These are for disassembling the big old 3-phase motor that came with my recently bought large lathe. I can't start on refurbishing the lathe yet, but I do have space to do the motor. It was made in the early 1950s, and looks like something out of a 1920s Amazing Stories (early SciFi) magazine illustration.
Edit to add: The plate says the motor is Y-wound, and there is no Neutral. Any one know if this is a problem for variable frequency drives?
Open frame (ventilated) 6 pole, yeah they made them big back then.
Interestingly, that sheet metal mesh outside around the end vents, is spotwelded to the cast iron endpiece. I didn't know that was possible.QuoteGunna spigot the 2 socket parts THz ?
That'd keep alignment good and it looks better too.....like you know what you're doing.
If I knew what I was doing, I'd probably know what you meant by 'spigot'.
Do you mean cut a lip in the faces on a lathe, to center the extension tube accurately? And chamfer the weld seams? I will be doing that. Just haven't found/bought a suitable bit of tube yet, so don't know dimensions.
Alignment will be by clamping the parts in a bit of L section.
In the motor, the windings/pole piece seems to be fixed in the frame solely by heat-expanding the frame onto it. I think I need to separate them for a few reasons, so heating the frame up (without wrecking the old windings) will be a bit nail-biting.
Edit to add: The plate says the motor is Y-wound, and there is no Neutral. Any one know if this is a problem for variable frequency drives?
Btw, did anyone else catch that company name on the brass plaque?
"Lancashire Dynamo & Crypto Ltd England"
Open frame (ventilated) 6 pole, yeah they made them big back then.
Interestingly, that sheet metal mesh outside around the end vents, is spotwelded to the cast iron endpiece. I didn't know that was possible.QuoteGunna spigot the 2 socket parts THz ?
That'd keep alignment good and it looks better too.....like you know what you're doing.
If I knew what I was doing, I'd probably know what you meant by 'spigot'.
Do you mean cut a lip in the faces on a lathe, to center the extension tube accurately? And chamfer the weld seams? I will be doing that. Just haven't found/bought a suitable bit of tube yet, so don't know dimensions.
Alignment will be by clamping the parts in a bit of L section.
In the motor, the windings/pole piece seems to be fixed in the frame solely by heat-expanding the frame onto it. I think I need to separate them for a few reasons, so heating the frame up (without wrecking the old windings) will be a bit nail-biting.
Edit to add: The plate says the motor is Y-wound, and there is no Neutral. Any one know if this is a problem for variable frequency drives?
Btw, did anyone else catch that company name on the brass plaque?
"Lancashire Dynamo & Crypto Ltd England"
It also says that individual motor was built in Oz by Nilsens.
They used to be big in all sorts of industrial electrical stuff--- we used to sell their battery chargers at my first job, & I saw a lot of their gear during the early part of my later technical career.
The very look of that motor takes me back---- a lot of the motors I ran into over the years would have been of a similar vintage.
They were pretty much unkillable, but if you did, there were motor rebuilders who could pull them apart & fix them, giving you another 20 years!
There still might be one or two of those Electrical Fitter/rebuilders around, who can give you some tips.
Being cast, it's not like it will rust away anytime soon like if it was steel. Hit it carefully with a flap wheel or a cup brush, smear some grease on the brass plaque and slop/spray some paint for decoration on as like I said cast ain't gunna rust away anytime soon.
For the socket tube, another thought.....diff axle tubes can be fairly thick wall tube if you have some of that sort of scrap lying about.
The plate says the motor is Y-wound, and there is no Neutral. Any one know if this is a problem for variable frequency drives?
That's pretty normal and shall work with an VFD. But I won't recommend doing so: The high dU/dt at the VFD's output might kill these old windings, the isolation material isn't made to cope with that and may break down over time. If you want to use a VFD with such an old motor, I'd recommend a sine filter (placed between VFD and motor).
Being cast, it's not like it will rust away anytime soon like if it was steel. Hit it carefully with a flap wheel or a cup brush, smear some grease on the brass plaque and slop/spray some paint for decoration on as like I said cast ain't gunna rust away anytime soon.
Rust is not the problem, it's the thick multiple coats of paint flaking off, same as on the lathe. With plenty of concave nooks, so forget flapper wheels. Plus wanting to get a painted finish on the motor consistent with the lathe. The lathe paint-removal will be a big job and WILL involve sand blasting. So, the motor too.
I took the motor frame to a motor rewinding place today, and asked advice about separating the frame and field assembly. Their opinion: forget it. Much harder than you'd expect. Better to sand blast with the windings in place, but protected with something.
Then driving home I found a roll of old thick carpet on the kerb, so that's my first choice of a protective layer.
That leaves the problem of getting the nameplate pins out. I think that won't be too hard.QuoteFor the socket tube, another thought.....diff axle tubes can be fairly thick wall tube if you have some of that sort of scrap lying about.The plate says the motor is Y-wound, and there is no Neutral. Any one know if this is a problem for variable frequency drives?
That's pretty normal and shall work with an VFD. But I won't recommend doing so: The high dU/dt at the VFD's output might kill these old windings, the isolation material isn't made to cope with that and may break down over time. If you want to use a VFD with such an old motor, I'd recommend a sine filter (placed between VFD and motor).
Oh. Good point. Never having used a VFD before, I had assumed they'd all (mostly?) use HF chopping with a filter, for reasonably sine-like outputs. Are there any like that?
Then driving home I found a roll of old thick carpet on the kerb, so that's my first choice of a protective layer.
That leaves the problem of getting the nameplate pins out. I think that won't be too hard.
For the socket tube, another thought.....diff axle tubes can be fairly thick wall tube if you have some of that sort of scrap lying about.Heh. There's not many kinds of scrap I don't have lying around. Yep, a couple of transmission shafts. But they are spares for my Subaru. What I'm using is a section cut from an exercise treadmill belt roller. Pretty much ideal.
Oh. Good point. Never having used a VFD before, I had assumed they'd all (mostly?) use HF chopping with a filter, for reasonably sine-like outputs. Are there any like that?
Great, the carpet should help protect the lathe bed when you get onto doing that.
The plaque pins, are you sure they're not screws with their slots full of paint ?
Will you turn a step (spigot) on the 2 socket pieces for the tubing ?
Gunna tap the hole out for some better looking brass screws ?
Yeah I wondered how you'd get on turning impact sockets.
Gunna tap the hole out for some better looking brass screws ?
Nope. With really old things I like to maintain historical accuracy. In another 60 years or so, the next person refurbishing this lathe may wish to put in newfangled brass screws.
What I'm really torn about, is whether to use boring gray paint (per 1950s original) or something a little more cheerful. I think the latter.
Nipple pink or breast flesh white ?
Gunna tap the hole out for some better looking brass screws ?
Nope. With really old things I like to maintain historical accuracy. In another 60 years or so, the next person refurbishing this lathe may wish to put in newfangled brass screws.
What I'm really torn about, is whether to use boring gray paint (per 1950s original) or something a little more cheerful. I think the latter.QuoteYeah I wondered how you'd get on turning impact sockets.
I was surprised actually. To do anything with the impact socket parts I'd half expected to have to use grinding in the lathe. Something I prefer to avoid, since the grit gets into the ways.
But actually they are not extremely hard. Silversteel bits do cut it. Just with a high wear rate, and only shallow cuts.
Maybe I'll still do the grooves with a plain cutting bit. They can be very shallow.
Motor rewinders used to have a fetish for slathering everything with blue Hammertex paint.
good old fashioned paint stripper.
The key words are 'old fashioned'. The modern stuff here is useless. I bought a large can of Nitromors in Homebase (Bunnings before they offloaded it) a few months ago. It was useless, did not even touch the surface of the 1960s metal paint on aluminium parts.
I ended up sending the parts off the be professionally striped.
According to the striper they changed the formula about 15 years ago, removing the 'good stuff'. It certainly did not smell as strong as I remember.
Oh. Good point. Never having used a VFD before, I had assumed they'd all (mostly?) use HF chopping with a filter, for reasonably sine-like outputs. Are there any like that?
California is really bad about restricting everything.
This state is turning into Cuba West, you can't get any good affordable paints here anymore and don't even think about getting anything stronger than acetone, they would ban that if they could get away with it.