A few weeks ago, I posted a thread on building some large oak bookcases from a logistics point of view. Well I've now taken delivery of the oak and started work on the smallest one - this one is 2m high by 0.9m wide by 240mm deep. I'm using 18mm american white oak - I wasn't best pleased with the oak when it arrived with some cupping across the width of the boards (no more than 1-2mm) - not sure if this is normal or not. I've only ever built bookcases from MDF and birch plywood in the past, which has always gone relatively smoothly, so I admit I am a complete novice when it comes to using oak.
After the discussion on the other thread, I opted for the following domino/connector layout:
Shelves into uprights (front to back): KV connector/8mm domino (tight)/KV connector/8mm domino (medium-wide)
There are also dividers on each shelf which are 30cm in from the left hand side (this was a customer request, rather than going central) - each divider has 3 x 6mm dominoes to align on the top and bottom of each shelf. The divider mortices are all on tight setting with the mortices in the shelves on the tight setting for the front domino and medium-wide for the middle and rear domino. I have morticed all the way through each shelf so that one 40mm domino goes through that shelf and then inserts 11mm into each divider (so I morticed to a depth of 12mm into the dividers).
I went to dry fit it this morning and ran into serious problems. Basically, I can get all the shelves into one side with the dividers but when trying to get the other side in, it was impossible. I just couldn't pull the shelves into the mortices no matter what I did. I've checked all my measurements and don't believe there are any errors with my machining.
I've been using chatgpt to help me out a lot on this - I work on my own and am relatively inexperienced so I find it a useful tool for advice. The problem they suggest is that I could be 0.5-1mm out on various joins, which multiplies over the whole unit and since oak has barely any flex on it, that's what's causing these issues.
Now, I've since dry fitted it without the dividers and it was tight but I managed to get it all together. So I think one solution is to reduce the height of dividers by 1-2mm each in order to give more wiggle room?? I don't really like doing this as I am so used to getting tight joins with my mdf and plywood builds but I don't see what other option I have. I'm wondering whether to also make all domino mortices in the uprights wider?
Any advice from more experienced hands on here very much appreciated. I'll attach some photos.
The other thing is chatgpt is suggesting I'm completely mad to be building this out of 18mm and should be minimum 25mm, especially for the other 3 which are bigger (2.1 x 2.3m and two at 1.2 x 2.7m high). Basically saying that there'll be splitting and cracks etc in the wood as it contracts and expands with heating over time. But there's no going back now - material has been paid for and delivered and margins are tight on this job as it is.
For reference, I've already done 5 bookcases from mdf for this customer, which went really well - both myself and customer very pleased with the outcome.
After the discussion on the other thread, I opted for the following domino/connector layout:
Shelves into uprights (front to back): KV connector/8mm domino (tight)/KV connector/8mm domino (medium-wide)
There are also dividers on each shelf which are 30cm in from the left hand side (this was a customer request, rather than going central) - each divider has 3 x 6mm dominoes to align on the top and bottom of each shelf. The divider mortices are all on tight setting with the mortices in the shelves on the tight setting for the front domino and medium-wide for the middle and rear domino. I have morticed all the way through each shelf so that one 40mm domino goes through that shelf and then inserts 11mm into each divider (so I morticed to a depth of 12mm into the dividers).
I went to dry fit it this morning and ran into serious problems. Basically, I can get all the shelves into one side with the dividers but when trying to get the other side in, it was impossible. I just couldn't pull the shelves into the mortices no matter what I did. I've checked all my measurements and don't believe there are any errors with my machining.
I've been using chatgpt to help me out a lot on this - I work on my own and am relatively inexperienced so I find it a useful tool for advice. The problem they suggest is that I could be 0.5-1mm out on various joins, which multiplies over the whole unit and since oak has barely any flex on it, that's what's causing these issues.
Now, I've since dry fitted it without the dividers and it was tight but I managed to get it all together. So I think one solution is to reduce the height of dividers by 1-2mm each in order to give more wiggle room?? I don't really like doing this as I am so used to getting tight joins with my mdf and plywood builds but I don't see what other option I have. I'm wondering whether to also make all domino mortices in the uprights wider?
Any advice from more experienced hands on here very much appreciated. I'll attach some photos.
The other thing is chatgpt is suggesting I'm completely mad to be building this out of 18mm and should be minimum 25mm, especially for the other 3 which are bigger (2.1 x 2.3m and two at 1.2 x 2.7m high). Basically saying that there'll be splitting and cracks etc in the wood as it contracts and expands with heating over time. But there's no going back now - material has been paid for and delivered and margins are tight on this job as it is.
For reference, I've already done 5 bookcases from mdf for this customer, which went really well - both myself and customer very pleased with the outcome.
