Thread: Help with electric motor

I was thinking about it , but it may be more than my finances can bear atm .
Then I would need a tachometer ,or do they come with a vfd ? .
I'm not clued up on them so may have to do some research first.
But I need to get the machine going as I have a few jobs to get finished .

Kev.

Originally Posted by A Duke

Hi,
It is not that we think every one is stupid, you just do not know, so if it is taken to the right person they can physically see it and not go on a vague and incomplete description. The thing that scares me is that some of the answers show absolutely no knowledge of the subject and those that know what they are talking about assume a knowledge the reader (who may or may not be the person who originally asked) may or may not posses.
So my advice is always call in some one qualified.
I am just explaining my position and not having a go at any one in this post so I hope I have not offended.
Yours in the hobby,

No offence taken , more I'm a little pi**ed off with the motor on my machine , and a bit short on the fuse atm.
I apologise if I came across a bit harsh .
As I said in my last post if I had no experience with electric motors , I would have taken it to some one with more quals than I have . But also there is a shortage of willing people to look at these things here and it happened on a weekend .
I can lay 100 bucks on what the guy will say tomorrow about the motor , and I'm sure he will make no attempt to repair it or replaced any wiring with crumbling insulation.
It will be deemed dead ,finished, an ex electric motor , not just pining for the fiords . I'm quite sure of that.
It's a throw away world these days which is a pity as this motor is a very solid cast iron framed affair and is quite well constructed apart from the old rubber type insulated wire they used in it.

Kev.

Originally Posted by Woodlee

It will be deemed dead ,finished, an ex electric motor , not just pining for the fiords.
Kev.

LMAO at the Python reference. So you're sure its not just taking a kip on its back then?

Back luck with the motor mate, I imagine the services in Katherine are much like where I grew up, and I can understand why you have to try and fix it yourself if at all possible.

Random thought though, do the mines have their own repair facilities and crew onsite, or do they ship everything out to get repaired? I just wonder whether you might be able to get onto a mate in the mines with access to motor rewinders, either onsite or chuck it in with something else they are getting done? Surely they must have motors failing fairly often in that environment?

[QUOTE=Woodlee;1266977Then I would need a tachometer ,or do they come with a vfd ? .
[/QUOTE]

all the good ones do that I am aware of

Originally Posted by Jekyll and Hyde

LMAO at the Python reference. So you're sure its not just taking a kip on its back then?

It probably wouldn't vroom if you put 10000volts through it, either.

Don't know if this is any help, but I've got the single phase motor I pulled off my mill when I converted to VFD, you're welcome to it, if you pay the freight cost. It's a 90L frame and I can measure the shaft and keyway if you're interested in it.

Regards
Ray

Originally Posted by eskimo

all the good ones do that I am aware of

Mine has a Hz display, but thats not a tacho. You need to do some maths depending on what gear the mill is in. I have a lazer tacho, but I'm not normally that fussed.

Just been buzzing Royce Cross' website ,they have variable speed drives available there is aTeco model 240V input 240 volt 3phase out put for 595.00 ,not sure if this would be suitable , by running a 240V motor off one phase .Is that possible?Don't really understand this stuff at all.
They also have a range or motors , but all have short shafts (50mm ) which means making extension bushings, re-boring the pulley and cutting a new key into it. etc
They also have a rewinding service so it maybe worth testing the water there and see what it would cost for them to check it out and see if they can repair it.I don't think the windings are cooked as there is no stink inside the motor ,it maybe just the crappy insulation on some of the internal wires that connect the windings.

Ray the shaft on my motor is 3/4" (.750") ands is 3 1/4 " long ,it takes a 3 step pulley ,the key is about 5 or 6mm sq.
I took a heap of measurements and am going to darken it a bit tomorrow on the photo copier at work (drew it in pencil) ,then I can scan it and post it up.

Kev.

Originally Posted by Jekyll and Hyde

LMAO at the Python reference. So you're sure its not just taking a kip on its back then?

Back luck with the motor mate, I imagine the services in Katherine are much like where I grew up, and I can understand why you have to try and fix it yourself if at all possible.

Random thought though, do the mines have their own repair facilities and crew on site, or do they ship everything out to get repaired? I just wonder whether you might be able to get onto a mate in the mines with access to motor re-winders, either on site or chuck it in with something else they are getting done? Surely they must have motors failing fairly often in that environment?

The mines don't have those facilities ,the local scrap dealer here is always getting heaps of big hp dead electric motors , the mines just change them out and sell them for scrap when they die.
Maintenance is carried out by contractors , but some do have a small maintenance crew(2 or 3 persons , a fitter or two and a sparkie) employed for smaller emergency repairs.

The biggest mine is the Ranger Uranium mine ,I worked there for a number of years in the machine shop and the power station and a few other areas .
They never bothered rewinding motors either , they just tossed them in the waste dump and buried them because of radiation contamination.

The days of big repair /machine shops and doing in house repairs are gone from the mining industry here at least ,
contractors and replace with new /sending broken stuff to the scrap dealer is the order of the day now.
They reckon its cheaper to replace busted stuff and employ contractors to do the maintenance work rather than employ workers .
They don't have to supply housing , workers compensation insurance , holiday pay etc.Of course this is all factored into the contractors fees and charges plus a bit of profit , so they do end up paying , and probably more so.


Kev.

Rays motor might come close, I am pretty sure they a 20mm shaft and would be close to that in length.

Dave

Originally Posted by Woodlee

Ray the shaft on my motor is 3/4" (.750") ands is 3 1/4 " long ,it takes a 3 step pulley ,the key is about 5 or 6mm sq.
I took a heap of measurements and am going to darken it a bit tomorrow on the photo copier at work (drew it in pencil) ,then I can scan it and post it up.

Kev.

Hi Kev,

The shaft on this one is 24mm diameter with an 8mm key and 48 mm long (measured from flange)

I checked another 2hp single phase that came off the bandsaw, and it's 24mm as well..

Regards
Ray

I'm just home from work for lunch , to pick up my motor and take to the electrical shop .
The shaft on the motor is 3 5/8" long including a 1/4" shoulder at the front housing so that's 3 3/8" of shaft for the pulley to fit onto ,the pulley is about another 1/2 longer than that ,but I could turn some of the boss at the rear of the pulley off.
The key is 5mm ,strange how this motor has all of it's dimensions and threads in imperial but a metric key.

I'll drop it off and get it tested properly and see what the verdict is.If its the windings Ill ask their advice as to a motor re-winder in Darwin and get a quote for a rewind. Failing that Ill get a quote from Royce Cross .
Ill post the sketch with the dimensions this evening.

Edit sketch added . but I noticed the dimension for the foot width got snipped off by the scanner ,its 8" wide

Kev.

Anyway how did you get on with motor. If your really stuck and can wait i am a 3rd year apprentice and have trade school in 4weeks and 2 out of the three of my teachers are old time rewinders. thanks

Thanks ,
turns out it was a dodgy terminal block ,some of the threads on the screws were rather less than ordinary .
I took it to an electrical repairer and he installed a new terminal block .I put it back on the machine and its all good.He reckons the repairs I did to the wiring are pretty good and will be ok.
Thanks for the consideration ,much appreciated.

Kev.