Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Well...did a bit more experimental tinkering...I had cut my carbon brush springs in half to get a useable length and now they have to few coils so they stack force to fast...its to late at night to come up with a .010 music wire guitar string...So...looking around For Something suitable I tried some rubber from my rubber band contest model airplanes!... It's much higher quality than an office rubber band and Bingo....my engine was running again! It's not a long term solution as rubber will degrade when in contact with petroleum products...and...it does not look to authentic...but I was happy to have my engine making putt-putt noises and my weights where finally moving like I see them on other run videos!....I am now playing with carb adjustments and the best run I could get tonight was 47-48 hits per min...so I am not really Slower than what others have achieved on the forum....but...it seems to be happening at a little lower RPM. My rubber called Tan Super Sport comes in 25ft length...I have to make a knot and make different size loops to make my rubber spring softer or stronger. I made a loop only 3/16 longer and the engine would not run...to soft...I need to find a way to have greater control almost like a screw adjustment on my tension. I have a fancy rubber splitter so tomorrow I will experiment with thinner rubber bands. I also need to make a solid engine base very soon...i feel with the engine jumping around when it hits prevents me from getting 100% of the power pulse into the flywheels...also the better base may help me tune for better carb setting.
   Part of me wants to go ahead and make a dished piston, I feel I could get the flywheels to coast down a bit more slowly and still carry me thru compression and keep running...but at the cost of a weaker power pulse...I freely admit I do not know enough about hit and miss to know what the best route is....I Did see a engine on YouTube...the owner said it weight was 2500 lb and he won a contest...he had it hitting only 2 times per min! I kept thinking it was no longer running then sure enough...it would hit!
  So...my little engine sure is fun, I feel sure if I keep at it I can get a slower result....please chime in...I would like to know if the general population thinks lower compression would get me running less hits per min With the heavy flywheels combo?

I am enclose a photo of my crude but soft rubber spring