How to make a train load a specific amount of items while also unloading?

[sigge]

New player here, just set up my first train line for my new oil refinery. The oil refinery is quite far from my main factory so i made defences for the oil refinery and to load them i made the train have a cargo wagon at the very back to load magazines, however whenever i tell it to load a small amount of magazines 20 to be exact, it loads the full 200, which causes my main factory to barely have any magazines.

How do i make it so the train unloads oil and then loads 20 magazines then leaves and unloads the said 20 magazines and loads the oil? Whenever i tried to make it work i was only met with failure so any help would be much appreciated!

[Lunacy]

You can middle click items in a cargo wagon to filter it so only that item can go into that slot. But that'll still go to the maximum stack size.
You can try using green or red wire connected to the inserter and train stop so that it reads train contents and is enabled when ammo < 20 (it'll work if there is less than 20 ammo in the wagon)

[Digitgidgit]

If you have filter inserters connected to combinators it can be done. It takes some effort basically you have to set a constant combinator to a negative value of whatever your trying to load into the train. The count of the item on the train will counteract the negative value and when it reaches zero it signals the inserter to stop loading. There are a few blueprints on the Factorio forums that are helpful

here is an unloader for an outpost train setup I built.


0eNq9Xd2OozgWfpUVl6tkZBvb2KXVPsXejVoRlVAp1AlkCamZ2la9+xqSSgj44GMDfdVTmfDl8/n38Q+/otfDJTtVeVFHL7+ifFsW5+jlz1/ROd8X6aH5rP48ZdFLlNfZMVpFRXps/qrS/BB9raK82GV/Ry/0a+V85FyXRbb+Kz10H2RfP1ZRVtR5nWfXH27/+NwUl+NrVhlk2/Or6FSezSNl0fyagVnHCf1DrKJP85+Myj/EV0OoB8XuUKfc8LOBECdIjOXTgUrsUDxgaACUeFLM+qYJC5ZUzhHKJzGt63K9r8pLsbPC6We4VbTLq2x7/Y60gCfIMXeBgTErLJRyQukOlBHg/r1etwZuQ0vuWDYkSu5Q+7S2GpmUz3yeZMZsmNSNmfhiMqz0uFN6FOsTUrixOk5xNDDrQ3o8uXgBhkwFlhdz85JYrNiNlfh4GBvxMKtm0X7hjlBUB2BB0ZdgsdzhjlFnKJeIfMACArAAsGKv5AKhcC8UDqCIgHFBWA+7fzOumNXvVflXVq3rS1VltT1yuyCTkGhrh3rY+mu+X2cH4xhVvl2fyoPdKB4KMI5UZOa3X8tL1RQesf5h+4EnB6jSvfHWtPjpclSOcdSYuI3YbTIxDXBRQDOxX4UUAyhxgPkxACukRoJ4Ca/RQYykW2vKjZK4UbQbRYV4UmyF6hj65fVcp+3Doy7E+i5kvJFKZXMj3jH1C5DPn9TndB5OveNSxz8Z4gdYgF8BlsfjACxA55z7B+QHKHFX6Dwke1CArM9cout8EF4SwI0AWMrLkSFGGluvaieWICHuTK1QD/eoytfyVFZ204hvKEQbwzBz/7oqD5vX7D39yMuq+VqVpbvNodzn5zrfGid/Sw/nbHX9uEGuN02sMP+jri7m8/TD8E1fD9n9mU15qU8X8zVrc8D8al3W6QH59fugvr++bjk0MI9fbloYhk1r4shfxz9yZ9B95JvFVYbF1bvOzaP0KsNdt7ORm78S+vXjy6q4kLAD2VNI2AG8RQQkYqIBrIAIQxSAJYc2sX3PzvX6lJ7P+Ue2PlXlR74z3x13yvYH0PqTSYfLuEK7ISvd/ly/5YfaxOu8OGdVDdBSfVrdZGV31G1ebS953Zjy7o72lldnpyXfA8R1+IZl0wskzR/HU1qldfMD0b9B895XWVb0BSR0T0BSNgJaRdfhX1t9381DCxVbFSFCyh0T2WxQOkArYkQrcm6t2OLLnPoZGDBB6MdGyqYpSfwjD+ThMmCCA0UeGTDjJ0APQgZMcwjUcuXTgoRcPkhkpzSvTFDd/pzVDqXs2aGimDjRZWM1QDFXWpDT0oIC0oKU0zSeLK7xntyq7L8X869htmgYkhyhfpia1RaSuWwh8bEF0bdsKSBbCMpr1uUHOTGvycXz2jHb5Zdjr1U3p0mZRNaLKBiTstOymVNCpok4WVzEw8nRgmWd9vHXkZIhoZO8lAdG7IGXCto3n7j/AeTHyaO62F+KsY7MfdotrTgB8zaoskh4ABZQ8SQC2+twVzyJDKiegBZ4EtAVIkALPFFzJQvhVTiIvpERyMj0tMKBL184pMVufcyLecO66vulxkwoO1xsQUeRubTNfbRtqsLeWKAyUdFp2haLa7vX1511bsD71TQm2fQJWfXOQiou+y6UeK685RUwwH6T4tPKE7F4eTJcqZ3VaPoVisLECQsnq92IuZTNPZX9PCZKQPXLaerni6u/s7w4a37gAxlhOlpdNlaNP2qLURGyERFyG67C1lKxs2ZRAbt0ICwd0rkD6jIdsHeTAMue2mtrAogSh61HkhijUx2yRgIsGWsRtguzHblzjVdP7D7Fy/cbb/uL52sL9PMCpQzTaWx52CKDTrAerNx2OdusI/bJK4oMZBIDeUWHbJElsX2L7MQOSrx4jmpDzKzZqd9moIwga1m79ZkKYK5SxM9kxMBkoLkLJcwnhvGRGGbd50rcWy67yRNwPUo4JMjbjj9XvgeBhbth7YC+qub29Y3DVLJqmxf7dSvh8/qY7tP/NRPfRrWXxoRbi7PxlO7t5cSZsChJvGBAqanAFE0gQB2QlSEwSrzKEArBhFRGIBiblszp4sn8zmTOkKoHIZUKREh9cLE6A43nysTUJ6xqNRgMh8Iq5XNRJD4Um9qgn8MSkKOYZpNkcZt8S43AFjHMprDsCwrTuOoxspunDCnDqF1HybQyjCy/kJWeHztbZ1URG1S+MWrh+YmQXUNqrrrMK4A0HaF+BNGgd+q5OHpGkEGUi6H5BmUTJwl0cevsrPHNaptkOCtLELbZpWO1TDZly3xjXu4zhQGbV8FSi4WsgkI1EvNvzVCtIDARAKYhsJk2sF7p4n2R9XfeUA5O5FgyF0ftFy8GPV0mQY5qSsXxLb0lK47n8+8z5rJBZ4tjyo0uHXu80NMkqn+DRBtaCxVxg0YHUyipPlOySjYOOOhh5Gk/e02n5EmL3cv5W7m7dGblxIPAIDiqmdsyseuEzVMT+cbheDCrEgyKcXE8F0fPODyIMDHMkU+zR724PdqKn3lDxyC1xphNzVZedlsVHp1PuPTAHGVl7nIoDrvOwKZqK7zyGizI0n+RFAbjJAAMUgP3ucxghBMLqErBWzjiADDoGg7Og1q6V0Dnqivl2G2JXWhw4LOV417bUEeKb55MK8Pkb9gCBiw9zBpVOW7zF0TFGki5mkvbid/ka9C75uDEhk8sw5c/KdIu98w7pRk0ijiqBdISsWpaBJXc9iuexMSSe/lDFs0Ii2b98jSvXsSw7m6433g2H2D2VHTZ2ZU1Wy3u55bxoHEvwP6kmK0W90sUgrlUQEHKE0vz5U+udPL3vHZLgyryLh27oT5Kj122bZS9Njxf86LlOXLyAx+Wb7gPYZ5HpPmRV/WlvfjvewTtN9Zp8Vm/m7Tokuoqgi4/gJCv8m5hT5+bdqfB5q0qj5u8MDi3+yI8lWUJKauIgQ8wQkCLl8H6kb9TP1m6fR/Xzb8CdPNA9VeNNfTEzWWddqU1x7d8lGZxycaZcHEsCZh9gXcEqgAwaPbQuVYAM5WDOEniBQNeWUjDrwqimiPm5jJkzskhuiFzTgGB+dykNwIjPC4JGoGRHtd9jcAkIUUsgKU8L/y6WgTizjzaOYT8HdBcYZc/Dx4TeLuZ23Plpd0OFzfbUD2uL37MctrHBencYbxC3Jd8b4K3j9PH4zHicbBn2efCEWDDbRV9FIGRR2/5+zasB4hEgIy3DlpI3oFMMJJ+us6mL2yFQAAOKPWFpDF3XvcOu/QxKEGAwEfmB3AYQ4ZulhkokGIM23bYfEArRpnCKYOIcOTz/YOIAyLCZ0TWiy8GkBgzH9yeMhwiyrTvhyJuG3o7zyuU4z+dzB2SwJh0v7fQ97DrNmN0UTm4rmFQSoJ1YOcmBmyeEQvnmeF69MBeMNF+uDcxJOeMI2B8sj8fH2YbH1VLcENa5/KHtMrrd5PrGv9DTtWwmnxAzzNbO2cNzOYxaVubYZSnrLoG/Jfon8GTti9fsY7PtbAdooR5rQhClXzic8yuu3iHujeZBtxpMcJVeM21QBgZwAmq85PEixMIowImVNC5jM69E9da1jGHgXbiKRJACjpz8nQ9AnpCZD+V1r0TAPnmAVhanVsBvPdaGlTMLf/cy1VBCfptJQBhQswfFF5IfwdkprwvrRkB0wHGC21w1SGeALmVDvIE+8GAzlnrp6niaHMAgIq9zAsUlZ+xgzAiwLBAMBl2vK9nGYsf79Mh3gSaWUBKUdDGFx3gTUpBbxchthnKyPspDK/e5pLpq1mIVZKRJa1HkZYV7U3Wu/zc/Pt9uXY7rk0zrlO2w//4f3wXy4R1Sfe7j/HSlrTluf7H+XI6HT4jqzZCwpHSds0y71zKu9bi3EHEOieJHRe3sTuwnapXnIIcg5GAOAU7RkBqhpkhr0OhCCjl/SY1U2ZAYNp/D5gCXy4UkJhBZgFHfUeYMe/Xp40wi/1fGjdCjXu/jm2EmggJH4kdS3q8ke1KyVl9M5p4vJINDaq838k2IkLt/VI2GAz/7q4YAUa9X8s2AsYCohtkwwFHzkaYce/3nd3AfqyubbiXzrs5V9GHqQ2vtqMoTzRLBBXUMPn6+j9RDsZo

[Digitgidgit]

And here is the blueprint string for the in base loader

They should be both for vanilla factorio I hope *crosses fingers*

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

[serker31]

Originally posted by sigge:

How do i make it so the train unloads oil and then loads 20 magazines then leaves and unloads the said 20 magazines and loads the oil? Whenever i tried to make it work i was only met with failure so any help would be much appreciated!

IIRC you can make your base station read train contents (there is literally a tickbox in train station), wire it to magazine loading inserter and set it to work only when there are less than 20 magazines in train.

[TigaTone]

Originally posted by Digitgidgit:

And here is the blueprint string for the in base loader

They should be both for vanilla factorio I hope *crosses fingers*

0eNq9Xd2OozgWfpUVl6tkZBvb2KXVPsXejVoRlVAp1AlkCamZ2la9+xqSSgj44GMDfdVTmfDl8/n38Q+/otfDJTtVeVFHL7+ifFsW5+jlz1/ROd8X6aH5rP48ZdFLlNfZMVpFRXps/qrS/BB9raK82GV/Ry/0a+V85FyXRbb+Kz10H2RfP1ZRVtR5nWfXH27/+NwUl+NrVhlk2/Or6FSezSNl0fyagVnHCf1DrKJP85+Myj/EV0OoB8XuUKfc8LOBECdIjOXTgUrsUDxgaACUeFLM+qYJC5ZUzhHKJz
...

Unfortunately I think you posted the same blueprint twice.
Can you in fact post the Base blueprint that would feed this outpost blueprint?

This is exactly what I'm trying to achieve.

[a-bullet]

2 year old thread... no wait, 3 years >.<

you can connect the train station itself with a logistic wire (and read train contents) to the inserter that handles the ammo and disable it once ammo >= your limit