Sounds "Penny wise and pound foolish" if you are going to spend 1,000 hours designing and building a machine when you don't even have a clue about materials requirements to save a couple hundred dollars in machine rental fees.
Couple hundred?! Its $500 a day, or $2000 a week, and you have to put your name on a waiting list where you get notified the evening prior to the machine delivered.
AND! If you don't have a 1 ton truck and trailer, you have to pay the $500 delivery fee. I live within viewing distance of the rental yard, and they wont let me drive it here; but when they deliver it, they drive it. Jerks
If your goal is a fun expensive hobby then I take back these comments.
If you enjoy tinkering for its own sake, then by all means, but designing and building your own excavator is not a way to save money
Calling this thing an excavator is a huge stretch. More like a power assisted shovel.
Now, Aside from the drive train, which I said I was ditching anyway - I could buy all the material, hydraulics, plasma cutter, a better welder, and a predator engine to power the thing, and still be well under the price of a new one.
Not only that, I think if I did use 1/4" material, and it bent, I would still have money left over to build version 2 out of thicker stuff.
Very experienced equipment manufacturers spend immense amounts designing and constructing competitive, desirable equipment.
Maybe the scale of the thing isn't coming across. The operator platform (or cab?) is less than 2'x4'
I put the images into Fusion 360, and calibrated using the known base dimensions to get the dimensions of the boom and arm, I don't remember what they are, but the boom is just under 3' long. Where its pictured driving into the van, at that stance its probably 7' long.
I agree on the money spent on every aspect of equipment, but this is not a John Deer or a Caterpillar, or even a Kubota. This is a cheaply made Chinese machine, being exported and rebranded all over the world. (except the US it seems)
Those aren't the cast iron track rollers you would find on a bobcat, those are stamped and formed steel rollers. It does have a steel cog wheel, but not the same quality you would find on a US machine - but it doesn't need to be. Each one is only responsible for moving a couple hundred pounds, unlike a Bobcat, where its closer to 7000 pounds.
Those are 180x72x31 tracks - dirt cheap ... in China.
31 being a less common size, but if you go with a 180x72x39, they are less than $80 each, unless you buy 25+ then you get the 50% off bulk price. But, shipping one set isn't cost effective compared to just buying them from someone in the US who imported hundreds of them to sell at a massive markup.
If you go with a 180x64, you get into modern snow mobile size, and more track wheel options (the more there are, the cheaper they are)
Simple fact of a 'real' machine is the quality, and mostly built to last. The manufacturing and markup on quality equipment is a whole subject by itself.
This is neither. Its a cheaply made machine with a huge markup. Most common complaint with cheap machinery is the lack of replacement parts - and there are many reasons for that which is a whole discussion by itself.
The machine pictured is certainly "cute", but I doubt very practical compared to renting a "real" mini excavator.
Of course. You aren't using this to break up concrete and load a dump truck.
You are using this to dig trenches for sprinkler pipe, holes for trees, and footings.
Its a small, light weight machine made for small uses.
You shouldn't compare this to anything that has more than one cylinder.
My first observation is that it has only one hydraulic pump. That means that if more than one function can be run at once, it'll steal hydraulic from another function, so it slows down.
Well yeah, but that's common on most machines.
there is a minimum practical weight for mini excavators. Too light is handy for getting it into the back of a van, but it won't have the oomph to dig into hard ground, or resist pulling against the bucket (you'll pull it along the ground, rather than digging a trench)
Correct. But again, you need to remember is use - light duty use. In my case its sand.
rental machine gets returned, and they replace it with a working one.
Not all rental places are created equal, at my local rental yard if it breaks, you pay for it.
They require a couple thousand dollar retainer to cover any equipment damage and mechanical failure.
This bother me, because if you are renting a machine with a few thousand hours on it, can you really be held responsible if the pump dies while you're using it?
Sure, tinker and build to your heart's content, but if you value your time, and have a job to do on time, use a proven tool....
So you think I should use 2"x3"x1/4" box for the boom & arm then?