I have already been through several revisions while doing initial prototyping and have found that Lego will be suitable and in fact preferable for creating layouts as it will provide the greatest flexibility with new ideas and not require much in the way of custom parts. So far I have successful proof of concepts for solenoid, speaker and stepper motor and will post some progress photos tonight. The coils can be easily made on sewing bobbins which also provides a great way to mount them. I originally figured steel would be best providing for better heat dissipation and an iron core the could be further improved by mounting with steel screws. This however proved problematic when creating pretty much each device for different reasons. In the end plastic bobbins are cheaper more consistent and interfere less, and while that may not make the most efficient electromagnet we are more concerned with teaching the how not getting the most out of each. It is still possible to mount with screws or pass an iron core through for individual configurations that require.