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[sunnybob]

I've bought two electronize motors, and each one has come with 3 small capacitors (I assume?) but no instructions. >:(

Are these capacitors just noise suppressors? if so, why 3 per motor?

Thanks.
Bob

[FullLeatherJacket]

Yep - that's what they are. There are generally two different values, often 10nF (marked 103) and 100nF (marked 104). The single, larger-value one is soldered across the two brush/wire connections, and the others are fitted between each of the brush terminals and the case of the motor.
FLJ

[DickyD]

Bob check this out. Nice picture of what to do.

http://homepage.ntlworld.com/fast.electrics/caps.pdf

[sunnybob]

FLJ.... thanks for that, but I have now checked the numbers, and I have 6 x 103. Should I still use them as directed? or are they wrong?

Dicky, great drawing, but now I'm even more confused. I have an electronize fr30hx speed controller which will be running both motors. I assume its reversible. so I should not bother with the diode? (which I dont have anyway).
All advice much appreciated, I didnt know what I was getting into when I agreed to complete this model :)

Bob

[FullLeatherJacket]

Bob
They should do. If not, PM me and I'll sort it out. Dicky's piccie is fine for your purposes if you ignore the quoted values of the capacitors and the presence of the Schottky diode; you ain't got one and you don't need one!
FLJ

[sunnybob]

FLJ... how important are they? will the motor make much noise?

I can solder them ok, just wondering why they arent included inside the motor if they are essential?

And if they have to be there, why dont they put a tag on the motor casing?

bob, beginning to hate electric motor makers

[DickyD]

Looks like FLJ has gone for a lie down.
You fit them because if your motor is not suppressed you will get interference that will affect your radio control reception.
Dont get uptight we all have to do it though some of the more expensive motors come already suppressed, but if your paperwork doesnt say they are you have to fit them..
Carry on soldering.

[Colin Bishop]

I must say I am finding it quite an eye opener hearing Sunnybob's fresh approach to things that we old lags always take for granted. Motors make electronic noise and need to be suppressed so why don't they come that way - what could be more logical? Why can't manufacturers of RC gear and chargers etc. standardise on plugs - seems only sensible!

Carry on asking questions Sunnybob, you are doing us all a favour. 

[DickyD]

My last Graupner and Deans Marine motors were suppressed Colin but they weren't cheap motors and were also 5 pole. 

[FullLeatherJacket]

Bob
I've first-hand experience of what happens when a suppressor cap comes unsoldered from the motor. In my case the whole radio went berserk and one had to wait while the butler got his waders on and fetched one's boat back. For the price and effort involved in fitting a set it's not worth not doing so.

On a more philosophical note (O, no! He's been on the G&T again....) it may come as a bit of a surprise/rude shock, but those motors from Electronize aren't manufactured specifically for the RC model boat fraternity. They are used in hundreds of thousands of different cheapo power-tools, car-window mechanisms, kiddies toys etc etc. They are churned out in numbers of millions per week in PRC and probably hand-wound on modified 19th century treadle-powered sewing machines by wind-wrinkled and sun-bleached Chinese peasants for about a dollar a dozen. If one in every squintillion finds its way into a model boat then that's about the sum of it. Suppressors? Why fit 'em if only 10^-23 % of your target customers actually need them?

As for standardising on plugs, Colin, most now seem to have done so - except for Mr Futaba. Shame he got it the wrong way around i.e. his servos won't fit anyone else's gear, but theirs will fit his..................or I can flog you a Futaba plug shell for about 25p!

Please pardon yet another piece of world-weariness from yours truly, but this is the era of global capitalism. From where I sit, we don't look much like beating them, chaps.   :(

FLJ

[Colin Bishop]

or I can flog you a Futaba plug shell for about 25p!

Most of my Futaba gear is M Series Mk1 version, stone age vintage. The wires haven't gone black under the insulation - they've fossilized! 

[FullLeatherJacket]

Most of my Futaba gear is M Series Mk1 version, stone age vintage. The wires haven't gone black under the insulation - they've fossilized! 

What will it take to drag you into the 1980's, Admiral? 

[sunnybob]

Colin... sorry, I'm a bit of a raver.. NO! ranter! thats the word!! I work with machinery all day long, and I could make every single item work more efficiently if I was in charge :angel: :angel: :angel:.

FLJ, a good explanation, but just how much would it add to the production cost to make all their motors spark free? Or at least put an earth tab on that case? maybe another grain of rice per employee per day? And even hair dryers and window winders still cause interference on radios and pace makers  .

Looking more closely at that motor casing, thats steel, and is going to be a pig to solder without overheating the wiring inside. I think I'm going to solder an M3 eye tag on to the capacitor and thread the motor mounting bolt through it. A dab of blue loctite will stop the bolt from loosening off.

Despite the steepness of the " learning curve", I'm looking forward to actually finishing the hull, and getting on with the important stuff.

C'mon wife, paint faster!!!!! ::) ::)

[Colin Bishop]

What will it take to drag you into the 1980's, Admiral?

I think you meant 1890's didn't you?

Sonnybob, your idea is a lot less messy than trying to solder the case.

[BarryB]

Hi sunnybob

FLJ is telling it how it is in this harsh world.

There is perhaps another reason (apart from economics) why the caps are left off.  The sparks generated can be rectified and used to give some indication of how fast the motor is going (back EMF).

I'm not saying the back EMF change (with or without caps) is particularly significant, but needs to be taken into account in some ESC designs.

e.g. I use this attribute when I design speed controls for model trains - I pump up the speed automatically when I sense the loco is labouring, e.g. by going up hill.

Barry