MSCs and low turn motors?

[Burmanater]

Well since I had a couple spare MSCs laying around I decided against better judgment to do a little testing. I order an 18T Ansmann Kong motor and dropped it in my VLB with the old electronics and the MSC.

So far after running it for near 3 hours straight with only enough cool down time to change a battery it's still going strong. Motor got warm but never hot thanks to the heat sink. Checked the temp on all the electronics and the MSC not even warm.

Has anyone else done anything like this and how long did it last? I'm not really a fan of ESCs but I'm biased because I just like old school things.

[Butler]

Did you check the temp on the white resistor?

An MSC is just a switch, no reason for it not to work fine as long is its clean and in good order.

[Gruntfuggly]

As Butler says - it should be fine. If you drive at full throttle most of the time you shouldn't have too many problems. If you use the lower speeds you might - because the resistor has to burn off the excess current. The only other problem you might have is that if the MSC gets too hot, it will probably just desolder itself...

[Burmanater]

I did check the white resistor and it was warm but not hot. It wasn't anything I had to pull my finger away from. Thanks for the tips guys.

[pizzachaude]

Tamiya msc are very tough and will handle lower turn motors just fine. Its usually the tamiya battery connectors and also the bullet connectors for the motor that could give you problems if you are still using them. Kyosho msc uses aluminum and they don't hold up well (they burn right through!)

[markbt73]

Tamiya msc are very tough and will handle lower turn motors just fine. Its usually the tamiya battery connectors and also the bullet connectors for the motor that could give you problems if you are still using them. Kyosho msc uses aluminum and they don't hold up well (they burn right through!)

Yep, we used to call the Kyosho ones "spot-welder specials" because they would sometimes actually melt the wiper contact to the board. No good.

The hottest motor I ever ran with a Tamiya MSC was a 17 turn double. The battery connector got hot (and I mean HOT) but it held.

[pizzachaude]

Ha ha! I ''spot welded'' a Kyosho rotary MSC with a vintage Speedworks 350 (I think its 15 turns).

But if you use the Tamiya MSC then your best bet is to use aftermarket battery connectors such as Deans, and I usually solder the motor wires directly to the speed controller. Mind you I personnally dont use MSCs, prefer the peace of mind of ESCs in my runners.

[Klausen]

I used to run a modified Yokomo motor in my Grasshopper II back in the days with the msc. I am not sure which turn it was, but it was really fast compared to the 540 silvercans. Only issue I ever had was wires desoldering from the msc.

I do prefer esc's as well though, way more smooth.

[XV Pilot]

I have never had any issues with the MSC mechanism itself, even on low-turn motors and twin motor installations.

The resistor on the other hand is another story. Before I switched to a dual ESC setup on my Twin Detonator, I cracked two ceramic resistors and melted the insulation off the thin wires that run between the resistor and the MSC. I also burned my fingers on it more than once, and nearly started a grass fire with it too!

[94eg!]

Put dielectric grease (silicone) on the contacts of the MSC. That will reduce arcing (welding) and increase the life of the component. The other trick with running a low-turn motor on an MSC is to use part-throttle as little as possible. This will reduce the use of the resistor and thereby reduce the amount of heat within it. That means you are mostly full throttle and no throttle.

I ran a 16T Speedworks 427 back in the day in my brand new Vanquish. Needless to say the Tamiya resistor didn't last too long (cracked right in half). The replacement one I got at the hobby store (hollow & round instead of square) lasted much longer, but the ceramic coating eventually started to break apart. Motor & car were brand new.

BTW: Use of part throttle on an MSC is simply wasting your battery energy as heat.

You could probably reduce the load on the resistor by running two resistors wired in parallel. You would have to solder another 3-wire resistor pigtail onto your MSC. But that would certainly make them last longer. I'm not sure if that would change part-throttle performance though.

[danb1974]

Do I get it right, the msc actually has only three positions, off, though resistor and full power? No point then in actually running a msc nowadays, only for use in rebuilding old cars for display

[94eg!]

Depends on the one you have, but Tamiya's typical one from the late 80's had 7 positions.

- Reverse 3 (no resistor reverse polarity)

- Reverse 2 (half resistor reverse polarity)

- Reverse 1 (full resistor reverse polarity)

- Neutral (off)

- Forward 1 (full resistor)

- Forward 2 (half resistor)

- Forward 3 (no resistor)

Kyosho also had this one with only 1 speed reverse (can't remember the resistor position if any)

There were also earlier racing MSCs that featured an externally wound resistor where the wiper blade would move across the surface as you pulled the trigger. This gave the effect of more subtle steps. Tamiya's was called the "Swtich Set SP1054", but you can bet it was only made to handle silver cans and maybe black motors. This featured back-emf braking but I can't quite tell how that functioned. From the look I would say it is forward & brake only, but I'm not 100% sure.

http://www.tamiyaclub.com/trades_model.asp?cid=105274

[markbt73]

The early Associated MSCs, in the RC12E and RC12i and the early RC10, were forward and brake only. Brakes just shorted the motor to itself and, on the little 1/12 cars, basically locked up the rear axle. You only used it if the alternative was hitting something.

[Burmanater]

I personally run MSCs because I like how you can get that reverse to forward snap that just seems to not be there in an ESC. That being said I would only run them in LB/MP or any of the Frog chassis kits where wheelies are a must.