old one you have there.
The channels on mine are 125x65 and extend back to just behind the coolant sump/motor. The feet are scaffold legs cut down and mounted into short lengths of pole welded to steel plates. The foot plates sit on squares of 4mm thick synthetic rubber, sold for making lorry mudflaps amongst other things. Does make quite a difference. Without them you can see bits of dust and such dancing around the floor some distance from the machine when it's at full chat, the rubber deadens it out and makes it much quieter. The feet can be swapped out for heavy duty castors which enable it to be pushed around single handed with ease, and the extra length makes it very stable. I used the original levelling bolts to secure the channels. Managed to find someone who had a load of NOS 7/8 BSW nyloc nuts to fit.
Have fun restoring it, looks like you have some interesting bits and pieces with it.

 

[ChaiLatte]

The suds pump will work on single phase with a suitable capacitor to provide the ghost phase. It is low power so this solution is acceptable. No suds pumps are variable speed. They are centrifugal pumps so you regulate the flow with a (metering) valve. The pump will not be harmed dead heading against a closed valve.

The controls on the machine can be repurposed to control the VFD. You will have to read the VFD documentation as often they can be configured to use either momentary inputs or maintained inputs. Just be sure they are isolated from any previous mains input. VFD control circuitry is low voltage, minimal current. At worst, you might have to hang a microswitch behind some of the original buttons and use that to control the VFD. A machine always looks better if the original controls can be retained.

Look after the large double gear pictured in one of the boxes. That will be the metric translation gear and would be expensive to replace if it gets damaged.

 

[Fergie 307]

Maybe a bit OTT but on mine I have run the coolant pump from its own small VFD. It's controlled via a paddle on off switch and pot mounted in a metal project box on the splash back, so I can vary the speed of the pump and amount of coolant via the pot. Easy enough as my machine is quite a bit later, 1961, so pump was dual voltage. Yours might be or might not.
I rebuilt the original pump switch to have two positions, which I use to give high and low speed ranges to the main motor via presets on the vfd. Suitably re labelled as motor hi and lo.
This mimics the set up of a factory two speed motor. I have the front lever control on mine, which I find really convenient. It is set up to control the vfd forward reverse etc inputs.
I use mine via the gearbox and have no variable speed control, just because I'm an old git and that is what I am familiar with. Can certainly see the attraction of variable speed, jog etc.
I have seen an article where someone set up an Arduino to automatically vary the speed on an old lathe using a tacho and inputs from the cross slide dro, interesting idea.
The very nasty modern stop switch is on the to do list to be replaced with the original red and green buttons, just haven't got around to it. As suggested just a case of mounting modern switches behind the old faceplate and buttons.
I find with my HuanYang vfd the machine will come to a halt in a couple of seconds without having any additional braking options added.

 

[Fergie 307]

One thing you want to pay very close attention to is the Norton gearbox. Not a design highpoint on Harrison's part, and can cause you a lot of problems if not set up correctly.
Common problems are that the knob detents wear so the selectors aren't positioned correctly. Worth spending some time on thoroughly checking this with it on the bench, so you make sure the gears are correctly positioned relative to the knobs. Often necessary to redo the detents, but even at their best they are not great. Well worth putting a spot of paint or similar on the casing opposite the end of the knob lever as a double check that it is in the correct position.
And you have to lubricate it, there being no automatic lubrication. You will see that there really is little provision for lubricating the gear train on the right hand side of the box. It relies entirely on oil making it's way down from the shaft bearings, not very satisfactory.
If you look closely on mine you will see I have drilled a hole in the casing just below the right hand knob, this is so you can squirt oil directly into the gear train on that side.
The other side is very similar, but you can at least get at the gears through the hole below the banjo. I use motorcycle chain lube as it stays put and doesn't drip straight out all over the tray.
Hopefully you won't have the other common problem on these where people have filled all the nipples with grease, endless fun getting rid of it all if that is the case. All the lube points are for oil, the only ones that take grease are on the motor bearings.
And if you haven't already then join the Harrison lathe group at groups.io.
Lots of good people on there, including quite a few with the same older machine you have. Wealth of information and can be a good source of spares.

 

[Sideways]

Look after the large double gear pictured in one of the boxes. That will be the metric translation gear and would be expensive to replace if it gets damaged.

Amen to that.
I had to buy the 127 tooth changewheel as the second lathe came imperial only.
It cost me a pound a tooth and I considered myself lucky enough to be able to buy a nice clean one at all !

 

[Slooby]

Thanks chaps!

Both of your (Fergie and Sideways) threads are what brought me to this forum. I joined the Yahoo Harrison group years ago, must dust off my access! Thanks also for the top tips there Chai...

As it happens another mate (Herbert as we call him, and former minion of Siesmologist mate aka Crankshaft) is a bit of a dab hand at electro mechanical management and firmware development...and just last night I was pondering roping him in to build me a touch screen speed controller with various look up tables for speed control relative to material, diameter, hole diameter etc etc all driven from an Arduino (his preferred development weapon) maybe with a 36-1 pick up on the head and a DRO encoder on the tool head slide...