Engine Problems !!

[ricksta]

Hi there everyone,

i am hoping that one of the experts out there might be able to help out with a bit of a problem that i have with my Scalex cars.

I run a Scaley setup which is fairly large 3.6 x 2.0 with a 14v 15 amp tranny (Large) Parma economy controllers 45ohm.

The problem i have is that some of the motors tend to laydown after some use and get hot , excuse my ignorance but, is this cause simply by over use or is the 14 v power unit too big.

 

Cheers

Rick

[rick1776]

How many extra magnets have you addd to the chassis? All that magnetic downforce comes at a price. There is no such thing as a free lunch. Perhaps get rid of some of the magnets and run some MJK tyres instead. A true 14V might be a little high, try 12V.

 

cheers

rick1776

Edited June 18, 2008 by rick1776

[ricksta]

How many extra magnets have you addd to the chassis? All that magnetic downforce comes at a price. There is no such thing as a free lunch. Perhaps get rid of some of the magnets and run some MJK tyres instead. A true 14V might be a little high, try 12V.

 

cheers

rick1776

 

Hi Rick,

I am only running one extra neo button magnet as well as MJKs. with all that amps i might look at cutting back on the V,s to 12 v

[Holty]

All that magnetic downforce comes at a price. There is no such thing as a free lunch. Perhaps get rid of some of the magnets and run some MJK tyres instead. A true 14V might be a little high, try 12V.

 

cheers

rick1776

Another thing that could help is to have a few more slow twisty sections of track. Then the motors will draw less current for some of the lap.

 

Holty

[rick1776]

MJK tyres should provide reasonable traction on plastic I would have thought even with no magnets. Try non magnet racing using only driver skill to get around the track. I bet your motor will still be stone cold even after 30 minutes of non stop racing.

 

cheers

rick1776

[espsix]

Do you ever oil your cars ricksta?

Edited June 18, 2008 by espsix

[ricksta]

Do you ever oil your cars ricksta?

 

G,day there

Yes i do maintain the cars by cleaning and oiling the axles & end bell bearings lightly.

The cars tend to run well for a hour or so then start to slow down. what is the longest period that you can run a these cars ??, maybe i am expecting too much from them.

 

Rick..

[SlotsNZ]

Hiya Ricksta.

 

The motor will only draw the amps it needs, so the amperage rating of your power supply is not an issue per se.

 

That extra neo magnet is probably loading those little Mabuchi 18K motors up just a bit much though. They will gradually be getting hotter and hotter as you use them until you start to smell that funny, nasty burning smell as the windings get to melting point. Some motors recover, some are weakened either by buring out a winding, by heating the magnets past 80 degrees C and weakening them.

 

Some will tell you the humble Scalectric mabuchi motor is only rated at 12V. Actually, on the mabuchi site, it's specification is quoted at 3 volts from memory - for electric tooth brushes LOL. - It's more a statement of the actual revs at that "standardised test voltage", than the maximum voltage it can handle.

 

The whole "voltage rating" thing is actually a bit of "a piece of string". [AKA how long is a piece of string]

Older scaley wall warts put out 16 Volts, giving about 15 "at the rails" unloaded, but which drops quite a bit under load, so those motors have been coping with voltages probably 13 - 15 for many years.

 

Another thing is....after an hour of running with the "load" of 2 magnets..... how often do you clean your braids? I'd have thought they'd get pretty dirty after 15 - 20 minutes running. That will slow you down as well.

[Vinno]

It may just be the one hour thing that is cooking them along with the volts and magnets. Do you have enough cars to swap over occasionally?

[ricksta]

It may just be the one hour thing that is cooking them along with the volts and magnets. Do you have enough cars to swap over occasionally?

 

Hey there Vinno,

i just purchased a new car (BA Castrol Ford) and tried with and without an extra magnet and the extra mag does heat up the motor quite quickly....no more with the magnets.

Yea , i do have heaps of cars to swap about. the problem was that the last time i had the track set up.....Bathurst 2007 our annual race weekend , we raced each of our cars for 120 laps on a 60 ft track and we used all the advantages to get the best lap times so the motor only got a break at the 3 pit stops which took as long as one could drink the manditory schooner at each stop. i guess the 2008 Bathurst format will look at box stock racing, with more pit stops !!