How about creating an item called WoodenLog (or whatever) and making it a batched Item. Make the Stock UOM Kg. Now you create Batches that go:
WoodenLog-100Kg and as many weights as you want. You need to concatenate the Item Code with the weight as ERPNext expects a Unique Batch Number, so if you have another item called WoodenLogTeak, you wouldn’t be able to reuse a batch called 50Kg for WoodenLog and WoodenLogTeak. So concatenating the Item Code and the Weight will give you a Unique Batch.
Now as you receive these logs, you have to drop it into the correct Batches.
Now your Batch Wise Balance History report on ERPNext will look something like this:
Item | Batch | Qty | Stock UOM
WoodenLog | WoodenLog-50Kg | 50 | Kg
WoodenLog | WoodenLog-10Kg | 20 | Kg
WoodenLog | WoodenLog-100Kg | 100 | Kg
With not much coding you should be able to create a customized report that adds a column that reports the number of logs you have in each batch.
Pawan’s approach is also fine, where you have a separate item for each Weight,and you make the Stock UOM as Nos and alternate UOM as Kg and define the conversion factor in the Item Master. Now if you have too many items, or if you have too many weights, the batch is the better way to go. If you have items in the 100s, a separate Item is the way to go.
But if you can’t always group the Weights into those 10Kg and 50Kg and 100Kg, or if you have variability - like a 10Kg log could be anywhere from 9.8Kg to 10.2 Kg and you actually want to record the actual weight that has been received, you’d need have each log defined by a Batch Number and have the Stock UOM as Kg.
Hope this helps.