Pulping your apples
This is a key part of the process and one which requires a little thought in advance.
According to Wikipaaedia, historically pulping apples was done by means of pressing stones with circular troughs, or by a hprse or human powered cider mill. Most of us do not have access to a stone mill, so domestic apple juice extractors at first seem like a better idea than pulping and pressing your apples.
If you only want to make one glass of apple juice, then these kitchen gadgets can be useful, but to process 16Lb of apples using a kitchen juice extractor will take all day. I am qualified to tell you this because I tried it once. I gave up after about two hours suffering from extreme boredom.
A much better option is to adopt a more industrial solution to the problem.
Pulping cider apples
What you basically want is a rotating blade that will chop your apples quickly and cleanly.
Traditional apple pulping machinery consists of two bladed or spiked rollers that spin toward each other, mashing the apples which then drop through to a hopper. The versions with spikes were known as scratters. I have also seen a german equivelent where one roller rotated against what was essentially a giant cheese grater. This sliced tiny chunks from the apple as the roller pushed them down against the grater.
To make your own apple scratter you can consider canibalising the drum and motor from an old washing machine. I saw one of these in use in Normandy and the cider that farm produced was first class.
A simpler technique for home use is to obtain a Pulpmaster, which is essentially a lidded bucked with stainless steel blade attachment for your mains powered drill. You attach your drill to the lid, close the pulpmaster, turn on the drill and in a minute you have mashed a bucketful of apples.
The correct term for the apple mush you now have in the bucket is the ‘pomace’.
Some juice will already separate out from the pomace, but to get enough juice to make it all worthwhile, you will need to press the pomace.