My husband recently took a remote job and we’ve been working on our home office space to make it comfortable for both of us. My daughter made frequent visits to the office and immediately latched onto an old keyboard and monitor we had lying around. I decided I wanted to set up a little desk space in there for her as well so she could pretend to work on the computer like Mom and Dad sometimes.
I looked around a bit, but most desk/chair combos for kids were intended for older kids and a bit tall for her. We went to IKEA to try out chairs and see if anything would work. As anticipated, all the chairs were too tall for her. However, I realized that the UTTER table and stools had legs that screwed on. So, I decided to just grab those and make my own legs at whatever height I desire. It didn’t hurt that they were extremely inexpensive.
Originally I thought I’d like to make something modular. Something where each leg is made up of a bunch of segments that snap together. That way I could play around with what size I wanted and change the size as my daughter grows. However, I was concerned that my daughter would just constantly be taking them apart and I’d be stepping on random chair leg pieces for the foreseeable future. Plus I realized the Ender 3 has over 9in of build height so I didn’t need to worry about it being too big to print.
I also considered doing a wider base at the bottom of the leg to make it more supportive, but I decided to just leave it as is for now and tweak if we run into problems. No need to overengineer this thing. So, I started out just making a replica of the existing leg, but a bit shorter.
Fun With Fusion 360
I’ve never done anything with screw threads before, so that was a new thing to figure out. There’s a built-in “Thread” button in Fusion360, but I couldn’t use that because apparently it doesn’t work on a tapered cylinder. It has to be a perfect, normal cylinder.
Luckily, there’s another way to achieve threading on a tapered cylinder. I followed this screencast to learn how to do it. The gist is that you make a coil, using the top or bottom face of your cylinder. One of the options on the box will allow you to add an angle to account for the tapering.
Printing in Circles
I don’t know why exactly, but almost every time I’m having issues with something coming off the bed during a print, it’s a round object. In this case, I printed 2 legs that were absolutely perfect until they turned into blobs of sadness at the top. The first time I wasn’t sure what happened. The print was still sitting on the bed when I came in but looked like they usually do when the print comes loose from the bed. It came off really easy so I suspected it had come unattached, but just not moved enough to make it obvious. The second time it was more apparent, as the leg was lying on its side.
I’d been using a brim, but apparently that wasn’t enough. For print attempt #3, I tried a raft. Usually, that’s not needed, but I thought because this is tall and skinny and round it just was starting to cool too much at the bottom and get loose before the print was done. I babysat print #3 toward the end and actually heard it cracking and coming loose. Then I saw it come loose completely and had to stop the print. The raft fell right off the print when I picked it up so it obviously wasn’t doing much to adhere it.
Turns out we just needed to increase the temperature on the heated build platform. Once I did that, I was able to print all four legs in a row with no issues. Now the chair is perfect for my daughter. She sits on it and uses it as a step stool. She loves it and carries it around, sitting on it in different rooms of the house just for fun. I’m thinking about grabbing one or two more next time I go to IKEA.
I figure it wouldn’t be cost-effective for me to try to sell these. Since the original stool costs $5, I doubt I would find a lot of people who’d want to pay more than that for a new set of legs. $5 would barely cover materials and shipping to make 4 legs, and they take a long time to print.
I’ve uploaded the file on Thingiverse so you can print your own if you want.
- Ender 3 (Buy One)
- Fusion 360 (Free Download) – Free for personal use. You can apply for a startup license if you have a new business.
- Calipers (Review|Buy One)