Author Topic: vintage lathe restoration - 3 phase supply.  (Read 24864 times)

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Offline xygor

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Re: vintage lathe restoration - 3 phase supply.
« Reply #75 on: September 01, 2016, 05:19:46 pm »
You can't go from Fast to Slow and vice versa because they lock each other out.  Nothing should happen if you press Fast while it is already running in Slow, which is what you said happens.
There does appear to be a centrifugal switch called HS which activates 2R.
 

Offline xygor

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Re: vintage lathe restoration - 3 phase supply.
« Reply #76 on: September 01, 2016, 05:33:26 pm »
I think Jeroen3 nailed it.
"Similarly, a control transformer and/or lighting transformer with a primary winding of 415v must be fed from the L1 and L2 phases."
The control and lighting is on L1 and L3 on the lathe, so these must connect to L1 and L2 (or L2 and L1) on the converter.
 

Online edpalmer42

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Re: vintage lathe restoration - 3 phase supply.
« Reply #77 on: September 01, 2016, 05:39:55 pm »
Congratulations!  So now that you've got it working, what do you plan on doing with it?

Ed
 
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Offline capnahab

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Re: vintage lathe restoration - 3 phase supply.
« Reply #78 on: September 01, 2016, 06:10:37 pm »
Yes I think Jeroen was on the right track , and RTFM of course. The answer was in the manual for the converter.
It still needs a lot of cleaning and restoration. The recommended oil at the time was Castor oil and its congealed everywhere. There are quite a few bits to make. My neighbour is into car rallies , - the ones where you can't have a car thats cost more than £100. So they require a bit of repair , so I have made parts for him.
BTW
the switch had a protective cover over it which is one of the few parts that is damaged (see pic ) - what is this material ?, or , what can i use to replace it ?.
 

Offline Andy Watson

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Re: vintage lathe restoration - 3 phase supply.
« Reply #79 on: September 01, 2016, 06:17:16 pm »
Looks like SRBP/Paxolin. Try ebay for small quantities.
 

Offline eKretz

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Re: vintage lathe restoration - 3 phase supply.
« Reply #80 on: September 01, 2016, 06:20:54 pm »
You could also use micarta or G10.
 

Online IanB

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Re: vintage lathe restoration - 3 phase supply.
« Reply #81 on: September 01, 2016, 06:23:21 pm »
the switch had a protective cover over it which is one of the few parts that is damaged (see pic ) - what is this material ?, or , what can i use to replace it ?

It looks like some kind of resin bonded laminate. I think you could make a replacement out of PCB material, without any copper cladding.
I'm not an EE--what am I doing here?
 

Offline woodchips

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Re: vintage lathe restoration - 3 phase supply.
« Reply #82 on: September 01, 2016, 06:29:08 pm »
It seems that the circuit is for a two speed, two motor lathe, has yours actually got two physical motors rather than a multiwinding single motor where the windings are switched.

At least it works, start hacking metal now. Should be good to put a 1" drill straight in, no pilot!

What fixing doeas the lathe chuck have onto the spindle? Can't really see but is it an L2? Looking for an L2 spindle, so if you scrap the lathe........
 

Offline xygor

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Re: vintage lathe restoration - 3 phase supply.
« Reply #83 on: September 01, 2016, 06:38:46 pm »
It seems that the circuit is for a two speed, two motor lathe, has yours actually got two physical motors rather than a multiwinding single motor where the windings are switched. ...
The two motors are spindle (main) and coolant pump.
 

Online tautech

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Re: vintage lathe restoration - 3 phase supply.
« Reply #84 on: September 01, 2016, 08:03:25 pm »
Yes I think Jeroen was on the right track , and RTFM of course. The answer was in the manual for the converter.
It still needs a lot of cleaning and restoration.
Good old White Spirits and elbow grease worked great when I cleaned all the grud from my lathe.


Quote
The switch had a protective cover over it which is one of the few parts that is damaged (see pic ) - what is this material ?, or , what can i use to replace it ?.
As suggested it's Paxolin, an industrial Formica type material.
Any stiff plastic will suffice but it won't be as flame resistant.
Avid Rabid Hobbyist
 

Offline Delta

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Re: vintage lathe restoration - 3 phase supply.
« Reply #85 on: September 01, 2016, 08:04:37 pm »
Glad you got it working mate!   :-+

I'd I've learned something new!  https://en.wikipedia.org/wiki/Dahlander_pole_changing_motor
 

Offline eKretz

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Re: vintage lathe restoration - 3 phase supply.
« Reply #86 on: September 02, 2016, 01:59:33 pm »
It seems that the circuit is for a two speed, two motor lathe, has yours actually got two physical motors rather than a multiwinding single motor where the windings are switched.

At least it works, start hacking metal now. Should be good to put a 1" drill straight in, no pilot!

What fixing doeas the lathe chuck have onto the spindle? Can't really see but is it an L2? Looking for an L2 spindle, so if you scrap the lathe........

Haha! At least I HOPE you're kidding! That's a prime specimen of fine old British iron. I bet he'd scrap his wife before he scrapped that machine! And it ought to be able to drive way larger than a measly 1" drill straight in. Probably more like 3" - 4"! The spindle is likely a D1-6 anyway.
 

Offline capnahab

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Re: vintage lathe restoration - 3 phase supply.
« Reply #87 on: September 02, 2016, 02:26:15 pm »
Not sure the wife knows I have it..
The biggest drill I have is 60mm I think. Wil post some video.
Meanwhile I need some led bulbs , 2.5 v, 0.3 amp MES10  for the front panel and will try and source / make new coloured plastic domes. Perhaps I should start another thread.
 

Online IanB

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Re: vintage lathe restoration - 3 phase supply.
« Reply #88 on: September 02, 2016, 05:28:03 pm »
Haha! At least I HOPE you're kidding! That's a prime specimen of fine old British iron. I bet he'd scrap his wife before he scrapped that machine! And it ought to be able to drive way larger than a measly 1" drill straight in. Probably more like 3" - 4"! The spindle is likely a D1-6 anyway.

Even if the lathe has the power to do that, good practice would surely be to start small and increase the hole size in steps.
I'm not an EE--what am I doing here?
 

Online tautech

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Re: vintage lathe restoration - 3 phase supply.
« Reply #89 on: September 02, 2016, 08:16:59 pm »
Haha! At least I HOPE you're kidding! That's a prime specimen of fine old British iron. I bet he'd scrap his wife before he scrapped that machine! And it ought to be able to drive way larger than a measly 1" drill straight in. Probably more like 3" - 4"! The spindle is likely a D1-6 anyway.

Even if the lathe has the power to do that, good practice would surely be to start small and increase the hole size in steps.
Exactly.

Want to test it's capabilities, try a large free turning bar and if the slides are still tight it should peel a 3mm sorry 1/8" cut no problems. That"s 1/4" reduction in diameter each pass. With a lathe like this you can really knock some material off fast, just watch for them curly hot snakes trying to wrap you up when big cuts are taken.
Carbide tools are not so bad, the chip breaker design of the inserts sees to that.
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Offline eKretz

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Re: vintage lathe restoration - 3 phase supply.
« Reply #90 on: September 02, 2016, 11:37:16 pm »
No, best practice is to drill the hole size you need from the solid - unless you only need a drilled hole. Then it depends on run-out and diameter tolerance requirements. If the hole will be bored for finish, drill once slightly under finish size and bore. If reamed finish, drill slightly under finish size, true with boring bar or core drill and finish ream.

The whole point of a machine like this is to be able to eliminate all the unnecessary steps that need to be taken with a hobby grade machine. These machines were built to get work done FAST.

With 7.5 HP that machine would be good for between 1/8" to 1/4" depth of cut per side with carbide tooling. If the chips are peeling off it's running too slow. This will damage carbide as surely as running too fast. Good roughing speed for mild steel is 300 - 400 SFPM - for harder steel or tool steel alloys 250 SFPM. Finishing can be as high as 500 - 1100 SFPM with modern carbide tooling.
 

Online tautech

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Re: vintage lathe restoration - 3 phase supply.
« Reply #91 on: September 03, 2016, 12:00:40 am »
No, best practice is to drill the hole size you need from the solid - unless you only need a drilled hole. Then it depends on run-out and diameter tolerance requirements. If the hole will be bored for finish, drill once slightly under finish size and bore. If reamed finish, drill slightly under finish size, true with boring bar or core drill and finish ream.

The whole point of a machine like this is to be able to eliminate all the unnecessary steps that need to be taken with a hobby grade machine. These machines were built to get work done FAST.

With 7.5 HP that machine would be good for between 1/8" to 1/4" depth of cut per side with carbide tooling. If the chips are peeling off it's running too slow. This will damage carbide as surely as running too fast. Good roughing speed for mild steel is 300 - 400 SFPM - for harder steel or tool steel alloys 250 SFPM. Finishing can be as high as 500 - 1100 SFPM with modern carbide tooling.
Sure, all that applies if you're pumping suds. Many hobbyists don't as most suds these days are water soluble and unless the lathe is in daily use the risk of the beds and slides rusting is too great.
So lighter cuts and smaller steps for hole drilling until the target diameter is reached, quite easy without suds if you are patient. For much work tool steels are OK and cheaper to equip with from the outset, but firmly limits what is possible if hard steels are encountered.
One can of course apply cutting oils neat and even some of the Rocol metal working pastes work fine for bigger cuts and hard steels.
Boring is the only way to finish holes with reasonable accuracy once an undersize hole has been roughed out.

At the end of the day one must work with the accessories on hand and much like test equipment the cost of the base unit is only the start.
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Offline capnahab

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Re: vintage lathe restoration - 3 phase supply.
« Reply #92 on: September 03, 2016, 07:12:03 am »
Great machining discussion, I think we will be kicked off here soon for OT but have a look at this guys videos - https://youtu.be/0cOhA2y8y6A
About 18.5 minutes in. Fantastic metal mowing. He really knows his stuff. I won't be using flood coolant as Tautech suggests.
eKretz - exactly.
There is a bit of a move towards spray mist coolant.

My biggest problem now is lifting the chuck and work on and off. Will need some sort of engine lift / hoist.
 

Online tautech

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Re: vintage lathe restoration - 3 phase supply.
« Reply #93 on: September 03, 2016, 07:52:13 am »
Great machining discussion, I think we will be kicked off here soon for OT but have a look at this guys videos .....
I don't see why, this is your thread.

Quote
My biggest problem now is lifting the chuck and work on and off. Will need some sort of engine lift / hoist.
Will you really be doing such large/heavy work ?

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Offline Gyro

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Re: vintage lathe restoration - 3 phase supply.
« Reply #94 on: September 03, 2016, 09:28:29 am »

My biggest problem now is lifting the chuck and work on and off. Will need some sort of engine lift / hoist.

I'm not sure I'd want to be you first patient on a Monday morning - not after a weekend of lugging heavy chucks around and playing with your cutting depth!  ;D
Chris

"Victor Meldrew, the Crimson Avenger!"
 

Offline woodchips

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Re: vintage lathe restoration - 3 phase supply.
« Reply #95 on: September 03, 2016, 11:48:43 am »
I agree with eKretz. Pilot holes are only for underpowered and, more important, flimsy machines. Must say that a pilot the size of the central web on the drill is easier than relieving the web to cut better. Just the same on a drill press, but only if the work is bolted down.

Had a visit from Harrison lathes when at school, back in the 60's, and their idea of a pro[per lathe was for it to ruduce a bar the size of the headstock spindle bore in one cut. For years I had just such a piece of swarf, and it wasn't 2 thou feed rate either. Their vist impresse me so much that when I bought a decent lathe I got a Harrison L5A. Must say that my brothers Colchester Student is evem better, look at the width of the bed.
 

Offline capnahab

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Re: vintage lathe restoration - 3 phase supply.
« Reply #96 on: September 03, 2016, 04:43:51 pm »
Nothing too heavy and not a great chip but heres some 3 inch titanium as a starter. Titanium seems to have a bad reputation for machining but I like it more than steel. If you get it too hot you can have an exciting fire as it burns like magnesium wire..

https://youtu.be/ZmKt9hXkB20
 

Offline capnahab

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Re: vintage lathe restoration - 3 phase supply.
« Reply #97 on: September 03, 2016, 04:45:50 pm »
 

Offline SeanB

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Re: vintage lathe restoration - 3 phase supply.
« Reply #98 on: September 03, 2016, 08:00:02 pm »
Tip for those relays is simply to clean the contacts, using a contact file ( or the smallest flat file in a set of regular needle files) to get the surfaces mostly flat. Nothing too rough, just take the bumps off once every few years and the contacts will survive. The broken insulator is Bakelite, available from most industrial material suppliers of plastics, so just get a small offcut of the right dimensions and cut with metalworking saws, avoiding the dust.

LED lights for the lathe are available, but the original lights are still available from the larger industrial suppliers, or they have LED retrofit kits. LED lighting for the work area is good, buy a good quality waterproof one ( and 2 spare ones, they will be broken sometime or the other) with a separate 12V transformer, and a decent mount. A smaller one on a magnetic clamp will also be invaluable.
 

Online tautech

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Re: vintage lathe restoration - 3 phase supply.
« Reply #99 on: September 03, 2016, 11:34:07 pm »
It will be interesting to see how hard you can push this 3 phase lathe from a single phase supply.
Do you have access to a current clamp, preferably one with peak hold?
Bigger cuts at high speeds will be a good test.

If your supply is via a breaker at good trick is to the highest class "motor" rated breaker that allow significant periods and percentages of overload before they trip.
Avid Rabid Hobbyist
 


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