How To Make A Travel Hard Case Fitted For Specific Objects That Don't Otherwise Have Cases?

I have a 3D printer, a sewing machine, and a bunch of tools and am willing to learn a new trick to achieve the following.

I have a few keyboards that I would like to travel with more. The trouble is they do not have a hard case that is designed for them (or at least not a good one). I've shopped and shopped and shopped for similarly sized cases by searching by dimension in basic textual search engines and by searching for cases of similar (more mainstream objects). For some of these there is a decent option but it results in significant wasted space. I would love to be able to make my own but I am not really sure how to.

The key is I need this case to be as fitted as possible. The more excess dimensions the harder it will be to take with me once finished.

I am fine if it's not pretty or not the same material as your average hard case or if it doesn't have a zipper. I just want to be able to safely tuck it away and feel like it will be somewhat protected at least.

Technically I could 3D print one but some of these are larger than my print-bed and I would be concerned about durability/weight. It's fairly expensive from a print time perspective... possibly on cost but unsure. I know my 3D prints are "durable" but I dont really beat them up inside of a backpack while I travel. I think a software material would do better.

Any ideas?

One small piece of the problem would be to know if theres a way to easily make the fitted foam inserts companies will use in hard cases to make the object stay in place/a bit suspended within the case.

Object Dimensions

• 15.98x4.92x1.55 in
• 14x8.7x2 in
• 11x1x5.5 in

https://preview.redd.it/6x0exix74wnf1.png?width=1264&format=png&auto=webp&s=b8ea0bbb0dceff13b41d3b07f12658f48b69cf33