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I have just tested my Heilmann after the winters break.... I can only say that I am as unhappy with it as I was in the autumn. I would like some thoughts and suggestions as to doing a rebuild.
This is where I am at the moment.
A: Increase the number of cylinders from 4 to 6 and reconfigure either as a 60 degree Vee 6 or dual inline 3.
B: Step down the steam motor shaft speed to 50% by gearing down 2:1.
C: Replace the Gramme Ring Dynamo with an Poly Phase Alternator (maybe using a s/h stepper motor?)
D: Install water tubes into the Porcupine Boiler -or increase the number of quills.
E: Install water pump and feed heater to increase duration of boiler.
Thoughts and comments greatfully received!!!
Yes, I know it has taken the better part of 18 months to get to the point where I can race snails -but feel that I have proved the point that a model Heilmann can be built and that it will work (but with vile output!!!) Now is the time I think to progress the model to something that is normally usable.
The reason, (I believe), that the model has such a poor output are down to the fact that, as a model, the dynamo can only have a low radius of rotation -thus the number of lines of force cut per second per radial centimetre (AKA "rho" ) is low. The efficiency of the dynamo is better at higher speeds -which requires vast amounts of steam -but the torque required varies as the SQUARE of the rotation. I opted for a rotational speed of 1,900 to 2,400 RPM and worked out "rho" for this. I have been pretty succesful and my home made 1910 design dynamo is very nearly 40% efficient. I have got amps by the bucket load -but I cannot get the very high voltages (12+) that I feel I need to really get this moving.
regards
ralph
This is where I am at the moment.
A: Increase the number of cylinders from 4 to 6 and reconfigure either as a 60 degree Vee 6 or dual inline 3.
B: Step down the steam motor shaft speed to 50% by gearing down 2:1.
C: Replace the Gramme Ring Dynamo with an Poly Phase Alternator (maybe using a s/h stepper motor?)
D: Install water tubes into the Porcupine Boiler -or increase the number of quills.
E: Install water pump and feed heater to increase duration of boiler.
Thoughts and comments greatfully received!!!
Yes, I know it has taken the better part of 18 months to get to the point where I can race snails -but feel that I have proved the point that a model Heilmann can be built and that it will work (but with vile output!!!) Now is the time I think to progress the model to something that is normally usable.
The reason, (I believe), that the model has such a poor output are down to the fact that, as a model, the dynamo can only have a low radius of rotation -thus the number of lines of force cut per second per radial centimetre (AKA "rho" ) is low. The efficiency of the dynamo is better at higher speeds -which requires vast amounts of steam -but the torque required varies as the SQUARE of the rotation. I opted for a rotational speed of 1,900 to 2,400 RPM and worked out "rho" for this. I have been pretty succesful and my home made 1910 design dynamo is very nearly 40% efficient. I have got amps by the bucket load -but I cannot get the very high voltages (12+) that I feel I need to really get this moving.
regards
ralph