A Lesson in Cataloguing Your Parts

[Trevanion]

I've been rebuilding a Europa 340 power feeder unit for a while now intermittently and I had totally rebuilt the gubbins, new bearings, new wheel cover, changed the gearing ratio to facilitate a slower feed speed, and I'd even painted it all! In all I've probably spent £80 in parts, let alone hours spent!

Between taking apart and putting it back together it had been about a year and a half, and all the parts were just jumbled in a Celebrations tub. When re-attaching the motor, because I had no real clue what went back in, I used the incorrect screws to attach the motor via the flange to the feed unit itself, 25mm in length instead of 15mm! The screw born against the windings inside the motor and when I attempted to start it up it just blew fuses, at this point I didn't know what was wrong until I got a multimeter and found that the windings were all earthed. I had effectively turned my electric motor into an arc welder.









I just brought it back from the local rewinder, who quoted a cool £500 to rewind it (realistically a whole new feeder is ~£700). A new motor supposedly cannot be sourced/adapted because of the unique slotted shaft end and unique flange with seal.

My options as of right now are to try and find an identical new motor, which will be difficult and my first port of call would be CEG/Orange1 Motors who originally made it. Or, to have a crack at rewinding it myself, which will be nigh on impossible given my lack of magic electricity skills, but possibly given enough time and research it could be done.

So yeah, make sure you catalogue your parts properly so you don't end up like me! :lol:

 

[Robert]

Given there is nothing to lose it may be worth trying to repair the damage. Pull each broken pair up and solder a new bit of wire in to join them - say 50mm long piece and put sleeving on the wire to cover the joins. tuck the extra wire down the outside.

 

[Cabinetman]

Given there is nothing to lose it may be worth trying to repair the damage. Pull each broken pair up and solder a new bit of wire in to join them - say 50mm long piece and put sleeving on the wire to cover the joins. tuck the extra wire down the outside.

Sounds like a plan to me, if I remember correctly they used shellac on the wires.

 

[Mike G]

Oh how annoying!

 

[AJB Temple]

Unless there is hidden damage elsewhere, I too would have a go at fixing the relatively small number of damaged pieces.

Fully sympathise. I've taken to making a photo record now as I take things apart, and put matched components together in plastic boxes. Hope it works out.

 

[9fingers]

Excatly the problem brought me by a forum member years ago Olly Parry-Jones if anyone remembers him.

Screws driven into the windings on a disc sand I think it was.

Broken wires colour coded first


Crudely joined to check continuity



replace tidily with heat shrink and high temp silicone covered wires



Finally all up and running with the blur of a masking tape flag on the shaft.



Result and one happy customer.

Bob

 

[AJB Temple]

Dan, speak nicely to Bob. He has helped me in the past and saved me lots of money in the process. He is related to Paul Daniells.

 

[Pete Maddex]

Prise the wires apart paint with nail varnish job done.

Did it for the wifes hand mixer years ago, loose screw then she told me it had been rattling for a while!

Pete

 

[AJB Temple]

Some of the wires are severed Pete. He will need to establish both continuity and insulation.

 

[Trevanion]

Excatly the problem brought me by a forum member years ago Olly Parry-Jones if anyone remembers him.

Screws driven into the windings on a disc sand I think it was.

Olly's commented on a couple of my YouTube videos recently, so he's still about!

Your post is very interesting to me Bob as it shows that it possibly could be repaired, where the guy at the rewind place pretty much said that it was "completely boggered".

I'll have to pick your brains on it, as before, my knowledge is next to zero. I'm looking at your photos with widened eyes, trying to figure out how you managed to discern which wire goes where :lol:

 

[9fingers]

It just takes extreme care in working out which wire was laying next to which other wires and therefore which wires they went to on the other side of the break. DONT just pick out wires at random otherwise you will lose track. There is nothing technical about the process just observation, logic and care.
The damage appears to be only on the outer layer so you only have a 2D puzzle to solve rather than a 3D one.
If you want me to try and fix it then don't start yourself and then expect me to take over. That aint going to work. Either you start and finish it or I do if you follow me.
Either of us has to start with the realisation that is £$%cked at the moment and might end up the same way afterwards but there is a chance it will come back to life with luck.

Bob

 

[Trevanion]

Hurdle the first, in my ignorance I've already picked at them a bit :eusa-doh:

Not too extensively though and I think it's only a couple of wires that have blown through completely, I'll take another look at it when I get time as I won't get the chance to look at it again for a few days.

 

[Cabinetman]

I know this is going to sound stupid but, aren’t they just ordinary copper wires like you would find in the walls of your home without any insulation? So they are normally touching each other presumably. Why not just join the wires in that area together with a big blob of solder as they were touching each other anyway?

 

[DaveL]

The wires are all insulated, they have an enamel coating on them.

 

[Mike G]

Excatly the problem brought me by a forum member years ago Olly Parry-Jones if anyone remembers him....

I'm in occasional contact with Olly.

 

[Doug]

Olly’s big into walking these days & has a pretty active Instagram account showing the places he goes
https://instagram.com/walks.with.olly?i ... MyMTA2M2Y=

 

[Cabinetman]

The wires are all insulated, they have an enamel coating on them.

Whilst not doubting what you say, that surely must mean that in places the wires touch, as I mentioned earlier they used Shellac in the past to coat them and Just curious really what would happen if that coating allowed them to touch? Just not as an efficient motor?

 

[9fingers]

No Ian, the colour you see is a hard enamel over the whole surface of the copper. At no time must any part of the wire contact a neighbouring wire electrically otherwise shorted turns can occur leading to over heating and the magic smoke escaping.

Bob

 

[Cabinetman]

I suppose there is little chance of two bits with a not very good coating being next to each other, presumably originally they must have used properly insulated wires? Then to reduce the size of the motor they coated the wire? Doesn’t seem that it would be obvious that it should work to me, bet they were almost surprised that it did work the first time they threw the switch.

 

[Pete Maddex]

Enamel is proper insulation it will stand higher temperatures than pvc

The wife’s hand mixer has a couple of broken wires I had to solder together.

Pete

 

[Cabinetman]

Enamel is proper insulation it will stand higher temperatures than pvc

The wife’s hand mixer has a couple of broken wires I had to solder together.

Pete

Interesting, still not sure I’d like to touch wires with just a coat of paint on them lol.

 

[9fingers]

I suppose there is little chance of two bits with a not very good coating being next to each other, presumably originally they must have used properly insulated wires? Then to reduce the size of the motor they coated the wire? Doesn’t seem that it would be obvious that it should work to me, bet they were almost surprised that it did work the first time they threw the switch.

Enamelled copper wire is "properly" insulated. Ratings vary a bit with diameter but exceed 2500 volts for standard grades and rise to above 7500volts for the higher grades.
I just about remember SCC wire - Single cotton covered and DCC with a higher rating that my dad would bring home for work for me to make electromagnets from in the late 50s. This was soon replaced with an enamel that was a right s0d to remove by scraping to solder the wire. When I started work in 70s this had been replaced by "Self Fluxing" enamels which would just about melt with a hot soldering iron and act as a flux to aid soldering - a real step up in ease of use.

Modern motors are rated to a 60C rise above ambient temperature whilst maintaining their electrical isolation. Nowt wrong with enamel but it not proof against some prat driving screws into the windings :lol:
Bob

 

[Cabinetman]

Haha
:text-goodpost:

 

[Trevanion]

Modern motors are rated to a 60C rise above ambient temperature whilst maintaining their electrical isolation. Nowt wrong with enamel but it not proof against some prat driving screws into the windings :lol:
Bob

I didn’t need reminding :lol:

 

[AJB Temple]

I have a dim recollection of making a simple electric motor in physics class when I was at school. We had to coat the thin copper wire in resin of some sort and it involved knitting needles and a cork. We were also taught how to make a battery. Forgot the lot!

 

[AndyT]

I have a dim recollection of making a simple electric motor in physics class when I was at school. We had to coat the thin copper wire in resin of some sort and it involved knitting needles and a cork. We were also taught how to make a battery. Forgot the lot!

Adrian, here's your revision homework for this afternoon! :lol:

 

[AJB Temple]

:lol:

That's pretty much it!

 

[Trevanion]

The King Prat is back.

So I had a closer look at the motor, it looks like three out of four screws pushed on the windings, two were quite minor:





The one I showed before was not so minor:



I marked the wires in the orientation they were in (or at least, the way that seems the most likely from where they were sat, quite a large portion of the wire has disappeared) with a bit of electrical tape for the meantime.



Looking closer at the damage, it's hard to tell whether more wires are blown further in or whether the copper from above has melted down, it's not pretty regardless.

How do you think it would be best to proceed? I don't want to get carried away and do something stupid and make myself a bigger prat than I already have.

Interestingly, I noticed that the slots where the windings go had been colour coded, orange and red.

 

[9fingers]

Keep in mind that it is NBG at the moment so anything you are doing can't make it any worse.
Pick out any beads of copper and see if the enamel is intact if not then the nail varnish trick will sort out the insulation.
Anywhere the diameter of the wire has been reduced then cut out and re-join to remove the weak area which if left will burn you on the bum later.

Bob

 

[Trevanion]

I'll get on it when I have the chance, as you say, nothing ventured...

How do you deduce whether the enamel is intact or not? I know that it sort of has a slightly redder colour than the copper itself but it's still a bit tricky to tell, particularly further down in the area where everything is a bit black and burnt looking.

Another thing, is the wrapping very important? I've had to cut that one to expose the wires a bit better. I'm not sure what this stuff is but it's super sticky, a bit like fly tape.

 

[9fingers]

Clean the sooty bit off with IPA and a brush and yes the copper is a different colour from the enamel.

I tend to lace up after modifying windings ( usually when slitting out the delta point on 3 phase motors) otherwise they will move as a result of the current flowing in the wire according to Flemings left hand rule.

Bob