Motorized Mini Excavator Rises From Sheets of Plywood

Fathers of Hackaday, we’ve got bad news — you’ve been out-fathered. Behold the mechanism of your undoing: a working miniature excavator, executed in plywood.

To be fair, the rules of the game have changed lately. Time was when a nipper would ask for the impossible, and we dads would never have to deliver. But with CNC routers, 3D-printing, and industrial-grade CAD software you can use for free, the possibility hurdle is getting ever shorter. Still, when his son put in this request, [Alex Lovegrove] really delivered. Everything on this excavator works, from tracks to boom to bucket. There are hundreds of parts, mostly machined from plywood but with a smattering of 3D-printed gears and brackets. The tracks and slew gear are powered by gear motors, while linear actuators stand in for hydraulic rams on the boom. The videos below show the machine under test and the unbearable cuteness of it being loved.

Hacker parents need not despair, of course. There’s plenty of room left for your imagination to run amok. For inspiration, check out this working railway system, or any of the several backyard roller coasters we’ve featured.

51 thoughts on “Motorized Mini Excavator Rises From Sheets of Plywood

      1. there are activity that are “natural” for men and “natural” for woman. With “natural” i mean: in huge percentage” each of us prfere to address a particpular range of tasks. I.E. my wife prefere gardening (the good side: grow flowers under delicate shdow) and cooking, my tasks are more focused in home painting, gardening (the bad side: cuts grass for hours and hours under hot sun) and other masculine tasks. Thanks to Eaven, here in Europe we are still safe form the USA desease of “to be politically correct at any costs”. f++k off feminist from ’68, each of us has a “natural” role, what Nature plasmate all of us to do. Human wishes can fighth againnsta, but not win over Nature’s Laws.

          1. could be, but much more could not. Look israeli kibbuz back in ’50: they was a socialist sels suntained-indipndent-societies where all the members (man & womans) are called to server the same tasks: work the field, care animales, cock foods, care children, build houses, ecc. Slowly but progressively, man left “feminine” tasks and embrace masculine tasks (work the fileds, care the animales, build houses) and at the same time womans did the opposite, left masculine tasks and embrace feminine tasks.
            Now, i dont want to say that by force we must do only a particular sub-set of whole the activities available, simply i think that there are some tasks that we embrace easely in more natural way beause of “genetic” push to that side that we have coded in DNA.
            As m if i prefere care kids or drive a escavator, i prefere t second. Of course there are some “forcing” by Sociey: i.e. is demostatd that woman are at same level (or even better) than men in math, but majority of mathematicians are male. it is a “society crookedness” that say “math is not for womans”.

    1. The question is similiar to, why don’t you wear underpants on your head? It’s as if given free choice, people won’t wear pants on their heads.

      But you’d be wrong. When missionaries first went to the indigenous tribes in South America, they saw the people were going around buck naked, so they tried to make them wear boxers and shorts to make them “modest”. In the jungle heat, all natural fabric just gets wet and soon rots away, so the tribesmen found little use of the garments and in any case they were inconvenient to wear, so they wore them as fancy hats.

    2. Meh.

      We don’t know everything yet but studies of the human brain seem to suggest that it is more complicated than this. People who think a person’s gender will necessarily steer them into or out of certain fields are wrong. People who believe that given equal opportunity there will be equal people of both genders in every field are also wrong.

      Statistically there are differences in the makeup of the male and female brain. It is quite possible that this explains some of the ‘sorting’ that occurs. On the other hand that’s just statistics. Among individuals there is variance that is greater than the differences between male and female. You probably have some parts in your own brain that are more similar to the ‘typical’ brain of the opposite sex!

      The moral… stop looking at gender statistics. Absolutely do not discourage someone from doing what they want to do because of their gender. But.. also do not try to artificially boost the number of some ‘underrepresented’ gender in a particular field either! Let people chose something because they wanted it, not because you told them more girls (or boys) are needed.

      If you want a better world for all of human kind just look at the individuals. What percentage have the opportunity to attempt* to get into their field of choice? What percentage are happy with the field that they are in**? Keep those two high and we all win!

      *-It’s only an opportunity to attempt. If more people are not needed in a field or if you just aren’t any good at it or just plain lazy you are not entitled for someone to start paying you their own hard earned money to do that thing. You may be able to pick it up as a hobby though. (Not if you wanted to be a brain surgeon please)

      **-Being happy with the field you are in and being in the field you chose are not the same. Bad choices are a thing. They are an unfortunately common thing. Teach people to evaluate themselves as individuals and the work fields as market opportunities so that they might be better equipped to make a good decision. This will do far more to improve people’s happiness and well-being than pushing some gender to participate in a field more.

    3. Well said. Do not bring this up in an HR meeting: On the individual versus group topic, some very large meta-studies that to avoid influences of culture have shown a striking math ability distribution. They don’t show any limit for women or men, but the shape of the curve for women is much different than for men. Women are clumped near the center and men tail off much more slowly to the high ability end. In fact, IIRC they imply that the 1 in ten male is equal to a 1 in 100 female and 1 in 100 male is like a 1 in 1000 (or more) female, etc. Essentially, the result is that the ratio of males to females for example in engineering, matches the ratios we see in the statistics for the calculus level math needed for an engineering degree. It also means the women who have what it takes in engineering are as good or better than the men. But don’t expect proportion of women to go up if difficulty stays constant.

      By the way, I think the studies also showed that in the ensemble, if you do some kind of smartness comparison, women overall have better math brains than men, it is just that in the very high end, men have an advantage of 1000 to 1 or so. Now, an interesting question is, where do you have to be on the graph in order to understand the meaning of the graph?

    4. “feminist” is not something I’ve ever thought of in conjunction with HaD or its writers. Can we keep at least THIS site free of the identity politics that every other corner of the internet seems hell-bent on involving itself in?

        1. sorry your world is changing, that must be so hard on you. I for one welcome the inclusive change, seeing little girls think they can’t be engineers because of the word set up by oldtimers like you is disheartening. Luckily your views will be gone with your generation

          1. I fully appreciate that ‘SJW’s such as yourself are both intellectually and linguistically challenged but surely even you must realise that neither of the posters above said any such thing.

            The main thing stopping women from becoming engineers is scum like you going round schools telling them that they can’t because ‘men’ won’t let them.

  1. Very impressive! I want one so bad!! For myself of course – let the kids and grand kids get their own! I agree, the actuators could be faster, but it’s probably safer the way you have it. I’m a bit unclear on how pop rivets can hold the bucket steel plate onto plywood end grain. Seems they should pull right out, or do they attach to something metallic inside the wood? It’s projects like these that make me wonder what I’ve been spending my time on. Great use of available materials and parts.

    1. Blind [Pop (r)] rivets expand on the back side rather than needing a bucking form or other peening process, so you’d be far more likely to delaminate thin plywood installing them than pulling it out with no other failures.

        1. Hi I used rivets purely for aesthetic reasons. Rivers to my mond look nicer than screws. They actually work surprisingly well in the end grain of ply. None of them have pulled out and the bucket is strong. The hole drilled has to be just the right size to let the rivet expand but not delaminate the ply.

    1. Yeah, I changed the tweet for this one to say something about being the greatest thing you can build with plywood. With Mathias’ body of work that’s a bold claim. Superlatives aside, I just can’t get over how complete this is, especially the documentation. I love it!

  2. I can not describe how close to nirvana I would have been to have had this as a child. It ranks right up there with the 12 year-old “If I only had a dirt bike, everything would be perfect!” Or if the 1968 Ford Country Squire was a spaceship in disguise.

  3. Hi thanks for the comments, really appreciate the constructive input. This project took over a year from conception to completion. I am thinking of making another one refining the parts that don’t work so well. Thanks HaD for posting this on the blog. This is one of life’s ambitions achieved so I am very pleased!….

  4. I imagine that once he gets older and becomes physically too big to ride on it, it wouldn’t be too much of a stretch to put servos on the controls and make the whole thing radio controlled.

  5. This is really cool. I would think that it would be possible to find real, rubber tracks for the thing, and they’d provide a lot better longevity and be way less painful to manufacture.

    1. Cheaper and easier than that is to get conveyor chain, the flights are made in a variety of standard widths up to 12 inches. The stuff can be bought extremely cheap on ebay. I am currently working on a very similar excavator for my son ( a little larger than this one) and that is what I am planning on using.

  6. Not really the same thing, but in the spirit of “hacker parents”, I’ve been building this (http://lego-boats.oobergeek.net) for my son’s birthday on Sunday. He saw something similar in San Diego’s Legoland and loved it there. I’m kind of hoping he loves this one as much :)

    I built it to be modular, so we can disassemble after the party and trot it out whenever the mood takes us. It takes about 20-30 minutes to assemble from scratch since it’s all 4’x8′ plywood and foam. Stacks vertically in the garage.

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