Problem with machine in 1.7.10

package com.keegan.lyoko.tilenenity;

import java.util.ArrayList;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.nbt.NBTTagList;
import net.minecraft.tileentity.TileEntity;

import com.keegan.lyoko.recipes.CentrifugeRecipe;
import com.keegan.lyoko.recipes.Recipes;

public class TileEntityCentrifuge extends TileEntity implements IInventory
{

private ItemStack[] contents;

private float startTime;
private boolean spinning = false;

private ArrayList<CentrifugeRecipe> recipes;

public TileEntityCentrifuge()
{
	contents  = new ItemStack[2];
	recipes = Recipes.getCentrifuge();
}

private float getTime()
{
	//Returns time in minutes
	return System.nanoTime() / 60000000000L;
}

@Override
public void writeToNBT(NBTTagCompound tagCompound)
{
	super.writeToNBT(tagCompound);
	NBTTagList itemList = new NBTTagList();
        for (int i = 0; i < this.contents.length; i++)
        {
            ItemStack stack = this.contents[i];
            if (stack != null)
            {
                NBTTagCompound tag = new NBTTagCompound();
                tag.setByte("Slot", (byte) i);
                stack.writeToNBT(tag);
                itemList.appendTag(tag);
            }
        }
        tagCompound.setTag("Inventory", itemList);
        tagCompound.setFloat("startTime", startTime);
}

@Override
public void readFromNBT(NBTTagCompound tagCompound)
{
	super.readFromNBT(tagCompound);
	NBTTagList tagList = tagCompound.getTagList("Inventory", 10);
        for (int i = 0; i < tagList.tagCount(); i++)
        {
            NBTTagCompound tag = tagList.getCompoundTagAt(i);
            byte slot = tag.getByte("Slot");
            if (slot >= 0 && slot < this.contents.length)
                this.contents[slot] = ItemStack.loadItemStackFromNBT(tag);
        }
        startTime = tagCompound.getFloat("startTime");
}

private void spin()
{
	recipes = Recipes.getCentrifuge();
	for(int i = 0; i < recipes.size(); i++)
	{
		System.out.println(recipes.size());
		System.out.println(i);
		//System.out.println("wanted is not null " + (recipes.get(i).getInput() != null) + " = whether wanted isn't null");
		if(getStackInSlot(0) != null && getStackInSlot(0).equals(recipes.get(i).getInput()))
		{
			System.out.println("Beginning spin");
			startTime = getTime();
			spinning = true;
		}
	}

}

@Override
public void updateEntity()
{
	super.updateEntity();
	recipes = Recipes.getCentrifuge();
	if(startTime > 0)
	{
		float elapsedTime = getTime() - startTime;
		System.out.println("Started at " + startTime);
		System.out.println(elapsedTime + " = elapsed time");
		if((elapsedTime >= 5) && spinning && startTime > -1)
		{
			for(int i = 0; i < recipes.size(); i++)
			{
				if(getStackInSlot(0) == recipes.get(i).getInput())
				{
					startTime = 0;
					spinning = false;
					decrStackSize(0, 1);
					this.setInventorySlotContents(1, recipes.get(i).getOutput());
				}
			}
		}
	}
	if(getStackInSlot(0) != null)
	{
			System.out.println("Attempting Spin");
			spin();
	}
	else
	{
		startTime = 0;
		spinning = false;
	}
}

@Override
public ItemStack decrStackSize(int slot, int amt) {
	ItemStack stack = getStackInSlot(slot);
	if (stack != null)
	{
			if (stack.stackSize <= amt)
			{
				setInventorySlotContents(slot, null);
			}
			else
			{
				stack = stack.splitStack(amt);
				if (stack.stackSize == 0)
				{
					setInventorySlotContents(slot, null);
				}
			}
	}
	return stack;
}

@Override
public String getInventoryName() {
	// TODO Auto-generated method stub
	return "Centrifuge";
}

@Override
public int getInventoryStackLimit() {
	// TODO Auto-generated method stub
	return 64;
}

@Override
public int getSizeInventory() {
	// TODO Auto-generated method stub
	return contents.length;
}

@Override
public ItemStack getStackInSlot(int slot) {
	// TODO Auto-generated method stub
	return contents[slot];
}

@Override
public ItemStack getStackInSlotOnClosing(int slot) {
	// TODO Auto-generated method stub
	ItemStack stack = getStackInSlot(slot);
	if (stack != null) {
		setInventorySlotContents(slot, null);
	}
	return stack;
}


@Override
public boolean isItemValidForSlot(int slot, ItemStack stack) 
{
	for(int i = 0; i < recipes.size(); i++)
	{
		if(slot == 0 && stack == recipes.get(i).getInput())
		{
			return true;
		}
		if(slot == 1 && stack == recipes.get(i).getOutput())
		{
			return true;
		}
	}
	return false;
}

@Override
public boolean isUseableByPlayer(EntityPlayer arg0) {
	// TODO Auto-generated method stub
	return true;
}

@Override
public void closeInventory() {
	// TODO Auto-generated method stub

}




@Override
public boolean hasCustomInventoryName() {
	// TODO Auto-generated method stub
	return false;
}


@Override
public void openInventory() {
	// TODO Auto-generated method stub

}

@Override
public void markDirty() {
	// TODO Auto-generated method stub

}

@Override
public void setInventorySlotContents(int slot, ItemStack itemstack) {
	contents[slot] = itemstack;
	if(itemstack != null && itemstack.stackSize > getInventoryStackLimit())
	{
		itemstack.stackSize = getInventoryStackLimit();
	}

}
}

package com.keegan.lyoko.recipes;

import java.util.ArrayList;

import net.minecraft.item.ItemStack;

public class Recipes 
{
public static ArrayList<CentrifugeRecipe> centrifuge = new ArrayList<CentrifugeRecipe>();


public static void addCentrifugeRecipe(ItemStack input, ItemStack output)
{
	CentrifugeRecipe recipe = new CentrifugeRecipe(input, output);
	centrifuge.add(recipe);
}

public static ArrayList<CentrifugeRecipe> getCentrifuge()
{
	return centrifuge;
}
}

package com.keegan.lyoko.recipes;

import net.minecraft.item.ItemStack;

public class CentrifugeRecipe 
{
public final ItemStack input;
public final ItemStack output;

public CentrifugeRecipe(ItemStack in, ItemStack out)
{
	input = in;
	output = out;
}

public ItemStack getInput() {
	return input;
}

public ItemStack getOutput() {
	return output;
}
}