Author Topic: Variator for small lathe  (Read 29136 times)

Offline BillTodd

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Re: Variator for small lathe
« Reply #25 on: November 04, 2022, 09:31:44 AM »
Not much of an update....

After adjusting the backlash and topping up the oil (lucky we had some old tellus at work for some other machine ) ,
I mounted the Kopp and motor on a U chassis to raise it and the belt to clear the headstock.

Nothing is bolted down yet as I may try to hifde the enormous power train under the bench top.
Bill

Offline BillTodd

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Re: Variator for small lathe
« Reply #26 on: September 10, 2023, 06:41:01 AM »
Small update:

I have a small pile of 4040 extrusion with which I can make a stand for the lathe and motor.

Just a mock up ATM to check height
Bill

Offline BillTodd

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Re: Variator for small lathe
« Reply #27 on: September 12, 2023, 10:16:36 AM »
I've settled on the basic shape.

The black motor plate determines the 600mm width of the frame.   . I have to add a counter shaft and pulleys to get the drive up to the headstock.

Bill

Offline philf

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Re: Variator for small lathe
« Reply #28 on: September 12, 2023, 04:15:51 PM »
Bill, Good to see the Kopp being put to good use. Phil.
Phil Fern
Location: Marple, Cheshire

Offline BillTodd

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Re: Variator for small lathe
« Reply #29 on: September 13, 2023, 04:15:18 AM »
Yes  Phil, it's taken a while  :)
Bill

Offline BillTodd

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Re: Variator for small lathe
« Reply #30 on: September 14, 2023, 03:36:20 PM »
Fitted the top , feet and added rubber fillets to hold the panels in.

Bill

Offline BillTodd

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Re: Variator for small lathe
« Reply #31 on: September 19, 2023, 01:44:28 PM »
A bit more fiddling today. I've wired a control box with no-volt switch and psu for the speed adjustment motor.

I going to have to pull the kopp apart and clean out some debris, I noticed that since changing orientation,it has developed a click (the adjustment worm bearing show noticeable wear and I suspect crap from this has got into the mechanism. Changing oil didn't shift it.) And I have a oil leak from the speed adjustment port.

It'll be easier to make a motor driven speed change with it on the bench
Bill

Offline philf

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Re: Variator for small lathe
« Reply #32 on: September 19, 2023, 03:52:42 PM »
A bit more fiddling today. I've wired a control box with no-volt switch and psu for the speed adjustment motor.

I going to have to pull the kopp apart and clean out some debris, I noticed that since changing orientation,it has developed a click (the adjustment worm bearing show noticeable wear and I suspect crap from this has got into the mechanism. Changing oil didn't shift it.) And I have a oil leak from the speed adjustment port.

It'll be easier to make a motor driven speed change with it on the bench

Bill, I still have another and some spares if you need them. Phil. (I did have a flexible drive for the speed change knob so you could operate it remotely but don't know where it is - or even if I still have it.)
« Last Edit: September 19, 2023, 04:54:05 PM by philf »
Phil Fern
Location: Marple, Cheshire

Offline BillTodd

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Re: Variator for small lathe
« Reply #33 on: September 19, 2023, 05:51:13 PM »
Cheers Phil,

I'm sure it'll only need a clean I was fine until I ran it on its side. When I swapped the bungs the magnetic one was quite furry , so there is sludge in there.

Vill
Bill

Offline BillTodd

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Re: Variator for small lathe
« Reply #34 on: September 20, 2023, 10:21:10 AM »
Well, that was instructive. 


1, they are not difficult to take apart.

2, the largest piece of debris was a flake of paint (thst probably fell in when I opened it).

3, there is no perceivable wear , it's like new inside.

4, they are fiddly f####rs to put back together!

Still , I have fixed the leak


And decided the click is the motor coupling, which I may have to change along with the motor, as it lacks starting torque for the highest speeds.

Bill

Offline philf

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Re: Variator for small lathe
« Reply #35 on: September 20, 2023, 04:53:05 PM »
Good news Bill! 👍
Phil Fern
Location: Marple, Cheshire

Offline BillTodd

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Re: Variator for small lathe
« Reply #36 on: September 25, 2023, 02:13:59 PM »
 :proj:

Itis - suffix meaning swelling

Well, having found that the motor has insufficient starting torque, first thought was to increase capacitor ... Great 25u starts it at highest speed, but wots that smell :Doh:

A 180w motor drawing 456w is not going to last long.

Casting around for a motor a friend delivered a 1hp monster (looked about the right size in the photo  :bang:)

Today I swapped out 1/2hp one on my saw for the 1hp - had to get creative with the motor mounts, and bore the pulley.


So now I have to redrill the plate to mount the motor, which will move the kopp an inch further back , causing a rethink of the counter shaft....

 :proj: indeed.
Bill

Offline pycoed

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Re: Variator for small lathe
« Reply #37 on: September 26, 2023, 04:06:33 AM »
An absolutely CLASSIC example of the case! :thumbup:

Offline BillTodd

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Re: Variator for small lathe
« Reply #38 on: September 27, 2023, 07:19:38 AM »
I mounted the Gryphon 1/2 hp motor onto the plate with the variator . This assembly is as heavy as the rest of the lathe and stand.

Total weight is 60kg so far.

The variatir pulley is a inch or so to the left of where it was. Fortunately, spinning the counter shaft 180degrees brings the back into alignment.

Next, I have to make a motor drive for the kopp speed  adjustment.
Bill

Offline BillTodd

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Re: Variator for small lathe
« Reply #39 on: September 30, 2023, 10:02:35 AM »
Electrical vari-speed made...


Of course it was not as simple as that ,  involving three attempts at making the C shaped body , including throwing one out of the mill vice and jamming my 4" facemill into the spindle .

The motor coupling filed for divorce - now I'll have to remove the motor again which is getting heavier every time I lift it


But it is sort of working  giving a continuous 311 to 2320 rpm 

Bill

Offline Muzzerboy

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Re: Variator for small lathe
« Reply #40 on: September 30, 2023, 02:13:38 PM »
Nice work! Have you got some form of interlock to prevent the speed changer from running when the motor is stationery? Those Kopp variators don't like being moved when the shafts aren't spinning. Presumably powering the speed changer from the motor starter takes care of that.

Offline BillTodd

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Re: Variator for small lathe
« Reply #41 on: September 30, 2023, 02:17:55 PM »
Nice work! Have you got some form of interlock to prevent the speed changer from running when the motor is stationery? Those Kopp variators don't like being moved when the shafts aren't spinning. Presumably powering the speed changer from the motor starter takes care of that.

Yes, super simple, the transformer that powers the dc motor is powered from the main motor circuit
Bill