# Help driving a Lathe



## justinhcase (Jul 6, 2017)

I have come across an interesting old girl, A Lathe made by Cunliffe & Croom Ltd who operated from 1897 until 1964.
She is old but well made and should let me do some small fabrication.
Has anyone ever driven any old school machinery?
She is from the time when you had a steam engine or water race to drive a system of drive shafts above your workshop.Someone has taken off the original drive pully, The one it has fitted is a modern cast aluminum instead of the flat belt and pulley used in the 1800's.
I would love to find a home where I could install such a system but for now, I need to find the best way to mount an electric alternative.
Regards
Justin


----------



## Topher_osAUrus (Jul 6, 2017)

Looks like a nice old piece of machinery there.
If i recall correctly, old belt driven stuff like that didnt run at insane speeds. Somewhere between 25 and 1000rpm at the most.

I would think you could put a simple motor with different pulley sizes on the axle, and add a couple pulley spindles to your lathes drive axle and change out the speed that way. 

There are a couple good machinist forums around, one of which has a familiar face in the moderator list. Harold mods the chaski.org forums. I think it still has open registration.


----------



## justinhcase (Jul 6, 2017)

Topher_osAUrus said:


> Looks like a nice old piece of machinery there.
> If i recall correctly, old belt driven stuff like that didnt run at insane speeds. Somewhere between 25 and 1000rpm at the most.
> 
> I would think you could put a simple motor with different pulley sizes on the axle, and add a couple pulley spindles to your lathes drive axle and change out the speed that way.
> ...


Thanks, I will see if I they have any informative posts.
I wonder how tolerant they are of newcomers with a dubious understanding of their subject


----------



## Topher_osAUrus (Jul 6, 2017)

justinhcase said:


> Thanks, I will see if I they have any informative posts.
> I wonder how tolerant they are of newcomers with a dubious understanding of their subject



Haha! Well, I'm sure Harold would give an old friend a warm welcome.
If you have any issues registering, send me a pm and I can talk to him and put you in contact, or maybe I can have my father give you some advice as well. He ran some pretty old and beat down machines before he got his updated equipment some time ago.

It would take plenty of time and ingenuity, but you could have a really cool set up, with multiple step up/step down gears that are controlled by handy levers placed near the work station.
I cant describe them well, but, i think of them as very large gear shifts mechanisms from 10-speed bicycles that are operated by levers, that shift the belt from one spindle to the next. (Terrible analogy...any machinists reading this are shaking their head in disgust)
...heck, you could probably even rig up a bicycle to it and have it turn at low speed. :lol:


----------



## Topher_osAUrus (Jul 6, 2017)

I was close!
Rpms on those are generally between 24 and 850rpm.
You could probably max it out with modern drive tech at 1500rpm.
For tungston carbide cutter tips and what not, you would be best to stick between 1000 and 1200 rpm.

You could drive it a couple ways, a couple 5 tier pulley spindles set up in a reciprocal manner from the drive shaft on the lathe to a drive shaft on a 2 speed motor, or you could use a variable speed electric motor. The limitation with that though, would be the horsepower.

To figure rpm, there is a formula where you can crunch the numbers out by taking the distance between the pulleys(belt length), the distance from the center of the drive shaft to the edge of the spindle, on each one. Then some fancy maths will help you figure out the revolutions per minute. I can get the exact formula for you sunday if youd like.

After looking at your picture again and again, and taking into account the size of the head thats on it, it looks like its an old gun barrel lathe.
Still a very cool old lathe.
Id like to see a picture after you get it up and running.


----------



## justinhcase (Jul 7, 2017)

Topher_osAUrus said:


> I was close!
> Rpms on those are generally between 24 and 850rpm.
> You could probably max it out with modern drive tech at 1500rpm.
> For tungston carbide cutter tips and what not, you would be best to stick between 1000 and 1200 rpm.
> ...


Dear Topher
Thank you, that is very helpful.
We have our fire arm's curtailed so it is most unusual to find gunsmithing tools.
It is a pity we do not share the same regulations when it come's to home build as you have in the states.
£53 was quite reasonable to save the old girl from the skip.I will have to dig further and see if they have any reaming tools.


----------



## etack (Jul 7, 2017)

The simplest way would be an AC motor with a variable speed drive. Same size pulleys on both and control the speed with the controller.

You can get them off eBay pretty cheap used. You just need to make sure you HP, voltage, and phase (in and out) are what you need. 

Like this one.

http://www.ebay.com/itm/OMRON-SYSDRIVE-3G3MV-INVERTER-3G3MV-AB002-0-25KW-200V-1-PHASE-NICE-USED-M-OFFER-/172419043950?hash=item2824f9d26e:g:QqoAAOSwo4pYNa06

Eric


----------



## justinhcase (Jul 7, 2017)

etack said:


> The simplest way would be an AC motor with a variable speed drive. Same size pulleys on both and control the speed with the controller.
> 
> You can get them off eBay pretty cheap used. You just need to make sure you HP, voltage, and phase (in and out) are what you need.
> 
> ...


That is a very nice controller, Had you any though's on the horsepower of the motor?
Thinking about the job I was considering a flywheel to help smooth out inertia and drag.
A large flywheel was an integral part along with the water race such as they had at Ottery St Mary, where I went to school.
The photo is the water head they use to use for such work.
A workshop completely powered by renuable energy, electricity, and hydraulics.
Funny how tecnology come's full circle some time's.
Regards
Justin


----------



## Simon007 (Jul 7, 2017)

A lot of these old lathes were treadle powered, its easy enough to put a motor on, if you use a single phase motor get a pulley with different sizes so you can change the speeds, or get a three phase motor which can be wired up star and delta and wire it up in delta and use a vfd and then you can control the speed on the vfd, have a look at some pre war lathes on ebay which will give you some idea on a frame to mount the motor. Motor size of .75kw or 1hp will be plenty good enough

Sent from my EVA-L09 using Tapatalk


----------



## Topher_osAUrus (Jul 7, 2017)

Ample torque is a necessity.
So a bit more horsepower than that will be required.

If it doesnt have enough torque and you make a pass on some tough metal it will bog down and get nowhere fast.

This is especially important as I am sure you will be putting stuff bigger than a gun barrel in there to machine.
The flywheel is a good idea, but it can only help so much.


----------



## Simon007 (Jul 8, 2017)

In a small lathe hp isn't the only limiting factor, a modern motor in Europe are very efficient and do a great job compared to old ones, also using a three phase motor on a vfd will give you ample torque range from low to high.

Sent from my EVA-L09 using Tapatalk


----------

