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Hi Martin John and Jim,
 Thanks for your advice and information, I do see that you have both answered this question before so thanks again.
I do think that epoxy might be the best way forward and of course the most expensive but I wont spoil the ship for a "ha'p'orth of tar."
Yes Martin, she is really strong, probably why the real vessels were as well...
 Alan 17-09

100MHz are cheap - Gigahertz less so... :(




Shows £20 for me. And when do you need to measure 600A?

This happened when I posted a link to a dual esc. For my privacy I stripped off the url cookie before posting. As a result everyone sees the default option which can be changed at the page foot. There can be several stocked variations which can mean as little as a more popular colour, or a "pro" option, a carry case or more features. Aliexpress shopping means you have to put in the hours to know the process. So I'd recommend looking through the spec list and comparing with other Aneng meters after hitting the "find similar" button.
 It isn't so much the 600 amp range but frequency counter, true rms etc and you'd pay well over a hundred quid for a dc current type if you needed to rush to a trade counter in an emergency.

Here are a few pics of the Comet.  First the brushes, and to me they don't look too bad at all.

Brushes don't look too bad - commutator less so.


Check the thickness of the Beryllium copper strip brushes where they contact the commutator. They might be worn thin, and if so could break, then snag on the commutator.
The commutator tends to arc where the brushes cross over to the next section. Annoyingly, this is exactly where the holding tab into the backing paxolin is situated, so the tab conducts heat that makes the paxolin eventually crumble.
Do you fancy making up a new commutator? It's fairly easy if you use a Dremmel to sand the small pieces to size.


The Comet looks like a later one. The earlier Comets did not have the metal armature slices very well aligned, since they were hand-assembled. Yours are quite even.

I think you'll find high frequency digital storage scopes are needed to pick up that stuff.

100MHz are cheap - Gigahertz less so... :(

Next best pondside tech toy after a handheld scope is a dc current capable clamp meter. £14.34 is the discounted price for those new to the store. I don't need another, but I checked that is a hall effect type that does d.c.
Some reviewers have not sussed you have to store a reference zero reading before each true reading.https://www.aliexpress.com/item/1005005757085279.html

Shows £20 for me. And when do you need to measure 600A?

 I might have missed it... have you powered up the motors as yet?

  How do they run?


 

Hi Alan
Have a look at this post ,it may point you in the right direction 


Do I need to seal a solid obeche hull before painting?


John

...the draw will be around 110 Amps, so use a large battery...'  !"  - - - - - Rubber gloves and a hazmat suit


  Battery IS a car battery and you only give it a pulse, Never zapped the whiskers from a DEAC?


 Copy gone Dodgy.


  Regards Ian.


  Looking at this, just shows how the instant gratification era has pampered today's muddlers.

Afternoon All


I did have a quick look at the PDF sent over by Ian for the magnetiser, and must admit I wasn't quite prepared for the '...the draw will be around 110 Amps, so use a large battery...'  !


Moving on.  Here are a few pics of the Comet.  First the brushes, and to me they don't look too bad at all.





And the Commutator








Doesn't look too bad to me, this is as removed so I'll clean it up and post the results.  There could be some damage maybe done by the arcing to the commutator, see the 9 o'clock position where the brushes have been running.


The coils look OK but some of the varnish (?) is peeling away, is that an issue..? Shaft has no apparent damage or grooving so should clean up OK I think.








Any other observations..?


Best regards
David.

Alas, I have a dicky scope (hoping for a new one for Xmas!). When I get it, I will be able to have a look at the power leads with/without suppression...

I think you'll find high frequency digital storage scopes are needed to pick up that stuff.

Next best pondside tech toy after a handheld scope is a dc current capable clamp meter. £14.34 is the discounted price for those new to the store. I don't need another, but I checked that is a hall effect type that does d.c.
Some reviewers have not sussed you have to store a reference zero reading before each true reading.https://www.aliexpress.com/item/1005005757085279.html

I suspect that my operative word is 'Cheap'. Most of my boats are small and low-cost, and so ESCs at under a fiver are what I use a lot of. Mostly, they work. But I rarely use 12v...

I was seeing them for just over a pound each during the last sale.

Hi Dodgy you have a PM
Roy