What do you guys use for making quick mechanical prototypes of ideas? I had the idea of trying out something like the erector set. But erector itself is pretty expensive and I’m guessing not the most ideal. Is there anything similar that is either cheap or designed to be more robust, larger, etc?
To be honest, the last time I wanted to make a prototype of something (a catapult design I came up with), Erector is exactly what I used. But I already had the sets for decades, through a combination of inheritance and garage sales, so I didn’t need to go out and buy anything.
Depending on your definition of quick and inexpensive, and how custom and complex you want to get, many rapid prototyping websites have popped up that make it possible to get real machined parts (in plastic or metal) within a few days (and not at completely outrageous prices). Think of CafePress but with mechanical parts. Here’s one example. It might even be cheaper than going out nad buying up erector sets unless you plan on making a lot of varying prototypes.
By ‘erector’ you mean ‘Meccano’, right? The metal strips and brackets and gears and lots of nuts and bolts?
There’s a system used for making prototype machines that I’ve seen at trade shows and other places (even Ikea, for demonstrating the chair-bend test). It’s extruded metal pieces that go together into frames, on which people hang motors and pistons and whatnot. I think it’s from Europe. Does anyone know the system I’m talking about?
Those are incredible resources, but they aren’t cheap, especially for one-off parts. Up to $100 for a simple part. They also require the idea to be turned into a full digital design, which is a big investment of time. If I had access to a machine shop myself, and the knowledge to use one, it would be more realistic for a 1st prototype. But even then, having a quickly reconfigurable thing that lets you design physically with your fingers rather than in your head or in the computer, is a big benefit. The flow would be something like:
erector -> CAD -> mail-order rapid prototyping
Does anyone do this? Or does everyone start hands-on in a machine shop? (Or does everything inside CAD?)
This is cheap to use (and pretty cheap to build), but you have to build the machine and program it yourself. There are lots of on-line resources though. The Candyfab prototype creator. While it’s nowhere near a perfect solution(especially for close tolerance parts,) it’s a tested design.
There’s also Dexion frames and rails: Erector/Meccano for grown ups. No idea of the cost, there always seemed to be some lying around when I was in grad school. Dexion also makes tube construction parts.
I’ve heard of artists prototyping in foam or clay. I’ve also heard of using wood or cardboard or paper. If your prototype does not have to be load-bearing, most anything would do.
Works pretty well for prototyping and even low volume production.
Those look like solid products. (Aren’t there more like that? Seems something basic and essential, something you could pick up at home depot.) But they’re a far cry from erector sets. An erector set is complex, it has all sorts of parts, including mechanism components like gears. This is just simple frames, without even panels. Also, they want $100 to make an 18"x21" stool? That doesn’t make sense, because in their “look at what people did” page you see many big and mundane projects where such pricing would be highly uneconomical. So there must widely different pricing tiers. I can’t deal with companies that play such games.
Using wood is another possibility. It’s easier to work with than metal and you can even just use a hand-held rotary tool. However, for reasonable quality and precision you still need a shop of machines.
Got my Erector Anniversary Edition set yesterday. Pretty nifty. From my vague memory of ever handling one, I remember the beams were weak and bendable. These are pretty strong (and many are powder-coated). The whole thing comes with an organizing case, which is very useful. I’m a bit miffed though that they didn’t give me any gears, only belt drives. There’s a few other signs of simplification and modernization. Also there don’t seem to be enough corner brackets. But all in all, trying to prototype my idea already pointed out a design flaw, which is good. I just wish I had gears…
I’m also going to investigate woodworking, since that seems the most accessible way to make large custom parts at the moment. Does anyone have any pointers where to start as far as acquiring woodworking tools? A small drill press seems a must. Also a benchtop saw. (I don’t think I can get good tolerance with handheld tools.) But I really want to keep things minimal.
Anyone ever use this thing: http://www.amazon.com/Dremel-220-01-Rotary-Tool-Station/dp/B00068P48O/ref=pd_bxgy_hi_img_c Guy at home depot wasn’t a fan of dremels for anything.
Does Lego still make gears? Would that do? Or maybe buy an assortment from McMaster-Carr or some such catalog.
I’m not much of a wood worker, but the shop in the Woodcraft chain near me has a wood shop where one can rent time on the various tools. That’s all I got.
Gears apparently exist in other sets. But going on McMaster is a really good idea. The shafts are standard diameter, after all.
That’s a really good service. Nearest woodcraft is 50 miles from me. Hmmm. If anyone knows something like this in NYC/Queens, let me know!
Lego Technic has gears of various types, racks, universal joints, etc.
It’s changed a bit over the years, so in order to make a really versatile prototyping kit, you might want to pick up some of the old stuff on eBay, as well as some of the new.
Lego Mindstorms is designed to work in conjunction with Technic, and adds programmable motorised and sensor functions for building robots and automated models etc.
Figured out why the erector set was sucking in the rotary motion department.
The axles aren’t round, they’re rounded triangles :smack:
It’s all a crackpot scheme to mate the axles to pulleys without using set screws. The gimmick results in another abomination, the rubber shaft collar. (Just as a nice f u, Meccan did bundle one proper shaft collar to let you know that yes, they still make those. Just not for you.) God… triangular axles. The asymmetry evens out if you get up to speed, but at low rpm it’s ludicrous.
Lego Technic was what I grew up on, but I figured Erector would be sturdier, smoother, I dunno, more advanced. And of course being metal and tightened with wrenches in part it surely is. Rather what I realized is that the tradeoff is that it’s a lot more work putting anything together. (That’s the general dilemma of metal, isn’t it?) Oh, and now that I think about it, Lego Technic didn’t have round axles either… those bastards
Now THIS is what i’m talking about!