Soldering to the case can be a nuisance. I tend to mount my motors by bolting them by the front securing holes to a piece of right angled metal plate which acts as a motor mount. With small motors you can use aluminium alloy angle.

One end of each capacitor is soldered to the respective motor power tag connection and the other ends are soldered together and to a piece of wire which is brought out over the top of the motor and connected to a tag screwed to the motor mount face which of course is electrically conductive to the motor case.

Colin

Having extension wires could also cause radio interference…..So Google tells us?

"Telstar" Tom and I wouldn't disagree with that; neither would Malcolm F. Keep 'em short.

DM

Hi Bob and all,

I've just been trying to solder to a motor casing, a 600 motor from Mtroniks, and no matter what way I tried the casing would not take solder [ filing, small drilling, scrapping, 100 W iron, even red hot poker!] I resorted to very carefully drilling a "slow hole" (so as to catch the swarf) and put in a small self tapping screw and used that for the case contact.

Sometimes It can't be done – or am I wrong?

Kim

Hi Kim 9 out of 10 times when soldering to steel some form of flux is needed to keep the area to be soldered from oxidizing as soon as the heat from the soldering iron is applied. Bakers Fluid is ideal, BUT it is very corrosive and needs to be cleaned off after soldering, I normally get good results with Fluxite Paste, this is slightly corrosive, but if you wipe the surface clean after 'tinning' then solder on the components .

Sure thing Dave, long leads and oxidized nut & bolts connections are a no no with RF

cheers Tom

I have always thought that it is the plating on the motor casing you are soldering to, and I only ever clean the casing with thinners or whatever..no filing or sanding. Certainly I had a large amount of Hornby "O" guage track re-plated with tin, and I made repairs to junctions and so on after and it was a doddle to solder to.

Most motors have tapped holes at the front end to use if desperate although the leads might then be a bit long.

Personally i have never had much of an issue with suppression other than in boats that have all the gear crammed together. I usually only fit a capacitor across the terminals and see how we go. No one else on the pond has suffered because of this "lack" of suppression, before anyone says anything

Ashley

Re: solder and Tinning

Found this link may shed some light on things

Ashley As you said, once the job is tinned it's easy. However some motor cases are Nickle plated or galvenised (zinc plated) to prevent corrosion these metals are much more difficult to 'tin'

Tom

I can't recall any problem with any motor I've done, but then I use a half-round warding file to grind off any plating and reveal bright metal underneath.
DM

Dave,

The subject of fitting capacitors has been discussed in many threads. Previous discussions have covered fitting a diode across the motor terminals with a heavy sparking (noisy) motor. You kindly provided details of the correct diode in a thread on this forum.

If it is necessary to replace the motor terminal to motor terminal capacitor with this diode, should the motor case to motor terminal capacitors be removed or left in place? or is it irrelevant.

Tony