A reverse engineered Tripp Trapp


  • Founder

    Alright, Aras, finally, here you go.

    This is my current project, and right after I shake off the morning cobwebs here on the internet, I’ll be going down to do a little bit of work on it.

    I am a minimalist parent. I don’t buy any sort of baby-care or parenting gadget until I see clearly that it is necessary. My son is 1.5 years old, and I have never had a baby monitor, have never bought disposable diapers, don’t own a stroller, etc. However, he has been sitting in this little booster seat that hangs off of a regular chair. In my kitchen right now I don’t really have the best chair for it, and he’s getting to be too big, and so he can pretty much stand up and walk away with this thing strapped to his ass. And he is a squirmy guy.

    So A new high chair is in the works. I bought some nice maple, around a 2"x 10" x 8’ board, a couple of months ago at Windsor Plywood. I decided on a european style chair, the popular model is called a “tripp trapp”, which means something is some sort of scandinavian dialect, but I forget. It is an incredibly simple design that is extremely functional. The chair has a series of housings along the inside of each rail, and floating seat and foot rest can be positioned wherever they are needed. In theory the chair can accomodate an infant all the way to an adult. Which makes my somewhat hard work very worthwhile.

    Here’s pictures of the commercial model…

    stokke-tripp-trapp-chairs-seating_9b3baf7b51_xxl.png

    tripptrapp stages

    I took some images and measured them, got the basic dimensions, scaled it up to the height of chair I wanted. The important thing is getting the angle about right, as that is the genious of this chair. It is what allows for the lengthening of different body parts to be accomodated by the chair.

    This project was done with one somewhat accurate but very simple scale drawing. I didn’t actually look at it when I was doing the work. The only concern I have is that I may have not made enough slots for the seat and foot rest going down to the floor, I probably could have put one or two more.

    Here is the project as it stands now:

    The feet are like so…
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    Construction and joinery are very simple, just an open mortise at the bottom of the siderail, and the tenon on the foot slides in and will be pegged this morning if I can get away from this blasted machine! Here is some detail of the tenon…
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    The side rails look like this…
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    And here is one fully assembled half of the chair, which has to be pegged yet. But I can still see a sliver of daylight through the joint, so my work is not entirely done yet. I’m going to draw-bore the pegs in and hopefully that will suck it all closed.

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    And some detail of the joint… And I must say, this is the first time I have made a proper joint out of proper furniture grade hardwood, and it is incredibly satisfying.

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    Still to be done:

    -Peg the assembled half
    -Cut the mortise and fit and peg the other joint (the pegs will be flush-cut 1/2" maple)
    -I need to drill a series of holes, as I have 2 1/4" threaded rods that I’ll use to sinch the whole thing together, I honestly don’t know how the commercial model hangs together, but it is much smaller dimension material, and must have some way of holding the seat and footrest in position.
    -I have to joint the footrest material
    -I have to glue up the seat and footrest, trim them to size
    -I need one supporting stretcher across the bottom, I am going to make a mortise for it on each side, and it will be held in place by the pressure from the threaded rod.
    -A friend who is a leather-worker is going to make a leather-weave to serve as the seat-back. I don’t have the ability to bend anything, and any solution to the back that I came up with seemed uncomfortable and labour intensive. Outsource!! I need to cut slots in the side-rails where the back will be threaded through an supported.

    The stretcher, the seat and footrest will all be the same length, sitting in 1/2" housings, giving an opening of around 16" between the siderails when the rod is tightened. The whole thing can be loosened to release the pressure, seat and footrest slide out of their slots for repositioning.

    This thing is going to be a tank, it’ll weight a ton. I figure my stock are almost 3 times the size of the commercial model. A couple of times I have considered that I could have almost resawn the boards and made 2! But Finnegan is a squirmy guy, and I’m sick of him having control over his seat! Not this one!

    And here’s a cute baby…
    DSC_0134.JPG


  • Founder

    My apologies for the pictures.

    I don’t have a very good lighting situation, and have no fancy flashes. The lens I had on the camera is a straight 50mm, which will allow the aperture to open really wide, but the trade of is that depth of focus shrinks. The in-camera thumbs always look great, but the actual picture is a bit to be desired…but you get the idea…



  • @Bradley-Maker the pictures are great, they really show your attention to details on the project.

    Great write up as well. Dont forget to post updates as you progress :), I really look forward to seeing how it turns out.


  • Founder

    @arasbm
    No worries, I’ll maybe even get some more up later this weekend.

    The other big job I didn’t mention is finishing. I can’t wait to see what it looks like finished. I’m going stain shopping right now…but generally end up going with something very simple and natural.

    My favorite finish is oil and beeswax. It is not a permanent finish, and isn’t a 100% stain and water proof finish, and needs regular application. But you can eat it, it is easy to make and apply, and it goes a long way. It looks great too.
    Although it isn’t going to work for this project.



  • I’m looking forward to seeing the final product too! @Bradley-Maker This is much more stylish than the usual commercial plastic high chair. PS your little one is adorable! :)


  • Founder

    Thanks!

    But I have run into dismal problems.
    I have owned my shopsmith for a couple of months, but have really not been able to use it fully. In trying to drill accurate holes, I hit a major stumbling block. The quill has a bit of a wobble to it. Which is why I had trouble horizontal boring, which was my plan to make the mortises - I cut it out with a skillsaw and did a whole-lot of old fashioned mortising with a chisel, which was fun.

    So I am just going to go down and do some layout so that I can quickly drill all of the holes at work, and since I’m in the shop, I’ll make the final mortise for the lower support with a router while I’m there.

    Not sure what to do about the quill though…The major project of dismantling the motor to see if I can diagnose and hopefully repair the problem, was not in my plans…


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